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Статті в журналах з теми "Pavements Cracking Testing"
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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.
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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.
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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.
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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
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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.
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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.
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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.
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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.
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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.
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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.
Дисертації з теми "Pavements Cracking Testing"
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Loria-Salazar, Luis Guillermo. "Reflective cracking of flexible pavements literature review, analysis models,and testing methods /." abstract and full text PDF (free order & download UNR users only), 2008. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:1453593.
Повний текст джерела
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Elseifi, Mostafa. "Performance Quantification of Interlayer Systems in Flexible Pavements Using Finite Element Analysis, Instrument Response, and Non Destructive Testing." Diss., Virginia Tech, 2003. http://hdl.handle.net/10919/26489.
Повний текст джерелаАнотація:
This study quantifies the benefits of two interlayer systems (steel reinforcing netting and a newly-designed geocomposite membrane) in different pavement applications. Steel reinforcing netting and geocomposite membrane have been installed at the Virginia Smart Road in four different sections. Ground penetrating radar (GPR) surveys and time domain reflectometer (TDR) validated the effectiveness of the geocomposite membrane in preventing water from infiltrating to the underneath layers. In pavement rehabilitation applications, based on finite element (FE) analysis, it was found that the geocomposite membrane would create a protective compressive field around the crack tip and separate the criticality of the stress field in the cracked area from the bottom of the overlay. However, if the crack passes through the interlayer, a faster propagation rate than in a typical pavement is expected. These results emphasize the importance of proper field installation. As to steel reinforcing netting, this study found that this interlayer system would be effective in new pavement systems in both the crack initiation and propagation phases when the cracks start at the bottom of the HMA layers. For the considered pavement structures, steel reinforcing netting was found effective to delay the initiation of the cracks. This delay depends on the stiffness of the hot-mix asphalt (HMA) layers, the reinforcing pattern, and the direction of the strain at the bottom of the HMA layers. After initiation of the crack, steel reinforcement contribute by delaying the rate of crack propagation to the pavement surface. In pavement rehabilitations, however, the crack is already well established in the existing pavement, and steel reinforcement contribution is expected from the time of installation. In this case, steel reinforcement will delay the initiation of the crack in the overlay, and reduce the rate of crack propagation afterwards. Two models, to predict the overlay service life against reflective cracking from existing HMA layers, were developed.Ph. D.
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Twagirimana, Emmanuel. "Evaluation of adhesion properties in bitumen-aggregate systems for winter surfacing seals using the bitumen bond strength test." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/95953.
Повний текст джерелаАнотація:
Thesis (MEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: Flexible pavement designers have a choice of two wearing course: either asphalt concrete or surfacing seals. The latter have been widely used by several countries as their preferred wearing course over other methods, especially countries with a limited number of average inhabitants per square kilometre. Moreover, the surfacing seals were identified as an efficient cost effective road preventive maintenance technique. Surfacing seals in New Zealand, South Africa and Australia cover about 65%, 80% and 90% of their surfaced road networks respectively. The preference of surfacing seals is due to their competitive initial cost and ease of construction. In South Africa, the life expectancy of surfacing seals varies between 8 and 12 years with an average of 10 years. This has not been the case in a number of surfacing seals constructed in winter, especially when the night recorded temperature is below 10oC. The dominant failure mechanism is ravelling (chip loss) soon after construction due to traffic loading. This chip loss is linked to the poor adhesion bond development rate in the bitumen-aggregate system during winter adverse conditions. In order to address the issue of premature chip loss the need for the development of a robust adhesion test method was identified. For that purpose, recently, researchers in the bitumen industry developed the Bitumen Bond Strength test method. This method was used in this study. This study intends to contribute to the understanding of binder-aggregate adhesion bond development for winter surfacing seals using the BBS test. Binder type, precoat type and conditioning, aggregate type and curing time are amongst the factors influencing winter seals adhesion bond performance. An experimental matrix involving three types of binder, two types of aggregate, four different precoating fluids, two precoat conditionings and two binder-curing times were then developed and investigated. Winter weather parameters affecting adhesion properties were also taken into consideration during the course of the investigation. Throughout the test, the procedure described in AASHTO TP 91-11 was followed. However, in order to enhance the control of the binder application temperature, a new method for hot applied binder sample preparation was developed as part of this study. The findings show that there is a significant difference between adhesion properties of the hot applied binders (70/100 and S-E1) and the emulsion (SC-E1). In most of the cases, the hot applied binders performed better than the emulsion. The failure mode observed was found to be linked to the condition of the precoating. The influence of the precoat type and conditioning, and effect of binder curing time were significantly highlighted. The use of a dry precoat benefited the adhesion bond strength up to around 50% relatively to the corresponding non-precoated combination. However, a decrement in the bond strength due to precoating of up to 28.7% was also observed. A statistical analysis using ANOVA did not illustrate any statistical significant effect of the aggregate type. The interaction effects analysis using ANOVA revealed the aggregate type interacting with precoat type to be the most influential interaction at level two. The precoat conditioning implication to the adhesion development rate, which influences the time for opening to traffic after construction, was illustrated. Insightful aspects on the compatibility between the binder type and precoat type and conditioning during the aggregate precoating practices and on the time for opening to traffic are highlighted. Finally, the repeatability analysis proved the BBS test to be a repeatable testing method with caution. Recommendations for further studies that could support the conclusions drawn in this study were provided.
