Papers by Keyword: Prestressing Strand

Abstract: Six I-section steel beams had been fabricated and tested to understand the influence of prestressing strand on the load deflection behavior of steel beam. All tested beams are simply supported having the same gross sectional area with clear span (2850) mm, five beams strengthened by two low relaxation seven wire strands, while sixth beam is the reference one. The strengthening beams were subjected jacking stress equal to (1120MPa) and subdivided according to prestressing strand positions (eccentricity). From the experimental tests, it can be noted that, the load deflection curves for strengthened beams are stiffer as compared with reference beam and the percentage of ductility for strengthened beams were decreased when the eccentricity positions change form (0 to 96)mm respectively, on the other hand, the percentage of increasing in maximum applied load for strengthened beams were increased with increasing of strands eccentricity and the maximum applied load reaches to 61.74% as compared with reference, also, the percentage increasing in maximum deflection at middle span for strengthened beams decreases with increasing of strands eccentricity and the minimum percentage of decreasing at middle span of strengthened specimens reaches to 36.31% as compared with the reference beam.

Abstract: Corrosion of prestressing strands is a main durability issue for prestressing structures. In general, the corrosion zones of strands are hidden in structures which lead to be hardly inspected by traditional methods. An instrument for detecting the non visible corrosion of prestressing strands using magnetostrictive guided waves is provided. The instrument is described in detail. The workflow to detect the strands is provided. Field trials and laboratory experiments show that the information of position, length and amount of the corrosion can be obtained from the data. The instrument provides support for ensuring the safety of prestressing structures.