Mechanical performance of strain-hardening cementitious composites incorporating reclaimed asphalt pavement and its application in bridge approach link slabs

To improve the utilization rate of reclaimed asphalt pavement (RAP) and also enhance the mechanical properties of ECC. RAP was finely grinding into small pieces with fine sand to fully replace the expensive silica sand in ECC, RAP-ECC was prepared. In this study, uniaxial tensile, compressive, and four-point bending tests were conducted on RAP-ECC with different RAP replacement ratios (0%-100%). The compressive strength of RAP-60% was 25% higher than that of RAP-0%; and at a RAP replacement ratio of 50%, the flexural strength of the RAP-ECC thin plates was 4.5 MPa higher than that of RAP-0%. Through a five-dimensional performance evaluation, RAP-50% was determined to be the optimal mix proportion. Then a RAP-ECC bridge approach link slab for jointless bridge approach connections was designed and fabricated, and the longitudinal tensile and vertical compression tests was carried out. The results showed that the RAP-ECC bridge approach ink slab exhibited typical multiple cracking characteristics under temperature-drop loading, with fine and uniformly distributed cracks, and a maximum crack width not exceeding 65 μm. Meanwhile, for the RAP-ECC bridge approach link slab subjected to slight cracking under vertical loading, both the vertical load-bearing capacity and rebound deflection still met pavement performance requirements.