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Predicting Pervious Concrete Pavement Performance for Usage in Cold ClimatesGolroo, Amir January 2010 (has links)
Pervious Concrete Pavement (PCP) has the potential to provide significant benefits. To better understand the technical, economical, and environmental impacts of PCP, the performance must be comprehensively evaluated and quantified. Because PCP is a new material, there is no mechanism for properly quantifying its performance. In addition, the application of this technology in cold climates is limited and therefore limited in-service performance data is available.
A comprehensive engineering based performance model quantifies the deterioration rate and predicts future performance. Pavement performance models are developed using a pavement condition index and extensive pavement condition databases. A pavement condition index is a value which expresses the overall condition of pavement by considering various factors such as surface distresses, structural defects, and ride quality. This research will assist pavement engineers and managers in the design, construction, and management of PCP.
The review of published literature reveals that there is currently a large gap in the performance evaluation of PCP in cold climates. Neither extensive condition indices nor comprehensive performance models have been developed for PCP. This research involves development of comprehensive performance models for PCP in cold climates using laboratory and field experiments and existing available data in order to predict functionality (permeability rate) and surface distresses of PCP. This study is, furthermore, aimed at developing an extensive condition index for better management of PCP by predicting and quantifying the various types of distresses and the associated functionality of PCP with particular emphasis on cold climate usage and performance.
The scope of this research is to design a comprehensive tool which is simple and cost-effective. The tool involves first defining the typical types of distresses that are occurring on PCP. This is facilitated through laboratory and field design, construction, and evaluation of two test sites located in Ontario. It also involves continuous evaluation of these sites and evaluation of several other sites in the United States. The main sources of data in this research are panel rating data and field investigations data. A panel rates the condition of PCP in terms of surface distresses and permeability rates. In addition to this, field measurements of distresses and permeability rates are obtained manually. As a result, the Pervious Concrete Condition Index (PCCI) is developed through incorporation of field measurements and panel ratings. By using regression analysis, performance models are developed between PCCI and pavement age. The performance models are validated using the data splitting technique. Ultimately, the performance models are calibrated using field data by applying the Markov Chain process (acquiring expert knowledge by distributing questionnaires) and the Bayesian technique.
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Predicting Pervious Concrete Pavement Performance for Usage in Cold ClimatesGolroo, Amir January 2010 (has links)
Pervious Concrete Pavement (PCP) has the potential to provide significant benefits. To better understand the technical, economical, and environmental impacts of PCP, the performance must be comprehensively evaluated and quantified. Because PCP is a new material, there is no mechanism for properly quantifying its performance. In addition, the application of this technology in cold climates is limited and therefore limited in-service performance data is available.
A comprehensive engineering based performance model quantifies the deterioration rate and predicts future performance. Pavement performance models are developed using a pavement condition index and extensive pavement condition databases. A pavement condition index is a value which expresses the overall condition of pavement by considering various factors such as surface distresses, structural defects, and ride quality. This research will assist pavement engineers and managers in the design, construction, and management of PCP.
The review of published literature reveals that there is currently a large gap in the performance evaluation of PCP in cold climates. Neither extensive condition indices nor comprehensive performance models have been developed for PCP. This research involves development of comprehensive performance models for PCP in cold climates using laboratory and field experiments and existing available data in order to predict functionality (permeability rate) and surface distresses of PCP. This study is, furthermore, aimed at developing an extensive condition index for better management of PCP by predicting and quantifying the various types of distresses and the associated functionality of PCP with particular emphasis on cold climate usage and performance.
The scope of this research is to design a comprehensive tool which is simple and cost-effective. The tool involves first defining the typical types of distresses that are occurring on PCP. This is facilitated through laboratory and field design, construction, and evaluation of two test sites located in Ontario. It also involves continuous evaluation of these sites and evaluation of several other sites in the United States. The main sources of data in this research are panel rating data and field investigations data. A panel rates the condition of PCP in terms of surface distresses and permeability rates. In addition to this, field measurements of distresses and permeability rates are obtained manually. As a result, the Pervious Concrete Condition Index (PCCI) is developed through incorporation of field measurements and panel ratings. By using regression analysis, performance models are developed between PCCI and pavement age. The performance models are validated using the data splitting technique. Ultimately, the performance models are calibrated using field data by applying the Markov Chain process (acquiring expert knowledge by distributing questionnaires) and the Bayesian technique.
