Predicting the Performance of Semi-Rigid Pavement with Partial Replacement of RAP in RCC and Designed Using a Mechanistic-Empirical Method

This research has the objective of the evaluating physical and mechanical properties of roller compacted concrete (RCC) with reclaimed asphalt pavement (RAP) to apply it to pavement base layer. In addition, the ideal percentage of RAP in the RCC was evaluated using the response surface methodology (RSM) considering the effects of pavement design variables: thickness of asphalt concrete layer, mechanical properties of the base layer and traffic volume in order to reduce the effects of cracked area and rutting of semi-rigid pavements. Four RCC mixtures were produced with different RAP incorporated ratios (0%, 5%, 15%, and 20%). The compaction test, compressive strength, splitting tensile strength, flexural tensile strength, elasticity modulus, porosity, density, and water absorption tests were performed to analyze the physical and mechanical properties of the RCC mixtures. Analysis of variance (ANOVA) one-way was used to identify the influences of RAP on RCC's mechanical properties. The sections of semi-rigid pavements were designed using the new Brazilian mechanistic-empirical method (MeDiNa). 33 factorial statistical analysis was performed with 3 different factor levels for statistical analysis of design. Laboratory results showed that mechanical properties of hardened RCC mixtures decreased with increasing RAP content. However, partial replacement of the coarse aggregate with lower content RAP (up to 20%) in RCC caused not large strength reduction of the mixtures when compared to the control mixture. From RSM, it was possible to observe that the adopted thickness asphalt concrete layer value is directly related to the cracked area values at the end of the project period and that increasing of RCC-base layer thickness may significantly reduce rutting and extend the fatigue life of RCC-base composite pavement. Besides that, it was observed that rutting is not as much a problem as fatigue cracking on RCC-base composite pavements. It was concluded that 15% RAP replacement for natural coarse aggregates in RCC mixture is the ideal percentage to reduce damages.