Ultra high performance fiber reinforced concrete as strengthening material

Abstract

The safety of structures is of high importance affecting people's lives. Structural evaluation, and possibly intervention, is considered necessary for old structures, structures which have been affected by accidental actions and also for structures in high seismic risk areas. Research should now focus on the development of new sustainable techniques which increase the safety of existing structures, and at the same time minimize the necessary to build new structures and to consume new materials and resources. The present research investigates the effectiveness of an advanced material, such as Ultra High Performance Fiber Reinforced Concrete (UHPFRC), for the strengthening of existing Reinforced Concrete (RC) structures. For this reason, an extensive experimental study on the properties of the material and the application for strengthening of RC beams has been conducted. More specifically, parameters such the effect of fiber content on the performance, the workability and the cost of the material have been investigated first. Based on the analysis, an optimum mixture design has been selected and has been applied for strengthening of RC beams using different configurations. The results indicated that the strengthening with UHPFRC is a well promising technique and the performance of the strengthened elements has been increased in all the examined cases.