Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : columns

Compressive Performance of Corroded Reinforced Concrete Columns

Mushtaq Radhi; maan s. hassan; Iqbal N. Gorgis

Engineering and Technology Journal, 2020, Volume 38, Issue 11, Pages 1618-1628
DOI: 10.30684/etj.v38i11A.1545

Corrosion of reinforcement has been identified as the deterioration mechanism of reinforced concrete structures, which seriously affects the safety and integrity of structures. The corrosion of the embedded reinforcing steel in concrete is a major problem facing civil engineers today, which initiates 80% of the reinforced concrete structures deterioration. This paper reveals the outcomes of an experimental investigation on the mechanical performance (residual strength) of circular steel reinforced columns which have been damaged by corrosion of the steel rebar. Small scale circular reinforced concrete columns with a diameter of 100 mm and 300 mm in height were adopted. Different rates of steel reinforcement mass loss (corrosion damage) ranged between 10%, 20% to 30 % were created in the columns by using a galvanostatic accelerated corrosion method combined with wetting-drying cycles. The uniaxial compression test was implemented for damaged columns up to failure. Based on the experimental outcomes, it was revealed that the corrosion damage had substantially reduced the performance of columns. The decrement of the load capacity of corroded columns ranged between 19% to 40% and for corrosion level ranged from 10% to 30%, respectively. The decrement of the final deformation of corroded columns ranged between 15% to 30% and for corrosion level ranged from 10% to 30%, respectively. Likewise, the failure mode and relationship between the stress and strain for corroded columns had been adversely affected by corrosion.

Determination the Optimum Shot Peening Time for Improving the Buckling Behavior of Medium Carbon Steel

Al-Alkawi H. J. M; AL-Khazraji A. N; Essam Zuhier Fadhel

Engineering and Technology Journal, 2014, Volume 32, Issue 3, Pages 597-607

The purpose of this paper is to estimate the optimum improvement of surface treatment on the dynamic buckling behavior of CK35 steel alloy due to shot peening based on the experimental results. Rotating circular column buckling test machine was used to evaluate the buckling life of column under compression and combined loading. The experimental results obtained show a favorable influence of shot peening treatment on mechanical properties and dynamic buckling behavior. A maximum significant life obtained at 25 min SPT (shot peening time) under dynamic buckling. The results showed that shot peening change the type of column from long to intermediate one based on Euler and Johnson formulas.

A Neural Network Model to Predict Ultimate Strength of Rectangular Concrete Filled Steel Tube Beam – Columns

Ahmed Sagban Saadoon; Kadhim Zuboon Nasser; Ihsan Qasim Mohamed

Engineering and Technology Journal, 2012, Volume 30, Issue 19, Pages 3328-3340

In this study, a model for predicting the ultimate strength of rectangular
concrete filled steel tube (RCFST) beam-columns under eccentric axial loads has
been developed using artificial neural networks (ANN). The available experimental
results for (111) specimens obtained from open literature were used to build the
proposed model. The predicted strengths obtained from the proposed ANN model
were compared with the experimental values and with unfactored design strengths
predicted using the design procedure specified in the AISC and Eurocode 4 for
RCFST beam-columns. Results showed that the predicted values by the proposed
ANN model were very close to the experimental values and were more accurate
than the AISC and Eurocode 4 values. As a result, ANN provided an efficient
alternative method in predicting the ultimate strength of RCFST beam-columns.

Design of Beam-Columns Using Artificial Neural Networks

Abdelmaseeh Bakos Keryou; Raid Rafi Al-Nima; Rafal Naheth Wadie

Engineering and Technology Journal, 2012, Volume 30, Issue 16, Pages 2843-2857

In this paper, manual design of beam-columns, based on the procedure adopted by
american society of steel construction, is described. an attempt has been taken to
apply artificial neural network to the design of steel beam-columns of hot-rolled
shapes. for this purpose, a set of data have been generated using the software package
staad pro, and then used in training and testing the neural network. the results showed
that artificial neural network after successful learning could specify the proper
sections with relatively high accuracy.

Behavior of Short Reinforced Porcelinite Concrete Columns Under Concentric Loads

Kaiss F. Sarsam; Ihsan A. S. Al-Shaarbaf; Mustafa S. Shuber

Engineering and Technology Journal, 2009, Volume 27, Issue 6, Pages 1219-1233

This study presents on experimental method to investigate the behavior of
reinforced porcelinite concrete columns subjected to concentric load. The experimental
work includes investigation of ten lightweight concrete columns with square cross
section 190×190mm and 1000mm in length subjected to concentric load to assess the
effect of the amount of longitudinal steel reinforcement, lateral tie reinforcement and
grade of concrete. From the experimental observation it was found that the porcelinite
aggregate is a good structural material to produce lightweight concrete columns. It is
noted from tested columns that keeping the amount of the longitudinal steel ratio
constant, the increase in the amount of transverse steel to about four times (by
decreasing the spacing to about a quarter according to the ACI-Code (318M-05)) gave a
significant influence on column post-cracking behavior. The improvements in the
column due to higher value of confinement include: (i) less brittle behavior; (ii)
significantly less damage to the concrete core; (iii) 12% increase in column load
carrying capacity. Also, A modified formula for column capacity is proposed to take
into account the influence of spacing of ties (effect of confinement).

Design charts for channel shaped reinforced concrete short columns subjected to axial compressive load and uniaxial bending

Asma; a A. Ahmad; Sarmad S. Abdul-Qader AL-Badri

Engineering and Technology Journal, 2009, Volume 27, Issue 4, Pages 809-820

Eight design charts are presented for reinforced concrete short C-columns subjected to
axial compressive load plus uniaxial bending. For design these charts can be used for
determining the required column dimensions and amount of steel, while for analysis
these charts can be used for estimating the loaded column capacity.
Four examples are given to explain the use of design charts for both design and
analysis, two of which are design examples while the other two are analysis. It has been
shown by these examples that the new proposed charts are very simple to use in
structural applications.