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Automated crack control analysis for concrete pavement constructionJang, Se Hoon 01 November 2005 (has links)
The focus of this research is on the control of random cracking in concrete paving by using sawcut notch locations in the early stages of construction. This is a major concern in concrete pavement construction. This research also addresses a probabilistic approach to determine the optimum time and depth of sawcutting for newly constructed portland cement concrete pavements. Variability in climate conditions and material characteristics during the hardening process affects the potential of cracking at any sawcut depth. Several factors affecting the probability of crack initiation are material strength parameters, method and quality of curing, slab/subbase stiffness, the amount and depth of steel reinforcement, friction between the slab and the subbase, and concrete shrinkage. Other factors relevant to concrete mixture characteristics such as cement content and type of coarse aggregate affect development of early aged stresses caused by shrinkage and thermally induced contraction. A probabilistic analysis of the factors that affect crack control using sawcut notches is presented in relation to different weather conditions (concrete placement temperature) at the time of construction, and concrete mixture characteristics such as fly ash replacement (FA) and cement factor (CF). Both of these significantly affect sawcut timing and depth requirement. The determination of crack initiation is based on fracture mechanics. Estimation of the time of cracking is based on predicted tensile strength and stress in the concrete at the bottom of the sawcut notch to assess the feasibility of crack control in the early stages of construction.
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Structural Performance Evaluation of Interlocking Concrete Pavement Crosswalk DesignsAdhikari,Sudip 05 December 2008 (has links)
Interlocking Concrete Pavements (ICP) have been successfully used in many pavement applications all across the world. ICP design and analysis methods, construction practices and materials specifications have been developed. However, there is very limited field data to quantify structural performance with respect to traffic and environmental loadings. The interaction between traffic loadings and environmental factors needs to be explored in order to improve relationships between pavement performance and response.
Pavement performance prediction in terms of fatigue cracking and surface rutting are essential for any mechanistically-based pavement design method. The estimation of the expected fatigue performance in the field is based on the quantification of the maximum tensile strain in bound base layers and the expected rutting performance is based on maximum vertical stress/strain in granular layers.
This thesis presents an innovative research project involving the design, construction, instrumentation, performance modeling and distress evaluation of seven ICP crosswalks with four different design assemblies. The research projects were constructed at the Centre for Pavement and Transportation Technology (CPATT) test track and at the University of Waterloo ring road. Each of the test sections is instrumented with structural and environmental sensors of sensors to monitor the pavement performance under heavy truck traffic, typical municipal loadings and to quantify environmental effects. A database is generated and the measured stress, strain, temperature and moisture measurements are analysed to evaluate the expected long-term performance of the structural components of ICP crosswalk designs.
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Structural Performance Evaluation of Interlocking Concrete Pavement Crosswalk DesignsAdhikari,Sudip 05 December 2008 (has links)
Interlocking Concrete Pavements (ICP) have been successfully used in many pavement applications all across the world. ICP design and analysis methods, construction practices and materials specifications have been developed. However, there is very limited field data to quantify structural performance with respect to traffic and environmental loadings. The interaction between traffic loadings and environmental factors needs to be explored in order to improve relationships between pavement performance and response.
Pavement performance prediction in terms of fatigue cracking and surface rutting are essential for any mechanistically-based pavement design method. The estimation of the expected fatigue performance in the field is based on the quantification of the maximum tensile strain in bound base layers and the expected rutting performance is based on maximum vertical stress/strain in granular layers.
