The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
Neeraj Buch - One of the best experts on this subject based on the ideXlab platform.
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ASSESSMENT OF RETROFIT DOWEL BENEFITS IN CRACKED PORTLAND CEMENT CONCRETE PAVEMENTS
Journal of Performance of Constructed Facilities, 2004Co-Authors: Jacob E. Hiller, Neeraj BuchAbstract:A parametric study was conducted using the finite-element rigid pavement program ISLAB2000. For cracks that utilize Aggregate Interlock as the sole means of load transfer, the integrity of the cracks was initially modeled using the Aggregate Interlock factor. A subsequent analysis was then performed on the same cracks for the case where both dowel bars and Aggregate Interlock were available for load transfer purposes. The latter scenario represents the case where dowel bar retrofitting (DBR) has been performed on the cracks. In both cases, the deflection load transfer efficiency and critical slab tensile stresses were computed in order to examine the immediate theoretical benefits of the dowel bars. The validity of these theoretical benefits was tested using data from falling-weight deflectometer testing on DBR sites in both Michigan and Washington. It was found that installation of dowel bars did not increase the load transfer efficiency for cracks that had levels greater than 89–95%, depending on paveme...
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Impact of Coarse Aggregates on Transverse Crack Performance in Jointed Concrete Pavements
Aci Materials Journal, 2000Co-Authors: Neeraj Buch, Michael A. Frabizzio, Jacob E. HillerAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements (JCPs). Maintaining adequate Aggregate Interlock load transfer across these cracks is essential for preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the effects of Aggregate type, size, and blending on the performance of transverse cracking in jointed concrete pavements. Field data collected from inservice JCPs located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture (VST) testing. VST results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. A parallel laboratory study was conducted to study the impact of Aggregate size and blending on transverse crack performance. Three performance parameters capable of mechanistically characterizing crack performance are discussed. A relatively simple procedure was described for determining these parameters and evaluating crack condition.
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Impact of Coarse Aggregates on Transverse Crack Performance in Jointed Concrete Pavements
Aci Materials Journal, 2000Co-Authors: Neeraj Buch, Michael A. Frabizzio, Jacob E. HillerAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements (JCPs). Maintaining adequate Aggregate Interlock load transfer across these cracks is essential for preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the effects of Aggregate type, size, and blending on the performance of transverse cracking in jointed concrete pavements. Field data collected from inservice JCPs located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture (VST) testing. VST results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. A parallel laboratory study was conducted to study the impact of Aggregate size and blending on transverse crack performance. Three performance parameters capable of mechanistically characterizing crack performance are discussed. A relatively simple procedure was described for determining these parameters and evaluating crack condition.
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Performance of Transverse Cracking in Jointed Concrete Pavements
Journal of Performance of Constructed Facilities, 1999Co-Authors: Michael A. Frabizzio, Neeraj BuchAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements. Maintaining adequate Aggregate Interlock load transfer across these cracks is essential to preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the design parameters that significantly affect transverse cracking and to demonstrate methods available for evaluating cracked pavements. Field data collected from in-service jointed concrete pavements located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture testing. Volumetric surface texture results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. Three performance parameters capable of mechanistically characterizing crack performance were discussed. A relatively simple procedure was described for determining these parameters and evaluating crack conditions. Field data were also used to demonstrate and validate a voids' analysis procedure. This procedure estimates the potential for loss of support near cracks and joints, thus allowing for proper rehabilitation actions to be taken prior to the manifestation of additional distresses.
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Investigation of design parameters affecting transverse cracking in jointed concrete pavements
Transportation Research Record, 1999Co-Authors: Michael A. Frabizzio, Neeraj BuchAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements (JCPs). Maintaining adequate Aggregate Interlock load transfer across these cracks is essential to preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the design parameters that significantly affect transverse cracking and to demonstrate methods available for evaluating cracked pavements. Field data collected from in-service JCPs located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called Volumetric Surface Texture (VST) testing. VST results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. Three performance parameters capable of mechanistically characterizing crack performance were discussed. A relatively simple procedure was described for determining these parameters and evaluating crack condition. Field data were also used to demonstrate and validate a voids-analysis procedure.
Stijn Matthys - One of the best experts on this subject based on the ideXlab platform.
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Shear-stress transfer across a crack in steel fibre-reinforced concrete
Cement and Concrete Composites, 2017Co-Authors: Tim Soetens, Stijn MatthysAbstract:Abstract The ability of cracked reinforced concrete to transfer shear stresses is of major importance for concrete members designed to sustain high shear forces. Thereby, the maximum shear capacity is mainly affected by the Aggregate Interlock mechanism, the dowel action of longitudinal reinforcement, the restraining action of stressed reinforcement crossing the crack interface and the possible presence of stirrups. In case of steel fibre reinforced concrete (SFRC), where fibres are used to replace either completely or partially traditional stirrups, research has proven that the direct shear transfer capacity of cracked concrete is increased significantly by using fibres. By means of 69 direct shear tests, the shear-friction behaviour of SFRC with or without confining pressure has been studied further and existing empirical formulations have been checked. Since these models only provide a maximum shear strength, a more fundamental approach to model the direct shear behaviour of cracked SFRC is proposed in this paper. This model deals with the fibre-matrix interaction by means of fibre pull-out and Aggregate Interlock, as a function of the shear crack opening behaviour (i.e. combined opening and slipping).
