聚羧酸系高效减水剂与缓凝剂复合对水泥水化历程的影响试验研究

Experiment Research on the Compound of Polycarboxylate Superplasticizer and Retarter Influence on Cement Hydration Process

通过用聚羧酸系高效减水剂与三聚磷酸钠、硼砂、六偏磷酸钠、葡萄糖酸钠、柠檬酸、木钙、糖钙、蔗糖等8种缓凝剂复合,研究其复合后对水泥标准稠度净浆凝结时间的影响,以及与葡萄糖酸钠、三聚磷酸钠、木钙、糖钙等4种缓凝剂复合研究其复合后对水泥水化历程的影响。研究结果表明:与三聚磷酸钠、六偏磷酸钠、柠檬酸、糖钙、蔗糖复合使用对标准稠度水泥净浆有促凝作用,而与硼砂、葡萄糖酸钠、木钙复合使用却能显著延长标准稠度水泥净浆凝结时间。但是,当其与葡萄糖酸钠、三聚磷酸钠、木钙、糖钙复合使用时与单独使用聚羧酸系相比,却能推迟水化温峰出现时间,降低1 d、3 d水化热,而且糖钙还能降低温峰。在实际工程应用前应先进行水泥适应性、缓凝剂品种的选择以及掺量试验,以便更经济更有效地满足具体施工要求。

After compounding polycarboxylate superplasticizer with eight retarders （sodium tripolyphosphate, borax, sodium hexametapbosphate, gluconic acid sodium salt, citric acid, wooden-calcium, sugar calcium, sucrose, etc. ）, this paper stud- ies the compound＇ s influence on the condensation time of normal consistent cement paste, as well as the compound of poly- carboxylate superplasticizer and four retarders （gluconic acid sodium salt, sodium tripolyphosphate, wooden calcium and sug- ar calcium） influence on the cement hydration process. The research results show： The compound of polycarboxylate super- plasticizer with sodium tripolyphosphate, sodium hexametaphosphate, citric acid, sugar calcium and sucrose will promote the condensation of normal consistent cement paste; while the compound of polycarboxylate superplasticizer with borax, gluconic acid sodium salt and wooden-calcium can significantly lengthen the condensation time of normal consistent cement paste. However, comparing the compound of polycarboxylate superplasticizer together with gluconic acid sodium salt, sodium tri- polyphosphate, wooden-calcium and sugar calcium, and the single polycarboxylate superplasticizer, the former can postpone the temperature summit time of the hydration, and reduce the hydration heat of 1 d and 3 d. What＇ s more, the sugar calcium can reduce temperature summit as well. Before real construction, the experiments on cement adaptability, the choice of re- tarders, and its amount should be carried out to meet the construction requirements more effectively and economically.