Study on Soil-Cement Concrete using Recycled Fine Aggregate

随着《回收法》的实施，对废旧混凝土再生骨料的利用和废土在新建工程中的利用进行了试验研究，利用1993财年生产的再生细骨料对土壤和再生细骨料进行了物理测试，并对土壤水泥混凝土的配合比设计、强度和收缩进行了测量。为建立再生细骨料-土-水泥体系混凝土的配合比设计方法，1994财年还研究了基于水灰比的土壤、再生细骨料及其混合料的饱和状态和表面干燥状况的评价方法。六种不同产地的土壤，一种是再生细集料，粘结剂包括水泥、高炉矿渣、粉煤灰、用石膏和石灰配制的水泥土混凝土，其强度的发展取决于土的类型。再生细骨料与土的配合比在0.2/0.8~0.5/0.5范围内可获得最大强度。应根据土的类型选择水泥以外的结合剂。混凝土工艺中有效用水量的概念可适用于水泥土混凝土工艺。体积收缩和线收缩取决于养护方法。结论是，再生细骨料与土壤结合可以有效利用，而常规配合比设计可以借助于新开发的土壤和再生骨料饱和和表面干燥状况的评价方法来应用。

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.