Author: Robert L. Lytton
Publisher: Transportation Research Board National Research
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 76
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 669: Models for Predicting Reflection Cracking of Hot-Mix Asphalt Overlays explores mechanistic-based models for predicting the extent and severity of reflection cracking in hot-mix asphalt overlays. Appendices A through T to NCHRP Report 669 are available online--
Models for Predicting Reflection Cracking of Hot-mix Asphalt Overlays
Author: Robert L. Lytton
Publisher: Transportation Research Board National Research
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 76
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 669: Models for Predicting Reflection Cracking of Hot-Mix Asphalt Overlays explores mechanistic-based models for predicting the extent and severity of reflection cracking in hot-mix asphalt overlays. Appendices A through T to NCHRP Report 669 are available online--
Publisher: Transportation Research Board National Research
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 76
Book Description
TRB's National Cooperative Highway Research Program (NCHRP) Report 669: Models for Predicting Reflection Cracking of Hot-Mix Asphalt Overlays explores mechanistic-based models for predicting the extent and severity of reflection cracking in hot-mix asphalt overlays. Appendices A through T to NCHRP Report 669 are available online--
Models for Predicting Reflection Cracking of Hot-Mix Asphalt Overlays
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
NCHRP Report 669
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Methodology for Predicting the Reflection Cracking Life of Asphalt Concrete Overlays
Author: Frederick P. Germann
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 158
Book Description
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 158
Book Description
Prediction of Reflection Cracking in Hot Mix Asphalt Overlays
Author: Fang-Ling Tsai
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Reflection cracking is one of the main distresses in hot-mix asphalt (HMA) overlays. It has been a serious concern since early in the 20th century. Since then, several models have been developed to predict the extent and severity of reflection cracking in HMA overlays. However, only limited research has been performed to evaluate and calibrate these models. In this dissertation, mechanistic-based models are calibrated to field data of over 400 overlay test sections to produce a design process for predicting reflection cracks. Three cracking mechanisms: bending, shearing traffic stresses, and thermal stress are taken into account to evaluate the rate of growth of the three increasing levels of distress severity: low, medium, and high. The cumulative damage done by all three cracking mechanisms is used to predict the number of days for the reflection crack to reach the surface of the overlay. The result of this calculation is calibrated to the observed field data (severity and extent) which has been fitted with an S-shaped curve. In the mechanistic computations, material properties and fracture-related stress intensity factors are generated using efficient Artificial Neural Network (ANN) algorithms. In the bending and shearing traffic stress models, the traffic was represented by axle load spectra. In the thermal stress model, a recently developed temperature model was used to predict the temperature at the crack tips. This process was developed to analyze various overlay structures. HMA overlays over either asphalt pavement or jointed concrete pavement in all four major climatic zones are discussed in this dissertation. The results of this calculated mechanistic approach showed its ability to efficiently reproduce field observations of the growth, extent, and severity of reflection cracking. The most important contribution to crack growth was found to be thermal stress. The computer running time for a twenty-year prediction of a typical overlay was between one and four minutes.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Reflection cracking is one of the main distresses in hot-mix asphalt (HMA) overlays. It has been a serious concern since early in the 20th century. Since then, several models have been developed to predict the extent and severity of reflection cracking in HMA overlays. However, only limited research has been performed to evaluate and calibrate these models. In this dissertation, mechanistic-based models are calibrated to field data of over 400 overlay test sections to produce a design process for predicting reflection cracks. Three cracking mechanisms: bending, shearing traffic stresses, and thermal stress are taken into account to evaluate the rate of growth of the three increasing levels of distress severity: low, medium, and high. The cumulative damage done by all three cracking mechanisms is used to predict the number of days for the reflection crack to reach the surface of the overlay. The result of this calculation is calibrated to the observed field data (severity and extent) which has been fitted with an S-shaped curve. In the mechanistic computations, material properties and fracture-related stress intensity factors are generated using efficient Artificial Neural Network (ANN) algorithms. In the bending and shearing traffic stress models, the traffic was represented by axle load spectra. In the thermal stress model, a recently developed temperature model was used to predict the temperature at the crack tips. This process was developed to analyze various overlay structures. HMA overlays over either asphalt pavement or jointed concrete pavement in all four major climatic zones are discussed in this dissertation. The results of this calculated mechanistic approach showed its ability to efficiently reproduce field observations of the growth, extent, and severity of reflection cracking. The most important contribution to crack growth was found to be thermal stress. The computer running time for a twenty-year prediction of a typical overlay was between one and four minutes.
