Ảnh hưởng của phụ gia xỉ theo công nghệ nghiền riêng từng cấu tử đến tính chất của xi măng poóc lăng xỉ lò cao bền sun phát

Abstract

The experimenting had fabricated the sulfate resisting cement samples with separate crushing technology for each constituent including Fico cement clinker, Thai gypsum and Japanese slag. The Japanese slag percentage surveyed in the cement blending mix was 0, 20, 30, 40, 50, 60 and 70 % of the total cement blending mix. The study results of properties of sulfate resisting cement samples were obtained: The higher the slag additives content, the lower the normal consistency in the cement samples (from 26.6 - 27.2 %) compared to the cement sample without slag additives (27.4 %). The initial setting time increases gradually in about 85 - 150 minutes and final setting time increases gradually in about 105 - 195 minutes when the content of substitute slag for cement of cement samples increases gradually from 0 - 70 %. Cement samples with increasing slag content in the range of 40 – 70 % had increased compressive strength (from 21.3 - 25.5 MPa), sulfate expansion and autoclave expansion were stable. Cement samples with low slag content of 20 – 30 % achieved compressive strength of 18.5 - 20.4 MPa which was smaller than sample B0 (20.6 MPa for the sample without slag additive), sulfate expansion was increased and thus the sulfate resisting of the cement samples was reduced.