Engineering and Technology Journal

Studying Characteristics and Strength of the Unsaturated Gypseous Soil with Various Saturation Degrees

Ahmed S. Abood; Mohammed Y. Fattah; Aqeel S. Al-Adili

Volume 41, Issue 11 , November 2023, , Page 1309-1324

https://doi.org/10.30684/etj.2023.140119.1453

Abstract

The main objective of this study is to determine the appropriateness of unsaturated gypseous soil as a subgrade layer for carrying foundations. A comprehensive laboratory testing program ... Read More ... The main objective of this study is to determine the appropriateness of unsaturated gypseous soil as a subgrade layer for carrying foundations. A comprehensive laboratory testing program was implemented to investigate the geotechnical characteristics and behavior of unsaturated gypseous soil. Tests that are physical included specific gravity, classification tests, relative density, Proctor compactions, single and double oedometer collapse potential, and static triaxial compression (CU-test). Chemical testing, Scanning Electron Microscopy (SEM), and Electronic Dissipation x-ray Scanning (EDS) analyses were also carried out. The tests were performed for samples prepared at 70% relative density of the natural gypseous soil. Tests are performed on the natural, unsaturated at degrees of saturation (30%, 60%, and 80%) and fully saturated gypseous soil to investigate the gypseous soil behaviors. In both single and double oedometer testing, it was discovered that the degree of specimen collapse is (Moderate) at 70% relative density, with a collapse index value ranging from (4%). The angle of internal friction for both total and effective stresses (f' and f) decreases as the moisture content of the gypseous soil increases at all saturation levels. In contrast, it was found that the strength of soil cohesion for both total and effective stresses (c' and c) increased with increasing gypseous soil moisture up to saturation (60%), which led to a rise in soil shear strength. The reduction value ranged from (38.50° to 7°) in respect of effective stresses and between (34.50° and 7°) with respect to total stresses. Effective stress increase varied from (10.0 – 26.0 kPa), and total stress increase ranged from (12.50 – 28.0 kPa). Then the strength started gradually decreasing at the saturation degrees 80 and 100%, respectively. As a result, the shear strength of the soil decreases with the value of reduction ranging from (20.0 – 11.50 kPa) for effective stresses and (21.50 – 11.50 kPa) for total stresses.

Elevated Temperature Corrosion of Mechanical Properties and Fatigue Life of 7025 Aluminum Alloy

Mohammed H. Alwan; Hussain J. Al-Alkawi; Ghada A. Aziz

Volume 40, Issue 1 , January 2022, , Page 1-7

https://doi.org/10.30684/etj.v40i1.1587

Abstract

Aluminum alloys are widely used in aircraft industry where good corrosion resistance, light weight and high strength are the primary requirements. In the present study, attempts have ... Read More ...

Effect of Starch Powder on Behavior of Silica Fume Biopolymer Concrete

Samir M. Atia; Waleed A. Abbas

Volume 39, Issue 12 , December 2021, , Page 1797-1805

https://doi.org/10.30684/etj.v39i12.2103

Abstract

The great economic development and the growth of modern means of construction have led to the spread of large quantities of chemical admixtures that we must be cautious of. As the world ... Read More ...

Punching Shear Resistance of Reinforced Concrete Flat Slabs Strengthened by CFRP and GFRP: A Review of Literature

Hadi N. G. Al-Maliki; Ali Al-Balhawi; Asma M. Ali

Volume 39, Issue 8 , August 2021, , Page 1281-1290

https://doi.org/10.30684/etj.v39i8.2011

Abstract

Flat reinforced concrete (RC) slabs or plates are still widely used in buildings and are most popular in single or multiple story floor construction systems. This is due to the ease ... Read More ...

Improvement of Soft Clayey Soil by Bio-polymer

Teba A. Abd; Mohammed Y. Fattah; Mohammed F. Aswad

Volume 39, Issue 8 , August 2021, , Page 1301-1306

https://doi.org/10.30684/etj.v39i8.2053

Abstract

This examination explains the utilization of bio-polymer powder for clayey soil enhancement. The article concentrates around examining the strength attitude of the clayey soils built ... Read More ...

