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1
Fried, Andrew, Haritha Malladi, and Cassie Castorena. "Impact of Crack Sealant on Pavement Skid Resistance." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 7 (June 2, 2019): 362–70. http://dx.doi.org/10.1177/0361198119849590.
Повний текст джерелаАнотація:
Crack sealing is often a cost-effective preventive maintenance strategy for prolonging pavement service life when applied to pavements in relatively good condition. Crack sealing is generally ineffective for extending the life of heavily cracked pavements. However, crack sealing is often applied to pavements with extensive cracking. The application of crack sealing to pavements with extensive cracking can pose a skid resistance hazard. This study investigates the relationship between the amount and distribution of crack sealant application and pavement skid resistance. Locked-Wheel Skid Tester (LWST) testing was conducted on several pavement projects in North Carolina, United States, with varying amounts and patterns of crack sealant. Images of the locations of LWST testing were obtained and processed to determine the percentage of the pavement surface area covered by crack sealant. A relationship between the percentage of the wheel path covered by crack sealant and LWST results was established that demonstrates the application of high amounts of crack sealant to the wheel path can pose safety hazards. The effect of crack sealant on pavement skid resistance is a function of the existing pavement’s frictional characteristics. The results of this study highlight the need for the development of crack sealant specification provisions to avoid the loss of skid resistance.
2
Jiang, Ze Zhong, Tao Xie, Yan Jun Qiu, and Bo Lan. "Crack Propagation Behavior of Asphalt Concrete; Part II: A Study into Influence of Loading Rates." Key Engineering Materials 385-387 (July 2008): 301–4. http://dx.doi.org/10.4028/www.scientific.net/kem.385-387.301.
Повний текст джерелаАнотація:
Cracking has long been accepted as a major mode of premature failure in flexible pavements. Expected life of pavements, pavement condition and maintenance cost are directly related to pavement cracking. It is crucial to have a sufficient understanding of cracking mechanism in order to produce a sound and safe material and structural design of asphalt pavements. Simulation, surveying, observation, and measurement of cracking in pavement structures have been reported in literature in last three decades. However, cracking process in asphalt mixtures in a three dimensional scale is still a great challenge to road engineers. Using SIEMENS SOMATOM plus X-ray CT (computerized tomography) and multi-functional testing rig, a dynamic observation of cracking propagation of hot mix asphalt was conducted in this research. Marshall samples of AC20 were used under uniaxial compressive stress state. Stress and strain behavior was observed during the compressive failure process of asphalt mixtures. Cracking propagation in the samples can be clearly observed and failure mode and stress-strain behavior can then be simulated. Research results show that loading rate is a critical factor influencing cracking velocity and cracking density.
3
Islam, M. R., S. A. Kalevela, J. A. Rivera, and T. B. Rashid. "Dynamic Modulus and Field Performance of Cold-in-Place Recycled Asphalt Pavement." Journal of Engineering Sciences 6, no. 2 (2019): b1—b7. http://dx.doi.org/10.21272/10.21272/jes.2019.6(2).b1.
Повний текст джерелаАнотація:
This study investigates the dynamic modulus of cold-in-place recycling (CIR) asphalt material and its performance using pavement performance data and laboratory dynamic modulus testing. Colorado Department of Transportation (CDOT) has 37 projects with over 8 million square yards using CIR materials. Sites from ten projects were selected to monitor the performances and collect samples for laboratory testing. Dynamic modulus testing on the CIR cores was conducted by the CDOT. Results show measured distresses of CIR rehabilitation techniques are mostly below the threshold values during the service period. International Roughness Index, rutting, and transverse cracking never exceeded the threshold values during the studied period. Only two CIR pavements exceeded the threshold values for fatigue cracking after 8-10 years of service. Measured distresses of CIR rehabilitation techniques are similar to conventional pavements based on engineering judgment. The laboratory dynamic modulus test results show CIR has about 50 % less dynamic modulus compared to the traditional asphalt mixture. Keywords: asphalt pavement, cold-in-place recycling, dynamic modulus, fatigue cracking, transverse cracking.
4
Perez, S. A., J. M. Balay, P. Tamagny, and Ch Petit. "Accelerated pavement testing and modeling of reflective cracking in pavements." Engineering Failure Analysis 14, no. 8 (December 2007): 1526–37. http://dx.doi.org/10.1016/j.engfailanal.2006.12.010.
Повний текст джерела
5
Bonaquist, Ramon F., and Walaa S. Mogawer. "Analysis of Pavement Rutting Data from FHWA Pavement Testing Facility Superpave Validation Study." Transportation Research Record: Journal of the Transportation Research Board 1590, no. 1 (January 1997): 80–88. http://dx.doi.org/10.3141/1590-10.
Повний текст джерелаАнотація:
Since 1986, FHWA has been performing accelerated pavement tests at its Pavement Testing Facility (PTF) located on the grounds of the Turner-Fairbank Highway Research Center. At this laboratory, FHWA uses two accelerated loading facility pavement testing machines to simulate the effects of heavy vehicle loading on full-scale test pavements. In 1992, FHWA, with help from Strategic Highway Research Program staff and contractors, started an experiment to validate selected aspects of the Superpave binder specification using accelerated pavement tests. Twelve test lanes with 48 individual test sites were constructed at the PTF in 1993. The results of accelerated pavement tests on these pavements will be used to validate the Superpave binder parameters for rutting and fatigue cracking.
6
Noorvand, Hossein, Kamil Kaloush, Jose Medina, and Shane Underwood. "Rejuvenation Mechanism of Asphalt Mixtures Modified with Crumb Rubber." CivilEng 2, no. 2 (May 12, 2021): 370–84. http://dx.doi.org/10.3390/civileng2020020.
Повний текст джерелаАнотація:
Asphalt aging is one of the main factors causing asphalt pavements deterioration. Previous studies reported on some aging benefits of asphalt rubber mixtures through laboratory evaluation. A field observation of various pavement sections of crumb rubber modified asphalt friction courses (ARFC) in the Phoenix, Arizona area indicated an interesting pattern of transverse/reflective cracking. These ARFC courses were placed several years ago on existing jointed plain concrete pavements for highway noise mitigation. Over the years, the shoulders had very noticeable and extensive cracking over the joints; however, the driving lanes of the pavement showed less cracking formation in severity and extent. The issue with this phenomenon is that widely adopted theories that stem from continuum mechanics of materials and layered mechanics of pavement systems cannot directly explain this phenomenon. One hypothesis could be that traffic loads continually manipulate the pavement over time, which causes some maltenes (oils and resins) compounds absorbed in the crumb rubber particles to migrate out leading to rejuvenation of the mastic in the asphalt mixture. To investigate the validity of such a hypothesis, an experimental laboratory testing was undertaken to condition samples with and without dynamic loads at high temperatures. This was followed by creep compliance and indirect tensile strength testing. The results showed the higher creep for samples aged with dynamic loading compared to those aged without loading. Higher creep compliance was attributed to higher flexibility of samples due to the rejuvenation of the maltenes. This was also supported by the higher fracture energy results obtained for samples conditioned with dynamic loading from indirect tensile strength testing.
7
CHEN, Can, Shibin LIN, Ronald Christopher WILLIAMS, and Jeramy Curtis ASHLOCK. "NON-DESTRUCTIVE MODULUS TESTING AND PERFORMANCE EVALUATION FOR ASPHALT PAVEMENT REFLECTIVE CRACKING MITIGATION TREATMENTS." Baltic Journal of Road and Bridge Engineering 13, no. 1 (March 27, 2018): 46–53. http://dx.doi.org/10.3846/bjrbe.2018.392.
Повний текст джерелаАнотація:
Reflective cracking is a common type of pavement distress, which manifests as cracks in an underlying layer propagating through to the surface of a pavement structure. To minimize reflective cracking of asphalt layers in composite pavements, four treatments are commonly used: standard/full rubblization, modified rubblization, crack and seat, and rock interlayer. The four types of treatment were evaluated to determine their effectiveness in mitigating reflective cracking via non-destructive Falling Weight Deflectometer tests and Surface Wave Method tests to measure layer modulus, along with field pavement performance surveys. It is found that moduli measurements from Surface Wave Method tests have reduced uncertainty comparing to those from Falling Weight Deflectometer tests, (2) the moduli of thin rock interlayers were captured by Surface Wave Method, but missed by Falling Weight Deflectometer. In addition, the Surface Wave Method results show that (1) crack and seat treatments provide the highest moduli, followed by modified rubblization, and (2) standard rubblization and rock interlayers provide moduli that are slightly lower than the other two treatments. Pavement performance survey was also conducted concurrently with the in-situ modulus tests. Based on the results of this study, modified rubblization and rock interlayer treatments are recommended for mitigation of reflective cracking.
8
Khazanovich, Lev, Raul Velasquez, and Edouard G. Nesvijski. "Evaluation of Top-Down Cracks in Asphalt Pavements by Using a Self-Calibrating Ultrasonic Technique." Transportation Research Record: Journal of the Transportation Research Board 1940, no. 1 (January 2005): 63–68. http://dx.doi.org/10.1177/0361198105194000108.
