机制砂高性能混凝土在高速公路工程中的应用研究

针对机制砂混凝土应用中出现的级配不良，结合重庆沿江高速工程实际，通过分析不同配合比下机制砂混凝土的工作性能、力学性能、耐久性能，提出改善措施。结果表明：机制砂混凝土的坍落度损失较大，粉煤灰对其有明显改善作用；机制砂级配不良时，抗压强度不能满足使用要求，需掺配河砂调整级配。提出机制砂质量不稳定等是机制砂在高性能混凝土中应用受到制约的主要原因，并提出推广机制砂在高性能混凝土中应用的建议。

On the Application of High-Performance Concrete with Machine-Made Sand to Projects of the Expressway

For the sake of solving the problem of being poor in grading resulting from machine-made sand,and with the project of the expressway along the river in Chongqing as a practical example, the working performance,mechanical properties, and the durability of concrete with machine-made sand of various mix ratios are analyzed in the paper, with some improving measures presented. The results of our research show that the loss of the slump of the concrete with machine-made sand is great,and fly ash can much improve it;when the grading of machine-made sand is poor the compressive strength of the concrete will not be up to the requirements,in which case river sand has to be mixed into the concrete to improve its grading. It is pointed out in the pa- per that the instability of the quality of machine-made sand is the main cause that limits the application of machine-made sand to high-performance concrete. A few suggestions on how to popularize the application of machine-made sand to high-performance concrete are also put forward in the paper.