Development of Self-Compacting concrete Using Whole Recycled Materials from Demolished Concrete Structure as Aggregate and Powder by High grade Recycling System

研究了采用日本东京某混凝土结构墙体部分粉料和全再生骨料配制的自密实混凝土的力学性能、长度变化和抗冻融性能，再生骨料分为粗骨料、大细骨料和小细骨料3种粒径。再生粗骨料的各项性能指标均达到日本JIS H级再生粗骨料标准。大粒径细集料和小粒径细集料的性能分别接近JIS草案的M级。采用偏心转子再生设备，从拆除的混凝土结构中选取3种再生骨料，按相同比例配制出坍落度为65±55cm的10种混合料，得到了全再生骨料自密实混凝土。再生混凝土的抗压强度和杨氏模量在28天的年龄满足要求的值，分别在JASS 5。掺膨胀剂的再生混凝土在28天龄期的长度变化满足JASS 5的要求。再生自密实混凝土的抗冻性和抗融性均未达到要求水平，考虑到使用面积、结构局部等使用方法，认为全再生材料再生自密实混凝土适用于普通混凝土结构。

It is investigated that the mechanical properties, the length change and the resistance to freezing and thawing of the self-compacting concrete using whole recycled aggregate and powder from a part of wall of a concrete structure which was build in 1950's in Tokyo.The recycled materials used were divided into three sizes such as coarse aggregate, fine aggregate large and fine aggregate small. The properties of recycled coarse aggregate are satisfied the standard on recycled coarse aggregate of class H of JIS. The properties of fine aggregate large and fine aggregate small are nearly satisfied the class M of the draft JIS, respectively. A recycling equipment was used an eccentric rotor.The 10 mixes were selected having 65±55cm in slump flow using the same proportion of three recycled aggregates from the demolished concrete structure.As the results, it is obtained the self-compacting concretes using whole recycled aggregates. The compressive strength and Young's modulus of recycled concretes are satisfied the required value at the ages of 28 days in JASS 5, respectively. The length change of the recycled concretes with an expansive additive are satisfied the required value at the ages of 28 days in JASS 5. The resistance to freezing and thawing of recycled self-compacting concretes are not satisfied the required level.It is considered that the recycled self-compacting concretes using whole recycled materials are applicable to normal concrete structure in consideration for using method such as area, part of structure etc.