AFRIKAANSE OPSOMMING: Buigbare plaveiselontwerpers het 'n keuse van twee deklae: óf Asfalt of oppervlak seëls. Laasgenoemde word algemeen gebruik deur verskeie lande as hul voorkeur deklaag, veral die lande met beperkte aantal gemiddelde inwoners per vierkante kilometer. Verder, is die seëls geïdentifiseer as 'n doeltreffende koste-effektiewe deklaag tegniek. Oppervlakseëls in Nieu-Seeland, Suid-Afrika en Australië dek ongeveer 65%, 80% en 90% van hul padnetwerke onderskeidelik. Die seëls se voorkeur is te danke aan hul mededingende aanvanklike koste en eenvoudige vorm van die konstruksie. In Suid-Afrika wissel die seël se lewensverwagting tussen 8 en 12 jaar met 'n gemiddeld van 10 jaar. Dit is egter nie die geval van 'n aantal seëls wat in die winter gebou word nie, veral wanneer die aangetekende nagtemperatuur onder 10o C daal nie. Die dominante swigtingsmeganisme is stroping (klipverlies) kort na konstruksie. Hierdie klipverlies is gekoppel aan die power kleef-ontwikkeling van bitumen gedurende die winter. Ten einde die probleem van voortydige klipverlies aan te spreek het die behoefte vir die ontwikkeling van 'n robuuste toetsmetode ontstaan. Om hierdie rede het navorsers onlangs in die bitumenbedryf die “BBS toetsmetode” ontwikkel en is dié toetsmetode in hierdie studie gebruik. Hierdie studie beoog om by te dra tot die begrip van bindmiddel-klip kleefontwikkeling vir die winter seëls dmv die BBS toets. Die faktore, insluitend maar nie beperk tot bindmiddeltipe, voorafdekking (“PRECOAT”) -tipe en kondisionering, aggregaattipe en kuurtyd beïnvloed winter seëls se kleefeienskappe. 'n Eksperimentele matriks met drie tipes bindmiddels, twee tipes aggregate, vier verskillende voorafdekking-vloeistowwe, twee voorafdekking kondisionering en twee bindmiddel kuurtye is toe ontwikkel en ondersoek. Winter weer parameters wat kleefeienskappe beïnvloed is ook in ag geneem tydens die verloop van die ondersoek. Regdeur die studie is die prosedure AASHTO TP 91-11 gevolg, maar ten einde die beheer van die bindmiddel spuittemperatuur te verbeter, is ‘n nuwe metode vir warmspuit-bindmonsters voorbereiding ontwikkel as deel van hierdie studie. Die bevindinge toon dat daar 'n beduidende verskil tussen die kleefeienskappe van die warm aangewende bindmiddels (70/100 en S-E1) en die emulsie (SC-E1) is. In die meeste van die gevalle het die warmspuit-bindmiddels beter as emulsie gevaar. Daar is gevind dat die swigtingsmeganisme verbind word met die toestand van die voorafdekking. Die invloed van voorafdekkingtipe, kondisionering, en die effek van bindmiddelkuurtyd is duidelik uitgelig. Die gebruik van droë voorafdekking het die kleefkrag tot sowat 50% verhoog relatief tot die ooreenstemmende onbedekte klipkombinasie. Daar is egter ook ‘n verlaging van die kleefkrag weens voorafdekking gevind van tot so hoog soos 28,7 persent. Die statistiese ontleding met behulp van ANOVA het geen statisties beduidende effek van die verksillende aggregaattipe te vore gebring nie. Die interaksie-effek analise, met behulp van ANOVA, het wel die interaksie met voorafdekkingtipe met aggregaat die mees invloedryke bevestig. Die voorafdekking kondisioneering het ver rykende kleefkrag implikasies bloot gelê, wat die tyd vir die opening van die verkeer na konstruksie beïnvloed. Insigwekkende aspekte oor die versoenbaarheid tussen die bindmiddeltipe, voorafdekkingtipe, kondisionering, voorafdekkingpraktyk en tyd tot opening vir verkeer word uitgelig. Ten slotte, die herhaalbaarheidsanalise het die BBS toets as 'n herhaalbare toetsmetode met omsigtigheid bewys. Daar is aanbevelings tot verdere studies, wat uit die gevolgtrekking gekom het, gemaak.
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Nwando, Tiyon Achille. "Flexibility and performance properties of bitumen stabilised materials." Thesis, Stellenbosch : Stellenbosch University, 2014. http://hdl.handle.net/10019.1/86594.
Повний текст джерелаАнотація:
Thesis (MScEng)--Stellenbosch University, 2014.ENGLISH ABSTRACT: This research investigates the flexibility and the performance properties of bitumen stabilised materials under the influence of mix variables. The laboratory testing consisted of two main phases. During the first phase (mix design), the strength and the flexibility of the mixes were assessed through ITS (Indirect Tensile Strength), UCS (Unconfined Compressive Strength), displacement at break, strain at break and fracture energy. The second phase consisted of a series of triaxial tests done to assess the performance properties (shear strength: cohesion and angle of internal friction; and stiffness: resilient modulus) of the mixes. The mineral aggregates used in this study were milled from different locations of the R35, near Bethal. This was a blend of granular material (dolerite, from various locations of the existing base and subbase layer of the R35) and Reclaimed Asphalt (RA) milled from the existing surfacing. During the mix design phase, two types of bituminous binders were used (bitumen emulsion and foamed bitumen) at bitumen content ranges of 2%, 2.4% and 2.8% each. Two types of active filler were used separately and in combination at a proportion of 1% and 2%. Finally, specimens were tested in wet and dry conditions for each mix combination. During the triaxial testing phase, only the optimum bitumen content of 2.4% was used, both for bitumen emulsion and foamed bitumen, with only cement as active filler in a proportion 1% and 2%. The specimens were tested at different ranges of densities and saturation levels. The flexibility of the mix was assessed through the fracture energy, the strain and the displacement at break parameters. An analysis of variance (ANOVA) was conducted on the data to assess the significance of experimental variables on this property. This property was found to be very sensitive to bitumen and cement content added to the mix. When assessing the combined effect and the significance of the variables on the flexibility of the mixes, it was found that fracture energy is mostly influenced by the cement content, followed by the bitumen content, then the type of treatment and finally the testing condition. However, the level of significance was not in the same order for the other two parameters (displacement and strain at break). It was also found that the combined effect of some independent variables (cement content + testing condition, type of treatment + cement content + bitumen content) had a significant effect on the fracture energy and the strain at break respectively. From the ITS and UCS tests, an increase in strength was noticed with the increase of cement content. On the other hand, the increase in bitumen content led to a decrease in strength of the material. The statistical analysis on the ITS and UCS values show that the independent variable with the most significant effect on the ITS is the cement content, followed by the testing conditions, then the bitumen content and finally the type of treatment. The combined effect of cement content + bitumen content was found to be significant both for ITS and UCS. In