Influence of Seawater on Strength of Concrete Beams Strengthened With Glass Fiber Reinforced Polymer Sheet

Abstract

Concrete structures close to seawater cannot be avoided in the construction of current facilities and infrastructure. Concrete submerged in seawater will reduce its strength and increase the corrosion rate of reinforcing steel. With Glass Fiber Reinforced Polymer Sheet (GFRP-S) technology, it is possible to increase the strength of concrete and protect reinforcing steel from the effects of seawater corrosion. Several laboratory studies were carried out on GFRP-S coating as an addition and protection against seawater environmental conditions. However, this research is limited by time and equipment, so it is necessary to carry out a finite element analysis. This modeling uses Abaqus CAE 2017 software. The Abaqus modeling results are then validated with laboratory research to find out what percentage of deviations occur. After optimization, several variables were added to determine the load capacity under different conditions. Some additional research variables are the length of immersion of 12, 24, and 48 months. Apart from the period of time, additional variations were made with the thickness of GFRP-S, which was originally only 1.3 mm, increased to 1.5 mm and 1.8 mm. The results obtained were that the immersion time of 12 months decreased the load capacity by 11.21%, the decrease in the immersion time of 24 months was 14.34%, and the decrease in the immersion time of 48 months was 17.63%. The addition of GFRP-S with a thickness of 2 mm increases capacity by 0.89% and the addition of 5 mm GFRP-S increases capacity by 3.74%. This very significant reduction resulted in the beam being recommended for additional repairs or strengthening.