Study On Reinforced Concrete Columns Combination Strengthening With Bonding Steel Angles And Carbon Fiber Reinforced Polymer Sheets Under Eccentric Loading

Wrapping carbon fiber reinforce polymer sheet (CFRP) and bonding angle steel are two common methods in reinforced concrete columns reinforcement engineering nowadays. There are different limitations when these two methods are applied to R.C. engineering, especially to seismic strengthening of R.C. columns under eccentric loading in which ultimate loading capacity and ductility of the column need to be greatly improved. in order to solve this problem in practice ,a strengthening method is presented by using both bonding carbon fiber reinforced polymer sheets and steel angles. The mechanical properties of the combination reinforcement under ultimate state are studied in this thesis. It mainly includes,1 The influence of eccentricity ratio, angle steel ratio, CFRP ratio, slenderness ratio and bonding patterns of CFRP are considered in this thesis. 14 R.C. columns under eccentric loading are conducted to experiment. The failure mode, loading capacity and the relation between axial load and strain of the column under ultimate state are analyzed, the figures and tables are also made in this paper.2 Analysis of the mechanics of CFRP bonding, angle steel strengthening and combination reinforcement are carried out. Strip and simplified methods are presented. Comparisons are made between the solutions and experimental data. The results show good agreement which can be referred by practical engineering.3 Analysis of the total procedure of strengthened R.C. column under eccentric loading are carried out. The axial load-deflection curves in different cases are compared with the experimental curves, showing good results. According to the result of calculation, the axial load-moment correlation curves are plotted when CFRP ratio, slenderness ratio, angle steel ratio and eccentricity are all varied, and the influences of above parameters on mechanical properties of strengthened R.C. columns are also analyzed.4 The influences of glue thickness, glue elastic modulus, thickness of angle steel and planted bar anchorage on bondage and anchorage of combination strengthened R.C. columns are also analyzed, proposing concerning measures for preventing strengthened R.C. columns from bonding failure.