ABSTRACT
Concrete members are normally subjected to service load stresses and deformations. Even in the plastic stage, which is very short, the concrete shrinks and induces cracking. To mitigate the impact of shrinkage in concrete, Shrinkage Reducing Admixtures (SRA) and supplementary cementitious materials can be used in concrete. But the effect of SRA on the plastic period of concrete is not well defined, so there is a need for study in this area. Supplementary Cementitious Materials (SCM) are commonly used in concrete due to their unrivalled pozzolanic behavior. The performance of SCM on early age shrinkage properties of concrete is still miscellaneous. This is achieved by measuring the slump, compressive strength and plastic shrinkage cracks of concrete mixes. ASTM C1579 mould is used for the study of plastic shrinkage concrete. The concrete mixes were studied by combining the optimum dosage of SRA. The optimum percentage of SRA used is 2%. Concrete mixes were analyzed at varying contents of 20%, 25% and 30% fly ash. This paper quantifies the combined effectiveness of fly ash and SRA on cracking of plastic concrete. Also, the usage of SCM’s and reduction of repairs due to cracks will open a door to make sustainable construction practices.