This thesis presents an innovative research project involving the design, construction, instrumentation, performance modeling and distress evaluation of seven ICP crosswalks with four different design assemblies. The research projects were constructed at the Centre for Pavement and Transportation Technology (CPATT) test track and at the University of Waterloo ring road. Each of the test sections is instrumented with structural and environmental sensors of sensors to monitor the pavement performance under heavy truck traffic, typical municipal loadings and to quantify environmental effects. A database is generated and the measured stress, strain, temperature and moisture measurements are analysed to evaluate the expected long-term performance of the structural components of ICP crosswalk designs.
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Automated crack control analysis for concrete pavement constructionJang, Se Hoon 01 November 2005 (has links)
The focus of this research is on the control of random cracking in concrete paving by using sawcut notch locations in the early stages of construction. This is a major concern in concrete pavement construction. This research also addresses a probabilistic approach to determine the optimum time and depth of sawcutting for newly constructed portland cement concrete pavements. Variability in climate conditions and material characteristics during the hardening process affects the potential of cracking at any sawcut depth. Several factors affecting the probability of crack initiation are material strength parameters, method and quality of curing, slab/subbase stiffness, the amount and depth of steel reinforcement, friction between the slab and the subbase, and concrete shrinkage. Other factors relevant to concrete mixture characteristics such as cement content and type of coarse aggregate affect development of early aged stresses caused by shrinkage and thermally induced contraction. A probabilistic analysis of the factors that affect crack control using sawcut notches is presented in relation to different weather conditions (concrete placement temperature) at the time of construction, and concrete mixture characteristics such as fly ash replacement (FA) and cement factor (CF). Both of these significantly affect sawcut timing and depth requirement. The determination of crack initiation is based on fracture mechanics. Estimation of the time of cracking is based on predicted tensile strength and stress in the concrete at the bottom of the sawcut notch to assess the feasibility of crack control in the early stages of construction.
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Reciclagem total de pavimentos de concreto como agregados para construção de novos pavimentos de concreto: o caso do Rodoanel Metropolitano Mário Covas. / Concrete pavement recycling for use as aggregates in new concrete for pavements - Mario Covas Metropolitan Road Ring case.Tseng, Ester 11 August 2010 (has links)
O estudo da reciclagem de pavimentos de concreto para utilização em novos pavimentos tem se mostrado de grande importância haja vista a quantidade de materiais necessários para a reconstrução dessas vias. Além do ganho ambiental, devido a uma menor extração de agregados, obtém-se um ganho econômico, com menor custo de transporte e de aquisição de materiais. O agregado proveniente da britagem de antigas placas de concreto se mostrou, historicamente, apto a ser utilizado para a produção de um novo pavimento de concreto. Entretanto, existem certas limitações, pois o seu uso não resulta em um concreto com características totalmente idênticas àquelas do concreto convencional. O presente trabalho apresenta resultados da análise das características dos agregados produzidos através da britagem de antigas placas de pavimentos de concreto do Rodoanel Metropolitano Mário Covas em britador de mandíbula e em britador de impacto, bem como a influência do uso de agregados reciclados nas propriedades mecânicas do concreto. No estudo comparativo entre os tipos de britador foi verificado que agregados obtidos por britador de mandíbula e por britador de impacto possuem características muito semelhantes. No estudo das características mecânicas dos concretos a resistência à tração na flexão, a resistência à tração na compressão e o módulo de elasticidade diminuíram conforme se aumentou a absorção de água ponderada dos agregados. No que se refere à resistência à compressão, contudo, não foi observada queda ao se substituir somente a fração de agregados graúdos na mistura. Quando se procedeu com a substituição da fração miúda, porém, a resistência ficou abaixo daquela do concreto de convencional. / The study of concrete pavement recycling for its use in new pavements has shown to be of great importance considering the quantity of materials that are necessary to reconstruct these roads. Besides the environmental gain, due to a lesser extraction of aggregates, there is also an economic gain, with smaller transportation and material purchasing costs. The aggregate originated from the crushing of old concrete slabs has historically been shown to be able to be employed in the construction of a new concrete pavement. However, there are limitations, since its utilization does not result in a concrete with the exact same properties of the conventional concrete. The present work presents the results from the analysis of the characteristics from the aggregates produced through the crushing of old concrete slabs using a jaw crusher and an impact crusher, as well as the influence of the use of recycled aggregates on the concrete mechanical properties. The crusher type comparative study has shown that aggregates obtained from a jaw crusher and from an impact crusher have very similar characteristics. The concrete mechanical characteristic study reveals that flexural strength, indirect tensile strength and modulus of elasticity decrease as the aggregates water absorption increase. Concerning compressive strength, however, there was no observed decrease when only coarse recycled aggregates were used. Nevertheless, when fine recycled aggregates were employed besides coarse recycled aggregates, there was a decrease in compressive strength.
