The relationship between rheological behavior and adherence properties of fiber-reinforced mortars produced by extrusion method

The extrusion method, compared to conventional concrete casting, provide advantages to the manufacturer due to reasons such as mold free applicability, fast production possibility, being economical, and providing production potential in complex architectural shapes. The number of academic studies on the extrusion method is increasing day by day due to this reason. In terms of improving structural performance, fiber reinforced mixture designs become popular in recent years. Within the scope of the project, extrudable/buildable composite designs were produced by using HTPP (high tenacity polypropylene) fiber in both binary and ternary binder systems. In the light of the literature knowledge, extrudability criteria were defined and slump-flow values were determined for mortar mixtures meeting these requirements. The fresh state rheological properties of these mixtures were investigated with both a rotational rheometer and a probe apparatus of Vicat device. In addition, the shear rate and the response of the mortar throughout the extruder have been simulated with a rheometer. The hardened unit volume weights of extruded specimens were measured. The compressive, flexural and interlayer bond strengths of specimens were determined at 7th and 28th days. The interlayer bond strengths between the layers were individually determined by applying three different "interlayer waiting times (0 min, 30 min. and 1 day)". In addition, the bond strengths between layers were determined by both pull-off and uniaxial direct test methods, and the relationship between these two methods was investigated.