隧道洞渣机制砂混凝土和易性与强度特性研究

Study on workability and strength characteristics of tunnel hole slag mechanism sand concrete

为提高工程经济效益,实现废物利用,本着可持续发展的原则,用隧道开挖时产生的废石料研制机制砂,代替外购黄砂应用到混凝土拌合中去。采用试验研究的方法,结合工程混凝土设计要求对隧道洞渣机制砂混凝土进行试配,与已顺利应用于工程的外购黄砂混凝土进行对比,研究两者的和易性与强度特性,分析隧道洞渣机制砂混凝土的工程适用性,为其配合比优化问题提供一定的参考。隧道洞渣机制砂混凝土试配结果表示,混凝土强度满足工程要求,水灰比对强度起着主要作用,但受级配及含泥量影响,极易出现离析泌水,水石分离现象,和易性较差,难以进行工程应用,亟需配比优化方案改善和易性差的问题。

In order to improve the economic benefit of the project and realize the utilization of waste,in line with the principle of sustainable development,tunnel hole slag mechanism sand was developed by using the waste stone of tunnel excavation to replace the purchased yellow sand in concrete mixing.Using the methods of experimental research,according to the design requirements of engineering concrete,the tunnel hole slag mechanism sand concrete is tested and compared with the purchased yellow sand concrete which has been successfully applied in engineering,to study the workability and strength characteristics of both,analyze the engineering applicability of tunnel hole slag mechanism sand concrete,to provide a certain reference for the optimization of its mix ratio.Tunnel hole slag mechanism sand concrete test results,the concrete strength meets the engineering requirements,and the water-cement ratio plays a major role in the strength.However,affected by the gradation and silt content,segregation and water-stone separation are easy to occur,and the workability is poor,which is difficult to be applied in engineering.Therefore,it is urgent to improve the problem of poor workability with proportion optimization scheme.