the second phase triaxial tests were performed in order to evaluate the performance properties of the mixes. It was found that the increase of the active filler content significantly improves the shear strength of the material. It was also found that at a fixed cement content, specimens tested at low density and/or high level of saturation show low shear strength. The Mr-θ model was used to model the resilient modulus of the mixes and the model coefficients used to evaluate the effect of experimental variables on the resilient modulus. It was found that the resilient modulus of the mixes increases as the bulk stress increases. This confirms the stress dependent behaviour of bitumen stabilised materials. The analysis show that increasing the percentage of active fillers content results in a significant increase in the resilient modulus values. An increase in relative density also resulted in an increase in the resilient modulus of the mixes, while the opposite effect was observed with the increased of the saturation level. Besides the engineering properties and the mechanical test parameters, other parameters such as the Tensile Strength Ratio (TSR) was calculated in order to evaluate the moisture sensitivity of the mixes. Weakening due to moisture was found to be more predominant in the mixes with less active filler. In addition, bitumen emulsion mixes were found to have a better resistance to moisture weakening effects compared to foamed bitumen. In addition, a comparison between the rapid curing and the accelerated curing was done. Higher ITS and UCS results were obtained for specimens cured using long term curing compared to specimens cured using the accelerated curing method. In conclusion, flexibility is an important property of bitumen road construction material (bitumen stabilised material include) however, it is not an easy property to measure. Although, displacement/strain at break and fracture energy from ITS and UCS were able to give us some indications on the main factors governing the flexibility of bitumen stabilised materials (the bitumen and active filler content), more accurate and adequate tests are required to evaluate the parameter.
AFRIKAANSE OPSOMMING: Die buigsaamheid en gedragseienskappe van bitumen gestabiliseerde materiale was getoets om sodoende die invloed van verskeie mengselveranderlikes te evalueer. Die ondersoek het uit twee fases bestaan. Tydens die eerste fase (mengfase) is die sterkte en buigsaamheid deur middel van indirekte treksterkte toetse (ITS), onbegrensde druksterkte toetse (UCS), verplasing – en vervorming by breekpunt sowel as breek-energie toetse gedoen en ondersoek. Die tweede fase het bestaan uit ʼn reeks drie-assige triaksiaal toetse. Triaksiaaltoetse is uitgevoer om die gedragseienskappe soos die skuifsterkte, kohesie, hoek van interne wrywing, styfheid en weerstand modulus te ondersoek. Die gemaalde mineraal-aggregaat wat in hierdie ondersoek gebruik is, was verkry op verskeie areas van die R35, geleë naby Bethal. Die materiaal is ʼn mengsel van granulêre materiaal (van die bestaande kroonlaag en stutlaag van die pad) en herwonne asfalt (RA). Tydens die mengontwerp fase is twee tipes bitumen gebruik naamlik bitumenemulsie en skuimbitumen in hoeveelhede van 2%, 2.4% en 2.8%. Twee tipes aktiewe vulstof (hoeveelhede van onderskeidelik 1% en 2%) was saam met elk van die verskeie bitumen-hoeveelhede gebruik. Proefstukke van elk van hierdie mengsel kombinasies is onder beide nat en droë kondisies getoets. Tydens die tweede fase, is slegs die optimum binder inhoud (2.4%) gebruik vir beide emulsie- en skuimbitumen, gekombineer met 1% en 2% aktiewe vulstof. Proefstukke was getoets by ʼn reeks van verskillende digthede en versadigingvlakke. Die buigsaamheid was ondersoek deur middel van breek-energie, vervorming en die verplasing by breekpunt. ʼn Analise van variasie (ANOVA) is uitgevoer op die toetsdata om sodoende die te evalueer of die veranderlikes beduidend is ten opsigte van buigsaamheid. Daar is gevind dat die buigsaamheideienskap sensitief is vir beide bitumen en sement inhoud. Met assessering van die gekombineerde effek en betekenis van die veranderlikes op die buigsaamheid van die mengsels, is daar gevind dat die hoogste beduidende veranderlike t.o.v breek-energie die sement inhoud is, gevolg deur die bitumeninhoud, tipe behandeling en laastens die toetskondisie. Die orde van belangrikheid verskil vir die ander twee parameters (verplasing en vervorming by breekpunt). Daar is ook gevind dat die gekombineerde effek van sommige veranderlikes (sement inhoud en toets kondisie, tipe behandeling en sement inhoud tesame met bitumen inhoud) ook beduidend was t.o.v breek-energie en vervorming by breekpunt. Vanuit die ITS en UCS toetse was daar ʼn toename in sterkte waargeneem soos die sementinhoud toeneem. Aan die anderkant, het ʼn toename in bitumeninhoud ‘n afname in sterkte veroorsaak. Die statistiese analise van ITS en UCS resultate, toon dat die grootste beduidende onafhanklike t.o.v ITS waardes ook die sement inhoud was, gevolg deur toets kondisies die grootste effek, bitumen inhoud en die tipe behandeling. Die gekombineerde effek van sementinhoud en bitumeninhoud, was betekenisvol vir beide ITS en UCS. Drie-assige triaksiaaltoetse was uitgevoer om die gedragseienskappe van die mengsels te evalueer. Daar is gevind dat die toename in sement inhoud, die skuif sterkte van die materiaal grootliks verbeter. By ʼn konstante sementinhoud, wys toetsresultate van proefstukke wat getoets is by lae digthede en hoë vlakke van versadiging, lae skuif sterkte. Die Mr – θ model was gebruik om die veerkragsmodulus van die mengsels te moduleer en die modelkoëffisiënte is gebruik om die effek van eksperimentele veranderlikes op die weerstand modulus te evalueer. Met toename in die omhullende spanning is ‘n toename in die veerkragsmodulus waargeneem, wat bevestig dat die gedrag van bitumen gestabiliseerde materiale spannings afhanklik is. ʼn Toename in die sement en relatiewe digtheid het ʼn merkwaardige toename in die veerkragsmodulus tot gevolg gehad, terwyl die teenoorgestelde waargeneem is met toename in versadigingsvlakke. Buiten die ingenieurseienskap en meganiese toetsfaktore, is ander faktore (soos die trekspanning verhouding) bereken om die vogsensitiwiteit van die mengsels te evalueer. Mengsels met laer sement inhoud het groter verswakking ervaar met blootstelling aan water. Bitumenemulsie proefstukke toon beter weerstand teen water as skuimbitumen. Vergelyking tussen versnelde en korttermyn nabehandelingsprosedure van proefstukke, toon hoër ITS en UCS waardes vir die versnelde nabehandelingsprosedure prosedure. Buigsaamheid is ‘n belangrike eienskap van bitumen in padkonstruksie materiale (insluitend bitumen gestabiliseerde materiale), maar word moeilik gemeet. Alhoewel verplasing/vervorming by breekpunt en breek energie, bepaal vanaf ITS en UCS, ‘n indikasie toon van die hooffaktore (binder en sement) wat buigsaamheid van bitumen gestabiliseerde materiaal beïnvloed, word meer akkurate toetse benodig om die eienskap te ondersoek.