Повний текст джерелаАнотація:
To select the optimal strategy for treatment of a cracked asphalt pavement, it is important to determine the extent of cracking (partial depth or full depth). This paper presents the results of an explanatory study aimed at examining the applicability of the ultrasonic technology for evaluation of cracks and longitudinal joints in flexible pavements. It was shown that this technology, which has been used successfully for many years for the evaluation of concrete structures, could provide a simple, quick, and objective procedure for evaluation of surface distresses in asphalt concrete pavements. The results of laboratory testing and field testing at the Minnesota Road Research Project test facility demonstrate the potential of this technology.
9
Xie, Tao, Ze Zhong Jiang, Yan Jun Qiu, and Bo Lan. "Crack Propagation Behavior of Asphalt Concrete; Part I: A Study into Influence of Different Materials." Key Engineering Materials 385-387 (July 2008): 297–300. http://dx.doi.org/10.4028/www.scientific.net/kem.385-387.297.
Повний текст джерелаАнотація:
The fracture resistance of asphalt materials significantly influences the service life of asphalt pavements and consequently affects the maintenance and rehabilitation costs of the pavement network. Therefore, there is significant interest in understanding the mechanism of fracture in asphalt pavements and in developing analysis tools that would lead to the selection of asphalt materials with increased fracture resistance. Study of cracking behavior of asphalt mixtures should be conducted in a micro-scale level to have a real simulation of crack propagation. Using SIEMENS SOMATOM plus X-ray CT (computerized tomography) and multi-functional testing rig, a dynamic observation of cracking propagation of hot mix asphalt was conducted in this research. Failure process under compressive pressure was recorded using CT images and CT numbers. The direct responses in density change of Marshall Samples under a CT-compressive process are change of CT numbers. Cracking propagation in the samples can be clearly observed and failure mode and stress-strain behavior can then be simulated. The tests reported provide important theoretical fundamentals to study the cracking behavior and failure mechanism of asphalt mixtures.
10
Livneh, Moshe. "Determination of residual life in flexible pavements." Canadian Journal of Civil Engineering 23, no. 5 (October 1, 1996): 1012–24. http://dx.doi.org/10.1139/l96-908.
Повний текст джерелаАнотація:
In the field of pavement rehabilitation design, one finds a prominent absence of uniformity in the principles of calculation, a lack of clarity as to the testing methods, and a confusion of basic physical concepts. An example of this situation is the residual life of the pavement structure, which constitutes an important measure in the calculation of pavement bearing capacity. The basic question of how to establish such a parameter in practice is discussed in this paper by examining the relationships between the residual life parameter and the pavement surface state, the pavement structural state, the pavement functional state, and the effects of asphalt fatigue or the total structural deterioration on the residual life-span. Finally, this paper suggests a method for including the residual life parameter within the design process of flexible pavement rehabilitation. Key words: cracking, damages, deflection, permanent deformation, evaluation, fatigue, flexible pavements, overlay, rehabilitation, service level, visual testing.
11
Zhang, Weiguang, Shihui Shen, and Shenghua Wu. "Comparison of the Relative Long-Term Field Performance among Various Warm Mix Asphalt (WMA) Pavements." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 28 (June 19, 2018): 200–210. http://dx.doi.org/10.1177/0361198118780702.
Повний текст джерелаАнотація:
The use of warm mix asphalt (WMA) has increased greatly over the past decade because it provides potential to lower energy demands, reduce emissions, and increase haul distances. However, questions remain about the long-term performance of WMA pavements, including whether different WMA technologies can provide the same field performance. In this paper, field rutting and cracking (transverse and longitudinal) performance data for chemical, organic, and foaming WMA technologies are compared pairwise. Thirty-four WMA-WMA pairs from 13 field test roads are included, which cover different pavement ages, traffic volumes, pavement structures, WMA technologies, and four climate zones across the United States. For the WMA-WMA pairs that exhibited statistically different performance, their material properties were investigated further to identify potential factors that could be used to characterize such field differences. The results indicate that, generally, no statistical performance differences are evident between the WMA-WMA pairs. However, it is worth noting that over the longer term, there are individual projects whose organic pavement sections showed statistically higher amounts of cracking than the chemical and foaming sections. Based on the laboratory testing results on field cores, it is suggested that the greater amounts of transverse cracking exhibited by organic pavements may be caused by organic’s lower mixture fracture work density and lower binder failure strain values compared with those of the chemical and foaming sections. The greater amounts of longitudinal cracking exhibited by the organic pavements may be caused by organic’s higher mixture indirect tensile strength, lower mixture fracture work density, and lower binder fracture energy values compared with those of the chemical and foaming sections.
12
Zofka, Adam, Maciej Maliszewski, Ewa Zofka, Miglė Paliukaitė, and Laura Žalimienė. "GEOGRID REINFORCEMENT OF ASPHALT PAVEMENTS." Baltic Journal of Road and Bridge Engineering 12, no. 3 (September 30, 2017): 181–86. http://dx.doi.org/10.3846/bjrbe.2017.22.
Повний текст джерелаАнотація:
Geogrid materials applied within asphalt layers defer or prevent the occurrence of reflective cracking. The contribution of this work significantly adds to extending pavement serviceability and improving benefit/cost analysis. Since 1970s many studies have demonstrated the benefits of geogrid reinforcement in asphalt pavements, but this knowledge did not translate to their extensive usage in the actual construction practice. Among potential reasons are higher initial costs, lack of in-depth understanding of working mechanism within adjacent asphalt layers and lack of commonly standard design procedures. This paper presents a recent study, which investigated the effect of geogrid reinforcement on asphalt mixture specimens. Two types of laboratory experiments were conducted, namely monotonic (strength and fracture) testing and cyclic (fatigue and modulus) testing. The results demonstrated a significant strengthening contribution of geogrid, which was observed regarding fracture energy results and terminal deflections in the fatigue testing. This paper also presents a short example connecting pavement deflections with the allowable axle loading (also known as fatigue life) to demonstrate the practical implications of geogrid reinforcement. The undertaken analysis shows the reduction of pavement deflections due to the geogrid application, which potentially leads to a significant extension of pavement fatigue life. Paper concludes with several recommendations for further work in the area of geogrid reinforcement.
13
Qiu, Xin, Xiao Hua Luo, and Qing Yang. "Influence of Cracking Damage on Deflection Basin Test Data of FWD." Key Engineering Materials 620 (August 2014): 55–60. http://dx.doi.org/10.4028/www.scientific.net/kem.620.55.
Повний текст джерелаАнотація:
With the popularization of falling weight deflectometer (FWD) to calculate the stiffness related parameters of the pavement structures, non-destructive evaluation of physical properties and performance of pavements has taken a new direction. FWD backcalculation is mathematically an inverse problem that could be solved either by deterministic or by probabilistic approach. A review of the currently used backcalculation procedures indicates that the calculation is generally based on a homogeneous, continuous, and linear elastic multi-layer system. Identifying effective data of dynamic deflection basins seems to be an important task for performing modulus backcalculation. Therefore, the main objective of this paper was to discuss the distribution features of dynamic deflection basins of asphalt pavements with crack distresses, and present the reasonable criteria to filter the testing data of FWD deflection basins. Finally, the study aims to validate the established criteria by conducting in-situ case study.
14
Groenendijk, J., C. H. Vogelzang, A. Miradi, A. A. A. Molenaar, and L. J. M. Dohmen. "Linear Tracking Performance Tests on Full-Depth Asphalt Pavement." Transportation Research Record: Journal of the Transportation Research Board 1570, no. 1 (January 1997): 39–47. http://dx.doi.org/10.3141/1570-05.
Повний текст джерелаАнотація:
A 0.15-m-thick gravel asphalt concrete (AC) pavement on a sand subgrade was loaded with 4 million repetitions of a 75-kN super-single wheel load using the linear tracking device (LINTRACK) heavy-traffic simulator. Frequent measurements were carried out, including asphalt strain, temperature, rutting, cracking, and falling weight deflectometer measurements, to investigate the performance of full-depth asphalt pavements. The subsequent data analysis indicated that the life of the tested asphalt pavement, according to the Dutch fatigue-design criterion (halving the asphalt stiffness), was 2 to 4 times longer than predictions based on the pavement-design method of the Road and Hydraulic Engineering Division (RHED) of the Dutch Ministry of Transport, Public Works and Water Management. Thus, this method does not give an unsafe design. The analysis also indicated that halving of the asphalt stiffness, implying structural distress, occurred before any cracking was visible at the pavement surface. Almost all visible cracking occurring later in this test pavement consisted of surface cracking instead of structural cracking. Therefore, the structural distress did not grow upward to form the visible cracks at the surface, but the latter formed independently. The same was observed on Dutch highways, which are much thicker. These conclusions are based on only one test section, although supplemented with extensive materials testing, and verification with other tests is necessary.
15
Spadoni, Sara, Lorenzo Paolo Ingrassia, Giulio Paoloni, Amedeo Virgili, and Francesco Canestrari. "Influence of Geocomposite Properties on the Crack Propagation and Interlayer Bonding of Asphalt Pavements." Materials 14, no. 18 (September 15, 2021): 5310. http://dx.doi.org/10.3390/ma14185310.
