Experimental investigation on gas permeability characteristics and durability aspects of concrete with construction joint

Construction joint is a weak point for reinforced concrete structure because the interface at construction joint does not behavior as strongly as simultaneously placed concrete matrix. The property of construction joint is critical for infrastructures if the structures need to prevent leakage of hazardous substances or require longer service life. However, the knowledge gap on the performance of construction joint, especially on the evaluation of gas permeability and durability aspects of concrete, still exists. This study was designed to address this knowledge gap by performing experimental investigation on mechanical property, gas permeability, chloride ion penetration, and carbonation of concrete with construction joint. Microstructural observation around the construction joint was performed, and the effect of gauze used to reinforce construction joint was evaluated. According to experimental results, the presence of construction joint decreased the split tensile strength of the concrete. The effect of construction joint on compressive strength and elastic modulus was unclear, but all failures of concrete with construction joints occurred through the interface at construction joint, indicating that splitting stress was generated under compression and split tension. As expected, the gas permeability of concrete with a construction joint was higher than that of concrete without one. Depths of chloride penetration and carbonation were higher through the construction joint than through the concrete matrix. It was found that the presence of gauze did not provide any positive effects on properties of concrete with construction joint.