生石灰-碳酸钠掺量和矿渣活性对碱矿渣砂浆抗裂性能的影响

Effects of Quicklime-Sodium Carbonate Content and Slag Activity on Cracking Resistance of Alkali-activated Slag Mortar

采用生石灰和碳酸钠(物质的量比1∶1)为激发剂制备碱矿渣砂浆,分别研究生石灰-碳酸钠掺量(即Na_(2)O掺量,为2.5%、4.5%、6.5%和8.5%)和矿渣活性(取决于化学成分和细度等)对碱矿渣砂浆劈裂抗拉强度、内钢环应变、环向拉应力和抗裂性能的影响。研究发现:普通硅酸盐水泥砂浆的抗裂性能优于碱矿渣砂浆;随着Na_(2)O掺量的增加,碱矿渣砂浆劈裂抗拉强度及抗裂性能先提升后降低,当Na_(2)O掺量为6.5%时,抗裂性能最优;随着矿渣活性的增加,碱矿渣砂浆劈裂抗拉强度增大,但其抗裂性能降低。

Alkali-activated slag mortar was prepared using quicklime and sodium carbonate(the molar ratio of 1∶1) as activators. The effect of quicklime and sodium carbonate content(namely Na_(2)O content, 2.5%, 4.5%, 6.5% and 8.5%) and slag activity(depending on the chemical composition and fineness, etc.) on the splitting tensile strength, strain of interior steel ring, circumferential tensile stress and cracking resistance of alkali-activated slag mortars(AM) was investigated. It is found that the cracking resistance of Portland cement mortars is better than that of AM;with the increase of Na_(2)O content, the splitting tensile strength and cracking resistance increase firstly and then decrease. When the Na_(2)O content is 6.5%, the cracking resistance is the best;with the increase of slag activity, the splitting tensile strength of AM increases, but its cracking resistance decreases.