Experimental Study on the Impermeability of Concrete Construction Joints with Different Geometric Shapes

Abstract

Concrete construction joints are widely used in underground structures. The structure's impermeability is generally considered as its weak point. In this paper, influence of geometric shape and contact slurry on the impermeability of construction joints has been researched by a model test. Three joint types, including flat joints, arc joints and trapezoid joints, were constructed and tested. The tested construction joints were cast by half individually with a determined time interval to simulate the practical construction process. Each joint type has twelve samples, divided averagely into two groups, one of which was smeared by slurry on the contacts and the other was not. Test result shows that the structural type of construction joints has a great influence on the impermeability of samples. Trapezoid joints have the best impermeability, arc joints take the second place and flat joints are the worst. The contact slurry has a considerable unfavorable effect on the impermeability of construction joints.