地铁盾构管片混凝土用高性能聚羧酸减水剂的合成研究

Synthesize research on high-performance polycarboxylate superplasticizer for the subway shield tunnel segment concrete

采用丙烯酸、异丁烯醇聚氧乙烯醚(HPEG)、丙烯酰氧乙基三甲基氯化铵(DAC),通过自由基溶液聚合合成了地铁盾构管片混凝土用高性能聚羧酸减水剂。研究了不同分子质量大单体、酸醚比、DAC用量等因素对减水剂性能的影响。结果表明,当采用HPEG(Mn=4000),酸醚比为3.0∶1.0,DAC用量为大单体质量的1.3%时,合成的高性能聚羧酸减水剂应用于地铁盾构管片混凝土,具有初凝时间短、触变性好、粘聚性好。

High-performance polycarboxylate supe^lasticizer for the subway shield tunnel segment concrete was synthesized with acrylic acid,Polyoxyethylene（HPEG）,and acryloyl Oxyethyl trimethyl ammonium chloride（DAC）. It was synthesized by free rad- ical solution polymerization. The effect of different molecular mass macromonomer, acid/ether mole ratio,and DAC dosage on the properties of superplasticizer was resarched. The results showed that when HPEG molecular weight was 4000,acid/ether mole ratio was 3.0/1.0, DAC dosage was 1.3% of HPEG, syntheiic polycarboxylate was applied to the subway shield tunnel segment concrete, which had advantages of short initial setting time, good thixotropy, good cohesiveness, high strength and so on.