Erol Tutumluer - One of the best experts on this subject based on the ideXlab platform.
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bender elements successfully quantified stiffness enhancement provided by geogrid Aggregate Interlock
Transportation Research Record, 2017Co-Authors: Yong-hoon Byun, Erol TutumluerAbstract:Lateral restraint is a primary mechanism of geogrid base reinforcement contributing to the performance improvement of flexible pavements, and the Interlocking between the geogrid and Aggregate is responsible for stiffness enhancement in a zone formed around the geogrid. A novel application of bender elements is introduced: as shear wave transducers for quantifying local stiffness increase in the vicinity of a geogrid. Several triaxial test specimens of a dense-graded granite-type Aggregate were prepared at two moisture contents for resilient modulus testing. Reinforced specimens also included a punched and drawn geogrid piece placed at specimen midheight. Two pairs of bender elements installed on the membrane at two heights enabled measurement of shear waves horizontally across the specimen. Shear wave velocities and axial resilient strains were recorded under the applied stress states. The test results show that the resilient modulus of the reinforced specimen was similar to that of the unreinforced one ...
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Bender Elements Successfully Quantified Stiffness Enhancement Provided by Geogrid–Aggregate Interlock
Transportation Research Record: Journal of the Transportation Research Board, 2017Co-Authors: Yong-hoon Byun, Erol TutumluerAbstract:Lateral restraint is a primary mechanism of geogrid base reinforcement contributing to the performance improvement of flexible pavements, and the Interlocking between the geogrid and Aggregate is responsible for stiffness enhancement in a zone formed around the geogrid. A novel application of bender elements is introduced: as shear wave transducers for quantifying local stiffness increase in the vicinity of a geogrid. Several triaxial test specimens of a dense-graded granite-type Aggregate were prepared at two moisture contents for resilient modulus testing. Reinforced specimens also included a punched and drawn geogrid piece placed at specimen midheight. Two pairs of bender elements installed on the membrane at two heights enabled measurement of shear waves horizontally across the specimen. Shear wave velocities and axial resilient strains were recorded under the applied stress states. The test results show that the resilient modulus of the reinforced specimen was similar to that of the unreinforced one ...
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geogrid Aggregate Interlock mechanism investigated through Aggregate imaging based discrete element modeling approach
International Journal of Geomechanics, 2012Co-Authors: Erol Tutumluer, Hai Huang, Xuecheng BianAbstract:Geogrids are commonly used in road construction for stabilization and reinforcement purposes. Factors affecting the interaction or Interlock mechanisms between geogrids and Aggregates may include, but are not limited to, Aggregate size and shape and geogrid types and properties. To better quantify these effects, an Aggregate image aided discrete element method (DEM) modeling approach is introduced in this paper. DEM simulations of laboratory direct shear tests carried out on both unreinforced and geogrid-reinforced Aggregate shear box samples indicate that the Aggregate imaging aided DEM can accurately predict both unreinforced and geogrid-reinforced Aggregate strength properties. The use of geogrids increased the shear strength of the Aggregate assembly by constraining the movement of the Aggregates in the shear zone, which is often referred to as the geogrid’s stiffening effect in this Aggregate-geogrid composite system. Preliminary findings on the effects of geogrids with various opening shapes and geometries on the mechanical Interlock are also presented to demonstrate the effectiveness of the Aggregate image aided DEM model and its potential for quantifying the individual effects of geogrid aperture size and shape relative to Aggregate size and shape, gradation, and density, as well as the shape and stiffness of the ribs and the stiffness of the junction between the ribs of various geogrid products.
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geogrid base reinforcement with Aggregate Interlock and modeling of associated stiffness enhancement in mechanistic pavement analysis
Transportation Research Record, 2009Co-Authors: Jayhyun Kwon, Erol TutumluerAbstract:The main mechanism by which geogrids reinforce unbound Aggregate base and subbase layers of flexible pavements is the geogrid Aggregate Interlock. Geogrids prevent Aggregate material from moving laterally under applied wheel loading; this enhances local strengthening and stiffness in the base layer. This higher stiffness zone essentially benefits the geogrid's pavement response by better bridging over the weak subgrade soil and transmitting reduced critical stresses and strains on top of subgrade. The University of Illinois developed a mechanistic model for the analysis of geogrid reinforced flexible pavements based on the finite element approach. This approach was used to model successfully the development of a stiffer layer associated with Aggregate Interlock around the geogrid reinforcement by considering compaction-induced residual stresses as the initial condition in the mechanistic analysis. The predicted critical pavement responses matched with the measured values from full-scale pavement test stud...
