Strength improvement in silty clay by microbial-induced calcite precipitation

2021 ◽  
Author(s):  
Fuchen Teng ◽  
Yong-Cheng Sie ◽  
Colette Ouedraogo
Keyword(s):  
Silty Clay ◽  
Calcite Precipitation ◽  
Strength Improvement

scholarly journals Experimental investigations of using deep mixing method to stabilise problematic clays in Ontario

2021 ◽  
Author(s):  
Shuihan Li
Keyword(s):  
Shear Strength ◽  
Strength Properties ◽  
Undrained Shear Strength ◽  
Experimental Investigations ◽  
Silty Clay ◽  
Slag Cement ◽  
Mixing Method ◽  
Sensitive Marine Clay ◽  
Strength Improvement ◽  
Undrained Shear

Champlain Sea clay is a sensitive marine clay which can lose more than 90% of its strength when disturbed. Organic silty clay, commonly found in Ontario, has a high compressibility and a low shear strength. In this experimental study, different binders were applied to Champlain Sea clay and organic silty clay to improve its strength properties. The results indicate that cement and slag/cement can significantly improve the strength of these problematic clays. A cement dosage ranging from 150 kg/m3 to 250 kg/m3 can consistently improve the undrained shear strength of Champlain Sea clay and organic silty clay with the maximum strength improvement ratio of 10 and 18 respectively. A slag/cement dosage of 290 kg/m3 with a mass ratio of 3:1 can improve the undrained shear strength of Champlain Sea clay for more than 50 times. Lime was found to be effective in treating organic silty clay as well.

TEMPERATURE EFFECTS ON THE STRENGH PROPERTIES OF MICROBIALLY STABILIZED RESIDUAL SOIL

2016 ◽  
Vol 78 (7-3) ◽  
Author(s):  
Murtala Umar ◽  
Khairul Anuar Kassim ◽  
Kenny Tiong Ping Chiet
Keyword(s):  
New Technology ◽  
Atmospheric Temperature ◽  
Curing Temperature ◽  
Residual Soil ◽  
Calcite Precipitation ◽  
General Increase ◽  
Soil Matrix ◽  
Effects Of Temperature ◽  
Strength And Stiffness ◽  
Strength Improvement

Microbially Induced Calcite Precipitation (MICP) is a rather new technology that has shown greater potential in geotechnical engineering applications. The technique utilizes the concept of microbial involvements in carbonate precipitation within the soil matrix that lead to the improvement in strength and stiffness of the soil. This paper evaluated the effects of temperature variations on the performance of microbial calcite precipitations in residual soil. The soil specimens were cured under different temperature conditions; that are atmospheric temperature, 40, 45 and 50oC. Shear strength, pH and amount of calcite precipitated were determined for each curing condition. A bacterial concentration of 1×105 cfu/ml and 0.5 M concentration of the cementation reagents were used for the study. The results indicated a general increase in strength with increase in curing temperature; which is an indication of temperature influence in bacterial activity. The results so far obtained also revealed that the higher the amount of calcite precipitated the more the strength improvement up to 48 hours treatment duration; after which increase in calcite content does not results in the increase in strength.

scholarly journals Improvement of Organic Soil Shear Strength through Calcite Precipitation Method Using Soybeans as Bio-Catalyst

Crystals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1044
Author(s):  
Heriansyah Putra ◽  
Erizal ◽  
Sutoyo ◽  
Minson Simatupang ◽  
Dede Heri Yuli Yanto
Keyword(s):  
Shear Strength ◽  
Organic Soil ◽  
Mechanical Tests ◽  
Test Tube ◽  
Hydrolysis Rate ◽  
Precipitation Method ◽  
Calcite Precipitation ◽  
Soil Shear Strength ◽  
Precipitation Ratio ◽  
Strength Improvement

Organic soil has a high content of water and compressibility. Besides that, it has a low specific gravity, density, and shear strength. This study evaluates the applicability of the soybean crude urease for calcite precipitation (SCU-CP) method and its effectiveness in organic soil as a soil-amelioration technique. Various soybean concentrations were mixed with a reagent composed of urea and calcium chloride to produce the treatment solution. Its effect on the hydrolysis rate, pH, and amount of precipitated calcite was evaluated through test-tube experiments. SEM-EDS tests were performed to observe the mineralogy and morphology of the untreated and treated samples. The treatment solution composed of the reagent and various concentrations of soybeans was applied to organic soil. The increasing strength of the organic soil was evaluated using direct shear (DS) and unconfined compression (UCS) tests. The test-tube results show that a hydrolysis rate of 1600 u/g was obtained when using 50 g/L of soybeans with a precipitation ratio of 100%. The mechanical tests show a significant enhancement in the parameters of the organic soil’s shear strength. A shear strength improvement of 50% was achieved in this study. A UCS of 148 kPa and cohesion of 50 kPa was obtained in the treated samples of organic soil. This research elucidates that the SCU-CP is an effective technique for improving organic soil’s shear strength.

