再生混凝土全生命周期评价

Life Cycle Assessment of Recycled Concrete

摘要: 工程建设的需求促进了混凝土行业快速发展，2019年混凝土产量突破24亿立方米，并保持年产量2%~3%的增速，如此巨大的混凝土产量势必会消耗较多的天然骨料。采用再生骨料生产混凝土，不仅可以减少天然骨料的开采量，还可以减少废弃混凝土的填埋对土地的永久占用以及相应的环境污染。本文通过运用生命周期评价技术，对再生混凝土制备、使用、拆除废弃等阶段建立了环境影响评价模型。通过收集各阶段数据得到，修筑一段长1000米，宽3米，厚20厘米的路面所需的再生混凝土量与使用天然混凝土相比，对环境产生的影响明显减小，且随着再生骨料替代率的提高，所制成的再生混凝土对环境产生的影响整体减小。

Abstract: The demand of engineering construction promotes the rapid development of concrete industry, In the year of 2019, the concrete output will exceed 2.4 billion cubic meters and maintain an annual growth rate of 2%~3%, such a huge concrete output is bound to consume more natural aggregate. Using recycled aggregate to produce concrete can not only reduce the mining amount of natural aggregate, but also reduce the permanent occupation of land and corresponding environmental pollution caused by the landfill of waste concrete. Using life cycle assessment technology, an environmental impact assessment model is established for the preparation, use, demolition and waste of recycled concrete. According to the data collected at each stage, the amount of recycled concrete required to build a section of pavement with a length of one kilometer, a width of three meters and a thickness of twenty centimeters is significantly reduced compared with the use of natural concrete, and the impact of recycled concrete on the environment is reduced as a whole with the in-crease of the replacement rate of recycled aggregate.