C40低温升抗裂大体积混凝土设计制备及其性能研究
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摘要
针对普通C40大体积混凝土胶凝材料用量高、绝热温升大和易收缩开裂等问题,提出采用高掺粉煤灰+矿粉复合矿物掺合料,复配超分散减缩外加剂+水化温升抑制剂等措施,制备出的C40低温升抗裂大体积混凝土7 d绝热温升仅为31.87℃,60 d自收缩和干燥收缩为227×10~(-6)、241×10~(-6),抗裂等级达到L-V。研究成果已成功应用于白洋长江公路大桥主塔承台和锚碇,在取消通冷却水管情况下,混凝土未产生有害温度裂缝和收缩裂缝。
Aimed at solving the problem of cementitious material consumption,the adiabatic temperature rise and larger shrinkage cracking of ordinary C40 large mass concrete,by using high content of fly ash and slag as composite mineral admixtures and mixture of ultra dispersed admixture and temperature rise inhibitor,C40 mass concrete with 7 d adiabatic temperature rise of only 31.87 ℃,autogenous shrinkage of 227×10~(-6) and drying shrinkage of 241×10~(-6),and anti-cracking grade of L-V is prepared.The result has been successfully applied to in cushion cap and anchorage spread foundation of Bai Yang Yangtze River Highway Bridge.In case of cancellation of cooling water pipes,no harmful temperature cracks and shrinkage cracks are found.
Aimed at solving the problem of cementitious material consumption,the adiabatic temperature rise and larger shrinkage cracking of ordinary C40 large mass concrete,by using high content of fly ash and slag as composite mineral admixtures and mixture of ultra dispersed admixture and temperature rise inhibitor,C40 mass concrete with 7 d adiabatic temperature rise of only 31.87 ℃,autogenous shrinkage of 227×10~(-6) and drying shrinkage of 241×10~(-6),and anti-cracking grade of L-V is prepared.The result has been successfully applied to in cushion cap and anchorage spread foundation of Bai Yang Yangtze River Highway Bridge.In case of cancellation of cooling water pipes,no harmful temperature cracks and shrinkage cracks are found.
引文
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[3]丁庆军,黄修林,王红喜,等.采用密实骨架堆积法设计高掺量II级粉煤灰高性能混凝土[J].混凝土,2007(8):7-10.
[4]韦昊奇,林海燕,王玉江,等.水泥增效剂对普通硅酸盐水泥性能的影响[J].硅酸盐通报,2014(8):1920-1923.
[5]孔祥明,卢子臣,张朝阳.水泥水化机理及聚合物外加剂对水泥水化影响的研究进展[J].硅酸盐学报,2017,45(2):274-281.
[2]吕寅.低温升抗裂大体积混凝土研究与应用[D].武汉:武汉理工大学,2012.
[3]丁庆军,黄修林,王红喜,等.采用密实骨架堆积法设计高掺量II级粉煤灰高性能混凝土[J].混凝土,2007(8):7-10.
[4]韦昊奇,林海燕,王玉江,等.水泥增效剂对普通硅酸盐水泥性能的影响[J].硅酸盐通报,2014(8):1920-1923.
[5]孔祥明,卢子臣,张朝阳.水泥水化机理及聚合物外加剂对水泥水化影响的研究进展[J].硅酸盐学报,2017,45(2):274-281.