Horizontal Cracking in Continuously Reinforced Concrete Pavements

摘要

Horizontal cracking (HC) at the depth of longitudinal steel in CRCP was not known until 1999, when HC was observed in the section on IH 35 in the Waco District. At that time, no prior research was done on this topic and no reports published. Concerned about this type of cracking and its effect on the long-term performance of CRCP, TxDOT initiated this research study. The primary objective of this study was to identify the mechanism of HC in CRCP due to environmental loading (temperature and moisture variations). To this end, a numerical model was developed to predict the risk of HC in CRCP. Laboratory and field testing was also conducted to evaluate the actual behavior of concrete near longitudinal steel. The measured data was used to develop and validate a numerical model for the prediction of HC potential in CRCP. The mechanism of vertical stress development in concrete near longitudinal steel was investigated with a comprehensive numerical analysis. The results of the study indicate that pavement design, more specifically longitudinal steel design, concrete material properties such as coefficient thermal expansion (CoTE), modulus of elasticity, drying shrinkage and strength, and construction quality such as curing and temperature control, all have effects on HC development. Two-mat steel, lower values of CoTE and drying shrinkage and modulus, higher strength of concrete, good quality curing and temperature control will lower the potential for HC. Since there are almost an infinite number of combinations of design, materials and construction variables during the construction of CRCP, more general guidelines rather than prescriptive ones were developed.