高吸水性树脂应用于混凝土养护的研究进展

Research development of super absorbent resin applied in the curing of concrete

自收缩已经成为配制高性能混凝土的一个重要考虑因素。自收缩引起的拉应力超过混凝土的抗拉强度时,混凝土就会产生裂缝,进而降低了混凝土的耐久性。Neville提出当混凝土的有效水胶比低于0.42时,必须从外界补充水分以避免其内部的自干燥,而高性能混凝土的水胶比远低于0.42,所以只有通过养护才能消除自收缩产生的不利变形。高吸水性树脂(SAP)是一种功能性高分子材料,具有很强的吸水特性,且吸水膨胀后生成的凝胶具有较好的保水性,可作为混凝土内养护剂。本文主要从SAP的合成方法,SAP作为内养护剂的作用机理,SAP对混凝土的力学性能、耐久性、收缩性能的影响进行综述。

Self-constriction has become a vital important phenomenon of preparing high performance concrete. When the tensile stress caused by self-constriction is beyond tensile strength of the concrete, cracks will be caused to bring down the durability. Neville proposed that effective W/C<0.42 is a sign to supple water from outsides in order to avoid self-desiccation inside of the concrete. Water-binder ratio of the high performance is lower than 0.42, then the curing is the essential method to remove the bad deformation caused by the self-constriction. Super absorbent polymer(SAP) is a functional polymer material which possesses the features of powerfully absorbing water, water retaining property, so it can be chosen as the curing agent of concrete. In this paper, synthetic methods of SAP, functional mechanism of SAP as the curing agent, and the impacts of SAP on the mechanical properties, durability and shrinkage performance of the concrete will be discusse.