Influence of saturated activated carbon on the rheological and mechanical properties of cementitious materials

This work proposes a new investigation, which deals with the potentiality of the reuse of saturated activated carbon (SAC), as an additive into cementitious materials. According to recent studies, the addition of a small amount of activated carbon can considerably increase the adsorption of harmful gases; which limits environmental pollution. However, taking into consideration the high porosity of activated carbon, which gives a large specific area, this solution may present certain disadvantages in the rheological and mechanical behavior. Therefore, eight mixtures (four pastes and four mortars) were prepared with different percentages of activated carbon waste (0.5%, 1%, 2% and 4%), then they were compared with the reference mixture. The fluidity and the setting time were measured for the pastes. Whereas, rheological parameters, compressive strength and microstructure were studied for each mortar. The experimental results have shown that if the percentage of substitution is less than 2%, the SAC can be used as an organic additive in the cementitious materials without affecting the fluidity and the mechanical strength. However, when the amount of SAC is more than 2%, the viscosity and yield stress of the mortars increase. (C) 2018 Elsevier Ltd. All rights reserved.