Повний текст джерелаАнотація:
The application of geocomposites as reinforcement in asphalt pavements is a promising solution for the maintenance/rehabilitation of existing pavements and for the construction of new pavements, whose effectiveness strongly depends on the physical and mechanical properties of the geocomposite. This study aims at assessing the influence of four different geocomposites, obtained by combining a reinforcing geosynthetic with a bituminous membrane, on the crack propagation and interlayer bonding of asphalt pavements. First, a laboratory investigation was carried out on double-layered asphalt specimens. The crack propagation resistance under static and dynamic loads was investigated through three-point bending tests (carried out on specimens with and without notch) and reflective cracking tests respectively, whereas the interlayer shear strength was evaluated through Leutner tests. Then, a trial section was constructed along an Italian motorway and a Falling Weight Deflectometer (FWD) testing campaign was carried out. The laboratory investigation highlighted that—as compared to the unreinforced system—the geocomposites increased the crack propagation energy in the layer above the reinforcement from five to ten times, indicating that they can significantly extend the service life of the pavement by delaying bottom-up and reflective cracking. However, they also worsened the interlayer bonding between the asphalt layers (de-bonding effect). The field investigation indicated that all geocomposites decreased the stiffness of the asphalt layers with respect to the unreinforced pavement as a consequence of the de-bonding effect, thus corroborating the laboratory results. Based on the results obtained, it is desirable that the geocomposite possess a high energy dissipation capability and an upper coating ensuring good adhesion between the asphalt layers. The monitoring of the existing trial section in the future will provide useful data on the long-term field performance of reinforced pavements subjected to actual motorway traffic.
16
Hong, Geuntae, Jiyoung Kim, Jung Heum Yeon, Moon Won, and Seongcheol Choi. "Comparison of Stress Fields near Longitudinal Construction Joints of Tied and Doweled Sections in Portland Cement Concrete Pavements." Sustainability 13, no. 20 (October 12, 2021): 11217. http://dx.doi.org/10.3390/su132011217.
Повний текст джерелаАнотація:
In Portland cement concrete (PCC) pavements, tie bars are commonly used at longitudinal construction joints (LCJs) to prevent the lanes from separating. Meanwhile, the increase in multiple lanes due to greater traffic volumes has raised concerns about potential longitudinal cracking; this has led to the use of dowel bars instead of tie bars at LCJs. However, there is a paucity of studies focused on the comparison between the behaviors of concrete pavement based on the restrained conditions provided by tie and dowel bars at LCJs. In this study, we investigated the effects of the placement of tie and dowel bars at LCJs on the potential for longitudinal cracking in response to the increase in concrete stress that may occur when the lanes are tied together in PCC pavements. Field testing verified that the variation in concrete strain was more restrained in the case of a tie bar than a dowel bar, whereas it resulted in higher stress in the concrete element in the tie bar section. However, the use of dowel bars caused more movement in the transverse direction at LCJs as compared with tie bars. Thus, our results indicate that using dowel bars reduces the potential for longitudinal cracking; however, it may increase the potential for lane separation.
17
Emtazul Haque, MD, Musharraf Zaman, and Alan A. Soltani. "Cracking Characteristics of Model Continuously Reinforced Concrete Pavements." Transportation Research Record: Journal of the Transportation Research Board 1629, no. 1 (January 1998): 90–98. http://dx.doi.org/10.3141/1629-11.
Повний текст джерелаАнотація:
An experimental program was conducted in the laboratory to predict the behavior of model continuously reinforced concrete (CRC) slabs in tension. A tensile loading arrangement was devised using a Universal Testing Machine for this purpose. Model concrete slabs were cast for two types of reinforcement arrangements: a regular grid pattern, and an inclined grid pattern. Tests were conducted for different rebar spacings and orientations. In the numerical study, a two-dimensional model of the CRC slabs was developed using FLAC, a commercially available software package based on the finite difference method. Experimental and numerical results were compared and were found to be in close agreement. Finally, the average crack spacings for different rebar spacings and orientations from both experimental and numerical studies were compared with the results obtained from the Concrete Reinforcing Steel Institute design method.
18
Qadir, Adnan, Uneb Gazder, and Karam Un Nisa Choudhary. "Artificial Neural Network Models for Performance Design of Asphalt Pavements Reinforced with Geosynthetics." Transportation Research Record: Journal of the Transportation Research Board 2674, no. 8 (June 12, 2020): 319–26. http://dx.doi.org/10.1177/0361198120924387.
Повний текст джерелаАнотація:
Flexible pavements, made up of asphalt concrete, are commonly used for highways all around the world. These pavements suffer from distresses like reflective cracking, rutting and fatigue cracking. Performance-based design methods have been adopted to enhance the service life of flexible pavements. Other measures to enhance the life cycle of these pavements include reinforcement with materials such as geosynthetics. However, there is a gap in the literature on development of performance-based design models for reinforced pavements. In this study, artificial neural network (ANN) models are developed for predicting flexural stiffness and rutting depth of reinforced asphalt pavements using design parameters from the simple laboratory procedures for Marshall and rut depth tests. A multilayer feedforward neural network (MLFNN) was found suitable in this study when a larger dataset was available with a flexural stiffness model. On the other hand, radial basis neural network (RBNN) was found to give higher accuracy with the smaller dataset of rut depth available in this study. In both cases, ANNs were found to predict the parameters with sufficient accuracy. These models show that reinforced asphalt designs with central gradation have the best design. The models developed in this study will be helpful to design long-lasting pavements with geosynthetic reinforcement without the requirement for high-tech testing facilities.
19
Sangpetngam, Boonchai, Bjorn Birgisson, and Reynaldo Roque. "Development of Efficient Crack Growth Simulator Based on Hot-Mix Asphalt Fracture Mechanics." Transportation Research Record: Journal of the Transportation Research Board 1832, no. 1 (January 2003): 105–12. http://dx.doi.org/10.3141/1832-13.
Повний текст джерелаАнотація:
It has long been accepted that cracking of hot-mix asphalt (HMA) pavements is a major mode of premature failure. Many state departments of transportation have verified that pavement cracking occurred not only in fatigue cracking in which a crack initiates from the bottom of the asphalt layer but also in other modes such as low-temperature cracking and the more recently identified top-down cracking. Recent work at the University of Florida has led to the development of a crack growth law based on viscoelastic fracture mechanics that is capable of fully describing both initiation and propagation of cracks in asphalt mixtures. The model requires the determination of only four fundamental mixture parameters, which can be obtained from less than 1 h of testing using the Superpave® indirect tensile test (IDT). These parameters can account for microdamage, crack propagation, and healing for stated loading conditions, temperatures, and rest periods. The generalization of the HMA crack growth law needed for its successful implementation into a displacement discontinuity boundary element method is described. The resulting HMA boundary element approach is shown to predict the crack propagation of two coarse-graded mixtures under cyclic IDT loading conditions.
20
Heath, Andrew C., and Jeffery R. Roesler. "Top-Down Cracking of Rigid Pavements Constructed with Fast-Setting Hydraulic Cement Concrete." Transportation Research Record: Journal of the Transportation Research Board 1712, no. 1 (January 2000): 3–12. http://dx.doi.org/10.3141/1712-01.
Повний текст джерелаАнотація:
Test sections of jointed plain concrete pavement were constructed with fast-setting hydraulic cement concrete (FSHCC) as part of the California Department of Transportation accelerated pavement-testing program. Many of the longer slabs cracked under environmental influences before any traffic load was applied to them. Data from field instrumentation were recorded and analyzed along with laboratory test data to determine the cause of the cracking. Cores drilled through the cracks indicated that cracking began at the top of the slabs and propagated downward. This was confirmed with the ILLI-SLAB (ILSL2) finite-element package in which high tensile stresses were predicted at the top of the slab as a result of the differential drying shrinkage between the top and base of the slab and the nonlinear nature of the negative temperature gradients through the slab. Laboratory free-shrinkage tests with the test section concrete indicated significantly higher levels of shrinkage compared with that achieved with ordinary Type II portland cement. Load plus environmental stress analysis with ILSL2 suggested that the critical failure location for the FSHCC pavements would be near the corner of the slab and not at the midslab edge.
21
Qamhia, Issam I. A., Erol Tutumluer, Hasan Ozer, Heather Shoup, Sheila Beshears, and James Trepanier. "Evaluation of Chemically Stabilized Quarry Byproduct Applications in Base and Subbase Layers through Accelerated Pavement Testing." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 3 (February 21, 2019): 259–70. http://dx.doi.org/10.1177/0361198118821099.
