Fatigue performance of rubber-modified recycled aggregate concrete (RRAC) for pavement

•Rubber-modified recycled aggregate concrete with 3 different rubber contents was tested.•The best mix ratio of rubber content was provided.•Addition of recycled aggregate and rubber enhanced fatigue life of concrete.•Fatigue life equation of rubber-modified recycled aggregate concrete was presented.

Based on the performance requirements for airport pavement concrete, this study analyzes the mechanical properties, fatigue properties and damage characteristics of rubber-modified recycled aggregate concrete (RRAC) with waste rubber replacement rates of 10%, 20% and 30%. The test results for compressive strength, four-point flexural bending, elasticity modulus and fatigue life on RRAC showed that the compressive strength of recycled aggregate concrete (RAC) increased by 10.1% from that of normal concrete (NC) (rubber-free and recycled-aggregate-free concrete). The compressive strength, flexural strength and elasticity modulus of the RRAC decreased with the increase in rubber particle content. However, the peak deflection, peak strain and ultimate strain increased with the increase of rubber particle content with a certain range. When rubber particle content reached 20% of the sand, the ultimate strain of RRAC was 3.45 times that of rubber-free RAC. Based on the Weibull theory, statistical analysis was performed on the test results, and double logarithm fatigue equations for RRAC under different failure probabilities were provided, which could be used to predict the ultimate fatigue strength of RRAC. An analysis of the damage characteristics showed that both recycled aggregate and rubber particle could enhance the concrete’s fatigue life. This enhancement was most significant when the rubber particle content reached 20%.