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El-Gharib, Georges. "Evaluation of the Empirical Deck Design for Vehicular Bridges." UNF Digital Commons, 2014. http://digitalcommons.unf.edu/etd/489.
Повний текст джерелаАнотація:
This research evaluated the feasibility of the empirical design method for reinforced concrete bridge decks for the Florida Department of Transportation [FDOT]. There are currently three methods used for deck design: empirical method, traditional method and finite element method. This research investigated and compared the steel reinforcement ratios and the stress developed in the reinforcing steel for the three different methods of deck design. This study included analysis of 15 bridge models that met the FDOT standards. The main beams were designed and load rated using commercial software to obtain live load deflections. The bridges were checked to verify that they met the empirical method conditions based on the FDOT Structures Design Guidelines – January 2009. The reinforced concrete decks were designed using the traditional design method. Then the bridges were analyzed using three-dimensional linear finite element models with moving live loads. The reinforced concrete decks were designed using dead load moment, live load moment, and future wearing surface moment obtained from the finite element models. The required reinforcing steel ratio obtained from the finite element method was compared to the required reinforcing steel ratio obtained from traditional design method and the empirical design method. Based on the type of beams, deck thicknesses, method of analysis, and other assumptions used in this study, in most cases the required reinforcing steel obtained from the finite element design is closer to that obtained from the empirical design method than that obtained from the traditional design method. It is recommended that the reinforcing steel ratio obtained from the empirical design method be used with increased deck thicknesses to control cracking in the bridge decks interior bays.
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Zeinali, Siavashani Alireza. "DEVELOPMENT OF INDIRECT RING TENSION TEST FOR FRACTURE CHARACTERIZATION OF ASPHALT MIXTURES." UKnowledge, 2014. http://uknowledge.uky.edu/ce_etds/22.
Повний текст джерелаАнотація:
Low temperature cracking is a major distress in asphalt pavements. Several test configurations have been introduced to characterize the fracture properties of hot mix (HMA); however, most are considered to be research tools due to the complexity of the test methods or equipment. This dissertation describes the development of the indirect ring tension (IRT) fracture test for HMA, which was designed to be an effective and user-friendly test that could be deployed at the Department of Transportation level. The primary advantages of this innovative and yet practical test include: relatively large fracture surface test zone, simplicity of the specimen geometry, widespread availability of the required test equipment, and ability to test laboratory compacted specimens as well as field cores.
Numerical modeling was utilized to calibrate the stress intensity factor formula of the IRT fracture test for various specimen dimensions. The results of this extensive analysis were encapsulated in a single equation. To develop the test procedure, a laboratory study was conducted to determine the optimal test parameters for HMA material. An experimental plan was then developed to evaluate the capability of the test in capturing the variations in the mix properties, asphalt pavement density, asphalt material aging, and test temperature.
Five plant-produced HMA mixtures were used in this extensive study, and the results revealed that the IRT fracture test is highly repeatable, and capable of capturing the variations in the fracture properties of HMA. Furthermore, an analytical model was developed based on the viscoelastic properties of HMA to estimate the maximum allowable crack size for the pavements in the experimental study. This analysis indicated that the low-temperature cracking potential of the asphalt mixtures is highly sensitive to the fracture toughness and brittleness of the HMA material. Additionally, the IRT fracture test data seemed to correlate well with the data from the distress survey which was conducted on the pavements after five years of service. The maximum allowable crack size analysis revealed that a significant improvement could be realized in terms of the pavements performance if the HMA were to be compacted to a higher density. Finally, the IRT fracture test data were compared to the results of the disk-shaped compact [DC(t)] test. The results of the two tests showed a strong correlation; however, the IRT test seemed to be more repeatable.
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Simpson, Amy Louise. "Measurement of rutting in asphalt pavements." Thesis, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3055245.
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Kekana, Sello Levy. "Evaluation of laboratory test used to assess rut potential in the hot mix asphalt and the effects of compaction methods." 2014. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1001324.
Повний текст джерелаАнотація:
M. Tech. Civil Engineering.Evaluates various laboratory test methods to assess rutting potential in the hot-mix asphalt (HMA) and the effects of compaction methods. To achieve this objective, rutting potential of HMA samples prepared and compacted in the laboratory, and in the field was evaluated using different laboratory test methods under a range of temperatures and loads.
