A Study on Early Age Shrinkage Behaviour of Cement Paste with Binary and Ternary Combination of Fly Ash and Pond Ash

Abstract

Objectives: To investigate the early age shrinkage behavior of cement, when it is partially replaced with fly ash and pond ash individually and simultaneously by volume. Methods: Fifteen mixes were prepared by replacing ordinary portland cement with fly ash and pond ash up to 80 percentage by volume individually as well as combined. ShrinkageCone is used for early shrinkage measurement of above fifteen mixes and suitable combinations are proposed for local conditions. Findings: A comparative statement is prepared for reduction of shrinkage when cement is replaced with fly ash and pond ash individually and simultaneously. The shrinkage meter used in present study gives shrinkage in micron which gives more accurate result than other shrinkage meter used in previous research. Also ACI 209 model is modified to include supplementary cementitious materials. An equation is proposed which has given satisfactory results with partial replacement of cement with fly ash and pond ash. Applications/Improvements: Generally shrinkage of concrete depends upon temperature and humidity. Due to high rate of shrinkage, cracks develop on the surface of the structure and reduce its durability. Shrinkage strain reduces by replacement of cement with both fly ash and pond ash individually and simultaneously. Hence the binary or ternary combination of cement concrete with supplementary cementitious materials may be beneficial for construction of structure in hot humid region. Keywords: ACI 209 Model, Fly ash, Pond ash, Replacement Material, Shrinkage-Cone