Influence of low temperatures

Abstract

When strain-hardening cement-based composite (SHCC) with cracks is repeatedly exposed to freezing and thawing, accelerated deterioration of the SHCC, due to the expansion of water during freezing in the cracks, may be of major concern. This chapter summarises the results of studies on the frost damage of SHCC, in particular the frost damage of SHCC with cracks. In most cases described in the literature, the ASTM method C666A — Procedure A (2008) was applied. It has been found that even when cracking has occurred, SHCC has a high resistance with respect to frost damage. When the water-cement ratio is high enough, only a very slight decrease of the relative dynamic modulus of elasticity occurred, although a small amount of scaling was observed on the surface, regardless of the type of fibre or of the composition of the mortar matrix. In tests that simulated the case in which the concrete surface layer damaged by freeze-thaw cycles had been removed and the cross-section had then been repaired with SHCC, it was found that no deterioration of the repaired surface sections occurred due to freezing and thawing. The greater the depth to which the deteriorated concrete was removed, the less susceptible the repaired surfaces were to further freeze-thaw damage.