Книги з теми "Pavements Cracking Testing"
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Zanzotto, Ludo. Laboratory testing of crack sealing materials for flexible pavements. Ottawa: Transportation Association of Canada = Association des transports du Canada, 1996.
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Jennings, P. W. The Expanded Montana asphalt quality study using high pressure liquid chromatography. Bozeman, Mont: Montana State University, Dept. of Chemistry, 1985.
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Bahia, Hussain U. Investigation of modified asphalt performance using SHRP binder specification. Madison, WI: Wisconsin Dept. of Transportation, Division of Transportation Infrastructure Development, Bureau of Highway Construction, Pavements Section, 1997.
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Stuart, Kevin D. Validation of the superpave asphalt binder fatigue cracking parameter using an accelerated loading facility. McLean, VA: Office of Infrastructure Research and Development, Federal Highway Administration, 2002.
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Sposito, Brett. Geosynthetics for reflective crack control: Construction report. Salem, OR: Oregon Dept. of Transportation, Research Unit, 1999.
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Bush, Amanda Joy. Geosynthetic materials in reflective crack prevention: Final report. Salem, OR: Oregon Dept. of Transportation, Research Unit, 2007.
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L, Al-Qadi Imad, Scarpas Tom, and Loizos Andreas, eds. Pavement cracking: Mechanisms, modeling, detection, testing and case histories : proceedings of the 6th RILEM International Conference on Cracking in Pavements : Chicago, USA, 16-18 June 2008. Boca Raton: CRC Press, 2008.
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Chen, Hong-Jer. Interlayers beneath overlays on flexible pavements. Albany, NY: Engineering Research and Development Bureau, New York State Dept. of Transportation, 1992.
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Kerr, Arnold D. The assessment of concrete pavement blowups: A user manual. McLean, Va: U.S. Dept. of Transportation, Federal Highway Administration, 1993.
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Loh, Ssu-Wei. Contribution of performance-graded asphalt to low temperature cracking resistance of pavements: Final report. West Lafayette, IN: Purdue University, Joint Transportation Research Program, 1999.
Знайти повний текст джерелаЧастини книг з теми "Pavements Cracking Testing"
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Ogundipe, O. M., N. H. Thom, Andrew C. Collop, and J. Richardson. "Performance of ‘SAMI’S in Simulative Testing." In 7th RILEM International Conference on Cracking in Pavements, 93–102. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4566-7_10.
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Du, Rongyao. "Reflective Cracking in Composite Pavements—A Case Study." In Testing and Characterization of Asphalt Materials and Pavement Structures, 151–62. Cham: Springer International Publishing, 2018. http://dx.doi.org/10.1007/978-3-319-95789-0_14.
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Castaneda, Daniel I., and David A. Lange. "New Field Testing Procedure to Measure Surface Stresses in Plain Concrete Pavements and Structures." In 7th RILEM International Conference on Cracking in Pavements, 191–200. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4566-7_19.
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Pauli, A. T., M. J. Farrar, and P. M. Harnsberger. "Material Property Testing of Asphalt Binders Related to Thermal Cracking in a Comparative Site Pavement Performance Study." In 7th RILEM International Conference on Cracking in Pavements, 233–43. Dordrecht: Springer Netherlands, 2012. http://dx.doi.org/10.1007/978-94-007-4566-7_23.
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Dave, Eshan V., Benjamin Helmer, Chelsea Hanson, Jared Munch, and Luke Johanneck. "Implementation of Laboratory Testing to Predict Low Temperature Cracking Performance of Asphalt Pavements." In RILEM Bookseries, 993–1003. Dordrecht: Springer Netherlands, 2015. http://dx.doi.org/10.1007/978-94-017-7342-3_79.
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Gedafa, Daba S., Mustaque Hossain, Stefan A. Romanoschi, and Mbakisya A. Onyango. "Effects of Binder and Mix Properties on the Mechanistic Responses of Fatigue Cracking APT Sections." In The Roles of Accelerated Pavement Testing in Pavement Sustainability, 393–405. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-42797-3_25.
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Solaimanian, Mansour, Ghassan Chehab, and Marcelo Medeiros. "Evaluating Resistance of Hot Mix Asphalt Overlays to Reflective Cracking Using Geocomposites and Accelerated Loading." In The Roles of Accelerated Pavement Testing in Pavement Sustainability, 407–18. Cham: Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-42797-3_26.
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Gibson, N., J. Youtcheff, and X. Qi. "Fatigue cracking characteristics of accelerated testing pavements with modified binders." In Pavement Cracking. CRC Press, 2008. http://dx.doi.org/10.1201/9780203882191.ch4.
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"Laboratory testing and numerical modelling of overlay systems on cement concrete slabs." In Reflective Cracking in Pavements, 225–34. CRC Press, 2004. http://dx.doi.org/10.1201/9781482271799-34.
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de Freitas, A., Y. Kim, Felipe, and D. Allen. "A micromechanics-based computational model and testing protocols to characterize damage-dependent mechanical responses of asphalt mixtures in flexible pavements." In Pavement Cracking. CRC Press, 2008. http://dx.doi.org/10.1201/9780203882191.ch29.
Повний текст джерелаТези доповідей конференцій з теми "Pavements Cracking Testing"
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Lenngren, Carl, and Maria Hernandez. "Relating Field Energy Attenuation in Portland Cement Concrete Pavements to Fracture Mechanics." In 12th International Conference on Concrete Pavements. International Society for Concrete Pavements, 2021. http://dx.doi.org/10.33593/0xmxe2jw.
