考虑石粉含量的机制砂混凝土配合比设计方法研究  

Study on Mix Design Method of Manufactured Sand Concrete Considering Stone Powder Content

作　　者：赵尚传[1] 刘龙龙 刘忠凯 王少鹏 刘勇 ZHAO Shang-chuan;LIU Long-long;LIU Zhong-kai;WANG Shao-peng;LIU Yong(Research Institute of Highway,Ministry of Transport,Beijing 100088,China;China Overseas Construction Co.,Ltd.,Shenzhen Guangdong 518057,China)

机构地区：[1]交通运输部公路科学研究院,北京100088 [2]中海建筑有限公司,广东深圳518057

出　　处：《公路交通科技》2023年第8期37-42,共6页Journal of Highway and Transportation Research and Development

摘　　要：为解决高石粉含量的机制砂导致混凝土耐久性不足的问题,基于现有的混凝土配合比设计方法,将机制砂石粉含量作为配合比设计的一个参数,提出了根据机制砂石粉含量调节粗、细骨料比例的配合比设计方法。与原配合比设计方法相比,保持水胶比不变,从而有效保障其强度;保持骨料比例不变,有利于提升其耐久性。根据机制砂石粉含量调控机制砂用量,分析了部分或全部机制砂石粉替代胶凝材料的混凝土配合比设计方法对混凝土流动性、黏聚性、保水性能的影响。通过控制砂率和骨料各粒径比例不变,推导出配合比设计中机制砂和粗骨料的质量。试验结果表明:未考虑机制砂石粉含量的影响,或部分机制砂石粉作为胶凝材料的混凝土配合比设计方法忽略了石粉对混凝土性能的影响,得到的机制砂混凝土工作性能较差,容易离析;采用全部机制砂石粉尤其是高石粉含量的机制砂作为胶凝材料的混凝土配合比设计方法明显改善了混凝土的工作性能;提出的配合比设计方法能结合机制砂石粉的实际含量,保持水胶比和骨料比例不变,能保障混凝土工作性能和力学性能,充分发挥机制砂中石粉的作用,提升混凝土的耐久性能。To solve the insufficient durability of concrete caused by manufactured sand with high stone powder content,based on existing concrete mix design method,taking the stone powder content in manufactured sand as a parameter of mix design,a mix design method is proposed to adjust the proportion of coarse and fine aggregates based on the stone powder content in manufactured sand.Compared with the original mix design method,the water-binder ratio is kept unchanged effectively to ensure its strength,and the proportion of aggregate is kept unchanged to be beneficial for improving its durability.According to the stone powder content in manufactured sand,the influences of the concrete mix design method that partially or completely replace cementitious material with stone powder in manufactured sand on the fluidity,cohesion and water retention performance of concrete are analysed.By controlling the sand ratio and the proportion of each particle size of the aggregate unchanged,the masses of the manufactured sand and coarse aggregate in mix design are derived.The experimental result shows that(1)the mix design method of concrete without considering the influence of the content of stone powder in manufactured sand or using partial stone powder in manufactured sand as cementitious material ignores the influence of stone powder on the concrete performance,resulting in poor workability and easy segregation of manufactured sand concrete;(2)the mix design method of concrete using all manufactured sand with stone powder,especially the manufactured sand with high stone powder content,significantly improved the working performance of concrete;(3)the proposed mix design method can combine the actual content of stone powder in manufactured sand,maintain the water-binder ratio and aggregate ratio unchanged,ensure the workability and mechanical properties of concrete,fully utilize the role of stone powder in manufactured sand,and improve the durability of concrete.

关 键 词：道路工程 配合比设计 定量分析 机制砂混凝土 石粉 工作性能 

分 类 号：TU528[建筑科学—建筑技术科学]