Interface Bonding Behavior of Ordinary Concrete Reinforced with Lightweight High-Strength Engineered Cementitious Composite

A novel type of lightweight high-strength engineered cementitious composite (LHECC) is developed by incorporating ecological lightweight sand fines and fly ash cenospheres to reinforce ordinary concrete. Slant shear resistance and bending resistance tests were conducted to evaluate the impact of surface roughness and concrete strength grade on the interface bonding properties between LHECC and ordinary concrete. The results indicate that LHECC can lead to the remarkable volume stability of LHECC-ordinary concrete by internal fiber bridging and favorable interface bonding. The increase of interface roughness had little effect on the initial crack strength but increased the ultimate bending strength and the ultimate mid-span displacement. This study is expected to provide the data support for the maintenance and reinforcement application of LHECC to high-rise buildings, long-span bridges, and marine engineering structures.