The present study is dedicated to investigating the effects of Forta-Ferro (FF) fiber and calcium aluminate cement (CAC) on the flexural behavior of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) rebars subjected to acid attack. Bending tests were designed to assess the effects of the acidic environment, replacement of ordinary Portland cement (OPC) with CAC, and the addition of FF fibers on the flexural strength, the load-deflection curve, and the cracking behavior of the beam specimens. Based on the results, the optimum content of FF fibers for improving the mechanical properties of concrete, as well as the flexural behavior of beams, is 0.4%. Further, using 0.7% FF fibers proved to be very effective in controlling the mechanical strength reduction of concrete and the flexural strength of beams immersed in acid. In addition, substituting CAC for OPC enhanced the ultimate flexural capacity of the beams with and without immersion in acid. With regard to cracking behavior, the presence of FF fibers, the exposure of specimens to acid, and the replacement of OPC with CAC reduced the average width and spacing of cracks and increased the number of cracks in the beams.