PRO 11: 4th International RILEM Conference on Reflective Cracking in Pavement Research in Practice
Author: A. O. Abd El Halim
Publisher: RILEM Publications
ISBN: 9782912143143
Category : Pavements
Languages : en
Pages : 576
Book Description
Publisher: RILEM Publications
ISBN: 9782912143143
Category : Pavements
Languages : en
Pages : 576
Book Description
Methodology for Predicting Asphalt Concrete Overlay Life Against Reflection Cracking
Author: Priyantha Warnasuriya Jayawickrama
Publisher:
ISBN:
Category : Pavements, Asphalt concrete
Languages : en
Pages : 378
Book Description
Publisher:
ISBN:
Category : Pavements, Asphalt concrete
Languages : en
Pages : 378
Book Description
Minimizing Reflection Cracking of Pavement Overlays
Author: George Sherman
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 48
Book Description
"This synthesis will be of special interest to pavement designers, materials specialists, maintenance engineers, and others concerned with the performance of pavement overlays. Methods are presented for reducing reflection cracking in overlays."--Avant-propos.
Publisher:
ISBN:
Category : Technology & Engineering
Languages : en
Pages : 48
Book Description
"This synthesis will be of special interest to pavement designers, materials specialists, maintenance engineers, and others concerned with the performance of pavement overlays. Methods are presented for reducing reflection cracking in overlays."--Avant-propos.
Modeling Reflective Cracking Development in Hot-mix Asphalt Overlays and Quantification of Control Techniques
Author: Jongeun Baek
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Hot-mix asphalt (HMA) overlay is regarded as an efficient method to rehabilitate moderately deteriorated pavements. Despite the application of an adequately designed overlay, when HMA overlays are built on jointed concrete pavement (JCP) or a cracked surface, reflective cracking can develop shortly after the overlay application due to traffic loads and environmental changes. Several remedial techniques, including interlayer systems, have been incorporated into HMA overlays to control reflective cracking. This study examined the behavior of traffic-induced reflective cracking using a finite element (FE) model for an HMA overlay with and without interlayer systems, and evaluated the performance of interlayer systems in controlling reflective cracking. To achieve these objectives, a three-dimensional FE model was built for a typical HMA overlay constructed over JCP. A linear viscoelastic model and a bilinear cohesive zone model (CZM) were incorporated into the FE model to characterize continuum and fracture behavior of the HMA. Using the bilinear CZM, reflective cracking initiation and propagation were simulated. Transient moving vehicular loading was applied across a joint to develop reflective cracking. In order to force reflective cracking development by one pass of load application, various levels of overload were applied. Two distinct interlayer systems, sand mix and steel netting with slurry seal, were examined for their effectiveness in controlling reflective cracking. The sand mix was modeled with the LVE model and bilinear CZM. The steel netting interlayer system was modeled with beam elements for steel wires and membrane elements for slurry seal. To quantify the status of reflective cracking development, a representative fractured area (RFAOL), that is an equivalent stiffness degradation in the entire HMA overlay, was used. A limit state load approach was used to determine the resistance of the HMA overlay to reflective cracking in terms of normalized axle load of an overload equivalent to a 80-kN single-axle load. The service life of the HMA overlay regarding reflective cracking was specified by the number of load repetitions based on the Paris law. A reflective cracking control factor was defined as the ratio of the service life to the HMA overlay without an interlayer system; the factor was used to evaluate the performance effectiveness of these interlayer systems in controlling reflective cracking. It was found that the bearing capacity of existing JCP played an important role in developing reflective cracking. Reflective cracking potential increased inversely with the modulus of base and subgrade layers. Interface bonding conditions, especially bonding strength, affected the development of reflective cracking. Lower interface bonding strength resulted in greater potential for developing reflective cracking. The study concluded that the sand mix interlayer system extended the service life of the HMA overlay regarding reflective cracking due to its relatively high fracture energy. A macro-crack level of reflective cracking was initiated in the wearing course in the HMA, so-called crack jumping. The softer the sand mix, the tougher it may be, but it may cause shear rutting in HMA overlay. Hence, sand mix fracture energy and thickness thresholds should be identified. The steel netting interlayer system performed better than the sand mix; the performance of the latter is thickness and fracture energy dependent. When the steel netting interlayer system was installed properly, the reflective cracking service life of the HMA overlay was found to be six times longer than that of the HMA. The performance was still better than sand mix when localized deboning induced. However, severe debonding of steel netting can be detrimental to its performance.