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Stochastic Modeling of Future Highway Maintenance Costs for Flexible Type Highway Pavement Construction ProjectsKim, Yoo Hyun 2012 May 1900 (has links)
The transportation infrastructure systems in the United States were built between the 50's and 80's, with 20 years design life. As most of them already exceeded their original life expectancy, state transportation agencies (STAs) are now under increased needs to rebuild deteriorated transportation networks. For major highway maintenance projects, a federal rule enforces to perform a life-cycle cost analysis (LCCA).
The lack of analytical methods for LCCA creates many challenges of STAs to comply with the rule. To address these critical issues, this study aims at developing a new methodology for quantifying the future maintenance cost to assist STAs in performing a LCCA. The major objectives of this research are twofold: 1) identify the critical factors that affect pavement performances; 2) develop a stochastic model that predicts future maintenance costs of flexible-type pavement in Texas.
The study data were gathered through the Pavement Management Information System (PMIS) containing more than 190,000 highway sections in Texas. These data were then grouped by critical performance-driven factor which was identified by K-means cluster analysis. Many factors were evaluated to identify the most critical factors that affect pavement maintenance need. With these data, a series of regression analyses were carried out to develop predictive models. Lastly, a validation study with PRESS statistics was conducted to evaluate reliability of the model. The research results reveal that three factors, annual average temperature, annual precipitation, and pavement age, were the most critical factors under very low traffic volume conditions.
This research effort was the first of its kind undertaken in this subject. The maintenance cost lookup tables and stochastic model will assist STAs in carrying out a LCCA, with the reliable estimation of maintenance costs. This research also provides the research community with the first view and systematic estimation method that STAs can use to determine long-term maintenance costs in estimating life-cycle costs. It will reduce the agency's expenses in the time and effort required for conducting a LCCA. Estimating long-term maintenance cost is a core component of the LCCA. Therefore, methods developed from this project have the great potential to improve the accuracy of LCCA.
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Numerical Investigation of the Effects of Shrinkage and Thermal Loading on the Behaviour of Misaligned Dowels in Jointed Concrete PavementLevy, Cyril January 2010 (has links)
Dowel bars in jointed plain concrete pavement (JPCP) have the important function of transferring wheel loads from one slab to the other, hence ensuring that the deflections on each side of the joint are kept almost equal. As well, the dowels should not impede the concrete pavement movements due to environmental effects (temperature and moisture). Dowel bar misalignment, attributed to deficient construction practice, is a major cause of joint distress or faulting by inhibiting the free movement of the slab at the joint. To prevent these issues, tolerance guidelines on misalignment levels are implemented by transportation agencies. Review of previous studies indicate that many researchers analysed the effects of dowel bar misalignment on pavement behaviour using a pull-out test, that is a forcebased opening of the joint. These approaches neglect that joints movements in the field are strain-governed by non-linear temperature and shrinkage actions, leading to combined axial
movements and curling of the slab.
In this study, the fundamental dowel bar behaviour under shrinkage and thermal loading
was determined through detailed 3D finite element modelling (3D-FEM). To that end, models of dowel jointed concrete slabs were developed and subjected to realistic non-linear profiles of shrinkage and thermal strains. Studies were carried out on a single-bar model, taking into account bar-concrete friction and plastic concrete behaviour. The parameters that were investigated included different configurations and levels of bar misalignment and different friction coefficients between the steel and the concrete, simulating the use of bond-breakers. To interpret the results from the numerical analysis, criteria for concrete damage were developed and used in parallel with measures of joint load transfer efficiency; these were obtained by examining the response of the slab under a Falling Weight Deflectometer (FWD) drop at the joint. The results were verified by comparing the outputs of a model consisting
of one half of a slab to published data.
