RESUMEN
This paper deals with the long-term bonding and tensile strengths of textile reinforced mortar (TRM) exposed to harsh environments. The objective of this study was to investigate the long-term bonding and tensile strengths of carbon TRM by an accelerated aging method. Moisture, high temperature, and freezing-thaw cycles were considered to simulate harsh environmental conditions. Grid-type textiles were surface coated to improve the bond strength with the mortar matrix. A total of 130 TRM specimens for the bonding test were fabricated and conditioned for a prolonged time up to 180 days at varying moisture conditions and temperatures. The long-term bonding strength of TRM was evaluated by a series of bonding tests. On the other hand, a total of 96 TRM specimens were fabricated and conditioned at freezing-thaw conditions and elevated temperature. The long-term tensile strength of TRM was evaluated by a series of direct tensile tests. The results of the bonding test indicated that TRM was significantly degraded by moisture. On the other hand, the influence of the freezing-thaw conditions and high temperature on the tensile strength of the TRM was insignificant.
RESUMEN
The proportion of composites, mainly glass and carbon fibre-reinforced polymers (FRP) in the material cycle have been increasing for years in many sectors. Landfilling of FRP waste is forbidden and recycling is still an unsolved issue. Aim of this paper is the investigation of a feasible reuse of FRP as reinforcement in concrete as shredded material or as thermally recovered plain carbon fibres. A huge amount of glass fibre polymer waste is generated in the wind energy sector and shows low alkaline resistance which is not directly applicable as a reinforcement in alkaline concrete without any surface protection. Therefore, different surface treatments were conducted: on the one hand the aim is to protect FRP fragments in concrete and on the other hand to improve the adhesion. The results of pull-out tests show that a sanded surface of glass fibre polymers increases the averaged maximum shear strength by 16 %. Investigation of the influence of different volume contents (0.25, 0.5, 1 and 2 Vol.-%) of recycled, pyrolized carbon fibres with a varying fibre length show a maximum flexural strength at 1 Vol.-% in bending tests on fibre reinforced concrete. Compared to plain concrete an increase of +111 % can be observed.