Property changes of reactive magnesia–stabilized soil subjected to forced carbonation

2016 ◽  
Vol 53 (2) ◽  
pp. 314-325 ◽  
Author(s):  
Yaolin Yi ◽  
Kaiwen Lu ◽  
Songyu Liu ◽  
Abir Al-Tabbaa

A reactive magnesia (MgO) was used to stabilize a natural soil; the MgO-stabilized soil was subjected to forced carbonation with pressurized gaseous CO2 in a triaxial cell set-up. The change of physical properties, including bulk density, moisture content, dry density, specific gravity, and porosity, of the stabilized soil during carbonation was studied. The mechanical and microstructural properties of the carbonated MgO-stabilized soil were also investigated through unconfined compressive strength (UCS) test, X-ray diffraction analysis (XRD), scanning electron microscopy (SEM), and mercury intrusion porosimetry (MIP). The results indicated that the carbonation of MgO-stabilized soil consumed CO2 and water, and produced expansive carbonation products; this consequently increased the dry density, and reduced the moisture content, specific gravity, and porosity of the stabilized soil. After being carbonated for only 1.5 h, the MgO-stabilized soil yielded remarkable strength, with UCS higher than that of the 28 day ambient cured Portland cement–stabilized soil, mainly due to the high binding effect of carbonation products and the low porosity of carbonated MgO-stabilized soil. The carbonated MgO-stabilized soil achieved a high degree of carbonation in a few hours (≤12 h), with the maximum CO2/MgO ratio in a range of 0.76–1.07.

2013 ◽  
Vol 50 (8) ◽  
pp. 899-905 ◽  
Author(s):  
Yaolin Yi ◽  
Martin Liska ◽  
Cise Unluer ◽  
Abir Al-Tabbaa

This paper investigates the potential for carbonating reactive magnesia (MgO) to serve as a more sustainable soil stabilization method by providing rapid and significant strength development of the stabilized soil through absorbing substantial quantities of CO2. Gaseous CO2 was forced through laboratory-prepared reactive MgO-treated soil samples in a triaxial cell set-up, and their resulting mechanical and microstructural properties were investigated using unconfined compressive strength, X-ray diffraction, and scanning electron microscopy. The results showed that adequately carbonated MgO-treated soils could, in a few hours, reach a similar strength range to corresponding 28 day Portland cement (PC)-stabilized soils. Hydrated magnesium carbonates, namely nesquehonite and hydromagnesite–dypingite, were the main products of the carbonated MgO in the soil, and were responsible for the significant strength development.


2021 ◽  
Vol 3 (2) ◽  
pp. 276-285
Author(s):  
Brigita Suzanna ◽  
Irwan Lie Keng Wong ◽  
Monika Datu Mirring Palinggi

The purpose of this research is to determine the physical properties of clay soil and to analyze the effect of adding coconut shell charcoal ash to the clay soil. The soil samples used in this study came from Tanralili District, Maros Regency, two sample points were taken and the variations in the levels of addition of coconut shell charcoal ash is 0%, 4%, 6%, 8%, 10%. The test method used refers to ASTM (American Society for Testing Materials). The tests carried out were testing the physical properties of the soil in the form of moisture content, specific gravity, Atterberg boundaries, filter analysis, and hydrometer analysis, then a compaction test was carried out to determine the maximum soil density. The results of the test obtained a moisture content value of 28.811%, a specific gravity of 2.58 g / cm3 so that it is classified as organic clay. As well as the plasticity index value of 9.926% with moderate plasticity from the 7% -17% interval. Then from the test results of soil compaction testing with the addition of coconut shell ash, the dry density (gdry) equal to 0.862, 0.886, 0.914, 0.943, 0.962, this means that the soil sample experienced an increase in dry density (gdry) of 11.60%. From the research results it can be concluded that the addition of coconut shell charcoal ash can increase the value of soil dry density so that it can be used to increase the value of the carrying capacity of clay soil.


