Evaluation of Properties of Impregnated Reinforcement Textiles Cured Within Concrete for Applications in Concrete Extrusion

Abstract

Textile reinforced concrete (TRC) is a new material combination in which the traditional steel reinforcement in concrete constructions is replaced by textile reinforcement made of high-performance fibers, usually produced from glass or carbon. Since the textile reinforcement is not a monolithic material, bond behavior differs vastly from that observed in steel reinforced concrete. The textiles consist of thousands of individual filaments and are impregnated with a polymer or mineral solution to facilitate load transfer to all filaments. In the state of the art, the polymer impregnation is cured immediately after the impregnation, limiting the shapeability of the reinforcement. For novel additive manufacturing methods, such as concrete extrusion, this greatly limits the design flexibility. A novel approach for TRC extrusion is the use of prepregs, in which the textile is impregnated with a polymer material but the curing reaction is delayed until the textile is placed within the concrete matrix. This approach promises shapeable textiles with a high mechanical performance within the final concrete element. In this work the results of initial experiments into this novel prepreg approach are presented. A potential impregnation material is applied to a non-impregnated carbon reinforcement and evaluated based on its mechanical properties on a composite level. Additionally, microscopy images are taken and evaluated to analyze the bond between impregnated reinforcement and concrete.