铁路工程典型岩性机制砂混凝土性能研究
Study on Properties of Concretes with Manufactured Sands with Typical Lithology in Railway Engineering
王振 1李化建 1黄法礼 1易忠来 1杨志强1
作者信息
- 1. 中国铁道科学研究院集团有限公司铁道建筑研究所,北京 100081;高速铁路轨道技术国家重点实验室,北京 100081
- 折叠
摘要
为探讨不同岩性机制砂在铁路混凝土中的适用性,采用我国常用的典型岩性(石灰岩、石英岩、砾岩、花岗岩和玄武岩)机制砂,研究铁路工程机制砂混凝土工作性能、抗压强度和耐久性能的变化规律.结果表明:石灰岩、石英岩、砾岩机制砂的物理性能良好、化学性能稳定,在石粉填充正效应下,机制砂混凝土的工作性能、抗压强度和耐久性能均优于河砂混凝土;高亚甲蓝值和高吸水率的玄武岩机制砂不利于混凝土工作性能保持,其提高了混凝土内部饱水程度,显著降低混凝土抗冻性;花岗岩机制砂中高云母含量引发外加剂插层吸附,降低了硬化混凝土的引气效果和抗冻性能.机制砂混凝土电通量均小于1 234 C,氯离子扩散系数均小于9.5x10-12 m2/s,具有较好的抗氯离子渗透性能,花岗岩机制砂混凝土中有害孔体积分数高,导致其抗氯离子渗透性低于其他岩性机制砂混凝土.
Abstract
In order to discuss the applicability of manufactured sands with different lithology in railway concrete,manu-factured sands with typical rock types including limestone,quartzite,conglomerate,granite and basalt commonly used in China were used to study the developmental rules of workability,compressive strength and durability of manufactured sand concrete in railway engineering.The results show that the manufactured sand with limestone,quartzite and con-glomerate has good physical properties and stable chemical properties,with better workability,compressive strength and durability than those of river sand concrete under the positive effect of stone powder filling.Basalt manufactured sand with high methylene blue value and high water absorption,which is adverse to the maintenance of concrete workability,increases the internal water saturation of concrete,and significantly reduces the frost resistance of the concrete.The high mica content in granite manufactured sand leads to the intercalation adsorption of admixture,which reduces the air en-trainment effect and frost resistance of hardened concrete.The electric fluxes of all manufactured sand concretes are less than 1 234 C,with the chloride ion diffusion coefficients less than 9.5x10-12m2/s,indicating good resistance to chlo-ride ion penetration.The higher volume fraction of harmful pores in granite manufactured sand concrete leads to its resist-ance to chloride ion penetration lower than that of concrete with other lithological manufactured sand.
关键词
铁路工程/机制砂/岩性/混凝土Key words
railway engineering/manufactured sand/lithology/concrete引用本文复制引用
基金项目
国家自然科学基金(U1934206)
中国铁道科学研究院集团有限公司科研项目(2020YJ049)
中国国家铁路集团有限公司科技研究开发计划(J2022Z505)
出版年
2024
NETL
NSTL
万方数据