The Influence Of Pre-Load On Bearing Capacity Of Combination Strengthening RC Columns

Pasting CFRP and bonding angle steel are two common reinforcement methods in practical, RC compressive components strengthened by angle steel or CFRP have been studied comprehensively. but they have both advantages and disadvantages by their own in increasing bearing capacity and ductility of frame components. Some scholars have done experiments on the study of concrete columns strengthened with both angle steel and CFRP. But the report of the experimental study on the combination strengthening of columns under pre-load, is still vacant by now.Through the compression experiment of 4 centric and 6 eccentric rectangle reinfo- rced concrete columns, the failure types, confinement mechanism , performance character- ristics and stress-lag of the under pre-load and different eccentricities reinforced concrete columns strengthened with both CFRP and angle steel are demonstrated in detail. The ulti- mate bearing capacity, load-strain relationship of the reinforced columns strengthened with both CFRP and angle steel those have been bearing pre-load were researched and analyzed.The results of the experiment indicate: RC compressive components after be com- ponationly strengthened, the corresponded stain of concrete, steel bar and steel angle does accord with plane-section assumption; the higher the pre-stress, the lower the bearing capacity of the combination strengthening columns; the binding force of concrete decreases with the increasing eccentric distance.Through the experiment study and the analysis of the data from experiment, we known that the centrically and eccentrically loaded columns those after combination strengthened with steel angle and CFRP, the mechanical proformance and the bearing capacity of the concrete columns are improved apparently.Based on the theoretical analysis, and associate with the experimental results, the bearing capacity formula of combination strengthened centrically and eccentrically loaded RC is proposed.On the whole, the results that calculated by the formula are in concordance with the experimental results.