RESEARCH ON HYDRATION HEAT OF SILICATE CEMENT UNDER THE ACTION OF PHOSPHOALUMINATES

摘要

The compressive strength and the exothermic rate and exothermic capacity of hydration process of silicate cement mixed different amount of phosphoaluminate clinker were researched. The results showed that the compressive strength of all ages for the composite cement was higher than that of silicate cement when the mass fraction of phosphoaluminate clinker in composite cement was 3%. When the mass fraction of phosphoaluminate clinker increased to 6% and 10%,the compressive strength of all ages for the composite cement was lower than that of silicate cement. There were different hydration processes and the mutual effects of hydration products for silicate clinker and phosphoaluminate clinker. The suitable amount (3%) of phosphoaluminate clinker in the composite cement might break the original balance and accelerate the hydrating reactions of C3S、 C2S because of the rapid hydration of phosphoaluminates. When the amount of phosphoaluminate clinker increased (such as 6% and 10%),the dense hydration products of phosphoaluminates might wrap up the particles of silicate clinker and prevent the silicate particles from further hydration. So the second induction period of the composite cement hydration went on for a long time,which led to a slow hydration and a low early strength for the composite cement.