Дисертації: "Portland cement concrete pavement"

1

Khoury, Issam S. "Impact of Base Stiffness on Portland Cement Concrete Pavement." Ohio University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1448963853.

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2

Bermel, Bethany Noel. "Feasibility of reclaimed asphalt pavement as aggregate in Portland cement concrete pavement." Thesis, Montana State University, 2011. http://etd.lib.montana.edu/etd/2011/bermel/BermelB0811.pdf.

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Each year, the US highway industry produces over 100 million tons of reclaimed asphalt pavement (RAP) through the rehabilitation and construction of the nation's roads. Using RAP as aggregate in Portland cement concrete pavement (PCCP) is one attractive application for a further use of this recyclable material. Earlier research has demonstrated the feasibility of creating concrete with RAP aggregate; however, prior studies focus on mechanical properties of the material. This research project will further distinguish the properties of this material and draw conclusions on the concrete's aptness for use as a pavement in Montana. This thesis encompasses the development of candidate RAP in PCCP mixtures that will subsequently move forward for a more thorough evaluation of their material properties. The mixing experiment and preliminary testing phases of this project provided information to draw a number of conclusions about the appropriateness of RAP aggregate in PCCP, including: (1) using conventional practices, PCCP containing RAP aggregate (20 percent fine and 45 percent coarse) can achieve compressive strengths in excess of 3,000-psi; (2) as the RAP replacement rate is increased, the compressive strength of the concrete decreases; (3) fine RAP aggregate appears to have a more detrimental effect on the concrete than coarse aggregate; (4) concretes with a relatively high RAP replacement rate (50 percent fine and 100 percent coarse) may be suitable for transportation applications; (5) at high RAP replacement rates, there appears to be a benefit (relative to concrete strength) in using increased replacements of both fine and coarse RAP, rather than singly replacing just one aggregate gradation; and (6) concrete containing RAP displays increased flexural strengths as compared to traditional PCCP. This material research was performed using a Design of Experiments (DOE) method. The suitability of this statistical method as a mix design development tool was characterized through several important findings, which include: (1) the DOE method was effective in distinguishing mixture behaviors; (2) mix design optimization is readily accomplished using the statistical model generated from the DOE data; and (3) variability in the concrete mixing and testing processes has a significant effect on the capabilities of the statistical model.

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3

Priddy, Lucy Phillips. "Evaluation of Precast Portland Cement Concrete Panels for Airfield Pavement Repairs." Diss., Virginia Tech, 2014. http://hdl.handle.net/10919/56952.

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Both the identification and validation of expedient portland cement concrete (PCC) repair technologies have been the focus of the pavements research community for decades due to ever decreasing construction timelines. Precast concrete panel technology offers a potential repair alternative to conventional cast-in-place PCC because the panel is fully cured and has gained full strength prior to its use. This repaired surface may be trafficked immediately, thus eliminating the need for long curing durations required for conventional PCC. The literature reveals a number of precast PCC panel investigations in the past 50 years; however precast technology has only recently gained acceptance and increased use in the US for highway pavements. Furthermore, only limited information regarding performance of airfield applications is available. Following a review of the available technologies, an existing panel prototype was redesigned to allow for both single- and multiple-panel repairs. A series of various sized repairs were conducted in a full-scale airfield PCC test section. Results of accelerated testing indicated that precast panels were suitable for airfield repairs, withstanding between 5,000 and 10,000 passes of C-17 aircraft traffic prior to failure. Failure was due to spalling of the transverse doweled joints. The load transfer characteristics of the transverse joint were studied to determine if the joint load test could be used to predict failure. Results showed that the load transfer efficiency calculations from the joint load test data were not useful for predicting failure; however differential deflections could possibly be applied. Additionally, the practice of filling the joints with rapid-setting grout may have resulted in higher measurements of load transfer efficiency. To determine the stresses generated in the doweled joint, three-dimensional finite element analyses were conducted. Results indicated that the dowel diameter should be increased to reduce stresses and to improve repair performance. Finally, the precast repair technology was compared to other expedient repair techniques in terms of repair speed, performance, and cost. Compared to other methods, the precast panel repair alternative provided similar return-to-service timelines and traffic performance at a slightly higher cost. Costs can be minimized through modification to the panel design and by fabricating panels in a precast facility. Modifications to the system design and placement procedures are also recommended to improve the field performance of the panels.
Ph. D.

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4

Mohi, Amal A. "Performance Evaluation of Pavement Markings on Portland Cement Concrete Bridge Decks." University of Akron / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=akron1238350586.

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5

Von, Handorf Jeffrey J. "Pavement response to environmental factors." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1185207632.

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6

Vidalis, Sofia Margarita. "Relation between cost, quality, and risk in Portland Cement Concrete pavement construction." [Gainesville, Fla.] : University of Florida, 2005. http://purl.fcla.edu/fcla/etd/UFE0013025.

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7

Waters, Tenli. "Typical and Darkened Portland Cement Concrete Pavement: Temperature, Moisture, and Roughness Analyses." BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6091.

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The objectives of this research were to 1) investigate the effects of lower concrete albedo on the thermal behavior of concrete pavement by directly comparing temperatures and moisture contents of typical and darkened concrete pavements and 2) investigate changes in roughness of both typical and darkened concrete pavements as a result of changes in temperature and moisture gradients. The scope of the research included instrumentation, testing, and analysis of typical and darkened concrete pavements constructed in northern Utah.Procedures related to field testing included infrared thermography, thermocouple readings, sensor data collection, and roughness surveys. Elevation surveys and albedo measurements were also performed to further characterize the site. Procedures related to laboratory testing included elastic modulus, compressive strength, rapid chloride permeability, thermal conductivity, and Schmidt rebound hammer testing of cylinders prepared from typical and darkened concrete.When considered over the entire monitoring period, the average surface temperatures of the darkened pavement were higher than those of the typical pavement by 3.3°F, and the average subsurface temperatures of the darkened pavement were higher than those of the typical pavement by 3.1°F. A strong positive correlation exists between the air temperature and both the surface and the subsurface pavement temperatures. The difference between both the surface and subsurface temperatures of the darkened and typical pavements decreases as the air temperature decreases. The results of a simple linear regression suggest that, when the air temperature is 32°F, the surface temperature of the darkened concrete is just 0.2°F higher than that of the typical concrete and the subsurface temperature of the darkened concrete is 1.1°F higher than that of the typical concrete. The difference in surface temperature is expected to be 0°F when the air temperature is 30.5°F, while the difference in subsurface temperature is expected to be 0°F when the air temperature is 17.9°F. Therefore, the darkened pavement is unlikely to melt snow and ice faster than the typical pavement or provide significantly greater frost protection to subsurface layers and buried utilities during winter for conditions similar to those in this research. The roughness measurements for the typical pavement exhibit much more daily variability than seasonal variability. The roughness measurements for the darkened pavement also exhibit more daily variability than seasonal variability but less overall variability than that of the typical pavement. Neither pavement temperature gradient nor moisture gradient appears to be correlated to roughness for either the typical pavement or the darkened pavement.

