Preparation and properties of α-type high strength gypsum grouting materials
The gypsum-based grouting material was prepared using self-made α-type high strength gypsum as the main raw material by the desulfurization gypsum hydrothermal method,supplemented with a small amount of cement,fly ash,and additives.The effects of different raw material ratios and the dosages of water reducer,water repellent,and foaming agent on the strength,water resistance,shrinkage,and microstructure of the gyp-sum-based grouting material were studied.The results showed that with the increase of fly ash,water reducer,water repellent,and foaming agent dosages,the strength of the gypsum-based grouting material first increased and then decreased,while water resistance and shrinkage resistance improved.When the mass percentages of gypsum,fly ash,cement,sand,and other raw materials were 37％,10％,3％and 50％,respectively,with a wa-ter reducer dosage of 0.5％,water repellent dosage of 0.4％,and foaming agent dosage of 0.02％,the pre-pared grouting material had an initial flow of 308 mm,a flow of 248 mm at 30 minutes,an initial setting time of 170 minutes,a compressive strength of 50.2 MPa at 28 days,a softening coefficient of 0.66,a vertical expan-sion rate of 3.36％at 3 hours,and almost no change in the difference between the vertical expansion rates at 24 hours and 3 hours.
grouting materialα-type high strength gypsumcompressive strengthvertical expansion rate
万方数据
维普
