The Experts below are selected from a list of 786 Experts worldwide ranked by ideXlab platform
Steven G Sachs - One of the best experts on this subject based on the ideXlab platform.
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establishing the interlayer structural response for unbonded concrete overlays of existing concrete pavements
Transportation Research Record, 2018Co-Authors: Steven G Sachs, Julie M Vandenbossche, Derek TompkinsAbstract:An improved mechanistic empirical design procedure for unbonded concrete overlays of existing concrete pavements (UBOLs) should account for the effect of the interlayer on the structural response of the pavement. One approach is to use the Totsky model to characterize the interlayer. The Totsky model treats the interlayer as a bed of springs between two plates and is currently incorporated into the rigid pavement finite element software ISLAB. A difficulty encountered in implementing this model is that there are currently no guidelines as to what the interlayer k-value should be for different types of interlayers. The interlayer can be constructed of new or aged asphalt (open or dense graded) or a Nonwoven Geotextile fabric. To establish the k-values that accurately characterize each of these materials, an ISLAB model of a laboratory test was created so the k-values could be established by matching the measured and calculated difference between the deflections in the overlay and existing pavement. To supp...
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effects of interlayer systems on reflective cracking in unbonded overlays of existing concrete pavements
Transportation Research Record, 2016Co-Authors: Steven G Sachs, Julie M Vandenbossche, Kevin Alland, John W DesantisAbstract:Reflective cracking can be a concern in unbonded concrete overlays of existing distressed concrete pavements. In these structures, an interlayer, commonly hot-mix asphalt (HMA) or a Nonwoven Geotextile fabric, is placed to isolate the overlay concrete from the existing concrete pavement. The interlayer minimizes interaction between the overlay and the existing concrete pavement, which helps prevent distress in the existing pavement from propagating into the overlay. In this study, a laboratory investigation was used to examine the influence of HMA and Geotextile fabric interlayer systems on the potential for development of reflective cracking. A laboratory test was conducted by using stacked beam specimens separated by an interlayer to evaluate the potential for a discrete crack in the lower beam reflecting up through the interlayer and into the overlay beam. The study revealed that reflective cracking was more likely when there was loss of support beneath the existing pavement. Reflective cracking did no...
Julie M Vandenbossche - One of the best experts on this subject based on the ideXlab platform.
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establishing the interlayer structural response for unbonded concrete overlays of existing concrete pavements
Transportation Research Record, 2018Co-Authors: Steven G Sachs, Julie M Vandenbossche, Derek TompkinsAbstract:An improved mechanistic empirical design procedure for unbonded concrete overlays of existing concrete pavements (UBOLs) should account for the effect of the interlayer on the structural response of the pavement. One approach is to use the Totsky model to characterize the interlayer. The Totsky model treats the interlayer as a bed of springs between two plates and is currently incorporated into the rigid pavement finite element software ISLAB. A difficulty encountered in implementing this model is that there are currently no guidelines as to what the interlayer k-value should be for different types of interlayers. The interlayer can be constructed of new or aged asphalt (open or dense graded) or a Nonwoven Geotextile fabric. To establish the k-values that accurately characterize each of these materials, an ISLAB model of a laboratory test was created so the k-values could be established by matching the measured and calculated difference between the deflections in the overlay and existing pavement. To supp...
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effects of interlayer systems on reflective cracking in unbonded overlays of existing concrete pavements
Transportation Research Record, 2016Co-Authors: Steven G Sachs, Julie M Vandenbossche, Kevin Alland, John W DesantisAbstract:Reflective cracking can be a concern in unbonded concrete overlays of existing distressed concrete pavements. In these structures, an interlayer, commonly hot-mix asphalt (HMA) or a Nonwoven Geotextile fabric, is placed to isolate the overlay concrete from the existing concrete pavement. The interlayer minimizes interaction between the overlay and the existing concrete pavement, which helps prevent distress in the existing pavement from propagating into the overlay. In this study, a laboratory investigation was used to examine the influence of HMA and Geotextile fabric interlayer systems on the potential for development of reflective cracking. A laboratory test was conducted by using stacked beam specimens separated by an interlayer to evaluate the potential for a discrete crack in the lower beam reflecting up through the interlayer and into the overlay beam. The study revealed that reflective cracking was more likely when there was loss of support beneath the existing pavement. Reflective cracking did no...
