Durability Performance of Hybrid Carbon–Glass Fiber Reinforced Concrete Incorporating Alccofine: An Experimental Investigation

This paper presents a comprehensive experimental investigation on the durability performance of Hybrid Carbon–Glass Fiber Reinforced Concrete (HCGFRC) incorporating Alccofine 1203 as an ultrafine supplementary cementitious material. The study focuses on M25 grade concrete, which is widely used in medium-scale structural applications but often exhibits durability limitations under aggressive environmental conditions. Cement was partially replaced with 10% Alccofine, while hybrid fibers consisting of carbon and glass fibers were introduced at a combined dosage of 0.75% by volume of concrete. Mechanical properties were evaluated through compressive strength, split tensile strength, and flexural strength tests at 7, 28, and 56 days. Durability characteristics were assessed using sorptivity, water absorption, Rapid Chloride Penetration Test (RCPT), sulphate resistance, acid resistance, and accelerated corrosion tests. The results indicate that the incorporation of Alccofine significantly refines the pore structure and enhances hydration, leading to reduced permeability. The hybrid fiber system effectively controls crack initiation and propagation, thereby limiting ingress of moisture and aggressive ions. Compared to conventional concrete, HCGFRC exhibited substantial reductions in sorptivity, water absorption, and chloride ion penetration, along with improved resistance to chemical attack and corrosion. The study concludes that the synergistic action of Alccofine and hybrid carbon–glass fibers is an effective and practical strategy for enhancing the durability and service life of M25 grade concrete in moderate exposure conditions.