Relation between the molecular structure and the efficiency of superabsorbent polymers (SAP) as concrete admixture to mitigate autogenous shrinkage
Relation between the molecular structure and the efficiency of superabsorbent polymers (SAP) as concrete admixture to mitigate autogenous shrinkage
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DOI：
10.1016/j.cemconres.2012.03.011
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发表时间：
2012-06-01
影响因子：
11.4
通讯作者：
Gorges, Michaela
中科院分区：
文献类型：
--
作者：
Schroefl, Christof;Mechtcherine, Viktor;Gorges, Michaela
研究了高吸水性聚合物(SAP)作为外加剂对高强混凝土自收缩的抑制作用。与其他生理盐水和蒸馏水相比，碱性溶液中钙离子的存在改变了液体吸收和释放的动力学。具有高密度阴离子官能团的SAP迅速吸收水泥孔溶液，但随后又大量释放。交联度对这类SAP的行为没有明显影响。阴离子基团密度较低的SAP在实验时间内不释放液体。在水泥水化的加速期，所有保水剂都抵消了自收缩。对于释放吸附气孔溶液的材料，除初始阶段外，对自收缩没有影响。在液体实验中没有释放吸收溶液的SAP材料在减速期间继续缓解自收缩。内养护对砂浆的抗压强度没有负面影响。(C)2012爱思唯尔有限公司。保留所有权利。
Superabsorbent polymers (SAP) were studied as admixtures for mitigating the autogenous shrinkage of a high-strength concrete. The presence of Ca2+ ions in the alkaline solution modified the kinetics of the liquid uptake and release when compared to that in other saline solutions and distilled water. SAP with high density of anionic functional groups took up the cement pore solution quickly, but greatly released it subsequently. The cross-linking density had no pronounced influence on the behaviour of such SAP. SAP with lower density of anionic groups did not release the liquid over the time of experiment. All SAP counteracted autogenous shrinkage during the acceleration period of cement hydration. For the materials which released the absorbed pore solution no effect on autogenous shrinkage was found beyond the initial period. SAP materials which did not release the absorbed solution in the experiments with liquids continued the mitigation of autogenous shrinkage during the deceleration period. The internal curing had no negative effect on the compressive strength of the mortar. (C) 2012 Elsevier Ltd. All rights reserved.