Double vertical carbon fiber reinforced polymer plates strengthened to reinforced concrete beams for six months saltwater exposure

Abstract

Reinforced concrete structures might require rehabilitation after years exposed to extreme environment conditions. The use of Fiber Reinforced Polymer (FRP) material in construction industry has become popular due to its properties such as high tensile strength, durable and lightweight which can be used to improve mechanical behavior of structures. This research emphasis on the use of Carbon Fiber Reinforced Polymer (CFRP) to improve the flexural performance of reinforced concrete beam which is exposed to saltwater for 6 months. The purposes of this research are to determine the maximum flexural strength of normal reinforced concrete beam and reinforced beam strengthened with CFRP plate and to determine the effects of salt water on the flexural strength of concrete beam reinforced with CFRP plate. Two beam samples with dimension of 125mm x 300mm x 1800mm were prepared labelled as control beam and specimen beam respectively. The control beam was cure in fresh water while the specimen beam was cured in salt water for 28 days. All of the beams were tested using four point bending test. The control beam was tested until failure whereas the specimen was subjected to 30% of maximum load from control beam as pre-cracking load. The specimen beam was repaired by installing CFRP plate using near surface mounted (NSM) and is immerse in saltwater for another 6 months. After 6 months, the specimen beam was tested until failure. As a result, the flexural strength for normal beam and specimen beam is slightly the same. The specimen beam has form modes of failure known as concrete cover separation. It is also found that saltwater exposure did affect the performance of beam that has been repaired.