Influence of steel corrosion to the large eccentric compression behavior of coral aggregate reinforced concrete column

The large eccentric compression behavior of coral aggregate reinforced concrete column (CA/CC) with different types of reinforcement and concrete strength grade was tested. The failure mode, deformation and bearing capacity were investigated. The relationships of load-displacement and load-strain were established. The applicable calculation model for ultimate bearing capacity (N_u) of CA/CC under large eccentric compression was suggested. The results show that the compression behavior of CA/CC is similar to the ordinary aggregate reinforced concrete column (OA/CC). With the increase of concrete strength grade, the load corresponding to the sudden change of the strain of CA/CC longitudinal tensile steel gradually increases. In the loading process, a greater slip was produced in the layer between the organic new coated steel and coral aggregate concrete(CA/C). N_u of common steel is approximately 7.1%~20.8% higher than that of organic new coated steel. The application of organic new coated steel in the CA/C structure is suggested to effectively inhibit steel corrosion and extends the effective service life of the CA/C structure. Based on the comprehensive consideration on the effects of steel corrosion and slip of the coated steel, a calculation model for N_u of CA/CC under large eccentric compression is proposed.