Creating Strain Hardening Cementitious Composites (SHCCS) Through Use Of Additively Manufactured Polymeric Meshes As Reinforcement

Abstract

Strain hardening cementitious composites are a class of cementitious materials showing metal-like (i.e. pseudo-plastic) behavior in tension due to their multiple cracking ability. This is commonly achieved through use of fiber reinforcement (such as PVA) or, similarly, textile reinforcement (TRC). Increasing the ductility is important in applications such as e.g. earthquake zones, where this enables absorption of large amounts of energy. On the other hand, tight cracks are important for ensuring the protection of the reinforcing steel and hence the durability of a reinforced concrete structure. This research presents an alternative approach – creating strain hardening cementitious composites by using additively manufactured (3D printed) polymeric meshes instead of fiber or textile reinforcement. Different designs of polymeric meshes were manufactured and cast in mortar. They were subsequently tested in four-point bending and uniaxial tension. The results show that properly designed polymeric meshes enabled deflection hardening or strain hardening to be achieved, either through slip hardening of the polymeric reinforcement or through multiple microcracking. Furthermore, it was possible to create a simple functionally graded cementitious composite, in which denser reinforcement was used in the constant moment region of the 4-point bending specimen compared to the outer regions, without loss of ductility. This study shows great potential of 3D printing for customization of cementitious composites.