不同外加剂对地质聚合物凝结硬化性能的影响

Effect of Different Admixtures on the Setting and Hardening Properties of Geopolymer

采用复合溶液作为碱激发剂的矿渣粉基地质聚合物通常具有凝结时间快、和易性较低等缺点。为改善地质聚合物的和易性并有效延长凝结时间,测试了12种外加剂对地质聚合物凝结硬化性能的影响。通过维卡仪试验及水泥与减水剂相容性试验,对掺有不同外加剂的地质聚合物净浆进行凝结时间与经时流动度损失测定,选取效果最佳的外加剂;通过配制不同掺量该外加剂的净浆和胶砂测定了地质聚合物的凝结时间、经时流动度损失和抗压强度,研究不同掺量该外加剂对于地质聚合物的影响。研究结果表明,硼酸的缓凝效果最为明显,在0~4.0%掺量范围内,地质聚合物的凝结时间随硼酸掺量提高而大幅度延长,经时流动度损失减小,抗压强度略微提高。

The slag based geopolymer activated by complex alkali activator usually has the disadvantages of fast setting and low workability.In order to improve the workability and prolong the setting time,12 different admixtures were tested to investigate their effects on the setting and hardening properties of geopolymer.Through Vicat apparatus test and compatibility test of cement and water reducing agent,the setting time and flowability of geopolymer paste with different admixtures were carried out,and the best admixture was selected;through preparing the paste and mortar with different content of this admixture,the setting time,loss of flowability and compressive strength of geopolymer were tested to investigate the influence of different content of admixture on geopolymer.The results show that the boric acid achieved the best performance.In the range of 0~4.0%,with the increase of boric acid content,the setting time of geopolymer increases,the loss of flowability decreases and the compressive strength of the specimens slightly increases.