高吸水性树脂对碱激发矿渣收缩与开裂性能的影响

Influence of Super-absorbent Polymer on the Drying Shrinkage and Cracking of Alkali Activated Slag

碱激发矿渣收缩大、易开裂严重制约其工程应用。本研究基于高吸水性树脂(SAP)吸水-释水的性能特点,通过在碱激发矿渣加入适量SAP,研究了SAP对碱激发矿渣砂浆干燥收缩及干燥开裂行为的影响。研究结果表明:SAP通过释放吸收的水分降低砂浆硬化体毛细孔收缩压力,显著降低了碱激发矿渣砂浆的早期干燥收缩率;掺入的SAP失水后具有造孔功能,使得碱激发矿渣砂浆硬化体内大孔含量增多,降低毛细孔收缩压的同时缓解了毛细孔收缩应力,能有效降低碱激发矿渣砂浆的干燥收缩开裂风险。

The large shrinkage and cracking problems of alkali activated slag restrict its engineering application seriously.This study was based on the characteristics of water-absorbing and water-releasing properties of super-absorbent polymer(SAP).The effect of SAP on drying shrinkage and cracking behavior of alkali activated slag mortar was studied by adding proper amount of SAP in alkali activated slag.The results show that SAP can reduce capillary shrinkage pressure of hardened mortar by releasing and absorbing water,and decrease the early drying shrinkage rate of alkali activated slag mortar obviously.The addition of SAP has the function of making pores after dehydration,which makes the content of macro-pores in hardened mortar of alkali activated slag increase.This reduces the systolic pressure of the capillary and relieves the shrinkage stress of the capillary at the same time.It can reduce the risk of drying shrinkage cracking of alkali activated slag mortar effectively.