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8

Mann, Travis Aaron. "GROUT IMPREGNATION OF PRE-PLACED RECYCLED CONCRETE PAVEMENT (RCP) FOR RAPID REPAIR OF DETERIORATED PORTLAND CEMENT CONCRETE AIRFIELD PAVEMENTS." MSSTATE, 2006. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11092006-130114/.

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The U.S. military must have the ability to rapidly deploy troops and equipment anywhere in the world as part of a contingency operation. Recent military operations have highlighted the critical need for rapid repair procedures and materials for military use on sub-standard, in-theater airfields. The U.S. Army Corps of Engineers, Engineer Research and Development Center is currently addressing these problems through a program titled ?Joint Rapid Airfield Construction?. This study involves the development of a method using rapid setting grouts and recycled concrete pavement (RCP) to repair portland cement concrete (PCC) pavements. A laboratory study was conducted to evaluate material properties in order to gain an understanding of expected field performance. Eight full scale repairs were constructed using two rapid setting grouts, two types of equipment, and two concrete slabs. The repairs were successfully trafficked with simulated C-17 aircraft wheel loads to verify the structural capacity, and ultimately the procedures.

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9

Morrison, Jill A. "Effects of slab Shape and load transfer Mechanisms on Portland cement concrete pavement." Ohio University / OhioLINK, 2005. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1177012605.

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10

Ballock, Craig. "CONSTRUCTION SPECIFICATIONS AND ANALYSIS OF REHABILITATION TECHNIQUES OF PERVIOUS CONCRETE PAVEMENT." Master's thesis, University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2772.

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The primary objective of this study is to evaluate the clogging potential of installed pervious concrete systems, to analyze rehabilitation techniques and develop construction specifications for the construction of portland cement pervious concrete specific to the state of Florida. Currently, a consistent statewide policy has not been established in reference to credit for storage volume within the voids in pervious concrete and the coarse aggregate base. For this reason a current and updated assessment of pervious pavement is needed to benefit from the advantages of pervious pavement use in low traffic volume areas. Initially by modeling a pervious concrete system in a field laboratory with test cells of typical Florida soil conditions and groundwater elevations and combining these data with field data from multiple sites of long service life, a Florida specific construction methodology has been developed. It is hoped that by developing a more standardized design criteria for pervious pavements in Florida a statewide acceptance of portland cement pervious pavement can be achieved and credit can be earned based on the volume of stored stormwater. This study of field sites was subsequently expanded to include locations in the southeastern United States. Pervious concrete has suffered historically poor support due to a number of factors, including concern about poor long term performance due to clogging of surface pores. Eight existing parking lots were evaluated to determine the infiltration rates of pervious concrete systems that have had relatively no maintenance. Infiltration rates were measured using an embedded single-ring infiltrometer developed specifically for testing pervious concrete in an in-situ state. The average infiltration rates of the pervious concrete that was properly constructed at the investigated sites ranged from 0.4 to 227.2 inches per hour. A total of 30 pervious concrete cores were extracted and evaluated for infiltration rates after various rehabilitation techniques, including pressure washing, vacuum sweeping and a combination of the two methods, have been performed to rehabilitate the infiltration capability of the concrete. By evaluating the effectiveness of these rehabilitation techniques, recommendations have been developed for a maintenance schedule for pervious concrete installations. In most cases it was found that the three methods of maintenance investigated in this study typically resulted in a 200% or greater increase over the original infiltration rates of the pervious concrete cores. It is therefore recommended that as a general rule of thumb one or a combination of these rejuvenation techniques should be performed when the system infiltration rates are below 1.5 inches per hour to maintain the infiltration capability of pervious concrete pavements.
M.S.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering MS

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11

Wilde, William James. "Life cycle cost analysis of Portland cement concrete pavements /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.

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12

Fahmy, Michel Ramsis. "Finite element modeling of dowel jointed plain concrete pavement response to thermal and moving traffic loads." Morgantown, W. Va. : [West Virginia University Libraries], 2000. http://etd.wvu.edu/templates/showETD.cfm?recnum=1582.

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Thesis (Ph. D.)--West Virginia University, 2000.
Title from document title page. Document formatted into pages; contains xvi, 228 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 217-227).

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13

Phillips, Jason B. "Pervious concrete paste composition a thesis presented to the faculty of the Graduate School, Tennessee Technological University /." Click to access online, 2009. http://proquest.umi.com/pqdweb?index=17&sid=1&srchmode=1&vinst=PROD&fmt=6&startpage=-1&clientid=28564&vname=PQD&RQT=309&did=1759989161&scaling=FULL&ts=1250626528&vtype=PQD&rqt=309&TS=1250626549&clientId=28564.

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14

Brown, Ashley Vannoy. "Cement Stabilization of Aggregate Base Materials Blended with Reclaimed Asphalt Pavement." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1314.pdf.

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15

Tabbert, Toni Raenette. "Verification of the whitetopping thickness design procedure for asphalt concrete overlaid Portland cement concrete pavements." [Ames, Iowa : Iowa State University], 2006.

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16

Shanmugam, Harini. "Assessment and mitigation of potential environmental impacts of Portland Cement Concrete highway grindings." Online access for everyone, 2004. http://www.dissertations.wsu.edu/Thesis/Fall2004/h%5Fshanmugam%5F121304.pdf.

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17

Scabello, Daniel Torres. "Estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner e validação de resultados." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/3/3138/tde-16072018-084749/.

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O gerenciamento de uma malha rodoviária engloba avaliações constantes das condições estruturais e, principalmente, funcionais. Assim sendo, uma forma de coleta automatizada, realizada em velocidades de tráfego, em que a influência humana possa ser desconsiderada, está em desenvolvimento na engenharia rodoviária brasileira, assim como é visto internacionalmente. O presente trabalho tem como objetivo a contribuição para o processo de avaliação funcional de pavimentos através do estudo sobre a aplicabilidade do processo de inventário funcional de pavimentos rígidos com o emprego do equipamento Pavement Scanner. Para tanto, após a revisão bibliográfica sobre a sistemática de inventário de pavimentos rígidos e também sobre o equipamento Pavement Scanner, seções testes foram definidas e avaliadas de acordo com o método tradicional de levantamento da superfície do pavimento (ICP - DNIT 062/PRO, DNIT 060/PRO), o método volumétrico tradicional de mancha de areia para avaliação de macrotextura (ASTM E 965/96), através de imageamento com análise de imagens obtidas no trecho e sob a utilização do equipamento Pavement Scanner. Com os resultados foi realizada uma análise estatística destas técnicas utilizadas, demonstrando a viabilidade de utilização do equipamento e do procedimento de análise adotado.
The management of a road network encompasses constant assessments of structural conditions and, above all, functional conditions. Thus, a form of automated survey, carried out at traffic speeds, in which human influence can be unconsidered, is under development in Brazilian road engineering, as it is seen internationally. This present work aims to contribute to the process of functional assessment of pavements through the study of applicability of the functional inventory process of rigid pavements with the use of Pavement Scanner equipment. In order to do so, after the literature review of rigid pavement inventory and Pavement Scanner equipment, test sections were defined and evaluated according to the traditional method of surface survey (ICP - DNIT 062 / PRO, DNIT 060 / PRO), the traditional sand patch volumetric method for the evaluation of macrotexture (ASTM E 965/96), through imaging analysis from the test sections and under the use of Pavement Scanner equipment. With the results, a statistical analysis of these techniques were performed, demonstrating the feasibility of using the equipment and the analysis procedure adopted.

