摘要
养护温度与混凝土抗压强度的发展密切相关,季节性温差变化通常会影响混凝土配合比的可行性,导致混凝土的28 d龄期强度验收不合格。本文通过设定5个平均养护温度,研究其对10组不同配合比混凝土强度的影响,得出不同配合比混凝土的最佳养护温度以及不同温度下混凝土的最佳配合比。结果表明:当养护温度低于15℃、单掺粉煤灰时,混凝土的7 d和28 d强度相比基准组,均随着粉煤灰掺量的增加而下降,混凝土的60 d强度则随着粉煤灰掺量的增加而递增;复掺粉煤灰和矿粉时,混凝土的强度随着矿粉掺量的增加而降低。20℃以上为高掺量矿物掺合料混凝土的最佳养护温度,其整体强度与基准组接近甚至更高。单掺粉煤灰时,其最佳掺量为33%,最佳养护温度为30℃。当养护温度为20℃时,粉煤灰与矿粉复掺的最佳掺量为粉煤灰22%、矿粉22%;当养护温度为25℃以上时,粉煤灰与矿粉复掺的最佳掺量分别为粉煤灰22%、矿粉33%。
The curing temperature is closely related to the development of concrete compressive strength,and seasonal temperature differences usually affect the feasibility of concrete mix proportions,leading to unqualified acceptance of the 28 days age strength of concrete.This paper studies the effect of setting 5 average curing temperatures on the strength of 10 groups of concrete with different mix proportions,and obtains the optimal curing temperature for concrete with different mix proportions and the optimal mix proportion for concrete at different temperatures.The results show that when the curing temperature is below 15℃and fly ash is added alone,the 7 days and 28 days strengths of concrete decrease compared to the reference group with the increase of fly ash content,while the 60 days strength of concrete increases with the increase of fly ash content;when mixed with fly ash and mineral powder,the strength of concrete decreases with the increase of mineral powder content.The optimal curing temperature for high content mineral admixture concrete is above 20℃,and its overall strength is close to or even higher than the benchmark group.When adding fly ash alone,the optimal dosage is 33%and the optimal curing temperature is 30℃.When the curing temperature is 20℃,the optimal blending amount of fly ash and mineral powder is 22%for f ly ash and 22%for mineral powder;when the curing temperature is above 25℃,the optimal blending amounts of fly ash and mineral powder are 22%for fly ash and 33%for mineral powder,respectively.
出处
《混凝土世界》
2024年第4期29-32,共4页
China Concrete
关键词
混凝土
养护温度
矿物掺合料
抗压强度
Concrete
curing temperature
mineral admixtures
compressive strength
