机制砂特性和砂率对C130超高强混凝土的影响研究

Study on the Influence of Manufactured Sand Characteristics and Sand Rate on C130 Ultra-high Strength Concrete

在保持混凝土水胶比和胶凝材料用量不变的情况下,通过使用不同特性机制砂、设计不同砂率,从混凝土扩展度、倒桶排空时间、V形漏洞流出时间、含气量等数据,详细分析机制砂特性和砂率对C130超高强混凝土的影响。结果表明,选取中粗砂,石粉含量在2.0%~4.0%,MB值低于0.5的花岗岩机制砂可以配置出状态良好C130超高强混凝土。同时C130超高强混凝土随着砂率从43%增加至49%,混凝土扩展度先增大后减小,扩展度在49%砂率时达到最大值,砂率的增加使混凝土引入更多浆体,流动性变好。抗压强度随着砂率的增加出现先增大后减小的规律,抗压强度在47%砂率时达到最大值151.2MPa。选取合适的机制砂和砂率可以提高混凝土和易性及抗压强度。

By using different characteristics of manufactured sand and designing different sand rates while maintaining the same water cement ratio and dosage of cementitious materials,the effects of manufactured sand characteristics and sand ratios on C130 ultra-high strength concrete were analyzed in detail based on data such as concrete expansion,bucket emptying time,V-shaped hole outflow time,and air content.The results show that selecting medium coarse sand,with a stone powder content of 2.0%~4.0%and a MB value below 0.5,can prepare C130 ultra-high strength concrete in good condition.At the same time,as the sand rate of C130 ultra-high strength concrete increases from 43%to 49%,the con‐crete expansion first increases and then decreases.The expansion reaches its maximum value at 49%sand rate,and the increase in sand rate introduces more slurry into the concrete,improving its fluidity.The compressive strength shows a pattern of first increasing and then decreasing with the increase of sand content,reaching a maximum value of 151.2 MPa at a sand content of 47%.Choosing appropriate manufactured sand and sand rate can improve the workability and compressive strength of concrete.