Effect of steel fiber reinforced concrete on the heavy-weight floor impact sound performance

In South Korea, where apartment buildings in which the slabs of each unit are shared by the upper and lower floor units have become common, noises due to the floor impact sound from slabs between upper and lower floor units are coming to the fore as a serious social problem. The purpose of this study is to develop a method to improve the heavy- weight impact sound performance by increasing the stiffness of structural members using steel fiber reinforced concrete in order to reduce the impact sound of building floor slabs. Steel fiber reinforced concrete can increase the effective stiffness compared to ordinary reinforced concrete by suppressing cracks under the service load and is expected to reduce the heavy-weight impact sound in proportion to the stiffness through the foregoing. In this study, heavy-weight floor impact sound experiments were conducted using the compressive strength of concrete, the shape and amount of steel fibers included, and whether cracks occurred in the slab or not as variables, and the effects of the variables were analyzed. A total of nine slab specimens were fabricated, and floor impact sound experiments were conducted twice with each specimen, once before cracks occurred and once after cracks were caused by applying the service load. Therefore, a total of 18 floor impact sound experiments were conducted. As a result of the experiments, the inclusion of steel fibers was evaluated to enable the suppression of cracks under the service load, and the resultant increase in the effective stiffness was evaluated to enable the reduction of the heavy-weight impact sound of the bare slabs by up to 2 dB. The results of this study are judged to be a more efficient construction method than the existing method that increases the slab thickness, which is generally used as a method for reducing the heavy-weight floor impact sound of buildings.