scholarly journals Improvement of Strength of Locally Available Soils using Microbial Induced Calcite Precipitation

2019 ◽  
Vol 8 (3) ◽  
pp. 219-224
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Red Soil ◽  
Engineering Properties ◽  
Black Cotton Soil ◽  
Microbial Culture ◽  
Calcite Precipitation ◽  
Duration Of Treatment ◽  
Bacillus Pasteurii ◽  
Soil Microbial

Engineering properties of soils are improved by adopting various proven methods such as mechanical and chemical. Strength of locally available soil (Black cotton soil and red soil) was enhanced by application of Microbial Induced Calcite Precipitation (MICP) using species of Bacillus pasteurii. Microbial culture improves the unconfined compressive strength and shear strength of locally available soil. Microbial culture developed from Bacillus pasteurii, was used to stimulate and catalyze the process of calcite precipitation triggered by urea hydrolysis which includes reaction between urea and calcium chloride. This paper includes outcomes of effectiveness of MICP on locally available soil, on three parameters measure of the cementation reagent, measure of Bacillus pasteurii and duration of treatment process. The results elaborated that with the application of MICP, unconfined compressive strength of black cotton soil increased 1.6 to 2.3 times and red soil from 1.8 to 3 times. This gives optimum quantity of microbes and concentration of Cementation reagent as additive to improve strength of black cotton soil and red soil.

scholarly journals Evaluation of Cohesive Soil Mixed With Fly Ash and Reinforced With Nylon Fibre

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 193
Author(s):  
Utkarsh Gawande ◽  
Shubham Kanhake ◽  
Arjun Lahane ◽  
Prasanna Naghbhide
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Fly Ash ◽  
Bearing Capacity ◽  
Unconfined Compressive Strength ◽  
Expansive Soil ◽  
Engineering Properties ◽  
Black Cotton Soil ◽  
Nylon Fiber ◽  
Properties Of Soil

Black cotton soil is a expansive soil. And mostly found in Vidarbha region of Maharashtra, this soil is highly unstable and it should be stabilize for carry out construction work. Materials like fly ash, rise husk, nylon fiber are used to make soil stable. Addition of such material will increase the physical, chemical and engineering properties of soil. Some of the properties which are improved are CBR value, shear strength, liquidity index, plasticity index, unconfined compressive strength (UCS) and bearing capacity, etc. The main objective of this study was to evaluate the effect of fly ash in stabilization of Black cotton soil. Mainly UCS and other properties of soil were calculated. The tests were conducted on Soil-Fly Ash mixtures, by increasing the Fly Ash percentage in Black cotton soil like 25%, 50%, 75%, and 100%, and then the soil was tested on Soil-Fly Ash - Fibre mixture by adding the fiber in increasing order like 0.5%, 1%, 1.5%. Results were obtained for mixed proportion of 75% soil and 25% fly ash which has unconfined compressive strength of 173 KN/m2. And by adding 1% of nylon fiber in same proportion of soil – fly ash the unconfined compressive strength increased to 243.12 KN/m2. Increase in UCS value can help in reducing the thickness of earthen roads and pavements and increase the bearing capacity and shear strength of soil. With analysis of results it was found that the fly ash along with nylon fiber has good potential to be used as an additive for improving engineering properties of expansive soil.

scholarly journals Experimental Study on Improvement of Marine Soft Soil with Alkali Residue

2018 ◽  
Vol 53 ◽  
pp. 04021
Author(s):  
SHAO Yong ◽  
LIU Xiao-li ◽  
ZHU Jin-jun
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Void Ratio ◽  
Soft Soil ◽  
Compressive Modulus ◽  
Engineering Properties ◽  
Test Results ◽  
Use Of Resources ◽  
One Year

Industrial alkali slag is the discharge waste in the process of alkali production. About one million tons of alkali slag is discharged in China in one year. It is a burden on the environment, whether it is directly stacked or discharged into the sea. If we can realize the use of resources, it is a multi-pronged move, so alkali slag is used to improve solidified marine soft soil in this paper. The test results show that the alkali residue can effectively improve the engineering properties of marine soft soil. Among them, the unconfined compressive strength and compressive modulus are increased by about 10 times, and the void ratio and plasticity index can all reach the level of general clay. It shows that alkali slag has the potential to improve marine soft soil and can be popularized in engineering.