Повний текст джерелаАнотація:
Research conducted at the Illinois Center for Transportation evaluated sustainable applications of quarry byproducts (QB) or QB blended with coarse recycled aggregates in chemically stabilized base and subbase layers in flexible pavements. In total, eight full-scale test sections, including one conventional flexible pavement with no QB as the control section, were constructed over a subgrade with an engineered strength of 6% California bearing ratio. The test sections were stabilized with either 3% Type I Portland cement or 10% Class C fly ash by dry weight. Fractionated reclaimed asphalt pavements and fractionated recycled concrete aggregates were also used as the recycled coarse aggregates. Based on laboratory tests conducted to determine strength properties of the chemically stabilized samples, QB and recycled aggregates were blended in a ratio of 70% to30% by weight, respectively. A lightweight deflectometer was used to evaluate the quality of the construction and the curing of the test sections. The constructed test sections were then evaluated for performance through accelerated pavement testing (APT) and frequent measurement of surface deformations. The results of APT showed quite a satisfactory rutting performance of all the evaluated QB applications with no observed surface cracking after 135,000 cycles. Four of the test sections were also instrumented with soil pressure cells to measure the wheel load deviator stress on top of the subgrade. The pressure measurements indicated subgrade pressures 3−5 times lower for the stabilized QB sections compared with that of the conventional flexible pavement control section.
22
Khasawneh, Mohammad Ali, Khalid Ghuzlan, and Nada Bani Melhem. "Evaluation of Carbon Nanotubes Asphalt Modification Using the Superpave Criteria." Key Engineering Materials 902 (October 29, 2021): 135–43. http://dx.doi.org/10.4028/www.scientific.net/kem.902.135.
Повний текст джерелаАнотація:
Rutting, fatigue cracking and low temperature cracking are the most important distresses in asphalt pavements as a result of changes in rheological properties of asphalt binder. Many types of modifiers were used to enhance asphalt behavior at both low and high temperatures. In this study, carbon nanotubes (CNT) were used as one of many nanomaterials that take a large attention in the latest research related to asphalt modification against different types of distresses. Effect of CNT on rheological properties of asphalt binder was investigated by testing unmodified and CNT modified asphalt binders using two of Superpave devices: Dynamic Shear Rheometer (DSR) and Bending Beam Rheometer (BBR). Penetration, softening point, flash point and rotational viscosity (RV) tests were carried out as well. CNT was added in 0.1%, 0.5% and 1% by weight of asphalt binder. It was found that adding CNT in 0.5% and 1% increase stiffness of asphalt and consequently asphalt pavement rutting resistance. On the other hand, this increase in stiffness affected pavement behavior adversely which is not desirable for fatigue and low temperature cracking. However, Superpave specifications were still satisfied and asphalt binder’s relaxation properties were improved upon CNT modification. It was eventually found that 0.5% of CNT is the optimum percentage for the best performance.
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Safi, Fazal R., Imad L. Al-Qadi, Kamal Hossain, and Hasan Ozer. "Total Recycled Asphalt Mixes: Characteristics and Field Performance." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 12 (June 28, 2019): 149–62. http://dx.doi.org/10.1177/0361198119849915.
Повний текст джерелаАнотація:
The use of recycled materials in asphalt concrete (AC) pavement has increased significantly because of their economic and environmental benefits. The use of recycled materials can pose risks to the performance of asphalt pavements, however. The Illinois Department of Transportation developed five total recycled asphalt (TRA) mixes in the pursuit of environmentally sustainable pavements. These mixes contain up to 60% asphalt binder replacement (ABR) obtained from reclaimed asphalt pavement (RAP) and recycled asphalt shingles. Virgin aggregates were replaced by 100% recycled aggregates including RAP, steel slag, and recycled concrete aggregate (RCA). Based on laboratory testing, all the mixes offered excellent rutting resistance because of their high ABR content. The TRA mixes were relatively less compliant and not very sensitive to field aging, whereas indirect tensile strength tests showed indistinguishable results. All mixes had comparable complex modulus |E*| and phase angle ([Formula: see text]) values at low temperatures. Laboratory-compacted specimens had relatively low flexibility index (FI) compared with field cores taken after construction. The FI values of the field cores decreased with aging, higher recycled materials content, or both. An exponential increase in transverse cracking was observed in the field cores because of their relatively high ABR, RCA/steel slag content, or both. The progression of field transverse cracking over time and FI values are well correlated. A three-dimensionally balanced mix design was introduced and used successfully to distinguish between AC mixes; it is proposed as a tool for better control mix designs and optimum field performance.
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Hu, Sheng, Sang-Ick Lee, Lubinda F. Walubita, Fujie Zhou, and Tom Scullion. "Incorporation of Endurance Limit in the Mechanistic-Empirical Flexible Perpetual Pavement Design." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 40 (September 23, 2018): 108–21. http://dx.doi.org/10.1177/0361198118797781.
Повний текст джерелаАнотація:
In recent years, there has been a push toward designing long-lasting thick hot mix asphalt (HMA) pavements, commonly referred to as a perpetual pavements (PP). For these pavements, it is expected that bottom-up fatigue cracking does not occur if the strain level is below a certain limit that is called the HMA fatigue endurance limit (EL). This paper proposed a mechanistic-empirical PP design method based on this EL concept. The ELs of 12 HMA mixtures were determined using simplified viscoelastic continuum damage testing and the influential factors were comparatively investigated. It was found that HMA mixtures seem to have different EL values based on mix type and test temperatures. There is not just a single EL value that can be used for all mixtures. Thus, default EL criteria for different mixtures under different climatic conditions were developed and incorporated into the Texas Mechanistic-Empirical Flexible Pavement Design System (TxME). As a demonstration and case study, one Texas PP test section with weigh-in-motion traffic data was simulated by TxME. The corresponding TxME inputs/outputs in terms of the PP structure, material properties, traffic loading, environmental conditions, and ELs were demonstrated. The corresponding TxME modeling results were consistent with the actual observed field performance of the in-service PP section.
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Elseifi, Mostafa A., and Hasan Ozer. "Cracking in Flexible Pavements and Asphalt Mixtures: Theories, Modeling and Testing for Mitigation." International Journal of Pavement Engineering 19, no. 3 (January 15, 2018): 191. http://dx.doi.org/10.1080/10298436.2017.1298106.
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Roberts, Freddy L., Louay N. Mohammad, Ludfi Djakfar, and Amar Raghavendra. "Design, Construction, and Analysis of Pavements Using Accelerated Loading Facility." Transportation Research Record: Journal of the Transportation Research Board 1590, no. 1 (January 1997): 73–79. http://dx.doi.org/10.3141/1590-09.
Повний текст джерелаАнотація:
The Louisiana Transportation Research Center has recently completed the construction of a full-scale pavement test facility using the accelerated loading facility (ALF) machine. This facility contains nine pavement test sections, 12-m (38-ft) long and 3.66-m (12-ft) wide that are loaded by the ALF machine with loads ranging from 34.71 to 111.25 kN (7,800 to 25,000 lbf) on a dual-tire assembly. The advantage of this testing facility is its ability to cause a pavement to fail in a short period of time. In addition, the data acquisition methods and instrumentation used in this testing facility allow researchers to obtain reliable and representative performance data. The first test section has been loaded to failure and a preliminary analysis of the data is completed. VESYS 3A-M, a microcomputer version of the VESYS series, has been selected for the analysis due to its ability to predict damage and its flexibility. The analysis consists of the primary response analysis to determine strains, stresses, and deflection of the pavement and damage-prediction modeling that includes rutting, fatigue cracking, and roughness. The analysis was conducted by comparing the data obtained from field with that predicted by VESYS 3A-M. The performance data obtained from the field include fatigue cracking, rutting, and roughness. The analysis showed that VESYS 3A-M outputs are in good agreement with those obtained from the field.
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Qadir, Adnan, and Karam-un-Nisa Choudhary. "Performance Evaluation of Geocomposite Reinforcement in Flexible Pavements using Marshall Test Protocol." MATEC Web of Conferences 203 (2018): 06020. http://dx.doi.org/10.1051/matecconf/201820306020.
Повний текст джерелаАнотація:
Asphalt concrete pavements are prone to cracking due to external loads and extreme weathering conditions. Generally the failed asphalt concrete is over laid with new asphalt concrete surface to improve the riding surface; however after sometime the crack reappears in the form of reflective cracking. Studies have found that such cracks can be controlled by introduction of Geo-synthetics layer before overlaying. The presented study presents one such effort in which the performance of such modification was evaluated by testing a number of modified specimens using Marshall’s test protocol. The resulting Stability flow quotient at optimum asphalt content showed no appreciable improvement as expected. Hence it can be concluded that the performance of Geocomposite modified asphalt concrete cannot be evaluated using Marshall Test protocols.
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Françoso, Maria Teresa, Carolina Oyama Mota, Tadeu Rosanti Sugahara Medeiros Lima, and Creso De Franco Peixoto. "Nondestructive Testing in Asphalt Pavements Using Ground Penetrating Radar (GPR)." Applied Mechanics and Materials 303-306 (February 2013): 525–28. http://dx.doi.org/10.4028/www.scientific.net/amm.303-306.525.
Повний текст джерелаАнотація:
This paper presents the results of using the system GPR (Ground Penetrating Radar), as an alternative that uses radio waves at frequencies from 10 to 2500 MHz to get data that enable non-destructive conduct inspections of underground or concrete structures in real time. The research aims to investigate asphalt pavements, analyzing the variations in the responses, which can reveal the presence of pathologies or defects. A case study was made acquiring data, at the State University of Campinas - UNICAMP, in Campinas – SP – Brazil, with antennae 270 and 1600 MHz, in pavements with visible defects of patching and alligator cracks, initially with the dry structure and later, wet. The results were processed in specialized software (Radan 7.0) to generate terrain profiles. The GPR showed effective when there is a change in material employed as in the case of patching, because it was possible to detect layers compromised by intensive request of traffic, the start and end of application of the patching and even deformations in the new layer. In contrast, the alligator cracking did not reach the same result, not presenting accuracy in recognizing the defect. The extent of defect was the only well defined feature in the images.
