Galvín A P, Agrela F, Ayuso J, Beltrán M G, Barbudo A
Construction Engineering, University of Cordoba, UCO-Ed. Leonardo Da Vinci - Campus of Rabanales, 14071 Cordoba, Spain.
Construction Engineering, University of Cordoba, UCO-Ed. Leonardo Da Vinci - Campus of Rabanales, 14071 Cordoba, Spain.
Waste Manag. 2014 Sep;34(9):1693-704. doi: 10.1016/j.wasman.2014.05.001. Epub 2014 Jun 2.
Each year, millions of tonnes of waste are generated worldwide, partially through the construction and demolition of buildings. Recycling the resulting waste could reduce the amount of materials that need to be manufactured. Accordingly, the present work has analysed the potential reuse of construction waste in concrete manufacturing by replacing the natural aggregate with recycled concrete coarse aggregate. However, incorporating alternative materials in concrete manufacturing may increase the pollutant potential of the product, presenting an environmental risk via ground water contamination. The present work has tested two types of concrete batches that were manufactured with different replacement percentages. The experimental procedure analyses not only the effect of the portion of recycled aggregate on the physical properties of concrete but also on the leaching behaviour as indicative of the contamination degree. Thus, parameters such as slump, density, porosity and absorption of hardened concrete, were studied. Leaching behaviour was evaluated based on the availability test performed to three aggregates (raw materials of the concrete batches) and on the diffusion test performed to all concrete. From an environmental point of view, the question of whether the cumulative amount of heavy metals that are released by diffusion reaches the availability threshold was answered. The analysis of concentration levels allowed the establishment of different groups of metals according to the observed behaviour, the analysis of the role of pH and the identification of the main release mechanisms. Finally, through a statistical analysis, physical parameters and diffusion data were interrelated. It allowed estimating the relevance of porosity, density and absorption of hardened concrete on diffusion release of the metals in study.
每年，全球都会产生数百万吨垃圾，部分源于建筑物的建造和拆除。回收这些产生的垃圾可以减少需要制造的材料数量。因此，本研究分析了用再生混凝土粗骨料替代天然骨料在混凝土生产中潜在的建筑垃圾再利用情况。然而，在混凝土生产中加入替代材料可能会增加产品的污染物潜在性，通过地下水污染带来环境风险。本研究测试了两种用不同替代百分比制造的混凝土批次。实验过程不仅分析了再生骨料比例对混凝土物理性能的影响，还分析了其对作为污染程度指标的浸出行为的影响。因此，研究了诸如硬化混凝土的坍落度、密度、孔隙率和吸水率等参数。基于对三种骨料（混凝土批次的原材料）进行的可用性测试以及对所有混凝土进行的扩散测试来评估浸出行为。从环境角度出发，回答了扩散释放的重金属累积量是否达到可用性阈值的问题。浓度水平分析允许根据观察到的行为建立不同的金属组，分析pH值的作用并确定主要释放机制。最后，通过统计分析，将物理参数和扩散数据相互关联。这使得能够估计硬化混凝土的孔隙率、密度和吸水率对所研究金属扩散释放的相关性。