The analysis of the models revealead that none of the models showed signs of significant damage after the application of shrinkage and two thermal cycles. Analyses with up to ten thermal cycles did not indicate progressive accumulation of damage, suggesting that for the chosen parameters there is no the concrete around the dowel bar will not fail. Models with bars placed higher in the slab and bars with angular misalignment exhibited more damage than the non-misaligned models without reaching the damage criteria used in this study. The models did not exhibit the amount of damage reported in the studies on dowel bar misalignment having used pull-out tests. It was found that no significant difference existed between uncoated and coated dowel bars models results with regards to concrete damage at the joint. However, a high coefficient of friction between the dowel and the concrete, simulating dowel bar corrosion, proved to be the most detrimental to joint integrity. All of the models performed very well with respect to joint load transfer efficiency, suggesting that
the plastic strains in the concrete around the dowel did not have a significant impact on joint performance for the realistic range of parameters investigated.
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Numerical Investigation of the Effects of Shrinkage and Thermal Loading on the Behaviour of Misaligned Dowels in Jointed Concrete PavementLevy, Cyril January 2010 (has links)
Dowel bars in jointed plain concrete pavement (JPCP) have the important function of transferring wheel loads from one slab to the other, hence ensuring that the deflections on each side of the joint are kept almost equal. As well, the dowels should not impede the concrete pavement movements due to environmental effects (temperature and moisture). Dowel bar misalignment, attributed to deficient construction practice, is a major cause of joint distress or faulting by inhibiting the free movement of the slab at the joint. To prevent these issues, tolerance guidelines on misalignment levels are implemented by transportation agencies. Review of previous studies indicate that many researchers analysed the effects of dowel bar misalignment on pavement behaviour using a pull-out test, that is a forcebased opening of the joint. These approaches neglect that joints movements in the field are strain-governed by non-linear temperature and shrinkage actions, leading to combined axial
movements and curling of the slab.
In this study, the fundamental dowel bar behaviour under shrinkage and thermal loading
was determined through detailed 3D finite element modelling (3D-FEM). To that end, models of dowel jointed concrete slabs were developed and subjected to realistic non-linear profiles of shrinkage and thermal strains. Studies were carried out on a single-bar model, taking into account bar-concrete friction and plastic concrete behaviour. The parameters that were investigated included different configurations and levels of bar misalignment and different friction coefficients between the steel and the concrete, simulating the use of bond-breakers. To interpret the results from the numerical analysis, criteria for concrete damage were developed and used in parallel with measures of joint load transfer efficiency; these were obtained by examining the response of the slab under a Falling Weight Deflectometer (FWD) drop at the joint. The results were verified by comparing the outputs of a model consisting
of one half of a slab to published data.
The analysis of the models revealead that none of the models showed signs of significant damage after the application of shrinkage and two thermal cycles. Analyses with up to ten thermal cycles did not indicate progressive accumulation of damage, suggesting that for the chosen parameters there is no the concrete around the dowel bar will not fail. Models with bars placed higher in the slab and bars with angular misalignment exhibited more damage than the non-misaligned models without reaching the damage criteria used in this study. The models did not exhibit the amount of damage reported in the studies on dowel bar misalignment having used pull-out tests. It was found that no significant difference existed between uncoated and coated dowel bars models results with regards to concrete damage at the joint. However, a high coefficient of friction between the dowel and the concrete, simulating dowel bar corrosion, proved to be the most detrimental to joint integrity. All of the models performed very well with respect to joint load transfer efficiency, suggesting that
the plastic strains in the concrete around the dowel did not have a significant impact on joint performance for the realistic range of parameters investigated.
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