摘要
针对久马高速一标预制梁混凝土中蒸养时间久、胶凝材料用量高的技术难题,本文通过向混凝土中加入纳米水化硅酸钙尝试缩短蒸养时间及降低胶凝材料用量。混凝土坍落度、扩展度、凝结时间及力学性能测试后表明,纳米水化硅酸钙对混凝土初始工作性能无明显影响,损失较基准稍快,但仍可满足浇筑要求。纳米水化硅酸钙可缩短混凝土初凝时间3h以上,终凝时间2h以上。加入纳米水化硅酸钙后50℃蒸养24h或标养48h混凝土抗压强度均明显高于基准蒸养48h,可缩短至少50%的蒸养时间或在标养条件下实现免蒸养。另外,纳米水化硅酸钙对梁外观无影响,且至少可降低配合比中14kg水泥用量,可明显节约原材料及能耗成本。
In view of the steam curing time was long and the amount of cementing material was high in precast beam concrete of first segment at Jiuma high speed road,nano hydrated calcium silicate was added to the concrete in an attempt to shorten the steam curing time and reduce the amount of cementing material.The results of slump,expansion,setting time and mechanical properties of concrete showed that nano hydrated calcium silicate had no obvious effect on the initial performance of concrete,and the loss was a little faster than that of the reference concrete,but it can still meet the requirements of pouring.Nano-calcium silicate can shorten the initial setting time of concrete by more than 3h and the final setting time by more than 2h.The compressive strength of concrete with nano hydrated calcium silicate after steam curing at 50℃ for 24h or standard curing for 48h was higher than that of the reference concrete after standard curing for 48h,which proved that nano hydrated calcium silicate can shorten the steam curing time by at least 50% or realize no steam curing under standard curing condition.In addition,nano-calcium silicate hydrate had no effect on the appearance of the beam,and can reduce the dosage of 14kg cement in the mixing ratio at least,which can obviously save the cost of raw materials and energy consumption.
出处
《科技风》
2022年第16期76-78,145,共4页
关键词
纳米水化硅酸钙
预制构件
蒸养混凝土
缩短蒸养时间
降低胶材用量
Nano hydrated calcium silicate
prefabricated part
steam-curing concrete
shortening steam-curing time
reducing cementitious material consumption
