Investigating the influence of permeable formwork on the mechanical characteristics of glass fiber reinforced concrete

The controlled permeable formwork (CPF) liner is an innovative approach to enhance the quality of the concrete cover zone. This novel technique facilitates the drain of excess water and entrapped air from the freshly laid concrete's near-surface region, while retaining tiny particles like cement and other fine constituents. Therefore, the concrete becomes denser and less porous as a result of a decrease in the water-to-cement ratio at the surface zone. This strategic manipulation of the concrete's surface composition yields more robust and durable cover zone, enhancing the overall performance and longevity of the structural element. The effect of incorporating glass fiber (GF) into concrete with a CPF liner was investigated in this research. Different percentages of glass fiber (0.5, 1.0, 1.5, and 2.0) were added to the CPF concrete mix to prepare the samples, and tested at various ages. The Rockwell hardness, rebound number, dynamic hardness, split tensile, flexural strength, compressive strength, and superficial pore measurement tests were conducted. The results indicated that the dynamic and rebound hardness, split, and flexural strength of the CPF liner concrete with 1.5% of GF were significantly enhanced at a range of 74, 69, 49, and 47% correspondingly.