负10℃条件下缓凝剂对快硬硫铝酸盐水泥水化及强度的影响  

Effect of Retarder on Hydration and Strength of Rapid-hardening Calcium Sulphoaluminate Cement at -10 ℃

作　　者：王敬宇 叶家元 程华 史迪 任俊儒 张文生 WANG Jingyu;YE Jiayuan;CHENG Hua;SHI Di;REN Junru;ZHANG Wensheng(The State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,China;Department of Military Facilities,Army Logistics University of PLA,Chongqing 401331,China)

机构地区：[1]中国建筑材料科学研究总院有限公司,绿色建筑材料国家重点实验室,北京100024 [2]陆军勤务学院军事设施系,重庆401311

出　　处：《硅酸盐学报》2020年第8期1285-1294,共10页Journal of The Chinese Ceramic Society

基　　金：军队后勤科研计划开放项目(BLJ18C014)资助;国家自然科学基金项目(51572252)资助。

摘　　要：研究了-10℃环境中氯化钙溶液拌合冷物料条件下,硼砂、葡萄糖酸钠、L(+)-酒石酸对快硬硫铝酸盐水泥凝结硬化行为、强度发展的影响,分析了缓凝剂对水化产物的影响。结果表明:-10℃条件下采用氯化钙溶液拌合时,0.6%掺量硼砂可使初凝时间延长至25 min、终凝时间延长至28 min,而葡萄糖酸钠和L(+)-酒石酸对初终凝时间影响不显著。随着硼砂、葡萄糖酸钠掺量的增加,不同龄期强度均逐渐下降,28 d最大降低值可达到25.5 MPa;L(+)-酒石酸会使得强度下降得更为明显,0.3%(质量分数)掺量时便会使得1 d抗压强度下降10.9 MPa,0.6%掺量时28 d抗压强度下降27.3 MPa。掺0.6%硼砂的1 d试样中钙矾石的形貌未发生明显变化,但生成量减少5.31%;葡萄糖酸钠使钙矾石呈短柱状,生成量几乎不变;L(+)-酒石酸使得钙矾石呈针状,生成量无明显变化。-10℃条件下硼砂可显著延长快硬硫铝酸盐水泥的凝结时间,且适当掺量时强度损失可接受,是适宜的缓凝剂;葡萄糖酸钠、L(+)-酒石酸的缓凝效果不明显,且会改变钙矾石的形态与分布,并会使强度显著下降。The effects of borax, sodium gluconate and L(+)-tartaric acid on the hardening behavior and strength development of rapid-hardening calcium sulphoaluminate cement mixed with calcium chloride solution at -10 ℃ were investigated. The results show that the initial and final setting time of rapid-hardening calcium sulphoaluminate cement mixed with calcium chloride solution prolonge to 25 min and 28 min with 0.6% borax at -10 ℃, respectively. However, the setting time of pastes with sodium gluconate or L(+)-tartaric acid does not extremely change. The strength gradually decreases in the samples with increasing the dosages of borax and sodium gluconate at different ages. A maximum reduction of 25.5 MPa occurs in those samples. The strength of samples containing L(+)-tartaric acid sharply decreases. A reduction of 10.9 MPa in 3-day samples containing 0.3% tartaric acid and 27.3 MPa in 28-day samples containing 0.6% tartaric acid occur. The presence of 0.6% borax does not change the morphology of ettringite at 1 d, but decreases the amount of ettringite by 5.31%. A short column-like ettringite in the samples with sodium gluconate and a needle-shaped-like ettringite in the samples with L(+)-tartaric acid are detected, respectively. However, the amount of ettringite in those two samples above has no remarkable change. Borax is a suitable retarder for calcium sulphoaluminate cement at -10 ℃ because of the feasibility of setting prolongation and the acceptable strength reduction. Sodium gluconate and L(+)-tartaric acid have a slight effect on the setting time but change the ettringite morphology and deteriorate the strength.

关 键 词：快速硬化 硫铝酸盐水泥 缓凝剂 水化 强度 

分 类 号：TU528[建筑科学—建筑技术科学]