Reinforced Concrete Corrosion and Protection

摘要

This paper reports result of a study conducted to assess the effect of some locally produced materials on the protection of reinforcing steel against corrosion. Also the effect of period and the main consequences on mechanical properties of steel and concrete are evaluated. Reinforcing steel bars, 10 mm in diameter, that were corroded in reinforced concrete specimens were removed and tested in tension. Twenty seven concrete cylinders with dimensions (15 × 30 cm) provided with central steel bar were cast and tested after 28 days to demonstrate the effect of the protective materials on the bond strength. A total of ten reinforced concrete beams (10 × 15 × 100 cm) were cast using a self-compacted concrete mix. All beams were tested in flexure. The results of the tested beams are analyzed in terms of; cracking pattern, load deflection, ductility. The failure mode of each specimen was recorded. The tests recommended determining the mechanical properties of mix were; the compressive test, the splitting tensile test, and flexural strength test. Results cleared that with increasing duration of exposure to a corrosive environment, the steel mass loss increases appreciably. This leads to a significant increase of the applied stress. In addition, a reduction of the tensile ductility of the material was observed. The main result from the accelerated corrosion tests in bare steel bars, that the important ductility property of the elongation to failure is very sensitive to mass loss due to corrosion, it is valid and in real structures. Coating with epoxy resin increases the protective from the corrosion more cement-based resin by 15 %.