Experimental Study on the Physical and Mechanical Properties of Modified Ultra-fine Cement Slurry
Aiming at the shortcomings of superfine cement slurry,the water extraction rate,fluidity,initial and final setting time,uniaxial com-pressive strength and expansion rate of modified superfine cement slurry were studied by adding different contents of expansion agent UEA,nano water reducing agent FDN-C and triisopropanolamine accelerating agent TIPA.The results show that with the addition of water reducer FDN-C increasing from 0 to 0.8 g,the minimum water extraction rate of modified superfine cement slurry is 17ml,which is 37.04%lower than that of pure superfine cement slurry,and the fluidity decreases from 234 mm to 183 mm.The initial setting time of(U30F0.4T4.0)ratio is the shortest,and the initial setting time is 506 min,which is 33.68%faster than that of pure ultrafine cement slurry.The peak 3 d com-pressive strength of the U30F0.8T4.0 ratio is 10.46 MPa,and the peak 28 d compressive strength of the U30F0.8T1.2 ratio is 8.1 MPa,and the strength of each age is not less than 2.5 MPa,which meets the engineering requirements.When the expansion agent UEA content is 10%,the expansion rate of the test block is the largest,and the expansion rate of the 3~28 d test block is 0.803%~0.956%higher than that of the pure ultra-fine cement test block.The research results can provide some reference for special grouting reinforcement and water sealing pro-jects.