Повний текст джерелаАнотація:
Asset management of infrastructure is fundamental for maintenance planning and preservation of common property. A robust testing program is needed to assess the present-day status and for proper actions in time to minimize the ongoing depreciation of value. As a matter of fact, Portland Cement Concrete pavements show very little deterioration even after many years in service. Thus, it may be difficult to accurately predict the present asset value, other than using linear relations to the presumed design life. The primary reason for failure is cracking in concrete pavements, so assessing the dissipated energy from the load-deformation relation from a given load could be utilized for the purpose. The dissipated energy, i.e. the work data can be assessed by a falling weight deflectometer test, mimicking the passing of a truck or aircraft wheel load. In the present study, dynamic field data are evaluated, and the input data needed for the fracture mechanics model are used to predict the pavement life regarding cracking. To predict fracture energy and assess rolling resistance as well in concrete pavements, we need to consider the energy balance of the pavement system. To assess dissipated energy, falling weight deflectometer time histories are used to evaluate the pavement contribution to rolling resistance. Such analyses include all layers in the structure including the subgrade, so in the present case a way of sorting the dissipation at various depths is investigated. Field data were collected from a site, at mid-life of the predicted design life. The failure was confirmed several years later, and the remaining life was compared with the assumption that the dissipated energy near the edge was enough to initiate the cracks within the actual time to failure. Conversely, the dissipation at the mid-slab position was below the limit. The data from the field test were also used as an input for a finite element model to see if it was viable to further improve the prediction. The method seems to be promising, but more data are needed as the present set only represents the mid-life status.
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Feng, Zhen, Pu Zhang, Murthy N. Guddati, and Y. Richard Kim. "The Development and Evaluation of a Virtual Testing Procedure for the Prediction of the Cracking Performance of Hot Mix Asphalt." In Pavements and Materials: Characterization and Modeling Symposium at EMI Conference 2010. Reston, VA: American Society of Civil Engineers, 2010. http://dx.doi.org/10.1061/41129(385)13.
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Zhong, Yuguo, and Will Hansen. "Evaluation of Internal Curing and Hydrophobic Surface Treatment on the Durability of Concrete." In 12th International Conference on Concrete Pavements. International Society for Concrete Pavements, 2021. http://dx.doi.org/10.33593/txkqro30.
Повний текст джерелаАнотація:
The effectiveness of using pre-wetted lightweight aggregate (LWA) for internal curing was investigated based on a laboratory testing program with a primary objective to reduce or mitigate curing related shrinkage (i.e. autogenous), as this could pave the way for using LWA in concrete for repair projects such as bonded overlays or new construction (e.g. JPCP projects). A concern with the use of LWA is the high absorption coefficient and potential negative impact on freeze-thaw resistance. A laboratory study was developed to evaluate compressive strength and key durability properties, such as rapid chloride permeability, RCP, sorptivity, and freeze-thaw (F-T) resistance (i.e. combined resistance to internal cracking and surface scaling in the presence of a 3% salt solution on the surface during repeated F-T cycles). Concrete mix variables were LWA content (25% and 40%). A total of three air-entrained batches were produced. Total cementitious content was 390 kg/m3 (658 lb/yd3) with 30% slag cement. The major findings are: Autogenous shrinkage can be mitigated by using pre-wetted fine LWA at a 25% to 40% volume content of total fine aggregate. Excellent F-T resistance with respect to internal cracking and surface salt scaling was found for LWA contents of 25% or 40%. A silane surface treatment was found partially effective as surface scaling accelerates once a fully saturated pore condition occurs. This suggests that the hydrophobic treatment prevents pressure relief by air-voids and "surface-breathing".
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Lucido, Samuel P., and Willard Wilson. "Continued Performance and Economic Issues for the Polk County Minnesota Bituminous County Road Constructed With Municipal Solid Waste Combustor Ash." In 11th North American Waste-to-Energy Conference. ASMEDC, 2003. http://dx.doi.org/10.1115/nawtec11-1691.
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This paper is a follow up to previous installments presenting environmental, construction, performance and economic issues associated with Polk County CSAH 13. The CSAH 13 project was a demonstration of the use of municipal waste combustor (MWC) ash in bituminous. New structural and cost data is presented. The incorporation of MWC ash into bituminous pavements has been investigated in the United States since the middle 1970s. Thus far, most, if not all of these projects, have attempted to answer the questions: Is it safe? Is it feasible? Or does it provide an acceptable product? The presented project answers these questions on a new level. MWC ash amended bituminous was used to construct a portion of 2.25 miles of road in Northwest Minnesota. Significant environmental and structural testing was performed prior to, during and after construction. Environmental testing on this project has shown that the use of MWC ash in bituminous pavement, as performed, is safe. In addition, economic analysis shows important financial advantages by using ash-amended bituminous. Structural testing showed a 36% increase in stability, 19% increase in flow and a 17% increase in spring season axle load capacity. Improvement in resistance to freeze-thaw cracking was also shown.
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Tran, Quang, and Jeffery Roesler. "Paste Curing Effectiveness with Contactless Sensing and 2D Wavefield Analysis." In 12th International Conference on Concrete Pavements. International Society for Concrete Pavements, 2021. http://dx.doi.org/10.33593/mmj09v6u.
Повний текст джерелаАнотація:
The serviceability and performance life of concrete pavement are improved by temperature and moisture management during the initial cement reactions, which has been done successfully by various curing methods and compounds. However, the effectiveness of all curing compounds and methods has been difficult to measure spatially and rapidly in the field. In this paper, a new contactless ultrasonic testing system (UTS) and 2D wavefield analysis are introduced to evaluate the effectiveness of curing methods and compounds through monitoring of the near-surface damage of early-age hydrating paste. Cement paste specimens were cast and exposed to elevated drying conditions (23 C air temperature, 46% humidity, and 6.6 m/s wind speed) while subjected to no curing, plastic cover curing, and a wax- based compound. The UTS employed a fully contactless 50kHz ultrasonic transmitter and an array MEMS receivers. The paste specimens were monitored at ages 1, 4, 7 days after casting for the evolution of near-surface cracking. The non-contact UTS monitored the energy of leaky Rayleigh waves (LR-waves) signal over time and analyzed the frequency-wave number (f-k) domain to characterize the quantity of near-surface damage in the cement paste specimens. An ultrasonic surface damage index (USDI) was defined from f-k wavefield domain based on the ratio of the non- propagating and forwarding LR-waves. The contactless sensing and 2D wavefield analysis easily distinguished the specimen damage differences between the no curing surface, the plastic sheet cover cure, and the wax-based curing. Surfaces with low surface damage had little to zero non-propagating wave energy, which was seen in the wax-based curing specimens and the unexposed bottom surfaces of all cast specimens.
