Scott, Allan

Damage Evaluation and Residual Capacity of Concrete in Damaged RC Columns

Abstract eng:
The crucial need for reliable and practical technique to assess the structural conditions, including the level of damage and also the residual capacity of RC structures after an earthquake, has been highlighted in the recent earthquake events. Taking a decision on, whether a damaged structure should be demolished, repaired or accepted, directly depends on data and information associated with post-event damage evaluation. An experimental study was conducted to quantitatively evaluate both residual axial capacity and also the degradation of concrete material in previously damaged reinforced concrete (RC) columns. Three RC circular columns, all 500 mm in diameter and 1500 mm in height were caged such that to provide three confinement levels: low, medium and high. The columns were monotonically subjected to compressive force up to failure. All damaged RC columns were then cut into approximately three equal pieces with two cores taken longitudinally from each piece. The first core was prepared and instrumented for compression testing, while the second core was sliced into a number of 25 mm disks for oxygen permeability testing. Results from compression test on cored cylinders showed an average of 35%, 32% and 30% reduction in strain capacity, ultimate strength and elastic modulus of concrete in the damaged specimen, respectively. This demonstrated that adopting undamaged stress-strain behaviors of concrete material for the purpose of assessment in a damaged RC structure leads to overestimating of the capacity. Complementary investigation into permeability of damaged concrete disks also led to a damage profile through which the intensity and the extent of damage caused by cracking from the applied axial load, was determined at different locations over the height of the RC columns. The extent of damage was revealed to be up to 25% of the height of the column in the case of low and medium-confined column, while for the high-confined column this length increased to 40% of the column’s height.

Contributors:

Malek, Amirmasoud

Conference Title:

Proceedings of the 16th World Conference on Earthquake Engineering

Conference Title:

16th World Conference on Earthquake Engineering

Conference Venue:

Santiago (CL)

Conference Dates:

2017-01-09 / 2017-01-13

Rights:

Text je chráněný podle autorského zákona č. 121/2000 Sb.