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Mikolaj, Jan, Frantisek Schlosser, Lubos Remek, Martin Pitoňák, and Juraj Šrámek. "Properties of Asphalt Mixtures Using Reclaimed Asphalt Containing Polymer-Modified Binder and Technicoeconomical Considerations of Their Use." Advances in Materials Science and Engineering 2019 (October 17, 2019): 1–12. http://dx.doi.org/10.1155/2019/2030763.
Повний текст джерелаАнотація:
The article summarises findings from laboratory testing of asphalt mixtures using reclaimed asphalt containing polymer-modified binder and subsequent technicoeconomical considerations of their use in pavement management system. Tested mixtures had 0%, 15%, and 40% content of reclaimed asphalt (RA) containing polymer-modified bitumen (PMB) obtained by milling from surfacing layers of existing PA, AC11, and SMA11 pavement layers. A complete description of these mixtures is given, and testing methods used are described. The mixtures were tested for air void content, ITSR water sensitivity test, plastic deformation wheel tracking test, stiffness of the tested mixtures, and two-point bending test to ascertain fatigue. Concise and succinct conclusions from laboratory testing are derived and used as an input in the second part of the article. It is found that the addition of RA containing PMB increased stiffness modulus of the final mixture, which increases resistance to plastic deformation and leads to higher brittleness at low temperatures. It is found that virgin PMB also increases fatigue resistance as opposed to PMB content from reclaimed materials. In the second part of the article, findings from laboratory testing are addressed in the context of their practical use in pavement management. The key element identified, having a direct impact on pavement performance models, was the stiffness modulus for mixtures with different PMB-reclaimed asphalt contents. A method is described to evaluate pavement construction properties related to wearing course materials via the pavement performance model. Practical use of this method is described and applied in a case study. In this case study, the proposed method is used to evaluate the issues regarding practical use of asphalt mixtures with different ratios of reclaimed asphalt containing PMB and economic implications of their use. It is found that pavement performance of surfacing mixtures with reclaimed asphalt containing PMB is significantly better for plastic deformation at the cost of earlier initiation and progression of surface distress due to cracking and potholing. This paper suggests that due to cracking and potholing, periodic maintenance costs increase for pavements with reclaimed asphalt material containing PMB; however, they are outweighed by lower procurement cost and longer life expectancy due to slower plastic deformation of the pavement.
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Wu, Shenghua, Weiguang Zhang, Shihui Shen, Balasingam Muhunthan, and Louay N. Mohammad. "Short-Term Performance and Evolution of Material Properties of Warm- and Hot-Mix Asphalt Pavements: Case Studies." Transportation Research Record: Journal of the Transportation Research Board 2631, no. 1 (January 2017): 39–54. http://dx.doi.org/10.3141/2631-05.
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This paper presents case studies of the short-term field performance and material property evolution of four warm-mix asphalt (WMA) projects in Iowa, Louisiana, Montana, and Tennessee, constructed in 2011 and 2012. Each project had one or several WMA overlay sections and a control hot-mix asphalt (HMA). Two rounds of performance investigations were conducted, including a survey of field distress and characterization of material properties. Field cores from the two rounds (the first immediately after construction, the second 2 to 3 years after construction) were used to evaluate the performance of the mixtures in terms of dynamic modulus, creep compliance, fracture testing at intermediate and low temperatures, and the Hamburg wheel-tracking test. The following tests were also used to evaluate the extracted asphalt binders: performance grading, multiple stress creep recovery, and monotonic fracture at two temperatures. This study showed that the material properties (rutting and cracking resistance) evolved over time for both the HMA and WMA pavements; however, pavement maintenance (e.g., chip seals) affected this evolution. In general, the material properties of WMA and HMA pavements for the second-round samples were consistent with those of the first-round samples.
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Moraes, Raquel, and Hussain Bahia. "Developing Simple Binder Indices for Cracking Resistance of Asphalt Binders at Intermediate and Low Temperatures." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 28 (September 6, 2018): 311–23. http://dx.doi.org/10.1177/0361198118792999.
Повний текст джерелаАнотація:
Oxidative aging causes hardening of asphalt binders and, consequently, contributes to deterioration of asphalt pavements. Non-load related cracking of asphalt pavements (i.e., transverse and block cracks) is related to original properties and hardening of the asphalt binder. In recent years, researchers have proposed new indices derived from Superpave Performance Graded (PG) testing to identify changes in asphalt cracking susceptibility with aging. These indices include the parameter G′/(η′/G′) and the difference between continuous low temperature binder grade measured via Superpave creep stiffness and m-value (ΔTc). This study aims to develop interrelationships between tests allowing choice selection for the determination of simpler parameters that could be used for specification tests of asphalt binders. Two simpler asphalt binder indices for cracking resistance are investigated by means of Dynamic Shear Rheometer (DSR), Bending Beam Rheometer (BBR) and Single Edge Notched Bending (SENB) tests results. At intermediate temperatures, the slope of the |G*|-frequency curve obtained from a simple frequency sweep test is proposed as an alternative approach to directly calculate the durability parameter G′/(η′/G′). At low temperatures, results indicated a direct correlation between failure energy at fracture obtained from SENB and ΔTc. To confim the validity of these indices and the changes at molecular level, Gel Permeation Chromatograph (GPC) results are presented to indicate that asphalts with higher content of large molecular size (LMS) molecules are likely to crack. Limits for specifcations for the slope of |G*|-frequency curve and ΔTc can be derived based on testing a wide range of binders and field experience.
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Buttlar, William G., Diyar Bozkurt, and Barry J. Dempsey. "Cost-Effectiveness of Paving Fabrics Used to Control Reflective Cracking." Transportation Research Record: Journal of the Transportation Research Board 1730, no. 1 (January 2000): 139–49. http://dx.doi.org/10.3141/1730-17.
Повний текст джерелаАнотація:
The Illinois Department of Transportation (IDOT) spends $2 million annually on reflective crack control treatments; however, the cost-effectiveness of these treatments had not been reliably determined. A recent study evaluated the cost-effectiveness of IDOT reflective crack control System A, which consists of a nonwoven polypropylene paving fabric, placed either in strips longitudinally over lane-widening joints or over the entire pavement (area treatment). The study was limited to projects constructed originally as rigid pavements and subsequently rehabilitated with one or more bituminous overlays. Performance of 52 projects across Illinois was assessed through crack mapping and from distress and serviceability data in IDOT’s condition rating survey database. Comparisons of measured reflective cracking in treated and control sections revealed that System A retarded longitudinal reflective widening crack development, but it did not significantly retard transverse reflective cracking, which agrees with earlier studies. However, both strip and area applications of these fabric treatments appeared to improve overall pavement serviceability, and they were estimated to increase rehabilitation life spans by 1.1 and 3.6 years, respectively. Reduction in life-cycle costs was estimated to be 4.4 and 6.2 percent when placed in medium and large quantities, respectively, and to be at a break-even level for small quantities. However, life-cycle benefits were found to be statistically insignificant. Limited permeability testing of field cores taken on severely distressed transverse joints suggested that waterproofing benefits could exist even after crack reflection. This was consistent with the observation that, although serviceability was generally improved with area treatment, crack reflection was not retarded relative to untreated areas.
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Gurule, Abhijeet, Tejas Ahire, Akshay Ghodke, N. P. Mujumdar, and G. D. Ahire. "Investigation on Causes of Pavement Failure and Its Remedial Measures." International Journal for Research in Applied Science and Engineering Technology 10, no. 5 (May 31, 2022): 2786–88. http://dx.doi.org/10.22214/ijraset.2022.42934.
Повний текст джерелаАнотація:
Abstract: Pavement failure is defined in terms of decreasing serviceability caused by the development of cracks and ruts. Before going into the maintenance strategies, we must look into the causes of failure of bituminous pavements. Failures of bituminous pavements are caused due to many reasons or combination of reasons. Application of correction in the existing surface will enhance the life of maintenance works as well as that of strengthening layer. It has been seen that only 3 parameters i.e., unevenness index, pavement cracking and rutting are considered while other distresses have been omitted while going for maintenance operations. Along with the maintenance techniques there are various methods for pavement preservation which will help in enhancing the life of pavement and delaying of its failure. The purpose of this study was to evaluate the possible causes of pavement distresses, and to recommend remedies to minimize distress of the pavement. The report describes lessons learnt from pavement failures and problems experienced during the last few years on a number of projects in India. Based on the past experience’s various pavement preservation techniques and measures are also discussed which will be helpful in increasing the serviceable life of pavement. A comprehensive literature concerning the factors of road deterioration, common road defects and their causes were reviewed. The investigation involved field survey and laboratory testing on those projects to examine the existing pavement conditions. The results revealed that the roads investigated experienced severe failures in the forms of cracks, potholes and rutting in the wheel path. The causes of those failures were found mainly linked to poor drainage, traffic overloading, expansive subgrade soils and the use of low-quality materials in construction. Based on the results, recommendations were provided to help highway engineers in selecting the most effective repair techniques for specific kinds of distresses.