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18

ADRESI, MOSTAFA. "Concrete pavement prediction life model based on electrical response of concrete-CNTs sensors under fatigue loading." Doctoral thesis, Politecnico di Torino, 2017. http://hdl.handle.net/11583/2687875.

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Structural Health Monitoring (SHM) of important infrastructures such as Portland cement concrete pavements plays a key role in pioneer societies, to guarantee the optimum usability and performance of the infrastructure system. As an example, this is imperative to appraise the destruction level in Portland cement concrete pavements along time as to plan their maintenance with proper actions at the right time. Based on this premise, the goal of this study is to extend an extensive feasibility study to set up a novel approach for SHM of Portland cement concrete pavements and remaining life estimation, based on self-sensing concrete-CNTs sensors added with multi-walled carbon nanotubes (CNTs). The concrete-CNTs sensors are applied as piezoresistive sensors (i.e. to collect information such as weight and species of passing vehicles), or as destruction identification sensors (i.e. to detect crack propagation in the Portland cement concrete pavement). For casting the concrete-CNTs sensors, some parameters are important, such as the number of CNTs, species of surfactant, dispersion quality etc. In this research, the dispersion quality of multi-walled carbon nanotubes in the aqueous phase and cement matrix was experiment examined using Ultraviolet-Visible Spectrophotometry (UV-VIS), Scanning Electron Microscopy (SEM) and mechanical experiments for compressive and flexural strength. The outcomes demonstrated that a new specific surfactant composition (sodiumdodecylbenzene sulfonate (SDS) and superplasticizer carboxylate base (SP-C) with the ratio of 1:9 respectively) could disperse MWCNTs around 64% more than other surfactant combinations indicated in the previous studies while this has enough compatibility with the concrete to omit antifoam in the mixing process and maintain the concrete mechanical specifications pretty constant. To appraise the influences of the main parameters affecting concrete-CNTs sensors function, diverse criteria in static and dynamic loading patterns were defined such as sensitivity of the sensor (Se), the standard deviation of the prediction error, repeatability (Re), cross-correlation (CC) and hysteresis (SSE). The dynamic criteria such as sensitivity, internal repeatability, cross-correlation and hysteresis declared that the dispersion energy levels for the dispersion of MWCNTs have a major impact on enhancing the function of the sensor rather than the number of CNTs. The repeatability criterion, contrariwise, showed that the number of MWCNTs has a major impact on the function of the sensor compared to the dispersion quality (dispersion energy level) of MWCNTs. Consequently, both parameters have to be regarded as relevant. The overall outcomes showed that the sensors fabricated with 0.15 wt% CNTs, superplasticizer and SDS as a surfactant using the maximum dispersion energy level (ultrasonic bath for 2 hours and 90 minutes of ultrasonic probing) have the best function in both static and dynamic load mode. To explore the influences of traffic loads on the pavement, concrete-CNTs sensors were experiment examined under various value of dynamic loads. The outcomes demonstrated that the maximum exterior load applied on the sensor (Fmax) is linearly correlated to the maximum response of the sensor (Smax) via a constant coefficient tagα/tagβ, in which tagα is defined as the slope of the Force vs. Time graph and tagβ is defined as the slope of the Sensor’s response vs. Time curve. So, this can be concluded that the application of the indicated concrete-CNTs sensors for piezoresistive applications is feasible and the sensors can appraise the load with of high-goodness of fit (R2adj.> 0.99). In addition, to study the response of the concrete-CNTs sensor under the traffic loading, fatigue experiments were run. An alternative data processing log(G)-log(N) was applied instead of traditional S-log(N) fatigue graphs (Goodman curves), based on the electrical sensor response with a linear regression approach and the outcomes were verified by statistical tests. In this research, the concept of G has been defined for the first time as the slope of a sensor’s response that reflects the destruction created in a pavement because of one pass of vehicle load. Based on these findings, two various types of remaining life models for Portland cement concrete pavements were proposed.

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19

Sweet, Joseph G. "Vertical stiffness characterization of a geocomposite drainage layer for PCC highway pavements." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4268.

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Thesis (M.S.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xiii, 171 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 152-154).

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20

Akentuna, Moses. "CHARACTERIZATION OF RECYCLED CONCRETE AGGREGATES (RCA) FROM AN OLD FOUNDATION STRUCTURE FOR ROAD PAVEMENT WORKS." OpenSIUC, 2013. https://opensiuc.lib.siu.edu/theses/1207.

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The use of recycled concrete aggregates in Portland cement concrete and granular road base or sub-base works has increased steadily all over the world in order to conserve the limited natural aggregate deposits. The recycling of the demolished concrete aggregate for the use in concrete or granular pavement works will not only help to protect the environment but also an economical benefit to the user. The main drawback for the bulk utilization of demolished or recycled aggregate is its characterization and proper quality control during its production. The overall objective of this research was to characterize recycled concrete aggregates (RCA) obtained from a demolished foundation structure and to determine its suitability for Portland Cement Concrete (PCC) works and use as a granular road base or sub-base material. Tests were carried out on RCA samples to determine whether it meets the specification for concrete aggregate material or a granular road base and sub-base materials. Several concrete mixes consisting of 10, 20, 30, 40, 60, and 80 % replacement of natural coarse aggregates (NCA) with RCA were prepared and tested for compressive strength after curing periods of 7, 14, and 28 days. The compressive strength of concrete made with various percentages of RCA decreased with increasing RCA content but it increased with curing period for all concrete mixes. The durability parameters of the natural aggregates and RCA samples were investigated by using sulfate soundness, rapid freeze-thaw and micro-deval tests to ascertain their chemical and abrasive resistance. The California Bearing Ratio (CBR) of RCA base was also compared with that of a natural road base material to determine its suitability for road base or sub-base works. In this study, the flakiness and elongation indices of the RCA were found to be better than that of conventional natural aggregates. The RCA base material had lower maximum dry density, higher optimum moisture content, and low California Bearing Ratio (CBR) value compared to the natural crushed rock base (NCRB) material but was found to be a relatively good road base material.

