Abstract
•The amalgamation of 2.5–10 wt% mPbO into AAS mortars increased the workability.•The amalgamation of 2.5–10 wt% mPbO increased mechanical-strength, 7.5% was the optimal.•The amalgamation of 2.5–10 wt% mPbO improved transport properties, 7.5% was the optimal.•The amalgamation of 2.5–10 wt% mPbO increased accelerated-aging resistance, 7.5% was the optimal.
This is the first attempt to investigate the effect of micro-sized lead oxide (mPbO) on the properties of alkali-activated slag (AAS) mortars. Various ratios of mPbO ranging from 2.5 wt% to 10 wt% were added to the neat AAS mortar specimens. The variation in the workability, mechanical strength development, transport properties and accelerated aging resistance were investigated. The available advanced devices were used to analyze the results. The results indicated a positive effect of mPbO on the flowability of the mixtures. The addition of mPbO increased the mechanical strength and the resistance of accelerated aging, where 7.5% was the optimal. A higher ratio of mPbO than 7.5% (i.e 10%) did not show additional improvement, but an adverse effect was observed compared to that of 7.5% mPbO. The transport properties and accelerated aging resistance were improved with the addition of 2.5–7.5% mPbO, but slightly worsen with the addition of 10% mPbO compared to that of 7.5% mPbO. The microstructure was improved and refined with the addition of suitable ratios of mPbO.