Tim Soetens - One of the best experts on this subject based on the ideXlab platform.
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Shear-stress transfer across a crack in steel fibre-reinforced concrete
Cement and Concrete Composites, 2017Co-Authors: Tim Soetens, Stijn MatthysAbstract:Abstract The ability of cracked reinforced concrete to transfer shear stresses is of major importance for concrete members designed to sustain high shear forces. Thereby, the maximum shear capacity is mainly affected by the Aggregate Interlock mechanism, the dowel action of longitudinal reinforcement, the restraining action of stressed reinforcement crossing the crack interface and the possible presence of stirrups. In case of steel fibre reinforced concrete (SFRC), where fibres are used to replace either completely or partially traditional stirrups, research has proven that the direct shear transfer capacity of cracked concrete is increased significantly by using fibres. By means of 69 direct shear tests, the shear-friction behaviour of SFRC with or without confining pressure has been studied further and existing empirical formulations have been checked. Since these models only provide a maximum shear strength, a more fundamental approach to model the direct shear behaviour of cracked SFRC is proposed in this paper. This model deals with the fibre-matrix interaction by means of fibre pull-out and Aggregate Interlock, as a function of the shear crack opening behaviour (i.e. combined opening and slipping).
Michael A. Frabizzio - One of the best experts on this subject based on the ideXlab platform.
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Impact of Coarse Aggregates on Transverse Crack Performance in Jointed Concrete Pavements
Aci Materials Journal, 2000Co-Authors: Neeraj Buch, Michael A. Frabizzio, Jacob E. HillerAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements (JCPs). Maintaining adequate Aggregate Interlock load transfer across these cracks is essential for preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the effects of Aggregate type, size, and blending on the performance of transverse cracking in jointed concrete pavements. Field data collected from inservice JCPs located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture (VST) testing. VST results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. A parallel laboratory study was conducted to study the impact of Aggregate size and blending on transverse crack performance. Three performance parameters capable of mechanistically characterizing crack performance are discussed. A relatively simple procedure was described for determining these parameters and evaluating crack condition.
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Impact of Coarse Aggregates on Transverse Crack Performance in Jointed Concrete Pavements
Aci Materials Journal, 2000Co-Authors: Neeraj Buch, Michael A. Frabizzio, Jacob E. HillerAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements (JCPs). Maintaining adequate Aggregate Interlock load transfer across these cracks is essential for preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the effects of Aggregate type, size, and blending on the performance of transverse cracking in jointed concrete pavements. Field data collected from inservice JCPs located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture (VST) testing. VST results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. A parallel laboratory study was conducted to study the impact of Aggregate size and blending on transverse crack performance. Three performance parameters capable of mechanistically characterizing crack performance are discussed. A relatively simple procedure was described for determining these parameters and evaluating crack condition.
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Performance of Transverse Cracking in Jointed Concrete Pavements
Journal of Performance of Constructed Facilities, 1999Co-Authors: Michael A. Frabizzio, Neeraj BuchAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements. Maintaining adequate Aggregate Interlock load transfer across these cracks is essential to preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the design parameters that significantly affect transverse cracking and to demonstrate methods available for evaluating cracked pavements. Field data collected from in-service jointed concrete pavements located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called volumetric surface texture testing. Volumetric surface texture results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. Three performance parameters capable of mechanistically characterizing crack performance were discussed. A relatively simple procedure was described for determining these parameters and evaluating crack conditions. Field data were also used to demonstrate and validate a voids' analysis procedure. This procedure estimates the potential for loss of support near cracks and joints, thus allowing for proper rehabilitation actions to be taken prior to the manifestation of additional distresses.
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Investigation of design parameters affecting transverse cracking in jointed concrete pavements
Transportation Research Record, 1999Co-Authors: Michael A. Frabizzio, Neeraj BuchAbstract:Environmental effects and repetitive traffic applications can lead to the development of transverse cracks in jointed concrete pavements (JCPs). Maintaining adequate Aggregate Interlock load transfer across these cracks is essential to preserving the functional and structural integrity of these pavements. The objectives of this study were to determine the design parameters that significantly affect transverse cracking and to demonstrate methods available for evaluating cracked pavements. Field data collected from in-service JCPs located throughout southern Michigan were used to accomplish these objectives. Joint spacing, coarse Aggregate type, shoulder type, and pavement temperature were found to have significant effects on transverse crack development and/or performance. The surface texture of crack faces was assessed using a promising new test method called Volumetric Surface Texture (VST) testing. VST results provided an indication of the Aggregate Interlock potential of pavements containing various Aggregate types. Three performance parameters capable of mechanistically characterizing crack performance were discussed. A relatively simple procedure was described for determining these parameters and evaluating crack condition. Field data were also used to demonstrate and validate a voids-analysis procedure.
