Strengthening of a Reinforced Concrete Bridge with Polyurethane-cement Composite (PUC)

Abstract

This paper describes a new material, polyurethane-cement composite (PUC), used to strengthen a 29-year-old reinforced T-beam bridge in Harbin, China. Polyurethane-cement composite (PUC) is mixed with polyurethane raw material and cement. This technique is completed by pouring Polyurethane-cement composite (PUC) into the template. Ultimate bearing capacity of the bridge after reinforcement was discussed based on the concrete structure theory. The flexural strength of reinforced concrete T-beam bridges strengthened with Polyurethane-cement composite (PUC) was controlled by the design flexural strength of Polyurethane-cement composite (PUC). The main construction process was introduced which included concrete surface treatment, installing template and pouring. To investigate the feasibility of the strengthening method, load tests were conducted before and after strengthening. The results of concrete strain and deflection show that the capacity of the repaired bridge, including the bending strength and stiffness, is enhanced. The crack width measurement also indicates that this technique could increase the durability of the bridge. Thus, this strengthened technique with polyurethane-cement composite (PUC) is feasible, the bridge load posting possibly is removed through this technique.