Mechanical Properties of Concrete Used Coarse Slag Aggregate Made from Sewage Sludge
Naho TAKEDA and Takayuki KOJIMA
Abstract:The purpose of this study is to develop mechanical properties of concrete that using sewage sludge molten slag as coarse aggregate. As sewerage system spreads, sewage sludge that comes out from process of sewerage disposal is increasing. However remaining capacity of final disposal site is almost in the limit, and it is difficult to secure new disposal site. To build the recycling society is important to build sustainable development, and at present 70 percent sewage sludge is recycled. Sewage sludge slag is recycled as construction materials, fertilizer and fuel. The following were clarified by this research. Amount of elusion of heavy metals from sewage sludge molten slag were lower than environmental standards, and strength of molten slag was lower than natural coarse aggregate. Strength, durability factor of freezing thawing and compressive fatigue strength were decreased as the slag ubstitution ratio was increased, but drying shrinkage was not influenced from the slag substitution ratio. Key Words:Sewage sludge molten slag, Coarse aggregate, Drying shrinkage, Freezing and thawing, Compressive fatigue strength