快硬复合硫铝酸盐水泥用聚羧酸减水剂的制备与性能研究

Preparation and properties of polycarboxylic acid water reducer for rapid hardening composite sulphoaluminate cement

以聚醚大单体(HPEG)和丙烯酸(AA)为主要原料,通过改变酸醚比和滴加方式,合成一种适用于快硬复合硫铝酸盐水泥(R·SAC)的聚羧酸减水剂(PCE-1),研究了合成工艺参数和聚醚分子质量对减水剂性能的影响。结果表明,合成PCE-1的最佳工艺参数为:HPEG的分子质量为3200,酸醚比为7,将20%的AA加入底料中,n(催化剂)∶n(H_(2)O_(2))∶n(Vc)∶n(巯基乙醇)=1.0∶0.9∶0.15∶0.6;在饱和掺量下,掺PCE-1的R·SAC42.5和P·O42.5水泥净浆的初始流动度最为接近并达到最大;PCE-1对R·SAC水泥的分散性和分散保持性均优于市售普通型聚羧酸减水剂PCE-2;与空白水泥相比,掺0.4%(折固)PCE-1、PCE-2与PCE-3复配减水剂的R·SAC42.5水泥,初凝和终凝时间分别延长了42、35 min和41、36 min。

Using polyether macromonomer(HPEG)and acrylic acid(AA)as main raw materials,a polycarboxylic acid water reducer(PCE-1)suitable for rapid hardening composite sulphoaluminate cement(R·SAC)was synthesized by changing the acid ether ratio and dropping mode of AA.The effects of synthesis parameters and molecular weight of polyether on the properties of water reducer were studied.The results showed that the optimal process parameters are as follows:molecular weight of TPEG was 3200,the ratio of acid to ether was 7,and add 20%AA into the primer,and n(Cat)∶n(H_(2)O_(2))∶n(Vc)∶n(C2H6OS)=1.0∶0.9∶0.15∶0.6.Under saturated content,the initial fluidity of R·SAC42.5 doped with PCE-1 is the closest with P·O42.5 cement slurry and reaches the maximum.The dispersion and dispersion retention of PCE-1 to R·SAC cement are better than those of commercially available ordinary commercial Polycarboxylic acid water reducer PCE-2.Compared with blank cement,when the converted solid content of PCE-1,PCE-2 and PCE-3 is 0.4%,the initial setting time and final setting time of R·SAC42.5 cement with composite of PCE-1 and PCE-3,and composite of PCE-2 and PCE-3 were extended 42,35 min and 41,36 min,respectively.