Effects of dolomite powder on the properties of C30 and C50 concretes

Abstract

This study focused on the effects of dolomite powder on the properties of C30 and C50 concretes. The microstructure, splitting tensile strength, compressive strength and fracture toughness property of concretes incorporating dolomite powder were measured by mercury intrusion porosimetry (MIP), pressure testing machine and universal testing machine. Higher splitting tensile strength, compressive strength and fracture toughness of concretes could be seen with the increase of dolomite powder dosage within 90 days. After 1 day of curing, splitting tensile strength, compressive strength and fracture toughness of C30 and C50 concretes could be improved considerably. The positive effects of dolomite powder on the splitting tensile strength, compressive strength and fracture toughness decreased with the increase of curing age. Because the nucleation effect, micro-filler effect and mix proportions design of dolomite powder were beneficial to the refinement of pore structure of concretes, and dolomite powder had less influence on the later stage of cement hydration. The splitting tensile strength equations expressed in terms of the compressive strength was proposed. The analysis of regression equation proved that the equation of relationship between compressive strength and splitting tensile strength of concretes containing dolomite powder in this study had high prediction accuracy.