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21

Cannady, Kristina M. "Effect of Larger Sized Coarse Aggregates and Microsilica on Environmental Properties of Portland Cement Concrete Pavements and Structures." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1245250956.

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22

Goldsberry, Benjamin M. "Thermal effect curling of concrete pavements on U.S. 23 test road (DEL 23-17.28." Ohio : Ohio University, 1998. http://www.ohiolink.edu/etd/view.cgi?ohiou1176832475.

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23

Barbosa, Junior Alvaro Sergio. "Estudo da utilização de agregado reciclado em misturas de concreto de cimento Portland para pavimentação." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/258684.

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Orientador: Rita Moura Fortes
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-12T06:54:45Z (GMT). No. of bitstreams: 1 BarbosaJunior_AlvaroSergio_M.pdf: 1121830 bytes, checksum: e02fb4a353bc75b1933fd3e74153b6ea (MD5) Previous issue date: 2008
Resumo: O objetivo da presente pesquisa e apresentar uma contribuição ao estudo da utilização de agregados reciclados em misturas de concreto de cimento Portland (CCP) para pavimentação. São comparados os desempenhos de misturas utilizando-se agregados oriundos do gnaisse e também do entulho de laboratórios de controle tecnológico, para avaliar o potencial de sua utilização, minimizando a sua problemática deposição em aterros sanitários, contribuindo dessa maneira para a preservação do meio ambiente. Os agregados originados pela moagem desses entulhos serão estudados separadamente, ou seja, os provenientes de corpos de prova de concreto, de blocos de concreto e blocos de materiais cerâmicos. Pretende-se conhecer o potencial de utilização desse material reciclado como agregado contribuindo para a preservação do meio ambiente. E importante enfatizar que este material e de boa qualidade e tem sido usualmente descartado, ou melhor, desperdiçado. Este trabalho avalia os resultados levando em conta a sua seleção, dosagem e mistura, de maneira a atender as propriedades necessárias para a pavimentação
Abstract: The objective of this research is to contribute to the study of the recycled aggregate use in concrete Portland. It is compared the performance of these mixtures presented with the deriving aggregates and the rubbish of technological control laboratories, which the use minimizes the problematic deposition in sanitary earthworks, contributing in this way to the environment's preservation. The aggregates originated for the milling of these tested specimens will be studied separately, in other words, the preceding from specimens of concrete test, of concrete blocks and ceramic materials. In this research is studied the potential use of these recycled materials as aggregate contributing for the environment preservation. It is important to emphasize that this material presents good quality and is usually discarded or wasted. This paper evaluates the results taking into account the selection and mixing for the adequate pavement properties.
Mestrado
Transportes
Mestre em Engenharia Civil

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24

Dye, Jeremy Brooks. "Comparison of Winter Temperature Profiles in Asphalt and Concrete Pavements." BYU ScholarsArchive, 2010. https://scholarsarchive.byu.edu/etd/2240.

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Because winter maintenance is so costly, Utah Department of Transportation (UDOT) personnel asked researchers at Brigham Young University to determine whether asphalt or concrete pavements require more winter maintenance. Differing thermal properties suggest that, for the same environmental conditions, asphalt and concrete pavements will have different temperature profiles. Climatological data from 22 environmental sensor stations (ESSs) near asphalt roads and nine ESSs near concrete roads were used to 1) determine which pavement type has higher surface temperatures in winter and 2) compare the subsurface temperatures under asphalt and concrete pavements to determine the pavement type below which more freeze-thaw cycles of the underlying soil occur. Twelve continuous months of climatological data, primarily from the 2009 calendar year, were acquired from the road weather information system operated by UDOT, and erroneous data were removed from the data set. To predict pavement surface temperature, a multiple linear regression was performed with input parameters of pavement type, time period, and air temperature. Similarly, a multiple linear regression was performed to predict the number of subsurface freeze-thaw cycles, based on month, latitude, elevation, and pavement type. A finite-difference model was created to model surface temperatures of asphalt and concrete pavements based on air temperature and incoming radiation. The statistical analysis predicting pavement surface temperatures showed that, for near-freezing conditions, asphalt is better in the afternoon, and concrete is better for other times of the day, but that neither pavement type is better, on average. Asphalt and concrete are equally likely to collect snow or ice on their surfaces, and both pavements are expected to require equal amounts of winter maintenance, on average. Finite-difference analysis results confirmed that, for times of low incident radiation (night), concrete reaches higher temperatures than asphalt, and for times of high incident radiation (day), asphalt reaches higher temperatures than concrete. The regression equation predicting the number of subsurface freeze-thaw cycles provided estimates that did not correlate well with measured values. Consequently, an entirely different analysis must be conducted with different input variables. Data that were not available for this research but are likely necessary in estimating the number of freeze-thaw cycles under the pavement include pavement layer thicknesses, layer types, and layer moisture contents.

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25

Aslantas, Onur. "A Study On Abrasion Resistance Of Concrete Paving Blocks." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/12605709/index.pdf.

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Concrete block pavement (CBP) can be an alternative pavement to asphalt and concrete pavements. CBP is formed from individual concrete paving blocks (CPBs) that fit next to one another on a suitable sub base leaving a specific joint space among them to be filled with jointing sand. CBP differ from other pavements according to their mechanical behavior, manufacturing technique, structural design, installation technique and structural behavior. For a serviceable pavement all of these subjects have to be studied. The literature about the mechanical behavior of CPBs is not adequate. This study aims to determine the performance of CPBs formed from different mixes prepared with a white portland cement. For this purpose, 10 mixes with different cement contents and W/C ratios and 2 mixes from a commercial CPB manufacturer were tested. The compressive strength, tensile splitting strength, abrasion resistance, density and % water absorption tests were performed on each mix at 7, 14, 28 days. It was concluded that, the cement content in the mix, optimum water volume for a given cement content, the way the manufacturing equipment is operated and their interaction was effective on the mechanical properties of CPBs. It was also observed that there was no handicap to stop the abrasion resistance test at 8*22 revolutions instead of 16*22 revolutions given in TS 2824.

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Gusmão, Claudia Betine. "Evolução temporal da resistencia mecanica em laboratorio, de misturas simulando a reciclagem de pavimento asfaltico com adição de cimento portland." [s.n.], 2008. http://repositorio.unicamp.br/jspui/handle/REPOSIP/257804.

