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Development of new superplasticizer made of comb-like polymer for high-performance concrete

高性能混凝土用新型梳状聚合物高效减水剂的研制

基本信息

批准号：
10650553
负责人：
NAWA Toyoharu
金额：
$ 2.24万
依托单位：
HOKKAIDO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

项目摘要

The purpose of this study is to develop new superplasticizer for high-performance concrete such as high-strength concrete and self-compacting concrete. We have applied the comb-like copolymer having graft chain made of polyethylene oxide to newly developed superplasticizer. In this study, we investigated the effect of several factors such as kinds of cement, temperature and mixing condition on the fluidity of cement paste in order to optimize the chemical structure of comb-like copolymer. Moreover, the properties of fresh concrete were also examined in order to verify the results of paste test.The most important findings are summarized as follows;(1) The effect of chemical structure of copolymer on the fluidity of paste depended markedly on the kind of main polymer. In case of maleic anhydride based copolymer, the better the fluidity was, the shorter the length of polyethylene oxide chains became. In the opposite, in case of methacrylic based copolymer, the better the fluidity was, the … More longer the length of polyethylene oxide chains became.(2) The delay of the hydration decreased with an increase in the length of polyoxyethylene graft chain, an the degree of the delay was different depending on the kind of the main chain polymer. In case of maleic anhydride based copolymer, the hydration of alite (3CaO・SiOィイD22ィエD2) in cement inhibited remarkably when the length of polyoxyethylene graft chains was short. On the other hand, in case of methacrylic based copolymer, the hydration of alite was not inhibited significantly, regardless of the length of polyoxyethylene graft chains.(3) The fluidity of cement paste containing comb-like polymer, of which main chain makes of the methacrylic acid, was not affected easily by the kinds of cement used, temperature and mixing condition.(4) Fresh concrete indicated the same tendency of the cement paste; the longer the length of graft chains became, the better were the flowability, segregation resistance, passing ability and self-compactability of concrete.From the results in this study, we conclude that the comb-like methacrylic copolymer with a long graft chain has the best efficient chemical structure in terms of both fluidity and strength development. Thus it is possible that we can produce easily the high performance concrete by using the comb-like methacrylic copolymer with a long graft chain even when the kinds of the cement used, temperature and mixing conditions are varied. Less

本研究旨在为高强混凝土、自密实混凝土等高性能混凝土开发新型高效减水剂。将聚环氧乙烷接枝链的梳状共聚物应用于新开发的高效减水剂。为了优化梳状共聚物的化学结构，本研究考察了水泥种类、温度、搅拌条件等因素对水泥浆体流动性的影响。此外，为了验证浆体试验的结果，还对新拌混凝土的性能进行了检验。最重要的发现如下：(1)共聚物的化学结构对浆体流动性的影响明显取决于主要聚合物的种类。对于马来酸酐类共聚物，流动性越好，聚氧化乙烯链长越短。相反，在甲基丙烯酸基共聚物的情况下，流动性越好，…水化延迟随聚氧乙烯接枝链长的增加而减小，延迟程度因主链聚合物的种类不同而不同。当聚氧乙烯接枝链长较短时，马来酸酐接枝共聚物对阿利特(3CaO·SiOィイD22ィエD2)在水泥中的水化有明显的抑制作用。(3)以甲基丙烯酸为主链的梳状聚合物水泥浆体的流动性不易受水泥种类、温度和搅拌条件的影响。(4)新拌混凝土表现出与水泥浆体相同的趋势；接枝链长越长，混凝土的流动性、抗离析能力、通过能力和自密实性能越好。研究结果表明，接枝链长的梳状甲基丙烯酸共聚物在流动性和强度发展方面都具有最好的有效化学结构。因此，即使在不同的水泥种类、温度和搅拌条件下，使用长接枝链的梳状甲基丙烯酸酯共聚物也可以很容易地生产出高性能混凝土。较少