Study of the hydration of Portland cement pastes containing ceramic waste by thermal analysis

Abstract

In this paper, the influence of the use of waste from the ceramic industry (calcined clay brick) on the hydration products of Portland cement pastes. The content of chemically bound water was determined using thermo-gravimetric analysis (TG) and differential thermal analysis (DTA). Five cement pastes were used, including the reference paste and four cement pastes containing 10% to 40% of calcined clay brick as cement replacement, in mass. The water/cement ratio was kept constant and equal to 0.40. The TG and DTG curves were obtained from hydrated cement pastes after 28 days of curing at 21±1 oC. The results indicate a reduction in the content of water chemically combined due to calcium hydroxide with the increase of cement replacement by calcined clay brick. An increase in the content of chemically combined water was observed, corresponding to all hydration products for the cement paste containing 10% of calcined clay brick in the mixture.