scholarly journals Experimental investigations of using deep mixing method to stabilise problematic clays in Ontario

2021 ◽  
Author(s):  
Shuihan Li
Keyword(s):  
Shear Strength ◽  
Strength Properties ◽  
Undrained Shear Strength ◽  
Experimental Investigations ◽  
Silty Clay ◽  
Slag Cement ◽  
Mixing Method ◽  
Sensitive Marine Clay ◽  
Strength Improvement ◽  
Undrained Shear

Champlain Sea clay is a sensitive marine clay which can lose more than 90% of its strength when disturbed. Organic silty clay, commonly found in Ontario, has a high compressibility and a low shear strength. In this experimental study, different binders were applied to Champlain Sea clay and organic silty clay to improve its strength properties. The results indicate that cement and slag/cement can significantly improve the strength of these problematic clays. A cement dosage ranging from 150 kg/m3 to 250 kg/m3 can consistently improve the undrained shear strength of Champlain Sea clay and organic silty clay with the maximum strength improvement ratio of 10 and 18 respectively. A slag/cement dosage of 290 kg/m3 with a mass ratio of 3:1 can improve the undrained shear strength of Champlain Sea clay for more than 50 times. Lime was found to be effective in treating organic silty clay as well.

Effect The Treatments of Biofertilizer and Mineral Fertilizer on Content of N P K of Soil Cultivated With Crop Corn (Zea Mays L).

2019 ◽  
Vol 9 (2) ◽  
pp. 247-256
Author(s):  
Mohammed Aajmi Salman ◽  
Jawad A. Kamal Al-Shibani
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Mineral Fertilizer ◽  
Silty Clay ◽  
Clay Loam ◽  
Potassium Fertilizer ◽  
Clay Loam Soil ◽  
Silty Clay Loam ◽  
Fall Season ◽  
Loam Soil

Beneficial microorganisms play a key role in the availability of ions minerals in the soil and use Randomized Complete Block Desing ( R.C.B.D ). The objective of this paper to the study effect of the of biofertilizer and miniral treatments on availability of NPK for crop corn zea mays L.Two types of biofertilizer are Bacterial Bacillus subtilis and Fungal Trichoderma harianum. Three levels of potassium fertilizer are (2.9533, 0.4000 and 2.9533). A field experiment in fall season of 2018 Has been conducted in silty clay loam soil. The experimental Results indicated that Bacillus and Trichoderma inoculation separately or together Have made a significant effect to increase in the availability of N P K in the soil compare to other treatments. The grain yield is where (2.9533, 0.4000 and 2.9533) of bacterial and fungal bio-fertilizer and potassium fertilizers respectively as compared to the control.

Drip Irrigation and Stand Establishment Affect Yield and Quality of Cantaloupe

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 545d-545
Author(s):  
D.I. Leskovar ◽  
J.C. Ward ◽  
R.W. Sprague ◽  
A. Meiri
Keyword(s):  
Field Experiments ◽  
Irrigation System ◽  
Fruit Size ◽  
Growth Yield ◽  
Vegetable Production ◽  
Silty Clay ◽  
Dry Land ◽  
Stand Establishment ◽  
Yield And Quality

Water pumping restrictions of high-quality irrigation water from underground aquifers is affecting vegetable production in Southwest Texas. There is a need to develop efficient deficit-irrigation strategies to minimize irrigation inputs and maintain crop profitability. Our objective was to determine how growth, yield, and quality of cantaloupe (Cucumis melo L. cv. `Caravelle') are affected by irrigation systems with varying input levels, including drip depth position and polyethylene mulch. Stand establishment systems used were containerized transplants and direct seeding. Field experiments were conducted on a Uvalde silty clay loam soil. Marketable yields increased in the order of pre-irrigation followed by: dry-land conditions, furrow/no-mulch, furrow/mulch, drip-surface (0 cm depth)/mulch, drip-subsurface (10-cm depth)/mulch, and drip-subsurface (30 cm depth)/mulch. Pooled across all drip depth treatments, plants on drip had higher water use efficiency than plants on furrow/no-mulch or furrow/mulch systems. Transplants with drip-surface produced 75% higher total and fruit size No. 9 yields than drip-subsurface (10- or 30-cm depth) during the first harvest, but total yields were unaffected by drip tape position. About similar trends were measured in a subsequent study except for a significant irrigation system (stand establishment interaction for yield. Total yields were highest for transplants on drip-subsurface (10-cm depth) and direct seeded plants on drip-subsurface (10 and 30 cm depth) with mulch.

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