Eccentric Compressive Behavior of Reinforced Concrete Columns Strengthened Using Steel Mesh Reinforced Resin Concrete

Rapid strengthening is focused on recently to reduce the time for reinforcement process and decrease the losses. However, there are some limits for the existing reinforcement technologies to be used for rapid strengthening. The paper reports an experimental investigation on eccentric compressive behavior of reinforced concrete columns that are strengthened using steel mesh reinforced resin concrete (SMRC) for rapid strengthening. Four reinforced concrete columns with 180 mm x 250 mm test cross section and 1000 mm test height were fabricated and tested under large eccentric compressive load. Among the four columns, three columns were strengthened using SMRC with different numbers of steel mesh layers; the other column was not strengthened and was used as the control specimen. The effect of layer number of steel mesh on the failure mode, cracking load and load capacity of the columns were studied. Finite element analysis was carried out to evaluate the effects of the layer number of steel mesh, thickness of SMRC layer, and the load-holding level on the load capacity of the columns. Results show that the crack distribution of the strengthened columns was influenced by the layer number of steel mesh. The layer number was the dominant variable for the load capacity, rather than the thickness of the SMRC layer. With the increase of load-holding level, the load capacity of the strengthened column decreased following a bilinear trend. Some conclusions can be drawn that the reasonable reinforcement ratio of steel mesh is about 2%. Resin concrete is mainly used as bonding layer. The decreasing rate of the bearing capacity is higher at the high load-holding levels.