Development of Foam-Concrete Granules Coated with TiO2 Nanoparticles
Keun–Hyeok Yang, Ju–Hyun Mun, Seung–Jun Kwon, Jong-Won Kim
Appears on pages(s):
foam–concrete granules; NOX; porosity, SOX; TiO2 nanoparticles
The atmospheric purification capacity of concrete has not been adequately investigated. This study examines the feasibility of using sustainable foam–concrete granules as a porous material for reducing air pollutants in concrete. To enable the removal of nitrogen oxide (NOx) and sulfur oxide (SOx) using titanium dioxide (TiO2) nanoparticles, foamed concrete was crushed into granules with porosity exceeding 30%. Portland ordinary cement (OPC), fly ash (FA), and ground granulated blast-furnace slag (GGBS) were used as source cementitious materials. OPC was replaced with from 0% to 40% FA and 0% or 40% GGBS by weight. Test results indicate that 30% FA and unit cementitious material content exceeding 500 kg/m3 (31.2 lb/ft3) are optimal for replacing cement and foam–concrete granules, respectively. Considering the particle size distribution and specific surface area, 6 to 13 mm (0.24 to 0.51 in.) and 6 to 9 mm (0.24 to 0.35 in.) were selected as optimal granule sizes. The coating procedures yielded improved SOx and NOx removal, with the removal rates reaching 83.8% and 45% using granules of 6 to 9 mm (0.24 to 0.35 in.), respectively. Consequently, the foam–concrete granules coated with TiO2 nanoparticles are promising in developing porous concrete with the reduction capability of air pollutants.