Interfacial bonding of fine aggregate concrete to low modulus fibers

The present work describes the feasibility of using cost effective and low modulus polymeric fibers including Nylon 6,6 and Acrylic fibers as reinforcement of fine aggregate cementitious composites. For this purpose, the pullout energy and interfacial bonding strength of fibers to the different matrix compositions where evaluated using a pullout test. Surface free energy of the fibers and different fine aggregate composites were also evaluated using the sessile drop method. Fiber to cement bonding strength, thermodynamic work of adhesion and surface free energy (wetting affinity) were assessed by changing maximum aggregate size, water to cement (binder) ratio, using fly ash as supplementary cementing materials (SCMs) and fiber type. Both chemical and mechanical interfacial interactions were measured and it was found that the Nylon 6,6 fiber showed highest pullout energy and flexural toughness due to more mechanical interlocking to the matrix.