高吸水性树脂对自密实混凝土性能的影响

Influence of SAP on the Properties of Self-compacting Concrete

高吸水性树脂（SAP）具有很强的吸水性能,但是失水后形成SAP孔,使其在混凝土中呈现出与其它外加剂不同的特性。系统研究了SAP内养护水胶比及粒径对自密实混凝土（SCC）抗压强度、早期自收缩、干缩、吸水性、抗碳化能力、抗氯离子渗透性的影响。结果表明：当内养护水胶比增加时,SCC早期自收缩明显降低,且抗压强度未出现明显变化;虽然混凝土吸水性增加,但抗碳化性能和抗氯离子渗透性提高,而干缩与内养护水胶比有关。粒径为75～125μm的SAP改善自收缩、干缩效果较好,而粒径为30～75μm时SAP的抗碳化性能和抗氯离子渗透性提高较好。

Super absorbent polymer（SAP）has high water absorption but some large pores are formed after SAP releases water,so that the concrete adding SAP takes on some different features of the properties with the concretes adding other admixture.Influence of SAP on the fresh properties,compressive strength,early-age autogenous shrinkage,drying shrinkage,water absorption,carbonation and chloride-ion penetration of self-compacting concrete（SCC）were studied.The results show that with increasing internal curing water/binder ratio,the autogenous shrinkage of SCC significantly decreased,compressive strength were almost not affected on;water absorption increased but carbonation resistance and resistance to chloride ion permeability improved;the drying shrinkage was related to the water-binder ratio.75-125μm SAP improved autogenous and dry shrinkages well,while 30-75μm has evident effectiveness on the resistance to chloride ion permeability and carbonization.