Gravel aggregates had been used extensively in the Houston District of Texas Department of Transportation (TxDOT) for continuously reinforced concrete pavements construction for many years. However, some of these pavements have been subject to early age delamination and eventual spalling damage. Therefore, a series of studies funded by TxDOT since the early 1990's has been conducted to gain a better understanding of mechanisms, material properties, and construction practices, and to provide guidelines and recommendations for minimizing early-age delamination in concrete pavements made with gravel aggregates. In this study, a test protocol to measure the bond strength between aggregates and cement mortar was established, and the effects of different material and construction parameters on the bond strength of concrete at early ages using a fractional factorial design were investigated. The significances of each factor to achieve better bonding performance were determined, and the optimum design combination was subsequently chosen and validated. Geometric parameters were proposed to characterize aggregate shape properties relative to bonding performance with the facilitation of the Aggregate Imaging System. A rating system based on utility theory was developed to evaluate the overall contribution of aggregate properties (i.e. physical, geometric, and chemical) to the concrete bonding capability and the feasibility of certain mixture design combinations. As for theoretical representation of the bond strength across the interfacial transition zone, a model of interfacial fracture energy between aggregate and mortar that represents the energy necessary to create a crack along the interface was formulated. This model built the connection between concrete properties at the meso-level (represented by the interfacial fracture energy between aggregate and mortar) and the macro-level (represented by fracture toughness of concrete and significant influencing materials and construction factors). In addition, the moisture effects on stress development of concrete pavements at early ages using field data as inputs were numerically simulated, and a fracture mechanics-based approach was used to predict the occurrence of delamination. A delamination detection protocol for the field was developed to explore the feasibility and potential of utilizing Ground Penetration Radar technology in delamination detection. Research findings from laboratory investigation, field testing, theoretical modeling, and numerical analysis were further validated through field test sections, and the associated framework for delamination guidelines was established.

Gravel aggregates had been used extensively in the Houston District of Texas Department of Transportation (TxDOT) for continuously reinforced concrete pavements construction for many years. However, some of these pavements have been subject to early age delamination and eventual spalling damage. Therefore, a series of studies funded by TxDOT since the early 1990's has been conducted to gain a better understanding of mechanisms, material properties, and construction practices, and to provide guidelines and recommendations for minimizing early-age delamination in concrete pavements made with gravel aggregates. In this study, a test protocol to measure the bond strength between aggregates and cement mortar was established, and the effects of different material and construction parameters on the bond strength of concrete at early ages using a fractional factorial design were investigated. The significances of each factor to achieve better bonding performance were determined, and the optimum design combination was subsequently chosen and validated. Geometric parameters were proposed to characterize aggregate shape properties relative to bonding performance with the facilitation of the Aggregate Imaging System. A rating system based on utility theory was developed to evaluate the overall contribution of aggregate properties (i.e. physical, geometric, and chemical) to the concrete bonding capability and the feasibility of certain mixture design combinations. As for theoretical representation of the bond strength across the interfacial transition zone, a model of interfacial fracture energy between aggregate and mortar that represents the energy necessary to create a crack along the interface was formulated. This model built the connection between concrete properties at the meso-level (represented by the interfacial fracture energy between aggregate and mortar) and the macro-level (represented by fracture toughness of concrete and significant influencing materials and construction factors). In addition, the moisture effects on stress development of concrete pavements at early ages using field data as inputs were numerically simulated, and a fracture mechanics-based approach was used to predict the occurrence of delamination. A delamination detection protocol for the field was developed to explore the feasibility and potential of utilizing Ground Penetration Radar technology in delamination detection. Research findings from laboratory investigation, field testing, theoretical modeling, and numerical analysis were further validated through field test sections, and the associated framework for delamination guidelines was established.

Thesis (M.S.)--West Virginia University, 2002. / Title from document title page. Document formatted into pages; contains ix, 70 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 43-45).

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains vii, 65 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 52-53).

Thesis (M.S.)--West Virginia University, 2004. / Title from document title page. Document formatted into pages; contains ix, 57 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references (p. 40-42).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xiv, 146 p. : ill. (some col.), maps. Includes abstract. Includes bibliographical references (p. 107-109).

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains x, 98 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 62-63).

The concrete pavement industry is actively seeking new and innovative solutions to build more economical, more sustainable and more durable roads. Cupolex® is one innovative product that is being evaluated for use as a concrete pavement technology. This product consists of interlocking, modular, dome-shaped plastic units that serve as a permanent formwork within the concrete pavement structure. The resulting product is a concrete pavement slab with a system of interconnected vault-like voids below the surface. The dome shape is capable of providing carrying capacities equivalent to conventional slabs, but requires less concrete to do so, and also provides additional drainage and ventilation benefits. A collaborative research effort was undertaken to evaluate the feasibility of using Cupolex® in road and highway applications. As part of this study, a full-scale, instrumented trial section was designed and constructed to evaluate pavement performance in an accelerated loading scenario. This thesis presents this evaluation of the Cupolex® technology in a pavement application through the evaluation of numerous parameters during the pavement’s first year of service. Strain gauge data, pressure cell data, moisture probe data, Falling Weight Deflectometer testing results and visual condition surveys are all used to assess performance. The results obtained to date indicate that Cupolex® has great potential as a concrete pavement technology. The trial pavement sections are performing very well after one year of service, carrying heavily loaded aggregate trucks in the harsh Canadian climate. Over 1.3 million cumulative Equivalent Single Axle Loads (ESALs) have been applied to the pavement to date without any significant pavement degradation. The findings obtained also indicate that the Cupolex® technology can provide significant material and potential cost savings, when compared to conventional jointed plain concrete pavements.

The concrete pavement industry is actively seeking new and innovative solutions to build more economical, more sustainable and more durable roads. Cupolex® is one innovative product that is being evaluated for use as a concrete pavement technology. This product consists of interlocking, modular, dome-shaped plastic units that serve as a permanent formwork within the concrete pavement structure. The resulting product is a concrete pavement slab with a system of interconnected vault-like voids below the surface. The dome shape is capable of providing carrying capacities equivalent to conventional slabs, but requires less concrete to do so, and also provides additional drainage and ventilation benefits. A collaborative research effort was undertaken to evaluate the feasibility of using Cupolex® in road and highway applications. As part of this study, a full-scale, instrumented trial section was designed and constructed to evaluate pavement performance in an accelerated loading scenario. This thesis presents this evaluation of the Cupolex® technology in a pavement application through the evaluation of numerous parameters during the pavement’s first year of service. Strain gauge data, pressure cell data, moisture probe data, Falling Weight Deflectometer testing results and visual condition surveys are all used to assess performance. The results obtained to date indicate that Cupolex® has great potential as a concrete pavement technology. The trial pavement sections are performing very well after one year of service, carrying heavily loaded aggregate trucks in the harsh Canadian climate. Over 1.3 million cumulative Equivalent Single Axle Loads (ESALs) have been applied to the pavement to date without any significant pavement degradation. The findings obtained also indicate that the Cupolex® technology can provide significant material and potential cost savings, when compared to conventional jointed plain concrete pavements.

Thesis (M.S.)--Ohio State University, 1989. / Includes bibliographical references.