Experimental study on compressive behavior of low and normal strength concrete confined by low-cost glass fiber reinforced polymers (GFRP)

The main objective of this study is to investigate the performance of low-cost glass fiber reinforced polymer (GFRP) in strengthening normal (15MPa) and low strength (5MPa) concrete cylinders. Typically, the strengthening technique using FRP is often expensive and may not be economically used for reinforced concrete (RC) houses in rural area. In many cases, the concrete strength used for these house constructions is often low. Therefore, the capability of low-cost GFRP in strengthening low strength concrete compared with normal strength concrete has been investigated. A total of 8 cylindrical specimens with the dimensions of 150 mm x 300 mm (diameter x height) were tested under compressive loading. Half of these specimens possess compressive strength of 5 MPa and the rest have 15 MPa compressive strength. The specimens were unconfined and also confined with GFRP one, two and three layers. It was found that, for 5 MPa compressive strength cylinder, the compressive strength of the specimens has increase 2.27 MPa, 3.96 MPa and 4.31 MPa for one, two and three-layer GFRP wrapping respectively compared to the controlled specimen. For 15 MPa compressive strength cylinder, the compressive strength of the specimens has increase 1.75 MPa, 2.29 MPa and 2.95 MPa for one, two and three-layer GFRP wrapping respectively compared to the controlled specimen. The test result showed that the use of low-cost GFRP is one of the effective and economical method to improve compressive strength of low strength concrete.