Interaction of polycarboxylate-based superplasticizers with cements containing different C3A amounts
Interaction of polycarboxylate-based superplasticizers with cements containing different C3A amounts
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DOI：
10.1016/j.cemconcomp.2009.01.005
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发表时间：
2009-03
影响因子：
10.5
通讯作者：
A. Zingg;F. Winnefeld;L. Holzer;J. Pakusch;S. Becker;R. Figi;L. Gauckler
中科院分区：
文献类型：
--
作者：
A. Zingg;F. Winnefeld;L. Holzer;J. Pakusch;S. Becker;R. Figi;L. Gauckler
这种参数研究链接的羧酸盐型高效减水剂的分子结构与它们的性能在水泥浆体中具有不同的C3A含量。除了C3A含量的变化之外，实验合成的超增塑剂还通过聚氧化乙烯侧链密度和长度而变化。研究了高效减水剂与水泥浆体和易性、缓凝现象的关系以及水泥浆体中C_3A含量对减水剂性能的影响。通过量热、流变、吸附和zeta电位测量，研究了不同PCE结构和不同C3A含量之间的特征相互作用现象。这项研究表明，随着侧链密度的降低，PCE分子吸附更强，从而通过空间稳定降低水泥浆体的屈服应力。它还表明，PCE分子与长侧链延迟水泥浆的设置到更少的延伸比PCE分子与较短的侧链。因此，就分子结构的优化而言，通过添加具有长侧链的高电荷PCE可以实现良好的可加工性。后者使不希望的阻滞现象最小化。
This parametric study links the molecular structure of a carboxylate-type of superplasticizer with their performance in cement pastes with different C3A-contents. Beside the variation of the C3A-content, the experimental synthesized superplasticizers have been varied by polyethylene-oxide side chain density and length. The connection between the superplasticizers, their effect on workability properties and retardation phenomenon and the dependency of C3A-content in the cement paste has been investigated. The characteristic interaction phenomenons between different PCE-architectures and different C3A-contents have been examined by calorimetric, rheological, adsorption, and zeta potential measurements. This study shows that with decreasing side chain density the PCE molecules adsorb stronger and thus, lower the yield stress of a cement paste by steric stabilization. It is also shown that PCE molecules with long side chains delaying the setting of the cement paste to less extend than PCE molecules with shorter side chains. Consequently, in terms of optimization of the molecular architecture, good workability can be achieved by addition of highly charged PCE with long side chains. The latter minimizes undesired retardation phenomena.