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Khan, Zafrul, Hasan M. Faisal, and Rafiqul Tarefder. "Fracture Toughness Measurement of Asphalt Concrete by Nanoindentation." In ASME 2017 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2017. http://dx.doi.org/10.1115/imece2017-71840.
Повний текст джерелаАнотація:
Fracture toughness and fracture energy release rate are two important parameters to understand the crack propagation within any material. Fracture toughness of asphalt concrete (AC) is vital to explain the fatigue cracking and low temperature cracking of asphalt pavement. These two types of distresses are still unsolved issues for asphalt researchers. Measuring fracture toughness of AC is not a new phenomenon. Recently, researchers have used several techniques to measure the fracture toughness of AC. Tests like semi-circular bending (SCB) and disk-shaped compact specimen (DCT) testing have been used to measure the fracture toughness of the AC. From the SCB or DCT tests, past researchers have shown that crack in AC propagates through mainly binder and mastic phase. All these conventional tests are carried out in macro scale. It is important to understand that before propagation of these macro scale cracks, the cracks initiates at the nano/micro scale level. With the increment of the loads these nanoscale cracks become macro scale cracks and propagates through the sample. Therefore, it is important to understand the cracks at nanoscale. In this study, nanoindentation test was introduced to measure the fracture toughness of the asphalt concrete. In a nanoindentation test, the sample surface is indented with a loaded indenter. For this test, Berkovich indenter with load control method was used. A field cored asphalt concrete sample was used for this study. The sample was collected by coring at interstate 40 (I-40) near Albuquerque, New Mexico. The sample was field aged for four years. The maximum load applied in this study was 5-mn and the unloading was done at a faster rate than the loading rate. From the load-displacement curves of the nanoindentation tests, fracture toughness of the samples was measured. The unloading curve of the nanoindentation test was further used to obtain reduced modulus of the asphalt concrete using Oliver-Pharr method. In this study, fracture energy is thought of as a portion of irreversible energy. This irreversible energy is comprised of plastic energy and energy required for propagation of crack. By analyzing the load displacement curve along with the maximum indentation depth, energy release rate and mode I fracture toughness of asphalt concrete was measured.
Звіти організацій з теми "Pavements Cracking Testing"
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Wei, Fulu, Ce Wang, Xiangxi Tian, Shuo Li, and Jie Shan. Investigation of Durability and Performance of High Friction Surface Treatment. Purdue University, 2021. http://dx.doi.org/10.5703/1288284317281.
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The Indiana Department of Transportation (INDOT) completed a total of 25 high friction surface treatment (HFST) projects across the state in 2018. This research study attempted to investigate the durability and performance of HFST in terms of its HFST-pavement system integrity and surface friction performance. Laboratory tests were conducted to determine the physical and mechanical properties of epoxy-bauxite mortar. Field inspections were carried out to identify site conditions and common early HFST distresses. Cyclic loading test and finite element method (FEM) analysis were performed to evaluate the bonding strength between HFST and existing pavement, in particular chip seal with different pretreatments such as vacuum sweeping, shotblasting, and scarification milling. Both surface friction and texture tests were undertaken periodically (generally once every 6 months) to evaluate the surface friction performance of HFST. Crash records over a 5-year period, i.e., 3 years before installation and 2 years after installation, were examined to determine the safety performance of HFST, crash modification factor (CMF) in particular. It was found that HFST epoxy-bauxite mortar has a coefficient of thermal expansion (CTE) significantly higher than those of hot mix asphalt (HMA) mixtures and Portland cement concrete (PCC), and good cracking resistance. The most common early HFST distresses in Indiana are reflective cracking, surface wrinkling, aggregate loss, and delamination. Vacuum sweeping is the optimal method for pretreating existing pavements, chip seal in particular. Chip seal in good condition is structurally capable of providing a sound base for HFST. On two-lane highway curves, HFST is capable of reducing the total vehicle crash by 30%, injury crash by 50%, and wet weather crash by 44%, and providing a CMF of 0.584 in Indiana. Great variability may arise in the results of friction tests on horizontal curves by the use of locked wheel skid tester (LWST) due both to the nature of vehicle dynamics and to the operation of test vehicle. Texture testing, however, is capable of providing continuous texture measurements that can be used to calculate a texture height parameter, i.e., mean profile depth (MPD), not only for evaluating friction performance but also implementing quality control (QC) and quality assurance (QA) plans for HFST.
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Saadeh, Shadi, and Pritam Katawał. Performance Testing of Hot Mix Asphalt Modified with Recycled Waste Plastic. Mineta Transportation Institute, July 2021. http://dx.doi.org/10.31979/mti.2021.2045.
Повний текст джерелаАнотація:
Plastic pollution has become one of the major concerns in the world. Plastic waste is not biodegradable, which makes it difficult to manage waste plastic pollution. Recycling and reusing waste plastic is an effective way to manage plastic pollution. Because of the huge quantity of waste plastic released into the world, industries requiring a large amount of material, like the pavement industry, can reuse some of this mammoth volume of waste plastics. Similarly, the use of reclaimed asphalt pavement (RAP) has also become common practice to ensure sustainability. The use of recycled waste plastics and RAP in HMA mix can save material costs and conserve many pavement industries’ resources. To successfully modify HMA with RAP and waste plastic, the modified HMA should exhibit similar or better performance compared to conventional HMA. In this study, recycled waste plastic, linear low-density polyethylene (LLDPE), and RAP were added to conventional HMA, separately and together. The mechanical properties of conventional and modified HMA were examined and compared. The fatigue cracking resistance was measured with the IDEAL Cracking (IDEAL CT) test, and the Hamburg Wheel Tracking (HWT) test was conducted to investigate the rutting resistance of compacted HMA samples. The IDEAL CT test results showed that the cracking resistance was similar across plastic modified HMA and conventional HMA containing virgin aggregates. However, when 20% RAP aggregates were used in the HMA mix, the fatigue cracking resistance was found to be significantly lower in plastic modified HMA compared to conventional HMA. The rutting resistance from the HWT test at 20,000 passes was found to be similar in all conventional and modified HMA.