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de Backer, Hans. "The Use of Recycled Aggregates in Continuously Reinforced Concrete Pavements (CRCP)." Advanced Materials Research 711 (June 2013): 391–95. http://dx.doi.org/10.4028/www.scientific.net/amr.711.391.
Повний текст джерелаАнотація:
The use of recycled aggregates in concrete has increased in recent decades. Increasing scarcity of natural aggregates and the growing ecological importance promote this evolution. The first test section in Belgium of a two-layer continuously reinforced concrete pavement (CRCP) with recycled aggregates in the substrate layer was built on the highway E34/N49 in 2007. Horizontal cracking at the level of the reinforcement showed up after only a few years. This is a problem which was never seen before in CRCP and was probably due to the use of recycled aggregates. Therefore it is important to understand the impact of recycled aggregates on concrete. Recycled aggregates are a two-component material consisting of natural aggregates and adhering mortar. The adhering mortar is more porous than the rock particles which insures a higher water absorption and lower density. In addition, they have a lower abrasion loss in the Los Angeles-test and less resistance against weather and temperature changes. This is due to, respectively, the less strong mortar content, and the large pores of recycled granulates. A first cause of horizontal cracking can be found in the results of high drying shrinkage, high creep and low modulus of elasticity. These properties insure larger tensions in the concrete layer. In combination with a lower tensile strength it is a possible cause for the horizontal cracking. In addition, the paper reports on laboratory testing concerning the properties of concrete with recycled aggregates and discusses an alternative method to determine the concrete mixture which takes the influence of the adhering mortar into account.
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Birgisson, Bjorn, Gregory Sholar, and Reynaldo Roque. "Evaluation of a Predicted Dynamic Modulus for Florida Mixtures." Transportation Research Record: Journal of the Transportation Research Board 1929, no. 1 (January 2005): 200–207. http://dx.doi.org/10.1177/0361198105192900124.
Повний текст джерелаАнотація:
The new 2002 AASHTO guide for the design of pavement structures is based on mechanistic principles and requires the dynamic modulus as input to compute stress, strain, and rutting and cracking damage in flexible pavements. The 2002 AASHTO guide has three different levels of analysis; the level used depends on the importance of the pavement structure in question. Dynamic modulus testing is required for Level 1 pavement analysis, whereas no laboratory test data are required for Level 2 and Level 3 pavement analysis. Instead, a predictive dynamic modulus equation is used to generate input values. It is of significant importance to state agencies to understand how well the dynamic modulus for locally available materials compares with the predicted dynamic modulus. This paper presents the results of a study by the Florida Department of Transportation and the University of Florida that focused on the evaluation of the dynamic modulus predictive equation used in the new AASHTO 2002 guide for mixtures typical to Florida. The resulting research program consisted of dynamic modulus testing of 28 mixtures common to Florida. Results showed that on average the predictive modulus equation used in the new AASHTO 2002 flexible pavement design guide appeared to work well for Florida mixtures when used with a multiplier to account for the uniqueness of local mixtures. Results of the study also identified optimal viscosity–temperature relationships that result in the closest correspondence between measured and predicted dynamic modulus values.
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Crovetti, James A. "Construction and Performance of Fly Ash-Stabilized Cold In-Place Recycled Asphalt Pavement in Wisconsin." Transportation Research Record: Journal of the Transportation Research Board 1730, no. 1 (January 2000): 161–66. http://dx.doi.org/10.3141/1730-19.
Повний текст джерелаАнотація:
Cold in-place recycling (CIR) is a common rehabilitation practice used in Wisconsin to improve the ride quality and structural capacity of deteriorated asphalt pavements. In recent years, increased emphasis has been placed on incorporating stabilizers into the CIR materials to improve the structural capacity of the CIR base layer. This improvement can serve to increase the performance life of the completed pavement or to allow for a reduced hot-mix asphalt (HMA) surface thickness. The city of Mequon, Wisconsin, included asphalt emulsion and fly ash CIR stabilization over a portion of its CIR projects in 1997. Presented are the findings relating to the constructability of the fly ash–stabilized CIR pavement as well as performance trends for the CIR pavements based on distress and deflection testing results. CIR is a common rehabilitation practice used in Wisconsin to improve the ride quality and structural capacity of deteriorated asphalt pavements. In one type of CIR application, existing HMA layers are pulverized, graded, and compacted, then used as a base layer for a new HMA surface. The pulverization process is completed to provide uniformity of support to the HMA surface and to significantly reduce or eliminate the occurrence of reflection cracking of the HMA surface. In most CIR applications, pulverization is completed through the full thickness of the existing HMA layers, as well as through the top 25 to 50 mm of aggregate base. Penetration into unbound aggregate base materials aids in cooling of the bits on the pulverizer mandrel. After pulverization, graders typically are used to spread the materials to the desired width and shape. Compaction is achieved by using vibrating steel drum and pneumatic-tire rollers. The moisture content of the CIR materials is adjusted, as necessary, by surface spraying from a water tanker truck.
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Ponniah, Joseph, and Gerhard Kennepohl. "Polymer-Modified Asphalt Pavements in Ontario: Performance and Cost-Effectiveness." Transportation Research Record: Journal of the Transportation Research Board 1545, no. 1 (January 1996): 151–60. http://dx.doi.org/10.1177/0361198196154500120.
Повний текст джерелаАнотація:
Two trial sections were constructed to investigate the rutting resistance and low temperature performance of different polymer-modified asphalt (PMA) mixes at sites representative of highways experiencing rutting as a result of heavy traffic loading in cold climatic regions. The two-way average annual daily traffic for both sites was >35,000 (6,000 vehicles per day). Modified asphalts used in the trial sections include engineered bitumen type 306, premium asphalt, reprocessed polyethylene (Novophalt), Neoprene, scrap tire rubber, Vestoplast-S, Kraton 4460, Styrelf, and polyethylene. Representative test samples of aggregates, asphalt cement, modified asphalts, and hot mixes were taken for routine testing during production. In situ quality control tests were done by taking plate samples while laying the mix and by coring after compaction. Additional laboratory tests were done at temperatures ranging from 0°C to —35°C to evaluate the materials’ low temperature cracking resistance. Field performance of trial sections was monitored yearly by crack mapping and measuring transverse profiles at 30-m spacing on each test section. Levels were taken at 100-mm intervals by using a dipstick. A computer program was written to process the data and calculate the rut depths for each wheelpath. Crack mapping was done to assess the crack growth in each test section. The performance of the sections was compared with respect to average rut depth and crack growth. The following are described: (a) the modified mix design chosen specifically to produce accelerated test results, (b) the experience gained in the construction of trial sections, (c) the results of laboratory testing to evaluate the low temperature performance of the PMAs, (d) the field performance evaluation with respect to rutting and cracking, and (e) the life cycle cost analysis. Average rut depth measurements 5 to 7 years after construction show that PMA pavement sections are performing better than conventional asphalt with respect to rutting. With regard to cracking, polymers with 85 to 100 penetration (pen) base asphalt did not perform better than control sections. However, there is an indication that PMA, which has a soft grade (150 to 200 pen) base asphalt, tends to improve low-temperature performance comparable to the control section. In other words, PMA generally performs better than conventional asphalt, provided it contains a soft grade (150 to 200 pen) base asphalt. Life cycle cost analysis indicates that PMA is cost-effective in extending pavement life by 2 to 3 years if the cost of polymer modification does not exceed the cost of conventional asphalt by 100 percent.
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Lee, S. Joon. "Mechanical performance and crack retardation study of a fiberglass-grid-reinforced asphalt concrete system." Canadian Journal of Civil Engineering 35, no. 10 (October 2008): 1042–49. http://dx.doi.org/10.1139/l08-049.
Повний текст джерелаАнотація:
This paper presents constitutive design considerations for a semi-rigid, resin-impregnated fiberglass grid that enhances the mechanical performance of an asphalt concrete overlay and provides a pattern to retard crack propagation. An acrylic polymer resin covers the grid-structured fiberglass strands, thus making their viscoelastic nature compatible with the asphalt materials. The remarkable temperature susceptibility of the resin is observed using time–temperature superposition. The grid tensile strength of 100 kN/m was qualified using standard measurements. Three-point bending and cyclic fatigue loading mechanical tests affirm the retardation performance of the grid-reinforced system in terms of crack propagation. The retardation mechanism is affected by synchronizing the cracking pattern with the flexural stress–strain profile through image analysis. A National Center for Asphalt Technology full-scale road testing program provides assessment of the grid-reinforced pavements. A visual inspection of the grid extracted from the traffick zone showed fair condition of the pavement.
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Carvajal, Mateo E., Murugaiyah Piratheepan, Peter E. Sebaaly, Elie Y. Hajj, and Adam J. Hand. "Structural Contribution of Cold In-Place Recycling Base Layer." CivilEng 2, no. 3 (September 3, 2021): 736–46. http://dx.doi.org/10.3390/civileng2030040.
