Evaluation of Mechanical Hardened Properties of Mortar Using Carbon-Free Fly Ash and Normal Fly Ash

Usage of mineral admixture and chemical admixture in concrete or mortar is a usual solution to reach full compaction, particularly where reinforcement blockage and lack of skilled labour happen. In this paper effect of mineral admixtures (Carbon-free fly ash, hereafter CfFA, and nFA) on hardened properties of mortar such as compressive strength, Pore size distribution and, and micro structures have been investigated. As a result, it has been confirmed that mortar containing 15% CfFA slightly increased the compressive strength under water curing condition compared to those containing 15% normal fly ash. In addition, the pore-size distribution of the mortar has been affected by variation of materials and curing condition. Mortar containing 30% CfFA had a smaller threshold diameter in comparison to that of 30% FA; however, there is no significance differences in mortar containing 15% CfFA and FA. Furthermore, CfFA-based mortar increased the amount of entrained air compared to the mortar with normal fly ash.