Influence of concrete compressive strength on the seismic performance of non-engineered building: A numerical simulation

Abstract

A low concrete compressive strength is a dominant problem in non-engineered buildings because unskilled workers carry out the concrete manufacturing process, resulting in poor quality. The poor concrete compressive strength causes a low bond to the steel reinforcements, leaving the beam and column elements prone to destruction, especially when receiving earthquake loads. This study numerically simulates the influence of concrete compressive strength on the seismic performance of reinforced concrete portals using ATENA software. The reinforced concrete portal model comprises columns with 150 mm x 150 mm cross-section and 2500 mm high, and a beam of 150 mm x 200 mm cross-section and 3000 mm length. Both columns and beam are reinforced with longitudinal and stirrup reinforcement 4D10 and ø6-200 mm, respectively. There are three variations of the models, comprising models with the quality of concrete according to SNI 2847 for earthquakes design with f'c 21 MPa, the quality of concrete for general use f'c 17 MPa, and the quality of concrete representing non-engineered buildings with f'c 10 MPa. The structural performance analysis includes load capacity, displacement, pattern and width of cracks, stress patterns of concrete, and reinforcement. Based on the results of the ATENA analysis, reducing the concrete from 21 MPa to 10 MPa will reduce the capacity of the specimen model by 10.01%, reduce the energy dissipation capability by 3.91%, and change the collapse pattern from column element to beam-column joint element.