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Hot-mix asphalt (HMA) overlay is regarded as an efficient method to rehabilitate moderately deteriorated pavements. Despite the application of an adequately designed overlay, when HMA overlays are built on jointed concrete pavement (JCP) or a cracked surface, reflective cracking can develop shortly after the overlay application due to traffic loads and environmental changes. Several remedial techniques, including interlayer systems, have been incorporated into HMA overlays to control reflective cracking. This study examined the behavior of traffic-induced reflective cracking using a finite element (FE) model for an HMA overlay with and without interlayer systems, and evaluated the performance of interlayer systems in controlling reflective cracking. To achieve these objectives, a three-dimensional FE model was built for a typical HMA overlay constructed over JCP. A linear viscoelastic model and a bilinear cohesive zone model (CZM) were incorporated into the FE model to characterize continuum and fracture behavior of the HMA. Using the bilinear CZM, reflective cracking initiation and propagation were simulated. Transient moving vehicular loading was applied across a joint to develop reflective cracking. In order to force reflective cracking development by one pass of load application, various levels of overload were applied. Two distinct interlayer systems, sand mix and steel netting with slurry seal, were examined for their effectiveness in controlling reflective cracking. The sand mix was modeled with the LVE model and bilinear CZM. The steel netting interlayer system was modeled with beam elements for steel wires and membrane elements for slurry seal. To quantify the status of reflective cracking development, a representative fractured area (RFAOL), that is an equivalent stiffness degradation in the entire HMA overlay, was used. A limit state load approach was used to determine the resistance of the HMA overlay to reflective cracking in terms of normalized axle load of an overload equivalent to a 80-kN single-axle load. The service life of the HMA overlay regarding reflective cracking was specified by the number of load repetitions based on the Paris law. A reflective cracking control factor was defined as the ratio of the service life to the HMA overlay without an interlayer system; the factor was used to evaluate the performance effectiveness of these interlayer systems in controlling reflective cracking. It was found that the bearing capacity of existing JCP played an important role in developing reflective cracking. Reflective cracking potential increased inversely with the modulus of base and subgrade layers. Interface bonding conditions, especially bonding strength, affected the development of reflective cracking. Lower interface bonding strength resulted in greater potential for developing reflective cracking. The study concluded that the sand mix interlayer system extended the service life of the HMA overlay regarding reflective cracking due to its relatively high fracture energy. A macro-crack level of reflective cracking was initiated in the wearing course in the HMA, so-called crack jumping. The softer the sand mix, the tougher it may be, but it may cause shear rutting in HMA overlay. Hence, sand mix fracture energy and thickness thresholds should be identified. The steel netting interlayer system performed better than the sand mix; the performance of the latter is thickness and fracture energy dependent. When the steel netting interlayer system was installed properly, the reflective cracking service life of the HMA overlay was found to be six times longer than that of the HMA. The performance was still better than sand mix when localized deboning induced. However, severe debonding of steel netting can be detrimental to its performance.
Overlay Design and Reflection Cracking Analysis for Rigid Pavements
Author:
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 172
Book Description
Fatigue cracking and reflection cracking criteria were developed and incorporated into a design procedure for flexible and rigid overlays of rigid pavements. Linear elastic layered theory is the basic model used to compute stresses and strains in the pavement system, which are then input to the fatigue and reflection cracking models. The fatigue criteria developments resulted from analyses of the performance of rigid pavements at the AASHO Road Test.
Publisher:
ISBN:
Category : Pavements
Languages : en
Pages : 172
Book Description
Fatigue cracking and reflection cracking criteria were developed and incorporated into a design procedure for flexible and rigid overlays of rigid pavements. Linear elastic layered theory is the basic model used to compute stresses and strains in the pavement system, which are then input to the fatigue and reflection cracking models. The fatigue criteria developments resulted from analyses of the performance of rigid pavements at the AASHO Road Test.