Повний текст джерелаАнотація:
Cold in-place recycling (CIR) of asphalt pavements is a process that has successfully been used for many years. The use of CIR for rehabilitation offers many advantages over traditional overlays due to its excellent resistance to reflective cracking and its environmentally friendly impacts. Despite the good performance and positive sustainability aspects of CIR, the structural contribution of the CIR base layer has not been well defined. In this research, CIR mixtures were designed with different asphalt emulsions. The mixtures were then subjected to dynamic modulus, repeated load triaxial, and flexural beam fatigue testing over a range of temperature and loading conditions. The performance test data generated were then used to develop CIR rutting and fatigue performance models used in the mechanistic analysis of flexible pavements. The technique used to develop the performance models leveraged the fact that the rutting and fatigue models for individual CIR mixtures were all within the 95 percent confidence interval of each other. A mechanistic analysis was conducted using the 3D-Move Mechanistic Analysis model. With the laboratory-developed performance models, the structural layer coefficient for the CIR base layer were developed for use in the 1993 AASHTO Guide for the Design of Pavement Structures. This analysis led to the determination of an average structural coefficient of the CIR base layer of 0.25.
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Bowers, Benjamin F. "Laboratory Evaluation of Mixture Type on Highly Modified Asphalt Mixtures in Virginia." Transportation Research Record: Journal of the Transportation Research Board 2672, no. 28 (September 9, 2018): 59–68. http://dx.doi.org/10.1177/0361198118792998.
Повний текст джерелаАнотація:
The work presented attempts to address reflective cracking of asphalt-surfaced pavements through binder modification with a highly polymer (HP)-modified asphalt binder. Nine asphalt mixtures ranging from fine dense-graded mixtures to stone matrix asphalt (SMA) mixtures were investigated with conventional polymer modified binders and HP binder. The dynamic modulus test, overlay test (OT), and semi-circular bend (SCB) test were used to evaluate the mixtures. In the cracking tests, HP mixtures outperformed the conventionally modified control mixtures for the same mixture type. For HP mixtures, in general, SMA mixtures performed better in the cracking test than dense-graded mixtures. One of the dense-graded mixtures having larger nominal maximum aggregate size (NMAS) performed better than the mixture with a smaller NMAS, whereas the other having a larger NMAS was not significantly different in crack testing. Further, a discussion on the calculation of bulk specific gravity and percent air voids in a cut OT and SCB specimen using saturated surface dry or vacuum sealing methods is presented.
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Lane, Becca, and Tom Kazmierowski. "Implementation of Cold In-Place Recycling with Expanded Asphalt Technology in Canada." Transportation Research Record: Journal of the Transportation Research Board 1905, no. 1 (January 2005): 17–24. http://dx.doi.org/10.1177/0361198105190500102.
Повний текст джерелаАнотація:
Cold in-place recycling (CIR) is a pavement rehabilitation method that processes an existing hot-mix pavement, sizes it, mixes in additional asphalt cement, and lays it back down without off-site hauling and processing. The added asphalt cement is typically emulsified asphalt. A recent development in CIR technology is the use of expanded (foamed) asphalt rather than emulsified asphalt to bind the mix. This combination of CIR and expanded asphalt technologies is termed cold in-place recycled expanded asphalt mix (CIREAM). The Ministry of Transportation Ontario (MTO) constructed a CIREAM trial section on Highway 7 in July 2003. The 5-km CIREAM trial section was constructed adjacent to an 8-km section on which conventional CIR was performed. CIREAM placement resulted in a smooth, hard, uniform surface that provided an excellent platform for paving operations. The CIREAM placement progressed in a continuous and efficient manner, with 5 km placed over a 3-day period. Indirect tensile strength testing was carried out on both materials during construction. Falling weight deflectometer (FWD) testing and evaluation of pavement roughness and rutting by the use of MTO's automatic road analyzer (ARAN) were carried out. Resilient modulus testing of core samples of the CIR material and CIREAM was also carried out. The results of the FWD, ARAN, and resilient modulus tests indicated that the CIR and CIREAM pavements were performing similarly. A field review 1 year after construction showed no discernible distortion, rutting, or cracking. On the basis of short-term results, CIREAM appears to be an acceptable in-place recycling and rehabilitation strategy that provides an economical alternative to conventional CIR, reduces curing time, and extends the construction season.
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Scullion, Tom, and Pat Harris. "Forensic Evaluation of Three Failed Cement-Treated Base Pavements." Transportation Research Record: Journal of the Transportation Research Board 1611, no. 1 (January 1998): 10–18. http://dx.doi.org/10.3141/1611-02.
Повний текст джерелаАнотація:
Three cement-treated base (CTB) pavements constructed around 1990 near Houston, Texas, showed severe pavement deterioration after 3 to 4 years. The unusual distress patterns included wheelpath alligator cracking and severe pumping. A forensic investigation was initiated to determine the cause and to recommend modifications to materials specification, design, and construction practices to avoid future problems. The primary cause was determined to be chemical deterioration that resulted in destruction of the cement matrix. In all cases water was trapped within the CTB layer. In two bases moisture flowed rapidly by capillary action through the CTB; these bases showed the most rapid deterioration. Water flow in one case was attributed to smectite clay contamination of the fine aggregate and in another to a highly absorptive sandstone coarse aggregate. Extensive ettringite was found in one material. In one case deterioration was caused by the growth of two phases exhibiting different morphologies: hydrated calcium aluminum silicate with a radiating needle morphology and ettringite, which showed a bladed morphology in these samples. Practical recommendations to prevent recurrence of the problem were ( a) moisture absorption as acceptance testing for coarse aggregate and ( b) elimination of designs placing different stabilized materials on top of one another. The laboratory suction test that was developed is recommended as a screening test for molded CTB specimens.
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Wagoner, Michael P., William G. Buttlar, Glaucio H. Paulino, and Philip Blankenship. "Investigation of the Fracture Resistance of Hot-Mix Asphalt Concrete Using a Disk-Shaped Compact Tension Test." Transportation Research Record: Journal of the Transportation Research Board 1929, no. 1 (January 2005): 183–92. http://dx.doi.org/10.1177/0361198105192900122.
Повний текст джерелаАнотація:
In recent years the transportation materials research community has focused a great deal of attention on the development of testing and analysis methods to shed light on fracture development in asphalt pavements. Recently it has been shown that crack initiation and propagation in asphalt materials can be realistically modeled with cutting-edge computational fracture mechanics tools. However, much more progress is needed toward the development of practical laboratory fracture tests to support these new modeling approaches. The goal of this paper is twofold: ( a) to present a disk-shaped compact tension [DC(T)] test, which appears to be a practical method for determining low-temperature fracture properties of cylindrically shaped asphalt concrete test specimens, and ( b) to illustrate how the DC(T) test can be used to obtain fracture properties of asphalt concrete specimens obtained from field cores following dynamic modulus and creep compliance tests performed on the same specimens. Testing four mixtures with varied composition demonstrated that the DC(T) test could detect the transition from quasi-brittle to brittle fracture by testing at several low temperatures selected to span across the glass transition temperatures of the asphalt binder used. The tendency toward brittle fracture with increasing loading rate was also detected. Finally, the DC(T) test was used in a forensic study to investigate premature reflective cracking of an isolated portion of pavement in Rochester, New York. One benefit of the DC(T) test demonstrated during testing of field samples was the ability to obtain mixture fracture properties as part of an efficient suite of tests performed on cylindrical specimens.
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Grobler, J. A., A. Taute, and I. Joubert. "Pavement Evaluation and Rehabilitation Design Methodology Currently Used on Low-Volume Roads in Southern Africa." Transportation Research Record: Journal of the Transportation Research Board 1819, no. 1 (January 2003): 343–52. http://dx.doi.org/10.3141/1819b-44.
Повний текст джерелаАнотація:
A pavement evaluation and rehabilitation design methodology is currently employed in southern Africa on relatively light pavement structures used for low-volume roads. The pavements normally consist of natural gravel materials in most layers and thin bituminous surfacings. When nearing the end of their design lives, they exhibit distresses ranging from minor deformation through aging of the surface to structural cracking and potholes. Rehabilitation options normally involve light stone seals or other inexpensive and cost-effective treatments. The phases of investigation for pavement evaluation and rehabilitation designs start with desk study to establish the history of the road and its past performance from pavement management system outputs. Detailed visual evaluations are then conducted of road features and extent of various forms of distress. These data are presented followed by a decision-making process to select areas for more detailed testing. All the information is used to determine the causes of distress and likely rehabilitation alternatives. Further destructive and nondestructive testing is carried out to predict performance of rehabilitation designs and equivalent annual cost comparisons. Rehabilitation design is also done with use of the dynamic cone penetrometer. Decision criteria are set for use of tests undertaken in the assessments, and test results are evaluated. This procedure normally results in a wide range of rehabilitation options, from application of a diluted emulsion as a surface rejuvenator to more extensive patching and resealing to major rehabilitation and overlays. This process effectively produces cost-effective solutions that maximize limited budgets. It is essential that the road authority be prepared to share the risks of the low-cost options with the designer. In this way benefits of low-cost solutions are realized, whereas, in a limited number of instances, premature distress may have to be repaired under routine maintenance.
