Papers by Author: Shou De Wang

Abstract: The effect of MgO on performance of belite-barium calcium sulphoaluminate cement (B-CBAS) was investigated through orthogonal tests. The results show that the formation of C₃S can be improved at low temperatures by mixing MgO. SO₃ decreasing the viscosity of fused mass in sintering process was beneficial to solid solution of MgO in B-CBAS clinker. The solid solubility of MgO in B-CBAS was higher than that of Portland cement, which indicated that high-magnesium limestone can be used in B-CBAS. Even MgO content reached 5.14%, the soundness of B-CBAS was still in safe, whose compressive strength at 3d and 28d curing age were 49.1MPa and 81.9MPa. This indicated that this kind of cement has good mechanical properties.

Abstract: Different amounts of shell and calcium carbonate were added into the Portland cement, their influences on the compressive strength, sulfate corrosion resistance, hydration heat and porosity of the hardened cement paste were studied. Results show that with the increasing of shell content, the compressive strength decreases, however, modest reduction; as the increase of calcium carbonate content, the strength first increases and then decreases, the compressive strength reaches the highest value when the content is 15%. After addition of shell and calcium carbonate, the initial hydration reaction rate accelerates, meanwhile the induction period and acceleration period are brought forward. With the raising of shell and calcium carbonate content, the corrosion resistance coefficient increases gradually, and the sulfate corrosion resistance increases as well. The proportion of the harmless hole which diameter is smaller than 50nm increases after adding the shell and calcium carbonate, it’s beneficial to improve the performance of concrete.

Abstract: Calcination condition and mechanical performance of alite-rich Portland cement with barium calcium sulphoaluminate mineral(C2.75B1.25A3S ) were investigated by the orthogonal test method in which the influencing factors included sintering temperature, sintering time and cooling method. The composition, structure and performance of the clinker were analyzed by the means of X-ray diffraction, scanning electron microscopy-energy dispersive spectroscopy and metallographic microscope. The results show that C2.75B1.25A3S mineral and alite can coexist in one clinker system. The introduction of C2.75B1.25A3S mineral to clinker system is benefit to promote the formation of alite at lower temperature. The optimal sintering temperature, sintering time and cooling method are 1380°C, 60 min and two-stage cooling, respectively. Under these processing conditions, the compressive strength of alite-rich Portland cement with barium calcium sulphoaluminate reaches 43.4, 80.6 and 123.8 MPa at 3d, 7d and 28d curing ages, respectively, which shows excellent performance of mechanical strength.