Abstract
For concrete waste recycling, data for energy consumption were collected and the effect of concrete waste recycling on the reduction of emission of pollutants (CO2, NOx, and SOx) was evaluated using LCA methods. From the results, energy consumption unit for machine in the production process only had a size effect. The coefficients of variation of energy consumption units between the firms investigated were 30-70%, except for the landfill site construction process (108%) . Concrete waste recycling was effective for the reduction of pollutants only if in the recycling process electricity was used for the plant and light oil for machines. The amount of the reductions were 0.52 kg-C/ton, 2.2×10-3 kg-NOx/ton, and 3.5×10-3 kg-SOx/ton. The processes which contributed to emissions were mainly transport process and machines used in the recycling process. For all the pollutants, the annual amount of emissions from the recycling and disposal of concrete waste was negligible compared with total emissions in Japan. This means that the increase in the emission of the pollutants with the increase in the recycling of concrete waste should not limit the recycling of concrete waste.
