云南地区机制砂大体积混凝土温控研究

STUDY ON TEMPERATURE CONTROL OF MASS-CONCRETE SAND IN YUNNAN AREA

随在无天然砂资源地区和天然砂资源匮乏地区,使用更加环保的机制砂取代天然砂配制混凝土是未来发展的趋势。在云南地区机制砂特点表现为棱角多、颗粒级配差、石粉和含泥量较大,机制砂中石粉和含泥量将会影响混凝土工作性能,不利于冷缝控制。采用全机制砂配置混凝土并应用于2.1万m3大体积基础筏板中,须通过技术手段来控制混凝土的工作性能及混凝土浇筑后的温升在规范范围内。

In areas where there are no natural sand resources and where natural sand resources are scarce, the use of more environmentally friendly machine-made sand to replace natural sand to prepare concrete is a trend for future development. The characteristics of sands in Yunnan are characterized by large number of edges and comers, poor particle size distribution, and a large amount of stone powder and mud. The amount of stone powder and mud in the sand will affect the work performance of the concrete, which is not conducive to cold joint control. Then, using full-mechanized sand to dispose concrete and apply it to 21000m3 large-diameter foundation concrete slabs, how to control the performance of concrete through technical means and whether the temperature rise after concrete placement is within the scope of the specification is particularly important.