Laboratory Investigation of Influencing Factors on Early-Age Delamination in CRC Pavements

Abstract

Studies since the early 1990s have been conducted in Texas to gain a better understanding of mechanisms, material properties, and construction practices related to early-age delamination in continuously reinforced concrete pavements made with gravel aggregates. However, information was still needed on: (1) the individual and overall effects of aggregate and nonaggregate factors on the early-age delamination; and (2) how the interfacial transition zone (ITZ) affects the early-age bond strength in terms of these factors. In this research, the effects of key material and construction factors including aggregate type, water-cementitious ratio, ultrafine fly ash content, and curing method were investigated through laboratory studies. A rating system based on utility theory was proposed to represent the overall aggregate effect through proper weighted contribution of its individual physical, geometric, and chemical characteristics. The investigation of possible corrective measures to minimize early-age delamination was conducted and results were presented. Petrographic analysis through selective ITZ investigation was undertaken to verify laboratory research findings.