Impact of Wetting and Drying Cycles on the Performance of Fiber-Reinforced High-Strength Concrete

One of the important causes of structural deterioration in concrete structures subjected to a saline or maritime environment is chloride-induced reinforcement corrosion, which manifests as spalling, cracking, and delamination of the concrete cover. In addition, the loss of the link between the concrete and the reinforcement and the reduction in the cross-sectional area of the rebar may lead to additional damage to a corroded reinforced concrete element. Therefore, the samples were submerged in a solution of sodium chloride (NaCl), sodium sulfate (Na2SO4), and magnesium sulfate (MgSO4) to start the damaging process and achieve the anticipated chloride penetration. This study then examines wet-dry cycles (WDC) for 180-d. The volume fractions of date palm fibre (DF), polypropylene fibre (PF), and steel fibre (SF) of 0%, 0.2%, 0.6%, and 1.0%, respectively, were utilized for the fabrication of high-strength fibre-reinforced concrete (HSFRC). The crucial structural characteristics were assessed in this investigation, i.e., compressive strength, flexural strength, density, water absorption capacity, and load-displacement behaviour. The test results indicated that as the fibre contents increased under WDC exposure, the compressive strength of the high-strength concrete (HSC) with DF, PF, and SF increased by 25%, 27%, and 25%, respectively. Flexural strength increased by 37%, 28%, and 57%, respectively. The displaceability ductility, deformability, and energy ductility of the DF, PF, and SF-reinforced HSC were noticeably enhanced with the application of WDC. Hence, the natural DF fibres might be suitable to construct sustainable HSC and be applicable to protect against harsh weathering conditions compared to the PF and SF.