Shrinkage Behavior and Residual Stress Development in Mortar Containing Shrinkage Reducing Admixtures (SRAs)

This paper outlines the results of a research study which was intended to better document how commercially available shrinkage reducing admixtures (SRA) influence the early-age shrinkage and residual stresses that develop when shrinkage is prevented. The paper will describe surface tension measurements of water SRA solutions for a commercially available SRA to quantify how SRAs can be used to alter the surface tension of a pore solution. Length change measurements were performed to measure the autogenous length change of setting mortar, and free shrinkage was measured after 24 hours for sealed and drying mortar. The effect of shrinkage, mechanical property development, elastic stress, and relaxation are discussed.