Development of Utilization Methods of Various Stages for Ready-Mixed Concrete Wastes

从环境保护的角度来看，混凝土污泥的处置已成为一个大问题。本研究主要研究了以下三个阶段的利用方法。（1）混凝土污泥水浓度控制的现场实验（阶段：再利用）考虑到混凝土污泥的利用，在处理污泥的混凝土工厂内使用污泥水搅拌混凝土似乎基本上是最好的方法。为了实现混凝土厂污泥的资源化利用，保证排泥水中污泥颗粒的浓度是非常重要的。然而，当污泥水中含有大量的非常细的聚集体和污泥颗粒时，精确测量污泥颗粒的浓度被认为是相当困难的。作者提出了一种新型的虹吸式旋流器污泥浓度稳定系统。此外，他们还进行了实地试验，以检查拟议系统的有效性。（2）干化颗粒混凝土污泥的基本性质（阶段：再循环）预拌混凝土厂排出的混凝土污泥通常脱水成泥饼，泥饼中含有一定的水分。然而，与干污泥相比，污泥饼是相当困难的处理。本研究通过一系列的试验研究了以下几个方面：首先，热处理对污泥干化的影响，（波特兰水泥、水粒化铁高炉矿渣、石膏）;其次，研究了污泥干化过程中的颗粒化、贮存过程中的碳酸化，水渣细度对干化污泥砂浆强度发展的影响。（3）干燥的混凝土污泥作为混凝土中的掺合料的利用（阶段：再循环）

Disposal of concrete sludge has become a big problem from the viewpoint of environmental conservation, In the present study, mainly following three stages of utilization methods are examined.(1)FIELD EXPERIMENT ON CONSENTRATION CONTROL OF CONCRETESLUDGE WATER (Stage : Reuse)Considering the utilization of concrete sludge, it seems to be basically the best way to use sludge water for the mixing of concrete within a concrete plant from which the sludge is disposed. For the reuse of concrete sludge in the concrete plant, it is very important to assure the concentration of sludge particles in a sludge water. Accurate measurement of the concentration of sludge particles, however, is considered rather difficult when a large amount of very fine aggregate is contained together with sludge particles in a sludge water. The authors have proposed a new type of sludge-concentration-stabilizing system in which a siphon-type cyclone apparatus is incorporated. Also, they have carried out a field experiment to examine the effectiveness of the proposed system.(2)FUNDAMENTAL PROPERTIES OF DRIED GRANURATED CONCRETE SLUDGE(Stage : Recycle)Concrete sludge discharged from ready mixed concrete plant is usually dehydrated to be sludge cake which contains water to some extent. However, the sludge cake is rather difficult to be handled compared with dried sludge. In the present study, followings have been examined in a series of experiments : firstly the effects of heat treatment in making dried sludge, and of admixtures (Portland cement, water granulated iron-blast-furnace slag, gypsum) ; secondly the effects of granulation process in making the dried sludge, of it's carbonation in storage, and of fineness of water granulated slag as admixture on strength development of mortar with the dried sludge.(3)UTILIZATION OF DRIED CONCRETE SLUDGE AS ADMIXTURE IN CONCRETE(Stage : Recycle)It was found that the dried sludge can be used as an admixture in concrete.