Properties and Behavior of Starch Biopolymer Concrete

Waleed A. Abbas; Hawraa M. Mohsen

Volume 38, 10A , October 2020, , Page 1414-1420

https://doi.org/10.30684/etj.v38i10A.365

Abstract

Starch act as natural polymer has been got from Wheat, Tapioca, and Corn. Corn starch has been investigated as biopolymer and has been added to concrete in different percentages (0%, ... Read More ...

Resistance of High-Volume Fly Ash Self-Compacting Concrete to Internal Sulfate Attack

Tareq S. Al-Attar; Ahmed A. Taha

Volume 36, 12A , December 2018, , Page 1260-1266

https://doi.org/10.30684/etj.36.12A.7

Abstract

This paper investigates the durability of high-volume Fly ash self-compacting concrete, HVFASCC that exposed to internal sulfate attack. At the present work, HVFASCC was produced with ... Read More ...

Using Polyethylene Glycol to Produce Self Cured Cement Mortar

Rasha Rawdhan; Awham M. Hameed; Shakir A. Salih

Volume 36, 4A , April 2018, , Page 401-409

https://doi.org/10.30684/etj.36.4A.6

Abstract

The capacity of self-curing admixture is to reduce the evaporation of water from mortar, and subsequently they increase the ability of water retention from mortar contrasted with those ... Read More ...

Studying Strength and Stiffness Characteristics of Sand Stabilized with Cement and Lime Additives

Zeena W.S. Abbawi; Kawther Y.H.AL-Soudany

Volume 33, 8A , October 2015, , Page 1857-1875

https://doi.org/10.30684/etj.2015.108828

Abstract

The present work investigates the strength characteristics of sand stabilized with two additives (cement and lime) each alone at different percentages ranging between 1-10%. Sand mixed ... Read More ...

Effect of Internal Curing on StrengthDevelopment of High Performance Concrete by Using Crushed Lightweight Porcelinite

Tareq S. Al-Attar; Adil M. Abdullatif; Ayman J. Al-Saad

Volume 32, Issue 11 , October 2014, , Page 2803-2814

https://doi.org/10.30684/etj.32.11A.16

Abstract

High performance concrete, HPC, requires a low water-to-cementitious materials mass ratio w/cm and supplemental cementitious materials with silica fumes in the mixture, and use of a ... Read More ...

High Performance of Silica Fume Mortars for Ferrocement Applications

M. A. Mashrei; Gh. M. Kamil; H. M. Oleiwi

Volume 31, Issue 13 , August 2013, , Page 2477-2488

https://doi.org/10.30684/etj.31.13A.6

Abstract

The current study deals with obtaining the high performance mortars to use in the applications of ferrocement. The main problem that has greatly affected the performance of mortar is ... Read More ...

Strength and Consolidation Characteristics of Compacted Clayey Soil Having a Special Case of Standard Compaction Curve

Ibrahaim M. Al-Kiki; Abdulrahman H. Al-Zubaydi; Moafaq A. Al-Atalla

Volume 31, Issue 9 , June 2013, , Page 1791-1801

https://doi.org/10.30684/etj.2013.82190

Abstract

This paper deals with the results of an experimental study carried out on compacted clayey soil, to investigate the strength and consolidation characteristics of this soil. This soil ... Read More ...

Study the Effect of Glass Fibers on Mechanical Properties of Epoxy Composites

Raghad Hussein Mohammed

Volume 31, 5 B , May 2013, , Page 653-659

https://doi.org/10.30684/etj.31.5B.9

Abstract

The tensile behavior, flexural strength and impact strength were studied in this research for some epoxy composites. First, epoxy composite reinforced with carbon fibers (chopped), ... Read More ...

Strength and Ductility of Concrete Encased Composite Beams

Ammar A. Ali; Saad N. Sadik; Wael S. Abdul-Sahib

Volume 30, Issue 15 , September 2012, , Page 2701-2714

https://doi.org/10.30684/etj.30.15.11

Abstract

Experimental research was conducted to investigate the structural behavior of concrete-encased composite beams. Specimens were tested under lateral loading. The test results indicate ... Read More ...

Keywords = Strength

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