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Orientador: João Virgilio Merighi
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo
Made available in DSpace on 2018-08-12T12:23:13Z (GMT). No. of bitstreams: 1 Gusmao_ClaudiaBetine_M.pdf: 2591416 bytes, checksum: b106affc2585283a589b10f376f83035 (MD5) Previous issue date: 2008
Resumo: O presente trabalho visa estudar o processo de reciclagem de pavimento asfaltico com cimento Portland, atraves da analise de metodo de reciclagem, equipamentos utilizados, procedimentos empregados em campo, alem do estudo das vantagens e desvantagens do uso da reciclagem em pavimentos asfalticos. O trabalho trata ainda de uma forma detalhada o pavimento asfaltico com adicao de cimento Portland, atraves de ensaios tecnologicos simulando em laboratorio, para diferentes dosagens o comportamento mecanico em funcao do tempo do material obtido em campo.
Abstract: This work studies the process of asphalted pavement recycling with cement Portland additive through the analysis of recycling method, equipments and procedures used in the field, in addition to studying the advantages and disadvantages of the use of recycling in asphalted pavement. The work also approaches in detail the recycled asphalt pavement with Portland cement additive, through technological tests through laboratory simulation, to different dosage and the analysis of mechanical behavior through time of that material obtained in field.
Mestrado
Transportes
Mestre em Engenharia Civil

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27

Renzová, Martina. "Prodloužení životnosti cementobetonových krytů." Master's thesis, Vysoké učení technické v Brně. Fakulta stavební, 2013. http://www.nusl.cz/ntk/nusl-226449.

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The aim of the theoretical part of this Master´s thesis is to make a research of possible ways in repairing PCC pavements without anchoring transverse joints. The pratical part is focused on the design of PCC pavements segmentations in experimental sections and evaluation measurement by testing muted impact.

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Elgalhud, Abdurrahman Ahmed T. A. "Durability potential of Portland limestone cement concrete." Thesis, University of Birmingham, 2017. http://etheses.bham.ac.uk//id/eprint/7903/.

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There is an increasing global concern that has led to efforts to lessen the carbon footprint of the cement industry and make concrete manufacturing more sustainable by using other types of materials as supplements or alternatives, primarily for Portland cement (PC). This research work is concerned with the analytical systemisation, including the analysis, evaluation and structuring of global published experimental results, of ground limestone (GLS) used in concrete as a partial replacement of PC. The work is focussed on the physical and chemical characterisation of GLS and its effects on pore structure (in terms of porosity, water absorption and sorptivity), compressive strength and the durability of the concrete in terms of the carbonation and chloride ingress and the corrosion of steel reinforcement, including a statistical modelling of the carbonation of concrete with Portland limestone cement (PLC). Overall, it is suggested that, though the use of GLS up to 25% with PC should not impair the pore structure, the limit on GLS content for its effect on strength is likely to be about 15%. This should be considered where a higher proportion of GLS content is allowed in the standards. It is also shown that the carbonation rate and chloride ingress into concrete increase with increasing GLS content.

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29

Mostafa, Raqibul. "Wideband electromagnetic characterization of Portland cement concrete." Thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06112009-063132/.

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30

Wenglas, Lara Gilberto. "Quality evaluation of Portland cement concrete at early age with free-free resonant column." To access this resource online via ProQuest Dissertations and Theses @ UTEP, 2008. http://0-proquest.umi.com.lib.utep.edu/login?COPT=REJTPTU0YmImSU5UPTAmVkVSPTI=&clientId=2515.

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31

Gouru, Harinath. "Laboratory evaluation of asphalt-portland cement concrete composite." Thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-12232009-020518/.

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32

Al-Ghamdi, Hamed A. "Effect of curing and mix design parameters on durability of Portland cement and Portland cement-silica fume mortars in a hot-marine environment." Thesis, University of Aberdeen, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.301075.

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This study was conducted to evaluate the effect of curing and mix design parameters, such as cement content and water to cementitious materials ratio, on the strength and durability characteristics of plain and silica fume cements exposed to a hot-marine environment. Specifically, the effect of curing and mix design parameters on chloride diffusion, shrinkage and carbonation of cement mortar specimens exposed to a hot-marine environment was evaluated. The results indicated that high water to cement ratio significantly influenced the durability performance of concrete through: (1) accelerating chloride diffusion and carbonation, (2) increasing the shrinkage and weight loss, and (3) reducing the compressive strength. Similarly, increasing the cement content increased the shrinkage for a given w/c ratio. However, the chloride diffusion and carbonation were minimized and strength was enhanced due to increasing cement content. The mix design parameters, namely, water-cement ratio and cement content significantly influenced the performance of both Type I and Type V cements, while the influence of these parameters on the performance of silica fume cements was insignificant. Although Type I cement mortars performed better than Type V cement mortars, the performance of silica fume cement was the best in terms of reduced chloride diffusion, carbonation and shrinkage, and enhanced strength. The beneficial effects of silica fume cements, were however, only evident in specimens subjected to good curing. Therefore, to extend the useful service-life of reinforced concrete structures exposed to hot-marine environments, the following mix design is recommended: (i) cement content should not be less than 350kg/m³; (ii) Type I cement with 10% silica fume; (iii) water to cementitious materials ratio of not more than 0.45; (iv) good curing.

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33

Tank, Suresh Bhagwanji. "The use of condensed silica fume in Portland cement grouts." Thesis, University College London (University of London), 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.307794.

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34

McCabe, Christopher C. "An investigation into the influence of metakaolin on the properties of concrete." Thesis, Queen's University Belfast, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.247338.

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35

Mousavi, Marjan. "Life Cycle Assessment of Portland Cement and Concrete Bridge : Concrete Bridge vs. Wooden Bridge." Thesis, KTH, Industriell ekologi, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-122462.

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Today global warming mitigation, natural resource conservation and energy saving are some of the significant concerns of different industries, such as cement and concrete industries. For that reason, a streamlined life cycle assessment (LCA) model of one ton of a Portland cement, CEM I produced in Cementa AB’s Degerhamn plant, has been developed by using the LCA software KCL-ECO. LCA is a tool that identifies in which stages of a product’s life cycle the most environmental burdens occur. The environmental analysis was limited to identify total energy consumption and total carbon dioxide (CO2) emissions per ton of Portland cement. Results show that the most significant energy consumption and CO2 emissions are related to clinker kiln, due to the process of calcination of limestone and fuel combustion in the kiln. Of total CO2 emissions, 52 % and 46 % result from the calcination process and fuel combustion respectively. One of the applications of CEM I is in construction of concrete bridges. Therefore an LCA model of a concrete bridge located north of Stockholm was developed in KCL-ECO. Environmental indicators calculated are: total CO2 emissions and energy consumption through the entire life cycle of the bridge. CO2 uptake or carbonation of the concrete during the service life of the product and end of life treatment is one of the advantages of concrete products. During the carbonation process, some of the total CO2 released from calcination will be absorbed into the concrete. Results indicate that production of raw materials and transports during the life cycle of the concrete bridge, are main contributors to total CO2 emissions. Among raw materials, cement production has the highest CO2 emissions. Energy consumption is mainly related to concrete and concrete products production. CO2 uptake during the use phase of the bridge is small compared to total CO2 emissions from calcination. Furthermore, the results show that different waste handling practises result in different CO2 uptake behaviours. The total CO2 uptake from crushing and storing of the demolished concrete (scenario 1) and landfilling of the demolished concrete (scenario 2) is 10 % and 5 % of the total CO2 emissions from calcination respectively. Since comparison of different construction materials from an environmental point of view is always desirable, the LCA tool was used to compare the total energy consumption and the CO2 emissions from a concrete bridge and a wooden bridge. The functional unit was defined as 1 square meter of bridge surface area, since the bridges were of different sizes and shapes. In this comparison the total emissions and energy consumption were much higher for the concrete bridge than for the wooden bridge. In order to show how different assumptions could affect the results, a virtual concrete bridge with the same shape and size as the wooden bridge was designed and compared with the wooden bridge. The functional unit selected for this case was one bridge. In this case the virtual concrete bridge requires less energy, while the wooden bridge emits less CO2 to the atmosphere. For the wooden bridge, CO2 in growing forests was included, which could be debated. Overall, a comparison of the environmental performance of the wooden bridge and the concrete bridges was more complex than initially expected and great care is recommended in choosing material and application. With concrete, the design (and quantity of material used) seems to be a very sensitive parameter and may result in much larger energy used and CO2 emissions than a wooden bridge. On the other hand, the virtual bridge comparison showed that concrete advantages such as higher durability and lower maintenance may be theoretically combined with a comparable energy and climate performance as a wooden alternative.

