Understanding cracking evolution in textile reinforced cementitious composites using Acoustic Emission and other monitoring techniques

Prefabricated building walls of the future will be thinner and lighter than ever. Fiber textile reinforced concrete walls can be built up few millimeters thick, decreasing this way the environmental impact of the structure. The innovative design is discussed in literature the recent decade under the scope of ‘textile reinforced cementitious composites (TRC)’. The TRC wall elements carry layers of orthogonal fiber mats that can withstand and eliminate tensile cracks on concrete cover. The design of TRCs is still under investigation. Indicatively, research is done to optimize the textile geometry, introduce three-dimensional fiber waving techniques, enhance the interfacial concrete-fibers bonding conditions. Simulating service-life loading conditions, our study aims to thoroughly assess the mechanical response of TRC elements in tension. Small scale TRC coupons are cured in freeze-thaw and heat-rain conditions and afterwards are tested in crack opening fracture mode (mode-I). The main damage mechanisms (i.e. concrete multiple cracking, interfacial debonding, textile deformation and fibers pull-out) are monitored using Acoustic Emission (AE) and other optical measuring techniques. Based on AE hits analysis, the damage mode is identified at different loading stages. Furthermore, AE hits features are examined and their trends reveal the presence of early matrix micro-cracking. The latter can be attributed to the effect of durability loads on TRCs response to fracture.

Publication year:2018

Keywords:Japanese Society for Non-Destructive Inspection, Tension, Durability loads, Freeze-thaw, Heat-rain, Cracking patterns, Acoustic emission, Damage source, Integrated monitoring system