矿渣-粉煤灰基地聚物干燥收缩试验研究

Drying Shrinkage Experimental Study of Slag-fly Ash Based Geopolymer

为研究矿渣-粉煤灰基地聚物的干燥收缩特性,以矿渣和粉煤灰为原材料,开展了矿渣掺量比、硅酸钠与氢氧化钠溶液比,及收缩添加剂对地聚物砂浆强度和干燥收缩的影响。试验结果显示:地聚物的干燥收缩在前14 d能完成极限收缩的80%,后期发展较慢;矿渣掺量越少和溶液质量比越大,干燥收缩变形越大;适量的聚丙二醇和MgO可减小干燥收缩变形;粉煤灰与矿渣掺量为1∶1,硅酸钠与氢氧化钠溶液质量比为2.5时,制备地聚物的28 d抗压强度可达55 MPa,干燥收缩应变在1 250με。

To study the drying shrinkage characteristics of slag-fly ash based geopolymer, using the slag and fly ash as raw materials, the impacts of slag proportion, sodium silicate to sodium hydroxide solution ratio,and shrinkage additives on the strength and drying shrinkage of geopolymer mortar were tested. The result showed that the drying shrinkage of geopolymer completed 80% of the ultimate shrinkage in the first 14 days,and developed slowly in the later stage. The less the slag content, the larger the solution mass ratio and drying shrinkage deformation. Proper content of PPG and Mg O could reduce the drying shrinkage deformation. When the fly ash to slag ratio was 1 and the sodium silicate to sodium hydroxide solution ratio was 2.5, the compressive strength of the prepared geopolymer on the 28thday could reach 55 MPa, and the drying shrinkage strain was 1 250 με.