Development of an Integrated Concrete Sludge Treatment and Recycling System

本研究的目的是探讨一种一体化的混凝土污泥处理和回收系统，将预拌混凝土厂排放的混凝土污泥再生为高附加值的粉状材料。(1)研制了处理混凝土污泥的无机物含量在95%以上的混凝剂，收集了无机混凝剂最佳投加量和搅拌时间的试验数据。(2)将污泥水加压脱水得到的泥饼干燥后，用分流空气粉碎成粉状物质(粉状干泥，PDS)。收集了有关PDS制造条件的数据。结果表明，聚偏二苯醚是由大小为3~10μm的圆形超细颗粒组成，比表面积为8,000~10,000 cm~2/g，易于制备。(3)聚偏二苯醚用作…的实验进行了多种矿物掺合料和高流动性混凝土粉料的试验研究，取得了良好的试验效果。在掺加矿物掺合料的情况下，PDS对硬化混凝土没有不利影响，但由于混凝土污泥的高含量显著增加了拌和用水量，有时必须将PDS的掺量限制在水泥含量的10%左右。对于高流动性混凝土，尽管试验结果表明，PDS的体积分数高达60%的大流动性混凝土具有良好的性能，但根据JASS5法规，对于高流动性混凝土，PDS的限量为30vol.%。(4)探讨了本研究开发的完整回收体系在混凝土污泥以外的其他废物中的应用。研究发现，超细粉末粉碎和加工技术将有可能应用于其他废物，如有问题的建筑材料、废玻璃瓶和套砂，以及从采石厂和建筑工地排放的湿废物，如污泥。较少

The purpose of this study is to discuss an integrated concrete sludge treatment and recycling system that regenerates the concrete sludge discharged from ready-mixed concrete plants into a powdered material of high added value. The following conclusions may be drawn based on the current research project:(1) The coagulant including more than 95% of inorganic substance for the treatment of concrete sludge was developed, and the test data on the optimum dosage and the stirring time of inorganic coagulant were collected.(2) Sludge cake obtained by the process of pressurization and dehydration of sludge water was dried, and then crushed finely by forded air to produce the powdered material (Pulverized Dry Sludge, PDS). The data on the manufacturing condition of PDS were collected. It was found that PDS consisted of rounded ultra fine particles having a size of 3-10μm and a Blaine specific surface area of 8,000-10,000 cm^2/g, and was easy to produce.(3) The experiments on the use of PDS as a … More kind of mineral admixture and the powder material for high-fluidity concrete were carried out, and the good test results were obtained. It was confirmed that in the case of a mineral admixture, PDS had no harmful effects on hardened concrete although the dosage had sometimes to be limited to about 10% of the cement content because high content of concrete sludge significantly increased the demand of mixing water, in the case of high-fluidity concrete, the limitation of PDS content was 30 vol.%, according to Regulation JASS5 for high-fluidity concrete although test results showed that high fluidity concrete containing PDS up to 60% of volume content had a good performance.(4) The application of the complete recycling system developed in this research project to other waste materials other than concrete sludge was discussed. It was found that the ultra fine powder crushing and processing technology will become possible to apply other wastes such as the faulty construction materials, waste glass bottles and casing sand as well as wet wastes such as dirty mud discharged from the quarrying factory and the construction site. Less