Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Shear Strength

Study Shear Strength Characteristics of Gypseous Sandy Soil Using Additives

Hussein H. Karim; T. Schanz; Maha H. Nasif

Engineering and Technology Journal, 2013, Volume 31, Issue 8, Pages 1431-1446

The present study investigated the possibility of enhancing collapsible gypseous soil of Al-Qarma site (with relatively high gypsum content around 50%), which is located in Al-Anbar Governorate, using kaolinite and bentonite as additives. The essential idea is concentrated in mixing these additives with natural soil using different percentages (5, 10, 15 and 20% by soil dry weight) to investigate soil shear strength enhancement. The effect of such additives on soil shear strength parameters, cohesion (C) and angle of internal friction (Φ), and their behavior were studied using direct shear test. The results showed that shear strength parameters of soil sometimes increased and then decreased with increasing additives. Generally, higher shear strength parameters have been obtained from bentonite mixed soil than that of kaolinite mixed soil for the same percentages of additives. It was concluded that bentonite was much more effective in increasing C and reducing Φ than kaolinite. While, kaolinite was much more effective in reducing C than bentonite. It was also concluded that gypseous soil shear strength is improved using such additives (with only 5% kaolinite or with only 20% bentonite) which provide cohesion strength to the soil mass and also acts as a binder agent material.

Shear Capacity of High-Strength Fiber Reinforced Concrete Beam-Column Joints

Kaiss Sarsam; Zaid Muhammad Kani Al-Azzawi

Engineering and Technology Journal, 2010, Volume 28, Issue 6, Pages 1253-1266

This work examines the work of 13 high-strength concrete (HSC) beamcolumn
joints (BCJ)-with and without steel fibers. Several shear design methods
(with modification for fiber content, where applicable) were found to be
conservative within a range of the following variables: 1) concrete compressive
strength, 2) type and volume fraction of steel fibers, 3) content of hoops in the
joint, and 4) column axial load. The coefficient of variation (COV) of the ratio
of test strength to design strength (VTEST / VrDES) was found to be appreciably low
for two of the five existing safe design methods. A conservative design method,
which lowers the COV even further to a value of 7.8 percent, is proposed for HSC
joints, with and without steel fiber reinforcement



Engineering and Technology Journal, 2008, Volume 26, Issue 4, Pages 484-495

This paper deals with the effect of stabilizing gypseous soil using two liquid Asphalt
types (cutback and emulsion) on its behavior in shear strength and rebound
Soil-Asphalt specimens had been constructed using various percentages of both liquid
Asphalt types. One group of such specimens were tested in the direct shear box
apparatus to determine the effect of liquid Asphalt on shear strength, cohesion and
angle of internal friction using the unconsolidated un drained test.
Another group of the specimens were subjected to one dimensional confined
compression test using both dry and saturated testing conditions in the consolidation
The effect of liquid Asphalt on the behavior of mixes in consolidation and rebound
consolidation was studied.
It was concluded that gypseous soil is usually stiff in the dry condition, but it is weak
and had a collapsible behavior when saturated. The addition of liquid Asphalt provides
cohesion strength to the soil mass and also acts as a waterproof agent. It creates a type
of elastic properties and reduces the total strain.