A Fundamental Study on the Improvement of External Loading Crack Strength of the Chemically Prestressed Concrete Pipe by Mould Restraint Controlled Method.

Abstract

In the process of application of high-early strength type expansive admixture to chemically prestressed concrete pipes, the technology of improving the external loading crack strength has been developed. This technology is based on the mould restraint controlled method by mounting springs on the clamping bolts for the circumference direction mould. The expansive energy of expansive concrete in steam curing process can be utilized for introducing chemical prestress effectivelly by releasing the restraint of mould due to actuation of springs. In this paper, the mould restraint controlled method for the circumference direction mould are reported.