On the elastic modulus of rock-filled concrete

Rock-filled concrete (RFC) is constructed by placing large rocks into the prescribed formwork then pouring self-compacting concrete (SCC) to fill interstitial voids. The prelaid rock skeleton transfers forces and provides a certain degree of stiffness at the beginning of the hardening process, which makes the elastic modulus evolution of RFC different from that of conventional concrete. This study aims to reveal the elastic modulus evolution of RFC at early ages, bridging the gaps of RFC research in the numerical computational field. Firstly, RFC is modeled using a mesoscopic finite element approach in which prelaid rocks, SCC, and interfacial transition zone are represented explicitly. This model is validated by onsite full-scale test results. Secondly, the hardening process of RFC is simulated using the validated model, and a qualitative evolution function is obtained. Finally, the advanced Dual Eigenstrain method is employed and calibrated based on the simulation results to predict the elastic modulus of RFC at any curing age.