Study on Soil-Cement Concrete using Recycled Fine Aggregate

随着再生法的实施，对拆除混凝土再生线骨料的利用和废弃土在新建工程中的利用进行了试验研究，并于1993年进行了土和再生细骨料的物理试验、配合比设计以及用再生细骨料配制的土水泥混凝土的强度和收缩测定。在1994年度，为了建立再生细骨料-土壤-水泥体系混凝土的配合比设计方法，对基于水灰比的土壤、再生细骨料及其混合物的饱和状态和表面干燥状态的评价方法进行了研究。试验选取了六种不同来源的土，一种是再生细骨料与水泥、高炉矿渣、粉煤灰等结合料，结果表明：水泥土混凝土强度的发展与土的种类有关，当再生细骨料与土的配合比为0.2/0.8 ~ 0.5/0.8时，水泥土强度最大，当再生细骨料与土的配合比为0.2/0.8 ~ 0.5/0.8时，水泥土强度最大0.5.水泥以外的粘结剂应根据土的类型选择。混凝土技术中有效水量的概念可适用于土-水泥混凝土技术。体积收缩和线收缩取决于养护方法。得出结论，再生细骨料与土结合可以有效利用。采用新发展的土和再生骨料饱和和表面干燥状态评价方法，可进行常规配合比设计。

With the enforcement of the recycling law, experimental research into the utilization of the recycled line aggregate made of demolished concrete and the utilization of waste soil in the new construction were execued.Physical tests of soil and the recycled fine aggregate, and the mix design as well as measurement of strength and shrinkage of the soil cemtnt concrete using the recycled fine aggregate ware made in the 1993 fiscal year. Also in the 1994 fiscal year, the evaluation method of the Saturated and surface-dried condition of soil, the recycled fine aggregate and their mixture was investigated based on the water to cement ratio in order to establish a mix design method of the concrete of the recycled fine aggregate-soil-cement system. Six types of soil from different place, one type of the recycled fine aggregate and the binders including cement, blast furnace slag, fly-ash, gypsum and lime were used.Following results are obtained.Development of the strength of the soil-cement concrete depends on the type of soil.The maximum strength can be obtained with a mix proportion of the recycled fine aggregate and soil ranging from 0.2/0.8 to 0.5/0.5.Binders other than cement should be chosen according to the type of soil.The concept of effective amount of water in concrete technology can be applicable to the soil-cement concrete technology.Volumetric and linear shrinkage depend on the curing method.It is concluded that the effective utilization of the recycled fine aggregate can be possible in combination with the soil, and the conventional mix design can be applied with the help of newly develped evaluation method of Saturated and surface-dried condition of either the soil and the recycled aggregate.