Correlation of Unconfined Compressive Strength and California Bearing Ratio in Laterite Soil Stabilization Using Varied Zeolite Content Activated by Waterglass

2020 ◽  
Vol 998 ◽  
pp. 323-328
Author(s):  
Achmad Bakri Muhiddin ◽  
Marthen M. Tangkeallo
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Soil Stabilization ◽  
Dry Weight ◽  
Engineering Properties ◽  
High Plasticity ◽  
Curing Time ◽  
Laterite Soil ◽  
Zeolite Content ◽  
Meta Silicate

In remote areas, most roads still use pavements that are very sensitive to climate change, especially those using clay pavements with high plasticity. In addition to the issue of cost, the difficulty of obtaining a proper source of material is another problem that has led to soaring prices for materials. In this regard, a study was conducted using local materials, namely zeolite as a stabilizing material added with waterglass as activating agent. The research began with samples of laterite soil and natural zeolite for XRD test (microstructure testing), and then testing for laterite soil’s index properties and engineering properties, namely Unconfined Compressive Strength and CBR value. The purpose of the test is to determine the correlation between the Unconfined Compressive Strength (UCS) and the soil bearing capacity (CBR) caused by adding zeolite as stabilizer material and waterglass as activator with increasing curing time. Laterite soils contain a brownish red iron oxide. The stabilizing material zeolite contains a crystalline mineral of alumina silicate SiO2. While waterglass composed of sodium meta silicate. Stabilization carried out by mixing 4%, 8%, 12%, 16%, and 20% of zeolite with addition of 2% waterglass, percentage was measured based on soil dry weight. Specimens were tested at curing time of 0, 7, 14, and 28 days. The test result shows increasing UCS and CBR values with increasing percentage of zeolite. At mix of 20% zeolite and 2% waterglass, the unconfined compressive strength reaches 23.54 kg/cm2 with CBR value 58% at 28 days of curing time.

Lateritic Soil Treated with Waste Wood Ash As Liner in Landfill Construction

2019 ◽  
Vol 25 (2) ◽  
pp. 127-139 ◽  
Author(s):  
Johnson R. Oluremi ◽  
Adrian O. Eberemu ◽  
Stephen T. Ijimdiya ◽  
Kolawole J. Osinubi
Keyword(s):  
Compressive Strength ◽  
Hydraulic Conductivity ◽  
Unconfined Compressive Strength ◽  
Wood Ash ◽  
Engineering Properties ◽  
Volumetric Shrinkage ◽  
Lateritic Soil ◽  
Waste Wood ◽  
K Value ◽  
British Standard

ABSTRACTInherent variability in engineering properties of lateritic soil in relation to its plasticity, permeability, strength, workability, and natural moisture content, has made it an unpredictable material for use in civil engineering works, resulting in the need for its treatment by stabilization. A lateritic soil classified as A-6(6) and CL, according to American Association of State Highway and Transportation Officials and Unified Soil Classification System of ASTM (2011), was treated with up to 10 percent waste wood ash (WWA). Compaction was carried out using four energies, namely, reduced British Standard light, British Standard light (BSL), West African Standard, and British Standard heavy, on samples, which were then examined for hydraulic conductivity, volumetric shrinkage, and unconfined compressive strength as major criteria for use as liner and for the development of acceptable zones. Specimens with 4 percent WWA content compacted with a minimum BSL energy satisfied the maximum hydraulic conductivity (k) value of 1 × 10−9 m/s, maximum volumetric shrinkage strain of 4 percent, and minimum unconfined compressive strength value of 200 kN/m2 required for use as liner in engineered landfills. The overall acceptable zone was enlarged for up to 4 percent WWA content, thereby accommodating higher moulding water content, but the minimum compactive effort required to achieve it became reduced. The beneficial treatment of lateritic soil with up to 4 percent WWA will perform satisfactorily as liner and covers in waste containment application and will minimize the pollution and environmental impact of wood waste disposal.

