Flexural behavior of high-performance and non-high-performance textile reinforced concrete composites

The flexural behaviour of textile reinforced concrete (TRC) samples reinforced with two types of textile, (1) polypropylene (PP) roving with a low elastic modulus and (2) aramid roving with a high elastic modulus, is studied and compared. The TRC samples are reinforced using up to eight layers of plain weaved fabrics with the mesh size of 5 mm and 10 mm. Flexural behaviour and capacity of composite specimens are investigated using a four-point bending test. The microstructure of cement matrix and fibres is also studied using SEM images. It was found that the flexural strength of TRC samples strengthened with PP and Aramid textiles increased by increasing the number of fabric layers. Reducing the fabric mesh size increased the bending strength of Aramid TRC samples because of the chemical bond between Aramid fibres and concrete. On the contrary, PP fabrics with larger mesh sizes showed higher bending moment strength as the connection between PP fabrics and concrete is mechanical. A large number of PP fabrics in TRC specimens caused delamination; therefore, roving reinforced concrete (RRC) instead of TRC was used to increase the reinforcement ratio in specimens. The test results of TRC and RRC samples showed that the flexural behaviour of samples reinforced with PP longitudinal roving (reinforcement ratio of 1.60% PP roving) was similar or even better than samples reinforced with high-modulus Aramid fabrics (reinforcement ratio of 0.92% Aramid fabric) in terms of strength and stiffness.