Early-age strain and temperature measurements in concrete tank walls

Abstract

Synopsis The paper reports measurements of temperatures induced by heat of hydration in 12 reinforced concrete walls during construction. In-plane movements at early age are also given for one of the walls in which 27 vibrating wire strain gauges were installed. In-plane strains are deduced and estimates made of the restraint to free in-plane movement of the concrete. The concept of a restraint,factor is already applied in design for crack control. Restraint to free movement us cooling of the new concrete takes place, is provided externally by previously cast elements such as a all foundation, combined with internal effects, which arise from the fact that peak temperatures vary considerably between different parts of the wall itself. The experimental strain results are compared with the results of a finite element analysis in which base and wall panel are treated as an integral structural unit. Comparisons are also made with codes of practice and other guidance documents.