Derek Tompkins - One of the best experts on this subject based on the ideXlab platform.
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establishing the interlayer structural response for unbonded concrete overlays of existing concrete pavements
Transportation Research Record, 2018Co-Authors: Steven G Sachs, Julie M Vandenbossche, Derek TompkinsAbstract:An improved mechanistic empirical design procedure for unbonded concrete overlays of existing concrete pavements (UBOLs) should account for the effect of the interlayer on the structural response of the pavement. One approach is to use the Totsky model to characterize the interlayer. The Totsky model treats the interlayer as a bed of springs between two plates and is currently incorporated into the rigid pavement finite element software ISLAB. A difficulty encountered in implementing this model is that there are currently no guidelines as to what the interlayer k-value should be for different types of interlayers. The interlayer can be constructed of new or aged asphalt (open or dense graded) or a Nonwoven Geotextile fabric. To establish the k-values that accurately characterize each of these materials, an ISLAB model of a laboratory test was created so the k-values could be established by matching the measured and calculated difference between the deflections in the overlay and existing pavement. To supp...
John W Desantis - One of the best experts on this subject based on the ideXlab platform.
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effects of interlayer systems on reflective cracking in unbonded overlays of existing concrete pavements
Transportation Research Record, 2016Co-Authors: Steven G Sachs, Julie M Vandenbossche, Kevin Alland, John W DesantisAbstract:Reflective cracking can be a concern in unbonded concrete overlays of existing distressed concrete pavements. In these structures, an interlayer, commonly hot-mix asphalt (HMA) or a Nonwoven Geotextile fabric, is placed to isolate the overlay concrete from the existing concrete pavement. The interlayer minimizes interaction between the overlay and the existing concrete pavement, which helps prevent distress in the existing pavement from propagating into the overlay. In this study, a laboratory investigation was used to examine the influence of HMA and Geotextile fabric interlayer systems on the potential for development of reflective cracking. A laboratory test was conducted by using stacked beam specimens separated by an interlayer to evaluate the potential for a discrete crack in the lower beam reflecting up through the interlayer and into the overlay beam. The study revealed that reflective cracking was more likely when there was loss of support beneath the existing pavement. Reflective cracking did no...
Amit Rawal - One of the best experts on this subject based on the ideXlab platform.
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interface shear characteristics of jute polypropylene hybrid Nonwoven Geotextiles and sand using large size direct shear test
Geotextiles and Geomembranes, 2014Co-Authors: M M A Sayeed, Janaki B Ramaiah, Amit RawalAbstract:Abstract In this study, large-size direct shear tests were conducted to determine the interfacial shear characteristics of sand–Geotextile under three different normal stresses. The Geotextiles used in the present study were hybrid needlepunched Nonwovens containing defined weight proportions of jute and polypropylene fibers. Subsequently, the interfacial shear characteristics of hybrid and that of a Nonwoven Geotextile consisting of solely polypropylene fibers with sand were compared and analyzed under different normal stresses. Initial higher shear stiffness of sand-polypropylene Geotextiles was observed corresponding to sand-hybrid Geotextiles specifically under higher normal stresses. Nevertheless, the contact efficiency of sand-hybrid Nonwovens was similar to that of sand-polypropylene Geotextiles. The surface morphology of sand particles has been investigated based on the images obtained from scanning electron microscopy (SEM) and quantitatively analyzed by means of Wadell roundness and degree of angularity methods.
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Pore size distribution of hybrid Nonwoven Geotextiles
Geotextiles and Geomembranes, 2011Co-Authors: Amit Rawal, Harshvardhan SaraswatAbstract:Abstract Pore size distribution has become a prerequisite in determining the performance of Geotextiles for various functions including filtration, separation and reinforcement. The pore structure and morphology in a Nonwoven Geotextile are known to be complex and it becomes further complicated in hybrid Nonwoven Geotextiles consisting of two types of fibers. In this study, a modified model of pore size distribution of hybrid Nonwoven Geotextiles has been proposed based on sieving-percolation pore network theory. A comparison has been made between theoretical and experimental pore size distributions of hybrid needlepunched Nonwoven Geotextiles consisting of predefined weight proportions of viscose and polyester fibers. The weight proportions of the constituent fibers have been theoretically analysed for obtaining the desired pore size distributions of hybrid Nonwoven Geotextiles.