Application of Stabilizer to Improvement the Saline Soil in Lor Nur Lacustrine

2014 ◽  
Vol 912-914 ◽  
pp. 53-56
Author(s):  
Jun Ci ◽  
Yuan Fang Zhang
Keyword(s):  
Compressive Strength ◽  
Experimental Research ◽  
Unconfined Compressive Strength ◽  
Saline Soil ◽  
Engineering Properties ◽  
Saline Soils ◽  
Lop Nur ◽  
Engineering Standards ◽  
Special Soil

Considering the Lop Nur Lacustrine plain saline soil is a special soil which with poor engineering properties such as collapsible and expansion. Through an experimental research on the saline soils stabilized by lime, cement and a polymeric solidified material was conducted. The unconfined compressive strengths and water-related stability of stabilized saline soils were discussed. It was shown that unconfined compressive strength and water-related stability of stabilized Lacustrine plain saline soils attained corresponding engineering standards and that it could be used as roadbed fillings., which could provide a reference to prevent and treatment about the dangers of Lop Nur Lacustrine plain saline soil.

scholarly journals Influence of Lime for Enhancing Characteristics of Expansive Soils in Road Works

2021 ◽  
Vol 1197 (1) ◽  
pp. 012077
Author(s):  
K.S Chamberlin ◽  
M. Rama Rao
Keyword(s):  
Compressive Strength ◽  
Unconfined Compressive Strength ◽  
Expansive Soils ◽  
Black Cotton Soil ◽  
Dry Density ◽  
Test Results ◽  
Lime Treatment ◽  
Maximum Dry Density ◽  
Slaked Lime ◽  
Black Cotton Soils

Abstract Expansive soils are found in black cotton soils, which swell or shrink in volume when presented to changes in moisture content. Lime treatment is exhaustively used to increment the properties of sensitive and fragile soils. One of the hugest clarifications behind using lime is to decline the developing presentation of the earth soil. The arrangement of extra safeguards improves the reaction of quicklime (CaO) with water, structures hydrated (slaked) lime (Ca (OH)2), and thus earth characteristics. The vast inadequacy of employing lime is growing the deficiency of lime offset earth. Following that, the goal of this study is to see how re-establishing time affects the geotechnical qualities of settled Black cotton soils with lime. These discoveries recommend that adding Lime as a stabilizer works on the strength of black cotton soil. Some of the characteristics of the soil likely to be increased by using stabilizer in this work are UCS (Unconfined Compressive Strength) at different curing periods (7,14,28 and 56 days), CBR (California Bearing Ratio) value at unsoaked and soaked and MDD (Maximum Dry Density) decrease at different lime percentages(%) like 2.4.6.8 and 10. The result showed here untreated soil got stabilized by using the stabilizer in certain extent In this adjustment various rates of cementitious material is added to black cotton soil and directed tests like plasticity, compaction, swell pressure, free swell index(FSI), Coefficient of permeability (k) and CBR(soaked and unsoaked) at various conditions like OMC,OMC+2% water and OMC+5% water, UCS (Unconfined Compressive Strength) was performed. From the test results, it is identified that the stabilization agent decreases plasticity and improves strength characteristics. Addition of stabilizing agent makes the black cotton soil to non-plastic, non-swelling and attains increase CBR values which are greater than 25% for a dosage of 10% lime at OMC but remaining OMC+2%water & OMC+5%water CBR values are not various much difference as per test results. With the addition of lime, the black cotton soil becomes non-plastic, non-swelling, and has high strengths. Treated soils are used as a development material, for example, a subgrade layer in the development of adaptable asphalt pavements for roads.

