수압과 균열폭 변화에 따른 콘크리트 투수계수의 실험적 연구

Abstract

Cracks in concrete generally interconnect flow paths and increase concrete permeability. The increase in concrete permeability due to the progression of cracks allows more water or aggressive chemical ions to penetrate into concrete, facilitating deterioration. The goal of this research is to study the relationship between crack width and water permeability of cracked concrete. Tests have been carried out as a function of hydraulic pressure (0.1 ～ 2 bar) and crack width (30 ～ 100 ㎛). Splitting and reuniting method was used to manufacture cracked concrete specimens with controlled crack width. Crack widths are checked by using a microscope(×100). The results show a considerable increase of water transport with crack width and hydraulic pressure. When crack width is smaller than 50 ㎛, the crack width has little effect on concrete permeability. Due to the autogenous healing, the water flow through the crack gradually reduces with time. When crack width is 100 ㎛ and hydraulic pressure increase from 0.1 bar to 0.25 bar, concrete permeability increases rapidly about 190 times according to the test results.