PHYSICAL PROPERTY AND HEAVY METAL LEACHING BEHAVIOR OF CONCRETE MIXED WITH WOODY ASH

Abstract

In recent years, the woody biomass power generation has attracted a lot of attention since woody biomass is an alternative energy source to fossil fuels. In the future, further implementation of woody biomass power generation is expected, and a large amount of woody ash will be discharged. Several studies have been conducted on the effective use of woody ash for construction materials. However, woody ash has not been practically used because of concerns about the leaching of heavy metals from concrete mixed with woody ash. If the above problem can be solved, a large amount of woody ash is expected to be used. In this study, the fresh property and hardened properties, such as compressive strength and length change were measured to evaluate the feasibility of using concrete mixed with woody ash. Furthermore, a heavy metal leaching test was conducted to assess the environmental impact caused by concrete mixed with woody ash. As the result, the concrete mixed with woody ash has the slump and air content similar to that of normal concrete, the compressive strength meeting the standard durability design strength in Japan, and the shrinkage is similar to that of normal concrete. Additionally, the concentration of heavy metals exceeding the soil environmental quality standards in Japan was partially detected, but the leaching amount of heavy metals from the concrete mixed with woody ash was similar to that from normal concrete.