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Koubaa, Amir, and Mark B. Snyder. "Evaluation of Frost Resistance Tests for Carbonate Aggregates." Transportation Research Record: Journal of the Transportation Research Board 1547, no. 1 (January 1996): 35–45. http://dx.doi.org/10.1177/0361198196154700106.
Повний текст джерелаАнотація:
D-cracking is a progressive distress associated primarily with the use of coarse aggregates that deteriorate when they are critically saturated and subjected to repeated cycles of freezing and thawing. The present study was undertaken to consider better acceptance criteria for concrete aggregates and to allow for the use of more local Minnesota aggregates through selected aggregate beneficiation techniques. Condition surveys of concrete highway pavements were performed to document the field freeze-thaw performance of selected aggregate sources representing a range of frost resistance. Cores were obtained from these sections for laboratory testing and evaluation, and coarse aggregates were obtained from the original sources for use in performing environmental simulation tests [i.e., variations of ASTM C666 and the Virginia Polytechnic Institute (VPI) single-cycle slow-freeze test] and correlative tests (i.e., absorption and bulk specific gravity, Portland Cement Association absorption and adsorption tests, Iowa pore index test, acid insoluble residue test, X-ray diffraction analysis, X-ray fluorescence analysis, thermogravimetric analysis, and the Washington hydraulic fracture test). The tests that provided the best correlation with field performance included a modification of ASTM C666 Procedure B (specimens prepared with salt-treated aggregates), the VPI single-cycle slow-freeze test, and the Washington hydraulic fracture test. Other test procedures were correlated with field performance to lesser extents. It was noted that petrographic examination of pavement cores can help to distinguish between D-cracking and other conditions that can produce distresses with similar appearances (e.g., distresses caused by secondary mineralization, embedded shale, poor mix design, and alkali-aggregate reaction).
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Bai, Byong Chol, Dae-Wook Park, Hai Viet Vo, Samer Dessouky, and Ji Sun Im. "Thermal Properties of Asphalt Mixtures Modified with Conductive Fillers." Journal of Nanomaterials 2015 (2015): 1–6. http://dx.doi.org/10.1155/2015/926809.
Повний текст джерелаАнотація:
This paper investigates the thermal properties of asphalt mixtures modified with conductive fillers used for snow melting and solar harvesting pavements. Two different mixing processes were adopted to mold asphalt mixtures, dry- and wet-mixing, and two conductive fillers were used in this study, graphite and carbon black. The thermal conductivity was compared to investigate the effects of asphalt mixture preparing methods, the quantity, and the distribution of conductive filler on thermal properties. The combination of conductive filler with carbon fiber in asphalt mixture was evaluated. Also, rheological properties of modified asphalt binders with conductive fillers were measured using dynamic shear rheometer and bending beam rheometer at grade-specific temperatures. Based on rheological testing, the conductive fillers improve rutting resistance and decrease thermal cracking resistance. Thermal testing indicated that graphite and carbon black improve the thermal properties of asphalt mixes and the combined conductive fillers are more effective than the single filler.
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Matias De Oliveira, Jhenyffer, Tianhao Yan, Mugurel Turos, Debaroti Ghosh, Dave Van Deusen, and Mihai Marasteanu. "Simple Method to Evaluate Strength and Relaxation Properties of Asphalt Binders at Low Temperature." Transportation Research Record: Journal of the Transportation Research Board 2673, no. 6 (June 2019): 492–500. http://dx.doi.org/10.1177/0361198119853544.
Повний текст джерелаАнотація:
Low temperature cracking represents the main distress in asphalt pavements built in cold regions. During the Strategic Highway Research Program (SHRP) two test methods were developed to investigate the low temperature behavior of asphalt binders: bending beam rheometer (BBR) and direct tension tester (DTT). In this research, a simple testing protocol developed to obtain failure properties of asphalt binders at low temperatures is used to characterize the behavior of five asphalt binders used in the construction of MnROAD test cells in 2016. It is shown that a combination of creep followed by strength testing provides a more complete picture of the low temperature properties of asphalt binders and can improve the selection process. Binders with similar creep and relaxation properties have significantly different failure properties. It is also demonstrated that BBR strength data is obtained under linear viscoelastic conditions for the entire duration of the test and that creep and strength data can be interconverted using linear viscoelasticity.
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Hossain, Akhter B., Brad Pease, and Jason Weiss. "Quantifying Early-Age Stress Development and Cracking in Low Water-to-Cement Concrete: Restrained-Ring Test with Acoustic Emission." Transportation Research Record: Journal of the Transportation Research Board 1834, no. 1 (January 2003): 24–32. http://dx.doi.org/10.3141/1834-04.
Повний текст джерелаАнотація:
Early-age cracking has been found to occur in some concrete bridge decks, slabs, and pavements when the volumetric changes associated with drying, hydration, and temperature reduction are prevented. While free-shrinkage tests can quantify length change, they may not always be sufficient for detecting materials that are prone to cracking, since the potential for cracking is influenced by complex interactions of strength gain, stiffness development, creep, shrinkage, the degree of restraint, and toughness. The simplicity of the ring test enables it to be used as a comparative test to screen potential mixture designs. From the use of this test, AASHTO developed a provisional standard ring test that establishes specimen geometry; however, the provisional standard does not provide an approach for quantifying stress development or indicating how close a specimen may be to failure. Described is a simple stress solution for quantifying the results of the ring test. Issues related to ring and free-shrinkage specimen geometries are discussed to improve the fundamental understanding of the information provided by the ring test. Also described is how elastic stress and actual stress can be compared to measure the stress relaxation in a material. To better illustrate the microcracking and visible-crack development process, acoustic-emission testing was performed. These experiments indicated that specimens with a higher level of restraint exhibited more microcracking as a part of the stress relaxation process.
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Saliani, S. Saeed, Alan Carter, Hassan Baaj, and Pejoohan Tavassoti. "Characterization of Asphalt Mixtures Produced with Coarse and Fine Recycled Asphalt Particles." Infrastructures 4, no. 4 (October 26, 2019): 67. http://dx.doi.org/10.3390/infrastructures4040067.
Повний текст джерелаАнотація:
Utilizing recycled asphalt pavements (RAP) in pavement construction is known as a sustainable approach with significant economic and environmental benefits. While studying the effect of high RAP contents on the performance of hot mix asphalt (HMA) mixes has been the focus of several research projects, limited work has been done on studying the effect of RAP fraction and particle size on the overall performance of high RAP mixes produced solely with either coarse or fine RAP particles. To this end, three mixes including a conventional control mix with no RAP, a fine RAP mix (FRM) made with 35% percent fine RAP, and a coarse RAP mix (CRM) prepared with 54% of coarse RAP were designed and investigated in this study. These mixes were evaluated with respect to their rutting resistance, fatigue cracking resistance, and low temperature cracking performance. The results indicate that although the CRM had a higher RAP content, it exhibited better or at least the same performance than the FRM. The thermal stress restrained specimen testing (TSRST) results showed that the control mix performed slightly better than the CRM, while the FRM performance was adversely affected with respect to the transition temperature midpoint and the maximum tensile stress temperature. Both of the RAP incorporated mixes exhibited better rutting resistance than the control mix. With regard to fatigue cracking, the CRM performed better than the FRM. It can be concluded that the RAP particle size has a considerable effect on its contribution to the total binder content, the aggregate skeleton of the mix, and ultimately the performance of the mix. In spite of the higher RAP content in the CRM versus FRM, the satisfactory performance observed for the CRM mix indicates a great potential in producing high RAP content mixes through optimizing the RAP particle size and content. The results also suggest that the black curve gradation assumption is not representative of the actual RAP particles contribution in a high RAP mix.
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Wu, Yen Chieh, Giovanni Cascante, and Mahesh D. Pandey. "Condition assessment of longitudinal pavement joints using ultrasonic surface waves." Canadian Journal of Civil Engineering 41, no. 12 (December 2014): 1019–28. http://dx.doi.org/10.1139/cjce-2013-0301.
Повний текст джерелаАнотація:
Poor-quality longitudinal joints can cause premature failure on asphalt pavements; they are characterized by exhibiting low density and high permeability. These conditions generate surface distresses such as longitudinal cracking. Previous ultrasonic methods for condition assessment, e.g., Fourier and wavelet transmission coefficient, require user input, making the automatic data processing difficult. Furthermore, the coupling between ultrasonic transducers and the asphalt surface is not practical for testing in-service roads. This paper presents a new data analysis technique and the results of an experimental program for the condition assessment of longitudinal asphalt joints using ultrasonic surface waves. A new coupling system between the ultrasonic transducers and the asphalt surface is presented. The new data processing technique reduces user input and increases testing reliability. The new coupling system uses polyurethane foam and calibrated weights to provide a spring action on the transducers. The proposed data analysis technique, called instantaneous transmission coefficient (ITC), is based on the evaluation of instantaneous frequencies and damping ratios. The main advantage of the new procedure is that it can be performed automatically, reducing user input and increasing test repeatability. A laboratory scale asphalt slab is used to show the potential of the new methodology and coupling system. Laboratory validation results show good agreement between the new ITC method and previous methods, and a significant reduction in testing time, while improving test reliability.