Influence of thermal activation of natural pozzolan on the mechanical behavior of cement pastes

Abstract

This experimental work focused on the thermal activation of natural pozzolan (NP) from the town of Beni-Saf, in order to improveits reactivity. The present study consists of using natural pozzolan as partial replacement of ordinary Portland cement, with 10 to 40% by weight of cement. Various curing temperatures were used to assess the influence of thermal treatment on the mechanical properties of the pozzolan pastes. For this purpose, three curing modes were chosen, namely the normal curing at the temperature T = (20 ± 2) °C, taken as a reference, the curing at 40 °C, and another one at 60 °C. The experimental results obtained showed that the 40% natural pozzolan paste, which was stored at 40 °C, exhibited much better strengths than those of ordinary cement (CEM I), which was kept at room temperature. This finding leads us to consider that the replacement rate of 40% of NP, stored at the temperature of 40 °C, constitutes the best conditions for preparing an efficient eco-material. Natural pozzolan pastes thermally treated at 60°C gives better mechanical strengths with larger amounts of natural pozzolan.

Keywords

• natural pozzolan
• curing temperature
• mechanical strength
• thermal activation