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36

Igarashi, Hasegawa Lucia. "Carbonation curing and performance of pervious concrete using Portland limestone cement." Thesis, McGill University, 2011. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=104896.

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Pervious concrete is an innovative material with several environmental advantages. Studies on the properties and performance of ordinary Portland cement (OPC) pervious concrete have been done worldwide. Portland limestone cement (PLC) has recently been introduced into the Canadian market as a greener option than OPC. This thesis explores the possibility of using PLC in pervious concrete to achieve technical and environmental benefits.Since the major application of pervious concrete is pavements, it is important to find a way to accelerate the concrete curing process, as one of the most important factors in determining the cost and impact of road work is the construction time. Pervious concrete is the ideal material to cure by carbonation in a feasible way. It is usually designed without reinforcement, so the reduction of the concrete pH value resulting from the process has no impact. Additionally, the open massive pore structure provides a larger surface to optimize CO₂ penetration during the curing process. This study focuses on the effect of carbonation on early age strength and freezing and thawing durability of PLC pervious concrete. It was found that, under the same conditions, PLC pervious concrete shows lower compressive strengths and higher absorption than the OPC counterpart. The optimization of the mixture proportion by including admixtures would permit the use of PLC to generate a pervious concrete with strengths equivalent to OPC pervious concrete. Carbonation curing of PLC pervious concrete increased early age compressive strength, and maintained a comparable final strength. In addition, carbonation curing increased resistance to absorption, but decreased the resistance to freezing and thawing cycles in saline solution. Therefore, carbonation curing of pervious concrete is not recommended for cold climates.
Le béton drainant est un matériau innovant avec plusieurs avantages environnementaux. Des études portant sur les propriétés et la performance du béton drainant au ciment Portland ordinaire (CPO) ont été réalisées internationalement. Le ciment Portland au calcaire (CPC) a fait son arrivée sur le marché canadien récemment et s'avère une option plus écologique que le CPO. Cette thèse explore la possibilité d'utiliser CPC en béton drainant pour obtenir avantages techniques et environnementaux. Une des applications majeures du béton drainant est le pavage. Pour cette raison, c'est important de trouver une façon d'accélérer le processus de durcissement du béton, puisque le temps de construction est l'un des facteurs les plus importants déterminant le coût et l'impact des travaux routiers. Le béton drainant est le matériau idéal à mûrir au carbone de manière faisable. Il est fabriqué sans armature et donc, la réduction du pH du béton résultant du processus de carbonatation n'a aucun impact. De plus, la structure ouverte massive des pores offre une surface plus grande permettant d'optimiser la pénétration de CO₂ au cours du processus de mûrissement. Cette étude a pour but de déterminer l'effet de la carbonatation sur la résistance à jeune âge et la durabilité au gel/dégel du béton drainant fabriqué avec le CPC. Les résultats indiquent que, pour les mêmes conditions, il y a une réduction de la résistance à la compression et une meilleure absorption avec le béton drainant au CPC comparé avec ceux au CPO. L'optimisation du dosage par l'inclusion d'ajouts cimentaires et chimiques, permettrait l'utilisation du CPC pour générer un béton drainant avec des résistances équivalentes au béton drainant au CPO. Le mûrissement au carbone du béton drainant au CPC a augmenté la résistance à la compression à jeune âge, et a maintenu une résistance finale comparable. De plus, le mûrissement au carbone a augmenté la résistance à l'absorption, mais a réduit la résistance aux cycles de gel/dégel en solution saline. Par conséquent, le mûrissement au carbone du béton drainant n'est pas recommandé pour les climats froids.

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37

Al-Akhras, Nabil M. "Characterization and deterioration detection of portland cement concrete using ultrasonic waves." Diss., This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-06062008-170019/.

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38

Lindmark, Sture. "Mechanisms of salt frost scaling of portland cement-bound materials : Studies and hypothesis /." Lund, Sweden : Lund Institute of Technology, Division of Building Materials, 1999. http://www.byggnadsmaterial.lth.se/TVBM-1017.pdf.

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39

Thomason, James Charles. "Development of high performance structural lightweight Portland cement concrete a thesis presented to the faculty of the Graduate School, Tennessee Technological University /." Click to access online, 2009. http://proquest.umi.com/pqdweb?index=0&did=2000396271&SrchMode=1&sid=2&Fmt=6&VInst=PROD&VType=PQD&RQT=309&VName=PQD&TS=1277495413&clientId=28564.

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40

Byars, Ewan Alexander. "PFA concrete : strength development and permeation properties." Thesis, University of Dundee, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.343527.

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41

Rupnow, Tyson David. "Evaluation of laboratory and field techniques to improve portland cement concrete performance." [Ames, Iowa : Iowa State University], 2007.

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42

Alzaabi, Aref Alderbas. "Capacitor-Probe Calibration and Optimization for NDE Application to Portland Cement Concrete." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/28827.

