INFLUENCE OF MOLECULAR WEIGHT OF LONG SIDE-CHAIN OF POLYCARBOXYLIC ACID TYPE WATER-REDUCER ON EARLY-AGE CRACKING BEHAVIOR OF MORTARS
Several polycarboxylic acid type water-reducing agents (KHs) with different molecularweight of the long side-chain were synthesized. Effect of KHs on the setting time, chemicalshrinkage, strength and initial cracking time of the cement-based material has been researched.The results show that retarding effect on the setting time weakens, inhibition on hydration ofcement mineral reduces, the chemical shrinkage increases and the strength developmentaccelerates with the increasing of molecular weight of the long side-chain of KHs. Comparingwith molecular weight of the long side-chain of 2000, the KH with the 400 molecular weightof the long side-chain can prolong initial setting time by 1.5 h and the final setting time by 2-3h, reduce the 12 h chemical shrinkage of 50％, and prolong the initial cracking time by 35 h.Adjusting the molecular weight of the long side-chain can reduce the cracking sensitivity ofcement-based material. With increasing the molecular weight of the long side-chain of the KH,the cracking sensitivity increases and the maximum crack width becomes wider.
polycarhoxylic acid type water-reducing agent long side-chain cracking sensitivity maximum crack width hydration degree
Baoguo Ma Hongbo Tan Liang Li Man Zhang
Key Laboratory for Silicate Materials Science Engineering of Ministry of Education,Wuhaa University of Technology,Wuhan 430070,Hubei,the P.R.China
国际会议
南京
英文
953-958
2008-10-13（万方平台首次上网日期，不代表论文的发表时间）