scholarly journals Effect Lime and Recron Fibre on Geotechnical Properties of Black Cotton Soil

2019 ◽  
Vol 8 (2) ◽  
pp. 6252-6257
Keyword(s):  
Compressive Strength ◽  
Soil Sample ◽  
Unconfined Compressive Strength ◽  
Geotechnical Properties ◽  
Plasticity Index ◽  
California Bearing Ratio ◽  
Black Cotton Soil ◽  
Optimum Dose ◽  
Clayey Soils ◽  
Limit Test

Clayey soils are considered as the weakest subgrade soil from civil engineering point of view under moist condition. These soils attract and absorb water and loses their strength. Because of this reason certain inherent properties of these clayey soils need modification for their bulk use in construction of highways, embankments etc. Recently, many synthetic fibres have emerged to strengthen soft soils. Synthetic fibres are low-cost materials, hydrophobic and chemically inert in nature which does not allow the absorption or reaction with soil moisture. The inclusion of synthetic fibres provides reinforcement to the soil and use of lime as a soil stabilizer in BC soil cut down the plasticity index and also increase its strength. For this an extensive laboratory test program was conducted to analyse the variation geotechnical properties of soil by changing the percentage of recron fibre at an optimum dose of lime. The laboratory tests include Atterberg Limit Test, Modified Proctor Test, Unconfined Compressive Strength Test and California Bearing Ratio Test. To conduct different tests on soil sample the proportion of lime is kept fixed and proportion of polyester recron fibre is varied from 0% to 1% by dry weight of soil sample for different lengths of fibre(6 mm, 12 mm & 18 mm separately). Optimum dose of lime is find out by plasticity index of BC soil mixed with varying percentages of lime (4%, 6%, 8% and 10%). Results of the experiments shows that with the increase in the appropriate percentage in recron fibre the Unconfined Compressive Strength and California Bearing Ratio increases. On increasing the length of Recron Fibre, the Unconfined Compressive Strength and California Bearing Ratio also increases. Combination of lime and recron fibre in BC soil give higher CBR value. Therefore it can be used in the improvement of Clayey Soil Subgrade in pavement design and in the construction of embankements.

scholarly journals Using Steel Slag for Stabilizing Clayey Soil in Sulaimani City-Iraq

2020 ◽  
Vol 26 (7) ◽  
pp. 145-157
Author(s):  
Zozk Kawa Abdalqadir ◽  
Nihad Bahaaldeen Salih ◽  
Soran Jabbar Hama Salih
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Unconfined Compressive Strength ◽  
Clayey Soil ◽  
Steel Slag ◽  
Swelling Pressure ◽  
Geotechnical Properties ◽  
California Bearing Ratio ◽  
Engineering Properties ◽  
Clayey Soils

The clayey soils have the capability to swell and shrink with the variation in moisture content. Soil stabilization is a well-known technique, which is implemented to improve the geotechnical properties of soils. The massive quantities of waste materials are resulting from modern industry methods create disposal hazards in addition to environmental problems. The steel industry has a waste that can be used with low strength and weak engineering properties soils. This study is carried out to evaluate the effect of steel slag (SS) as a by-product of the geotechnical properties of clayey soil. A series of laboratory tests were conducted on natural and stabilized soils. SS was added by 0, 2.5, 5, 10, 15, and 20% to the soil. The conducted tests are consistency limits, specific gravity, hydrometer analysis, modified Proctor compaction, swelling pressure, swelling percent, unconfined compressive strength, and California Bearing Ratio (Soaked CBR). The results showed that the values of liquid limit, plasticity index, optimum moisture content, swelling pressure, and swelling percent were decreased when stabilized the soil. However, the values of maximum dry density, unconfined compressive strength, and California bearing ratio were increased with the addition of steel slag with various percentages to the clayey soil samples. The steel slag was found to be successfully improving the geotechnical properties of clayey soils.

Sign in / Sign up

Export Citation Format

Share Document