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Three main objectives have been set for this research. The first is to develop an accurate method for measuring the dielectric constant of PCC using a capacitor probe (C-Probe) that has been recently developed at Virginia Tech and validate it for field application to detect internal PCC flaws such as delamination. The C-Probe consists of two flexible conducting plates, connected to a Network Analyzer, with a specific separation between them. The second is to optimize the C-Probe design configuration for different PCC slab thicknesses. The third objective is to develop a predictive model that correlates the bulk dielectric constant of PCC with its critical parameters (cement, aggregate, and air content). Five calibration methods have been developed and evaluated for the C-Probe to measure the dielectric properties of PCC. This evaluation has demonstrated that open, short, Teflon material (OSM) calibration method is the most appropriate one for the C-Probe. The selected calibration method was used to validate the C-Probe fixture for field application by measuring 1.5 x 1.5 m PCC slabs prepared with different mix properties, thicknesses, and induced deterioration. The C-Probe has been proved to detect induced voids in the PCC slabs. In addition, the effect of steel reinforcement on measurements can be mastered by controlling the penetration of electromagnetic (EM) field in the PCC slabs. The effective penetration depth of the EM field for different C-Probe design configuration was optimized by computer simulation. The results have been used to develop a predictive model that correlates the effective penetration depth with the plates' size, separation between them, and the dielectric constant of the PCC under test. Thus, an optimum design for different desired penetration depth was achieved. Two experimental designs were developed to identify the critical parameters that affect the bulk dielectric constant of PCC. A computer simulation was used to identify the significance of each parameter. A predictive model has been developed to correlate the PCC bulk dielectric constant to the critical parameters. The estimated dielectric constant of PCC using the predictive model was correlated to that obtained by other theoretical mixture models; the predictive model has found to correlate well with Looyenga theoretical mixture model.
Ph. D.

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43

Touma, Wissam Elias. "Alkali-silica reaction in Portland cement concrete : testing methods and mitigation alternatives /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.

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Rasol, Mezgeen Abdulrahman Rasol. "Development of new GPR methodologies for soil and cement concrete pavement assessment." Doctoral thesis, Universitat Politècnica de Catalunya, 2021. http://hdl.handle.net/10803/671504.

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The study of surface geology by means of Ground Penetrating Radar (GPR) can provide information about abrupt lateral changes in the terrain. The location ofthese changes is very useful in seismic nanozonation studies, since it allows determining a priori the sectors in which the meas ures should be intensified . The thesis analyzes the effect of changes in granulometry and com paction in the subsurface radar records . lt is observed that a greater heterogeneity of the terrain produces an increase in the background noise ofthe signa! (clutter) dueto the backscattering ofthe waves. The analysis of the amplitude ofthe incoherent signa!, determined in each A-sean by means ofthe average value obtained in a certain time window, makes it possible to obtain graphs ofthe amplitude ofthe background noise versus the position ofthe trace in the profile . The results clearlydefine the sectors in which the amplitude value increases, associating them with the existence of heterogeneous materiaIs in the most superficial zone of the subsoil. On the other hand, the analysis of the frequency content ofthe received radar signa! shows abrupt changes that are sometimes related to the increase in the clutter amplitude. However, at other times they do not appear , even though there is an increase in noise. To analyze the effect, a seasonal study was carried out in an area eros sed by underground streams , comparing the results in the dry season with the results in the rainy season . In temporal space, the underground streams could be detected thanks to the increase in clutter. The results were compared with those obtained by passive seismic . In the frequency space, greater changes in frequencywere observed in the rainy season, while in the dry season these changes only appeared in the records obtained in the area where there was one of the streams. lt was concluded, therefore, that the study of the amplitude s pectrum could be used to determine the presence ofwater and, in the case ofstreams, to differentiate between active streams and drychannels. These results are of great interest for the planning of trans port infrastructures. In the second part ofthe thesis, damage to transport infrastructure is analyzed. Specifically, on rigid pavements. Often these pavements built by using reinforced concrete slabs, are covered by an asphalt layer, either by design or dueto periodical restorations. The interna! cracks that are generated are not observed on the surface until very advanced stages. Severa! laboratory experiments and field case studies were proposed to determine the ability of the GPR to locate cracks, studying the effect ofthickness, depth and fill material. lt was observed that cracks of a size that allow them to be considered as incipient can be detected, although the length ofthe vertical crack could only be detected in the case of cracks already in an advanced state of damage (of great width) or filled with saturated sand or water. The decrease in the speed ofthe signal due to the presence ofwater allowed a higher resolution. The experimental results were compared and verified with field case studies, on real roads. Similar effects were observed although with a more limited resolution. Us ing com putational methods, the anomalies recorded in the radargrams were related and verified in most ofthe cases, both experimentally and in field studies, with different types of cracks.
El estudio de la geologia superficial mediante georradar puede proporcionar información acerca de cambios laterales abruptos en el terreno. La localización de estos cambios resulta especialmente útil en los estudios de nanozonificación sísmica, ya que permite determinar a priori los sectores en los que se deben intensificar las medidas. En la tesis se analiza el efecto de los cambios de granulometría yde compactación en los registros de radar de subsuelo. Se observa que una mayor heterogeneidad del terreno produce un incremento del ruido de fondo de la señal ("clutter") debida a la retrodispersión de las ondas. El análisis de la amplitud de la señal incoherente, determinada en cada A-sean mediante el valor promedio obtenido en una cierta ventana temporal, permite obtener gráficas de amplitud de ruido de fondo frente a la posición de la traza en el perfil. Los resultados definen claramente los sectores en los que se incrementa el valor de la amplitud, asociándolos con existencia de materiales heterogéneos en la zona más superficial del subsuelo. Por otro lado, el análisis del contenido frecuencial de la señal de radar recibida presenta cambios bruscos que en algunas ocasiones están relacionados con el aumento de la amplitud de "clutter". Sin embargo, en otras ocasiones no aparecen aunque se registre un aumento del ruido. Para analizar el efecto se realizó un estudio estacional en una zona atravesada por rieras subterráneas, comparando los resultados en la época seca con los resultados en la época de lluvias. En el espacio temporal, las rieras subterráneas se podían detectar gracias al aumento del "clutter". Los resultados se compararon con los obtenidos mediante sis mica pasiva. En el espacio frecuencial se observaron mayores cambios en la frecuencia en la época de lluvia, mientras que en la época seca únicamente aparecían estos cambios en los registros obtenidos en la zona en la que había una de las rieras. Se concluyó, por lo tanto, que el estudio del espectro de amplitudes se podía utilizar para determinar la presencia de agua y, en el caso de las rieras, para diferenciar entre rieras activas y cauces secos. Estos resultados son de gran interés para la planificación de infraestructuras de transporte. En la segunda parte de la tesis se analizan los daños en infraestructuras de transporte. En concreto en pavimentos rígidos. A menudo estos pavimentos, construidos mediante losas de hormigón armado, están cubiertos por una capa asfáltica, ya sea por diseño o debido a restauraciones. Las grietas internas que se generan no se observan en superficie hasta fases muy avanzadas. Se propusieron ensayos para determinar la capacidad del georradar para localizar grietas, estudiando el efecto del grosor, la profundidad y del material de relleno. Se observó que se pueden detectar grietas de un tamaño que permite considerarlas como incipientes, aunque la longitud de la grieta vertical sólo se podía detectar en el caso de grietas ya en un estado de daño avanzado (de gran anchura) o bien rellenas de arena saturada o de agua. La disminución en la velocidad de la señal debido a la presencia de agua permitía una mayor resolución. Los resultados experimentales se comprobaron en estudios de campo, en carreteras reales. Se observaron efectos similares aunque con una resolución más limitada. Mediante métodos computacionales se relacionaron las anomalías registradas en los radargramas, tanto experimentalmente como en estudios de campo, con distintos tipos de grietas.

