Effectiveness of prestressed CFRP sheets in alleviating heavy-weight impact sound

초록

In recent years, inter-floor noise has become a significant issue in densely populated areas, particularly in high-rise residential buildings. Heavy-weight impact sound constitute a substantial portion of these inter-floor noise problems. However, current studies on inter-floor noise have predominantly focused on alleviating light-weight impact sound. This emphasizes the urgent need for the development of technologies to alleviate heavy-weight impact sound. Furthermore, the stiffness of members in reinforced concrete buildings decreases due to various factors, leading to reduced heavy-weight impact sound alleviation performance. This study proposed a method to alleviate heavy-weight impact sound by restoring structural stiffness using prestressed Carbon Fiber Reinforced Polymers (CFRP) strips. The effectiveness of the proposed method in alleviating heavy-weight impact sound was evaluated by measuring the Vibration Acceleration Level (VAL) due to impact ball force. In this study, dynamic analysis through the finite element method was conducted on both unit members and a remodeled multi-story housing unit with a bearing-wall system to obtain VAL. Variables for the unit members were member thickness, the strengthening of CFRP strips, and prestressing levels. For the bearing-wall system, the degree of damage before strengthening was considered. The results indicate that prestressed CFRP strips effectively alleviate heavy-weight impact sound by reducing both damage and vibration response. In the unit member analysis, applying a prestressing level of 900 MPa to CFRP strips significantly reduced the extent of damage, VAL, and Single Number Quantity (SNQ). As the prestressing level increased from 900 MPa to 1200 MPa, the extent of damage decreased. However, this increase in prestressing did not result in a significant reduction in VAL and SNQ. The bearing-wall system model with prestressed CFRP strips showed clear reductions in damage, VAL, and SNQ. This study demonstrates the effectiveness of prestressed CFRP strips in restoring damaged members and enhancing the heavy-weight impact sound insulation performance of the members.

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