Hardened property changes due to the pumping process of self-consolidating concrete

Abstract

Pumping of self-consolidating concrete (SCC) is a vital construction technique. Curiosities are aroused by the effect of this intense physical process on the hardened properties of SCC. To examine this issue, a total of seven SCC mixtures are pumped at constant flow rates in pipelines with lengths of 324, 600, and 912 m. Parameters related to the hydration stages, air-void system, compressive strength, elastic modulus, and shrinkage at early ages are tested on specimens made of concrete before and after pumping. Results of tested samples find that the spacing factor grows, but the specific surface lessens after pumping. Also, in most cases, the compressive strength and elastic modulus decrease due to the pumping. The variations of these two factors are linearly related to the pumping distance in most cases. Additionally, the variations in the early age of shrinkage cracking show a dependency on the concrete compositions, temperature, and pumping characteristics.