Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : Soil Stabilization

Assessing the Dynamic Behavior of Asphalt Stabilized Gypseous Soil

Mahmood D. Ahmed

Engineering and Technology Journal, 2014, Volume 32, Issue 4, Pages 822-841

The study presents the test results of stabilizing gypseous soil embankment obtained from Al- Faluja University Campus at Al-Ramady province. The laboratory investigation was divided into three phases, the physical and chemical properties; the optimum liquid asphalt (emulsion) requirements (which are manufactured in Iraq) were determined by using one dimensional unconfined compression strength test. In the first phase , the optimum fluid content was 11% (6% of emulsion with 5% water content). At phase two, the effect of aeration technique was investigated using both direct shear and permeability test. At phase three, a laboratory soil model of dimensions 50x50x30 cm was used as a representative of gypseous soil; pure soil, and asphalt stabilized soil have been compacted in five layers after practicing an aeration technique at maximum dry density (modified compaction) cyclic loading test was carried out on four gypseous soil models, two of them were pure soil under (dry and absorbed condition), and the other two were stabilized with emulsion also under (dry and absorbed condition). The impact of charging the hydraulic conductivity due to asphalt stabilization was investigated and the vertical deformations were determined using LVDT.
For the pure soil in dry condition the vertical settlement at the top surface was (7.45 mm) at (157 load cycles), while for pure soil model under absorbed condition, the water was raised to the surface in three days , so the vertical settlement at the top surface was (12.5 mm) at (29 load cycles), this means that the pure gypseous soil under absorbed condition show reduction in strength by(85%).
When the stabilized soil is in dry condition, the vertical settlement at the top surface was (9.75 mm) at (911 load cycles), while the soil was stabilized and subjected to water absorbed for seven days. The water stopped rising at second layer which is the same inlets level from the bottom, and the vertical settlement was (10.47 mm) at (897 load cycles), so there is no change in strength at failure.

Influence of Poypropylene Fibers on the Soil Stabilization

Heba Dawood Salim

Engineering and Technology Journal, 2013, Volume 31, Issue 20, Pages 316-323

In this paper the polypropylene fiber was chosen as the additive material to know how it is effect on the soil stabilization, which it is used as additive for concret mixture; the polypropylene fiber is inert material and does not interact with water. The paper studies the addition of this material to a silty clay soil and its effect on the consistency limits, shear strength and compaction of the blended materials. The results show that there is an improvement in the shear strength only when the addition of the rate 1% and 2%from soil weight; either the effective of the consistency limit it was increasing the water content with increasing the rate of the addition material, because it have drink of water. At the compaction test it was founded that the increasing in dry density at the addition of 1% and 2% and reducing its value at the addition of 3% with increasing of water optimization.

Studying some of the Geotechnical Properties of Stabilized Iraqi Clayey Soils

Ishraq Khudhair Abass

Engineering and Technology Journal, 2013, Volume 31, Issue 6, Pages 1117-1130

In many road construction projects, if weak soils exist, stabilization and improvement of their properties is necessary. The stabilization process aims at increasing the soil strength and reducing its permeability and compressibility. An experimental program was undertaken to study the effect of engineering properties of kaolin clayey soils ((the kaolin was supplied by the General Company of Geological Survey and Mining which originally obtains from Al-Dewiekhla near Aukashat district in the west of Iraq)) when blended with lime (L) and Silica Fume (SF). A series of laboratory experiments have been implemented for varieties of samples: 2.5%, 5.0%, 7.5% and 10.0% for (Lime) and 2.0%, 4.0% and 6.0% for(Silica Fume). These experiments are: consistency limits test, specific gravity test, compaction test, unconfined compression test and California bearing ratio test. For each test, the optimal quantity of Lime (L) and the optimal percentage of Lime Silica Fume (LSF) combination were determined. The results revealed that: the optimal percentage of LSF combination was attained at a (2.5%L+6.0%SF), which served as control in this study. This optimal percentage: decrease the liquid limit, plasticity index, specific gravity and maximum dry density; and raise the optimum moisture content, unconfined compressive strength and California bearing ratio. These results showed also, that the combination of LSF stabilization at (2.5% L+6.0% SF) is better than the optimal one which achieved by Lime alone: 2.5%L for plasticity index, 10.0%L for specific gravity, maximum dry density and optimum moisture content, 5.0%L for unconfined compression stress and 7.5%forCaliforniabearingratio. All of these results indicated that the engineering properties of clayey soils can be enhanced, by blending Lime and Silica Fume together.

A Laboratory Evaluation of Stabilization of Silty Clay Soil by Using Chloride Compounds

Muhanned Qahtan Waheed

Engineering and Technology Journal, 2012, Volume 30, Issue 17, Pages 3054-3064

Large areas of Iraq consist of soils with high clay contents which have low
strengths and bearing capacity.This problem has an influence on construction of
road and highway, if adequate support does not exist, the road will rapidly
deteriorate. The solution to these construction problems is by soil treatment with
chemical additives. The main objective of this study is to investigate effectiveness
of salts used as an additive in stabilization of silty clay soil. Three types of salts
used which are sodium chloride (NaCl), magnisum chloride (MgCl2) and calcium
chloride (CaCl2). Various amounts of salts (2%, 4%, and 8%) were added to the
soil to study the effect of salts on the consistency limits, compaction characteristics
and CBR value.The test results indicated that the liquid limit, plastic limit and
plasticity index decreased as the salts content increased. The addition of salts to the
soil increased the maximum dry density and reduced the optimum moisture
content. The addition of (2 %) salt to the soil causes increases the CBR value
between (8 to 28 %), while, in samples containing large amount of salt (4 and 8 %)
the increase was between (55 to 80%).The CBR value increased as the salt content
increases for different type of salt and the greatest value is found in the soil treated
with (4%) calcium chloride which was equal to (80 %).