Engineering performances of permeable concrete blocks using oyster shell, bottom ash, and biochar

Abstract

In this study, permeable concrete blocks using industrial by-products (Oyster shell, bottom ash, and biochar) were developed, and the recycling suitability of the industrial by-products and engineering performances were evaluated. The flexural strength of permeable concrete blocks using by-products decreased as the bottom ash aggregate replacement ratio increased. When using oyster shell and biochar, the 28 days flexural strength was increased, and the development of initial strength was faster. The permeability is about 41.6–102.9 times greater than the Korean standard for permeable concrete block (0.01 cm/s). Oyster shell cement and biochar lowered permeability, and bottom ash aggregate had the effect of increasing permeability. The porosity of each specimen increased as the bottom ash aggregate substitution ratio increased and the replacement ratio of oyster shell cement decreased, and the continuous porosity decreased when biochar was mixed. Comparing the test results with permeable concrete block quality standards of South Korea, the substitution ratio of oyster shell cement can be up to 40 % and that of bottom ash aggregate up to 20 %. By mixing 2 % BC, a permeable concrete block was applicable for sidewalks even the substitution ratio of both oyster shell cement and bottom ash was 40 %.