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45

Mbasha, Migabo Willy. "The effect of portland cements and superplasticisers on the rheology of cement paste." Thesis, Cape Peninsula University of Technology, 2015. http://hdl.handle.net/20.500.11838/2169.

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Dissertation submitted in partial fulfilment of the requirements for the degree MTech Degree in Civil Engineering in the Faculty of Engineering at the Cape Peninsula University of Technology
Self-compacting concrete is very sensitive to variation in cement properties and to the interaction between cement paste and additives such as superplasticisers. The assessment of these interactions can be done rheologically but there is as yet no consensus on how to evaluate the rheological properties (yield stress and viscosity) of cementitious materials. In addition, there is no clear understanding of the dependency of these rheological properties on early hydration, evaluations which are recommended to be done at paste scale. The evolution of rheological parameters in the early stage of hydration, of four CEM I 52.5N cements manufactured at different factories in South Africa, and their interaction with two different commercial superplasticisers (SPs) were investigated using three different rheometric techniques: conventional flow curve from hysteresis loops, amplitude sweep in oscillation mode and construction of flow curve. Amplitude sweep, time sweep, viscosity-time sweep as well as thixotropy tests were conducted to investigate the effect of hydration and the rate of rebuilding of each cement in the presence and absence of SP. The experiments were done on a MCR51 rheometer with roughened parallel plates under controlled temperatures and relative humidity.
PPC Cement

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46

Burden, Donald. "The durability of concrete containing high levels of fly ash." Skokie, Ill. : Portland Cement Association, 2006. http://www.cement.org/bookstore/profile.asp?itemid=SN2989.

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47

Pereira, Lúcia de Fátima Lacerda da Costa. "Determinação de cloretos em concretos de cimentos Portland: influência do tipo de cimento." Universidade de São Paulo, 2001. http://www.teses.usp.br/teses/disponiveis/3/3146/tde-26042002-104756/.

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A pesquisa aborda os métodos ASTM C 1152 e ASTM C 114, para determinação de cloretos em concreto. Os ensaios foram realizados em dois laboratórios, o da Escola Politécnica da USP, em São Paulo e o da Universidade de Pernambuco, em Recife. Foram preparados concretos com 5 tipos de cimento Portland. O estudo teve como objetivo fazer um levantamento de trabalhos publicados sobre métodos de determinação de cloretos total e solúvel, em concretos, especificamente, discutir a influência do tipo de cimento no teor de cloreto combinado e livre, em amostras de concreto. Foi também objetivo, determinar como se distribui o íon cloreto, solúvel e combinado ao longo da altura de corpos-de-prova de 10x20 cm de diâmetro e apresentar sugestões ao método proposto visando a sua normalização. Paralelamente foram realizados análises químicas e físicas dos cimentos, pela ABCP. O método proposto apresentou boa reprodutibilidade entre os dois laboratórios, através dos cálculos estatísticos, confirmando sua atualidade e, adequação para outros laboratórios. É importante no entanto dizer que este método é demorado, exige dedicação, equipamentos sensíveis e a resposta é lenta. Os cálculos encontram-se informatizados através de planilha interativa de cálculos, facilitando a sua aplicação. A metodologia pareceu adequada para elaboração de norma técnica nacional.
The aim of this research was the application of ASTM method for determination of chlorides in concrete. The tests were made by two laboratories, the EPUSP in São Paulo and POLI in Recife, on concretes prepared with five types of Portland cement. The purpose of this study was to make a survey of published works about the methods of determination of total and soluble chlorides in Portland cement concrete, to discuss the influence of each kind of cement on chlorides, combined and free, in samples of concrete. The purpose was too, determine how the free and linked chlorides are distributed through the height of the specimens of 10x20 diameter and to present suggestions to the standardization of this method. The method presented good results among the two laboratories, the statistical tests demonstrating the method\'s actuality and, adequate to anothers laboratories. It is important to say that this method is slow, needs dedication and specific facilities. The mix-proportion calculations from chemical analysis were made with a spreadsheet software. The methodology seemed to be adequated for the elaboration of a National Standard.

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Dennington, Simon P. J. "The effect of carboxylated acrylic polymer latices on the hydration kinetics of ordinary Portland cement." Thesis, University of Bristol, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.390101.

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49

Khan, Saadat Ali. "Pore pressure and moisture migration in concrete at high and non uniform temperatures." Thesis, King's College London (University of London), 1990. https://kclpure.kcl.ac.uk/portal/en/theses/pore-pressure-and-moisture-migration-in-concrete-at-high-and-non-uniform-temperatures(9016d00a-3f08-4eb8-a9b3-a78d405d6686).html.

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Diefenderfer, Brian K. "Development and Testing of a Capacitor Probe to Detect Deterioration in Portland Cement Concrete." Thesis, Virginia Tech, 1998. http://hdl.handle.net/10919/35397.

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Portland cement concrete (PCC) structures deteriorate with age and need to be maintained or replaced. Early detection of deterioration in PCC (e.g., alkali-silica reaction, freeze/thaw damage or chloride presence) can lead to significant reductions in maintenance costs. Portland cement concrete can be nondestructively evaluated by electrically characterizing its complex dielectric constant in a laboratory setting. A parallel-plate capacitor operating in the frequency range of 0.1 to 40.1 MHz was developed at Virginia Tech for this purpose. While useful in research, this approach is not practical for field implementation. In this study, a capacitor probe was designed and fabricated to determine the in-situ dielectric properties of PCC over a frequency range of 2.0 to 20.0 MHz. It is modeled after the parallel-plate capacitor in that it consists of two conducting plates with a known separation. The conducting plates are flexible, which allows them to conform to different geometric shapes. Prior to PCC testing, measurements were conducted to determine the validity of such a system by testing specimens possessing known dielectric properties (Teflon). Portland cement concrete specimens were cast (of sufficient size to prevent edge diffraction of the electromagnetic waves) having two different air contents, two void thicknesses, and two void depths (from the specimen's surface). Two specimens were cast for each parameter and their results were averaged. The dielectric properties over curing time were measured for all specimens, using the capacitor probe and the parallel-plate capacitor. The capacitor probe showed a decrease in dielectric constant with increasing curing time and/or air content. In addition to measuring dielectric properties accurately and monitoring the curing process, the capacitor probe was also found to detect the presence and relative depth of air voids, however, determining air void thickness was difficult.
Master of Science

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Дисертації з теми "Portland cement concrete pavement"

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