DEFECT STUDY ON SINGLE STOREY REINFORCED CONCRETE BUILDING IN WEST SUMATRA: BEFORE AND AFTER 2009 WEST SUMATRA EARTHQUAKE

Indonesia has a high number of damaged buildings due to earthquake excitation. An event in 2009 (Mw 7.6) affected the buildings and infrastructure of Padang, where more than one hundred thousand were damaged to severe, medium, or slight levels. Previous studies have found that structural defects in the typical reinforced concrete buildings are the major cause of the catastrophic results of damage. However, the research that presenting the predominant defects suffered by RC building is limited. Hence, this research aimed at assessing the defects on the single-storey RC building in West Sumatra to arrange the defects list and finding the predominant defects on the target building type. Furthermore, by analyzing the data statistically, this study compared the defect found on the buildings that were built before and after the 2009 West Sumatra Earthquake. Hence, the information about the progress on building quality after the earthquake event can be provided. This research uses field survey and data analysis of 100 single storey RC buildings with masonry wall aged from 77 years till 0 years. The samples were selected randomly in the area of Padang-Pariaman district in West Sumatra, Indonesia. The results show that common defects found are 18% of the building do not have structural columns, 38% without structural beams, and 60% of the building's structural elements concrete cover do not follow the minimum concrete cover required by Indonesia National Standard. This study also found that 20% of columns are indicated to be corroded.