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Ali, Ayman, Ahmed Saidi, Yusef Mehta, Christopher DeCarlo, Mohamed Elshear, Benjamin Cox, and Wade Lein. Development and validation of a balanced mix design approach for CIR mixtures using full-scale testing. Engineer Research and Development Center (U.S.), October 2022. http://dx.doi.org/10.21079/11681/45704.
Повний текст джерелаАнотація:
The main goal of this study was to improve the performance of cold in-place recycling (CIR) mixtures by using a balanced mix design (BMD) approach. This study involved preparing and testing CIR mixtures in the lab at varying contents of bituminous additives and constant content of 1% ce-ment and 3% water. Eight combinations of CIR mixtures were produced for this study using two binders (emulsion and foamed asphalt), compaction efforts (30 and 70 gyrations), and curing processes (72 hours at 140°F and 50°F). Results showed that asphalt pavement analyzer, semicircular bend, and indirect tensile strength tests presented the highest correlation with the change of binder contents. The study successfully used the developed BMD for designing CIR mixtures and selecting their optimum binder contents. It then used three balanced CIR mixtures to construct full-scale pavement sections to validate the BMD approach in the field. A heavy vehicle simulator was used to apply different accelerated loadings on each section. Results showed that the CIR section with 2% binder presented the best rutting performance under truck loading and the highest rutting susceptibility under aircraft loading. Conversely, the CIR section with 3% binder presented the highest cracking resistance under both truck and aircraft loading.
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Rahbar-Rastegar, Reyhaneh, Gerald Huber, Miguel A. Montoya, Christopher Campbell, and John E. Haddock. Demonstration Project for Asphalt Performance Engineered Mixture Design Testing. Purdue University, 2022. http://dx.doi.org/10.5703/1288284317382.
Повний текст джерелаАнотація:
The asphalt industry is moving towards performance-based methods for asphalt mixture design. The Federal HighwayAdministration (FHWA) is supportive of state departments of transportations (DOT) adopting index and predictive performance tests, especially those making use of the Asphalt Mixture Performance Tester (AMPT). The FHWA is therefore encouraging state DOTs to gain experience with the requirements of the procedures and analysis tools for Balanced Mixture Design (BMD). The main objective of this study is to evaluate fatigue cracking on three INDOT mainline pavement projects that have asphalt mixtures designed by the Superpave 5 mixture design, and to better understand the fundamental engineering testing capabilities of the AMPT. A total of four Superpave 5 asphalt mixtures were collected and tested from the three projects. The viscoelastic characteristics and fatigue behavior of plant-mixed, laboratory compacted (PMLC), laboratory-mixed, laboratory compacted (LMLC), and plant-mixed, field compacted (PMFC) specimens were assessed according to the AASHTO TP-132 and AASHTO TP-133 test methods. Two AMPT machines (IPC Controls and PaveTest) were used to conduct the dynamic modulus tests, while all fatigue tests were performed using a PaveTest AMPT. The raw data were analyzed using the FlexMAT software. The dynamic modulus and cyclic fatigue test results indicate that AMPT testing can be used to effectively evaluate INDOT asphalt mixtures during the mixture design and production phases. However, to do so, detailed planning and effective training are needed to help ensure the successful completion of AMPT testing.
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Singhvi, Punit, Javier García Mainieri, Hasan Ozer, and Brajendra Sharma. Rheology-Chemical Based Procedure to Evaluate Additives/Modifiers Used in Asphalt Binders for Performance Enhancements: Phase 2. Illinois Center for Transportation, June 2021. http://dx.doi.org/10.36501/0197-9191/21-020.
Повний текст джерелаАнотація:
The increased use of softer binders in Illinois over the past decade is primarily attributed to the increased use of recycled materials in asphalt pavement construction. The shift in demand of using PG 58-28 over PG 64-22 has resulted in potential alternative methods to produce softer binders more economically using proprietary products. However, there are challenges in using these proprietary products for asphalt modification because of uncertainty in their long-term performance and significant variability in binder chemistry. The current SuperPave performance grading specification for asphalt binders is insufficient in differentiating binders produced from these modifiers. Therefore, the objective of this study is to evaluate the performance of various softener-type asphalt binder modifiers using a wide array of rheological and chemistry tests for their integration into the Illinois Department of Transportation’s material specifications. The small-strain rheological tests and their parameters allowed for consistent grouping of modified binders and can be used as surrogates to identify performing and nonperforming asphalt binders. A new parameter, Δ|G*|peak τ, was developed from the linear amplitude sweep test and showed potential to discriminate binders based on their large-strain behavior. Chemistry-based parameters were shown to track aging and formulation changes. The modifier sources were identified using fingerprint testing and were manifested in the modified binder chemical and compositional characteristics. The two sources of base binders blended with the modifiers governed the aging rate of the modified binders. Mixture performance testing using the Illinois Flexibility Index Test and the Hamburg Wheel-Track Test were consistent with the rheological and chemical findings, except for the glycol amine-based modified binder, which showed the worst cracking performance with the lowest flexibility index among the studied modifiers. This was contrary to its superior rheological performance, which may be attributed to lower thermal stability, resulting in high mass loss during mixing. According to the characterization of field-aged binders, laboratory aging of two pressurized aging vessel cycles or more may represent realistic field aging of 10 to 15 years at the pavement surface and is able to distinguish modified binders. Therefore, an extended aging method of two pressurized aging vessel cycles was recommended for modified binders. Two different testing suites were recommended for product approval protocol with preliminary thresholds for acceptable performance validated with field-aged data.