고로슬래그 및 탄소섬유가 함유된 차수 그라우트재 개발에 관한 연구

Abstract

Cement is the most commonly used as a representative material in construction and civil engineering industry, and has been produced in large quantities. However, emissions of carbon dioxide generated during the cement's production have caused global warming and environmental pollutions, which has not been resolved for a long time. In order to replace such cement, many studies have been actively performed for utilizing Blast Furnace Slag(BFS) which is a by product of the steel industry, as the construction and civil engineering material. This study aims to investigate the physico-chemical properties of the BFS powder mixed cement, biogrout material and carbon fiber to determine whether it can be used as an environment-friendly cut off grout material. Slag is fine powder or mixed cement and used as concrete slag due to potential hydraulic property of powder itself, and it has an advantage of increasing long-term strength and dandification of the internal structure of concrete. In addition, if the slag powder, which is the industrial byproduct produced every year, is used as the grout material, it has a special characteristic that it is possible to secure not only environment friendly but also great economical efficiency. Therefore, this study aims to develop grout material with high strength and reinforced cut-off by mixing carbon fiber which is recycled resource, biogrout materials, blast furnace slag powder(BFS powder) and cement. For this thesis, Geltime tests of the grout material that biogrout materials, fiber crushing agents, BFS powder and cement are mixed, and unconfined compression strength(1, 3, 7, 14 and 28 days) of homo-gel samples to determine durability were performed. In addition, the permeability varying with the mixing ratio was tested. The ratio of water to synthetic silica was fixed at 9:1, and the W/C which is a ratio of water to cement, the existing fillers, was fixed at 200% in order to perform the experiment. Inclusion ratio of fiber crushing agents was 0, 0.5, 1.0 and 1.5%, and accordingly, analysis using SEM and EDX was performed to evaluate and verify the performance of the grout material. The experimental results showed that the compression strength increased as the inclusion ratio of fiber crushing agent increased. It is considered that the unconfined compression strength increases due to the bridge reaction of the fiber within the cement material. Moreover, as the amount of BFS powder increased, the early strength increased, and the coefficient of permeability decreased. Therefore, it can be used as a cut off wall grouting material in the field due to excellent early strength and cut-off effect.