Impact behaviour of reinforced concrete seawall panels with compressive strengths and GFRP reinforcement ratios

Concrete seawall panels were tested under impact loading, and the effect of concrete compressive strength (50, 60, and 75 MPa) and reinforcement ratios of glass fiber-reinforced polymer (GFRP) bars (0.33%, 0.50%, and 0.83%) was investigated. The experimental analysis included the comparison of crack, force, deflection, acceleration, GFRP bar strains, and energy absorption behavior. Moreover, an analytical study was conducted to compare the experimental results to the predicted analytical results. The experimental data showed enhanced force and maximum deflection behavior of seawall panels with a higher reinforcement ratio, whereas concrete compressive strength adversely affected the impact behavior of panels because of brittleness becoming dominant, especially after 60 MPa. The strain and energy absorption of GFRP bars was maximum for the panel with 200 mm bar spacing and 60 MPa concrete compressive strength, whereas the maximum post-cracking energy absorption in concrete was the highest for the panel with 200 mm bar spacing and 50 MPa concrete compressive strength. The SDOF equation reliably estimated the impact behavior of the panels with a compressive strength of 60 MPa or lower and a bar spacing of not less than 200 mm, in the case of the panels with a reinforcement ratio of 0.50% or less. The results demonstrate the maximum design configuration of GFRP bars in seawall structures under a 2 m impact. • Influence of concrete compressive strength and reinforcement ratios on the impact response is studied. • Failure behaviour, deflection, force, acceleration, strain, and energy absorption are investigated. • Analytical verification (SDOF) and comparison with experimental results are conducted. • Optimal design configuration of GFRP-reinforced seawalls under 2 m impact is presented.