Axially loaded RC columns repaired on one side with cement-based mortars

Abstract

This paper describes and analyses the results of an experimental programme carried out at the Universitat Politècnica de València on 18 reinforced concrete (RC) columns, 12 of which had been repaired on one side with cement-based mortar before being subjected to axial loading until failure. The objective of the research was to determine the performance of the columns that had been repaired using different mortars, evaluate the influence of Class R3 and R4 mortar used and of the application of a binder or bonding agent. The results obtained were compared with those of the undamaged control columns and those of the unrepaired damaged columns to obtain values for the efficiency of the repairs and for the improvement in the load-bearing capacity of the columns. The results obtained indicate that the columns repaired with Class R3 mortar, with a lower elasticity modulus, function in better way than the Class R4 repaired ones. The presence or absence of a binder was not found to be a determining factor in improving the behaviour of the repaired elements. The chief novelty of the study lies in the fact that it is the first experimental study on RC columns totally repaired on one side only, using different types of mortar with and without the application of a binder.

Cement-based mortar patch repair of RC columns. Comparison with all-four-sides and one-side repair

“…In previous research the authors studied the behaviour of square cross-section columns repaired on all four sides [28] and on one side only [29]. The results are given below for later comparison with the results of the present work.…”

“…Four types of repairs were thus involved: R3-mortar with BA, R3-mortar without BA, R4-mortar with BA and R4-mortar without BA. These results were then compared with the results of previous studies by the authors on repairs on all four column sides [28] and on one side only [29].…”

Investigating the structural contribution of patch repairs to reinforced concrete elements

“…An elastic modulus of 9-10 GPa was used by Kristiawan et al [13] to investigate patch repaired RC columns under eccentric compressive loads. In the study by Ortega et al, the columns repaired on either one [14] or all-four sides [15] was done using class R3 and R4 structural repair mortars, as defined by the European Standard EN 1504. Sharif et al [16] investigated the structural effectiveness of patch repairs on RC columns using two materials that were described as having a "high" and "low" modulus of elasticity, respectively.…”