Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Axial load


Effect of Re-vibration Process on Axial Capacity of Short Reinforced Concrete Circular Columns

S.A. Abbas

Engineering and Technology Journal, 2017, Volume 35, Issue 7, Pages 776-787

A considerable amount of research work has been performed on the effects of vibrating of fresh concrete on the reduction of shrinkage and creep, the improvement bond stress between reinforcing bar and concrete, reduction the concrete permeability and improvement of the mechanical properties of concrete (tension and compression). Series of tests on reinforced concrete circular column, cubes and cylinders were carried out to study the effect of re-vibration duration on axial strength of column, compression strength of concrete cubes, and tensile strength of cylinders. Different compressive strengths of concrete and different size of aggregate were considered in this investigation. The test results show that, the re-vibration operation improves the tensile and compressive strength of concrete. The stiffness of columns increased with increasing the re-vibration duration up to1.5 times the initial vibration duration. Size of aggregate has significant effect on the improvement properties of concrete due to re-vibration. Increase the time duration of re-vibration delay the appearance of first crack.

Behavior of Aluminum Columns Enhanced with CFRP and Filled by Lightweight Concrete

ad Fahad Resan

Engineering and Technology Journal, 2014, Volume 32, Issue 11, Pages 2658-2672

An experimental study of composite columns of hollow circular aluminum tubes enhanced with a fibers reinforced polymer (FRP) sheet and filled by lightweight concrete are presented in this paper. The study's scope is introducing and developing lightweight columns to be advantageous in lightweight and size limited structures. The test results discussed the influence of internal and external confinement effectiveness introduced by lightweight concrete and carbon fiber reinforced polymer (CFRP) retrofitting sheet, respectively. The column specimens were subjected to uniform axial compression load. Structural aluminum alloy circular hollow section has been used in this investigation. Carbon fiber reinforced polymer (CFRP) is used to piling aluminum tubes. Light weight expansion clay aggregate (LECA) is used to fabricate light weight concrete filling aluminum tubes. The strengths, shortening displacement, axial strains, lateral strains, and failure modes of columns were presented. The test results indicated that confinement and composite action between the constituent materials resulted in enhanced compressive strength, ductility and energy dissipation capacity of the proposed composite column. Finally, a simplified design equation is proposed to predict the compressive load capacity of this type of composite column.

One Parameter Composite Semigroups of Linear Bounded Operators in Strong Operator Topology of Schatten Class Cp

Samir Kasim Hassan; Al-Taie M; Al-Malki Anam; Al-Attar Abeer; Mustafa Khaleel Ismael; Fatema Ahmed Sadeq; Radhi A .Zboon; Jehad R.Kider; Samir K .Hassan; Hussain J. M. Alalkawi; Raad H. Majid; Rawaa A. Alomairy; Luma Abdul Ghani Zghair; Hadia Kadhim J.Al-Ogili; Assifa M. Mohamad; Abbas Sheyaa Alwan; Haider L. Aneed; Assim H Yousif; Salema Sultan Salman; Abbas Hussien Miry; Abduladhem A.Ali; Mohammed Zeki Al-Faiz; Sabah N. mahmood; Khansaa Dawood Selman; Shaymaa Tareq Kadhim

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1463-1470

For semigroups of linear bounded operators on Hilbert spaces, the problem of
being in Cp , 0 Keywords

Studying the Behavior of Axially Loaded Single Pile in Clayey Soil with Cavities

Shaymaa Tareq Kadhim

Engineering and Technology Journal, 2011, Volume 29, Issue 8, Pages 1619-1630

This paper deals with the interaction between cavities and adjacent axially loaded pile in clayey soil using the three dimensional finite element program (ANSYS 11.0).Three dimensional SOLID45 and SOLID65 elements were used to model the soil and the reinforced concrete pile respectively. Druger- Prager model is chosen to simulate the non-linear elastic-plastic clayey soil, concrete model is used to simulate the nonlinear behavior of concrete pile, the steel bars are assumed to be embedded in concrete section. A comparison of the behavior of load-settlement curve, shear stress on pile (τxy) and lateral soil stress on pile (σx) is made for cases of the variation in the cavity positions in the vertical direction (Z-direction) with case of no cavity. It has been found that the effect of the cavity on the shear stress along pile length (τxy) and on the lateral soil stress on pile
(σx) is ignored to the depth greater than (20%) of the pile length from the ground level. Furthermore, the load-settlement curves are quite difference if compared with reference case of no cavity due to the cavity position near the face of pile.