Hydration of mineral shrinkage-compensating admixture for concrete: An experimental and numerical study

The use of shrinkage-compensating admixture in concrete has been proven to be an effective way to mitigate the shrinkage of concrete. The hydration of a shrinkage-compensating admixture in cement paste and concrete is investigated in this paper with numerical simulation and experimental study. An ettringite-based mineral shrinkage-compensating admixture (MSA) is developed taking use of industrial by-products. The MSA is designed with special considerations to the stoichiometry of ettringite formation, i.e. it should provide stable sources of sulfate and alumina which are necessary for the ettringite formation. Experimental results prove that the new MSA can successfully compensate the autogenous shrinkage of concrete.

► We developed an ettringite-based mineral shrinkage-compensating admixture.
► Stoichiometry of ettringite formation is the major consideration in the design.
► The use of this admixture can compensate the autogenous shrinkage of concrete.
► Microstructure of cement paste with this admixture is studied with XRD.
► The hydration of the admixture is simulated with computer model CEMHYD3D.