Analysis of the residual safety level in R/C slabs with severe joist corrosion

An analysis until the failure on a series of one-way slabs with severe corrosion at the lower reinforcement of the R/C joists is presented. Different positions in the slab and number of damaged joists have been studied, obtaining the residual safety assessment in cases of slabs damaged by flexural failure mechanisms. Since the boundary conditions have proved decisive for obtaining the behavior, the damaged slab has been evaluated as part of the entire building, as precisely as possible, taking into account the different phases of the construction process and deterioration in time, and the complex behavior of concrete, steel and masonry. The results of the proposed methodology are consistent with the pathology of the observed cases. As a result of this study the authors propose practical recommendations to help in making decisions about the magnitude of the intervention, always necessary in this type of pathology.Vercher Sanchis, JM.; Gil Benso, E.; Mas Tomas, MDLA.; Cubel Arjona, FJ. (2014). Analysis of the residual safety level in R/C slabs with severe joist corrosion. Journal of Performance of Constructed Facilities. 1-14. doi:10.1061/(ASCE)CF.1943-5509.0000608S11

Repair of cracks in simply supported beams using epoxy injection technique

The research reported in this paper is a contribution in understanding the epoxy injection retrofitting technique to strengthen the existing RC cracked members. This technique consists of injecting epoxy resin adhesive in a cracked beam to increase the stiffness and the strength. A total of six full scale RC beams were constructed with the same material using the same mix and water-cement ratio. The beams were tested until the width of cracks reached a limiting value of 1 mm. The beams were then repaired with the epoxy injection technique. After 3 days of water curing, the beams were tested again and loaded till the failure occurred. A considerable enhancement in the load carrying capacity was observed in the beams after the retrofitting. A reduction in deflection was also observed due to the injection of epoxy. These results clearly demonstrate the effectiveness of the proposed technique in repairing the RC members for strengthening the existing structures