Experimental-Numerical Analysis of Bending Behavior of Reinforced Concrete Beam with Electrochemical Chloride Extraction-Strengthening

The magnesium phosphate cement (MPC)-carbon fiber reinforced plastics (CFRP) strengthening and electrochemical chloride extraction (ECE) integration experiment was carried out for reinforced concrete beams corroded by sodium chloride. Then the bending performance of the reinforced concrete beams was analyzed by test and numerical simulation. The reinforced concrete beams of the control group were energized to accelerate corrosion until the theoretical corrosion rate of the steel bars reached 10%. The second group of the beams were strengthened, and the other three groups of the beams were strengthened and the inside chloride was removed by electrochemistry method with different dechlorination current densities. The bending test results showed that the bending bearing capacity of the strengthened concrete beam increased by 18.22%. The bending bearing capacity of the strengthened and dechlorinated beam increased by 15.11%, 13.25% and 9.76%, respectively. The chloride ion content at the interface between steel bar and concrete reduced by 68.68%–82.64%. In addition, the numerical simulation method of “standard cube test block-central pull out test block-reinforced concrete beam” was proposed. A 3D mesoscopic finite element plastic damage model of the reinforced concrete beams strengthened by MPC-CFRP was established. The numerical results were in good agreement with the experimental results.