Bending load capacity of reinforced concrete slabs strengthened with textile reinforced concrete

The use of textile reinforced concrete (TRC) is a very effective method for strengthening reinforced concrete (RC) constructions. Within the Collaborative Research Centre 528 of the Technische Universität Dresden (TU Dresden) vast research on TRC was carried out, so as to examine the use of TRC for subsequently strengthening the bending load capacity of existing concrete or reinforced concrete components. As a rule, the experimental research was done at small format reinforced concrete slabs with span widths of 1.60 m and slab thicknesses of 0.10 m strengthened with TRC. At the same time calculation models were developed to predict the maximum bending load capacity of the reinforced components amongst others.This article describes the experimental and theoretical research reassessing the assignability of the results gained until now to large scale reinforced concrete slabs with a span width of 6.75 m and slab thickness of 0.23 m. By using textile high-performance carbon reinforcements based on so-called heavy-tow-yarns very high strengthening levels can be realized. The results show significant load bearing capacity increases compared to unreinforced reference slabs. Thus the safe use of bending reinforcements consisting of TRC could be demonstrated for components with even large span widths and high reinforcement degrees. Simultaneously a distinct decrease of deflection with growing reinforcement degree was verified at a comparable load level. Calculation results of the presented simplified calculation model for the estimated bending measurement are consistent with the load carrying capacities determined experimentally. Using the finite element method (FEM) not only the load bearing capacities but also the deformations were calculable keenly.

► Significant increase of load bearing capacity by strengthening with textile concrete.
► We study large span concrete slabs by using the finite-element-method.
► We introduce easily manageable equations to determine bending capacity.
► Excellent accordance between photogrammetric measurements, FEM and simplified analysis.