Experimental testing and modelling of roller compacted concrete incorporating RAP waste as aggregates

Abstract

In recent years, recycling reclaimed asphalt pavement (RAP) has been growing to resolve the waste storage problem and to limit usage of natural resources. One possible recycling technique is cold reuse of RAP as an alternative aggregate in manufacturing roller compacted concrete (RCC) which is an innovative technique for sustainable pavements. The objectives of this study are twofold. Firstly, the effects of substitution of natural aggregates by RAP on RCC mechanical properties (modulus of elasticity, splitting-tensile strength and compressive strength) are tested experimentally. Then, several existing compressive strength models (Bolomey, Tango, and de Larrard models), initially developed for ordinary Portland cement concrete, were tested to evaluate their relevance to the case of this particular concrete. Mechanical laboratory tests results carried on six designed RCC mixes showed that the RCC properties decrease as RAP content increases. Besides, compressive strength modelling results showed that the tested models are all relevant, to different degrees, for the case of the studied mixtures. de Larrard model which accounts for the adhesion quality between aggregate and cement matrix showed that this region is negatively affected by RAP presence. This finding can explain the observed decrease in the mechanical characteristics.