2019 ◽  
Vol 4 (1) ◽  
Author(s):  
Anigilaje B Salahudeen ◽  
Ja’afar A Sadeeq

The study investigate the suitability of subgrade soil in Baure Local Government Area of Kastina State Nigeria for road construction. The strength properties of the  subgrade was improved using lime and cement. Several analysis including the particle size distribution, specific gravity, Atterberg limits, compaction characteristics, unconfined compressive strength and California bearing ratio tests were performed on natural and lime/cement treated soil samples in accordance with BS 1377 (1990) and BS 1924 (1990) respectively. Soil specimens were prepared by mixing the soil with lime and cement in steps of 0, 3, 6, and 9% by weight of dry soil in several percentage combinations. The Atterberg limits of the weak subgrade soils improved having a minimum plasticity index value of 5.70 % at 3%Lime/6%Cement contents. The maximum dry density (MDD) values obtained showed a significant improvement having a peak value of 1.66 kN/m3 at 9%Lime/9%Cement contents. Similarly, a minimum value of 18.50 % was observed for optimum moisture content at 9%Lime/9%Cement contents which is a desirable reduction from a value of 25.00 % for the natural soil. The unconfined compressive test value increased from 167.30 kN/m2 for the natural soil to 446.77 kN/m2 at 9%Lime/9%Cement contents 28 days curing period. Likewise, the soaked California bearing ratio values increased from 2.90 % for the natural soil to 83.90 % at 9%Lime/9%Cement contents. Generally, there were improvements in the engineering properties of the weak subgrade soil when treated with lime and cement. However, the peak UCS value of 446.77 kN/m2 fails to meet the recommended UCS value of 1710 KN/m2 specified by TRRL (1977) as a criterion for adequate stabilization using Ordinary Portland Cement.            Keywords: Weak subgrade soil, Lime, Cement, Atterberg limits, Maximum dry density, Optimum moisture content, Unconfined compressive strength, California bearing ratio


2020 ◽  
Vol 6 ◽  
pp. 24-32
Author(s):  
Muhammad Israil ◽  
Muhammad Ashraf ◽  
Muhammad Fahim ◽  
Rashid Rehan ◽  
Sajjad Wali Khan ◽  
...  

This study presents experimental investigation of indigenous clays mixed with Bentonite to assess their suitability in potential use as clay liners. Soil samples with 0, 4, 8, and 12% Bentonite content from three different sites in Peshawar region were tested for various geotechnical properties. Grain size distribution, specific gravity, Atterberg limits and free swell were found through laboratory tests using appropriate ASTM procedures. Maximum dry density and optimum moisture content were calculated using Atterberg limits in available relationships. Finally, one dimensional consolidation tests were conducted to find relevant parameters for calculating hydraulic conductivity. A decrease in specific gravity, increase in free swell, and in optimum moisture content, decline in maximum dry density and hydraulic conductivity was observed with increase in Bentonite content across all three soil samples. During free swell, the soil clusters become larger leading to formation of floccules resulting in the narrowing of inter-particle space and thus blocking of permeable paths. It is concluded that 8% Bentonite content by weight yields a suitable mixture for a clay liner that has hydraulic conductivity in the range of recommended limits.


10.29007/8gxd ◽  
2018 ◽  
Author(s):  
Rima Dave ◽  
Ketan Timani ◽  
Priti Mehta

The sub grade is a layer of natural soil, prepared to receive the layers of pavement. The thickness of pavement depends upon the properties of sub grade. Sub grade should be strong enough to take up the stresses imposed due to loads with out shear failure and excessive deformation. Sub grade soil strength is evaluated in terms of California Bearing Ratio and is used for design of flexible pavement. It can be performed both in the laboratory and field. The CBR test is laborious and time consuming, even though use of CBR as a performance parameter is widely acknowledged. Also it is very difficult to prepare sample at desired in situ density for laboratory testing. The CBR value depends on factors like particle fines, plasticity index, maximum dry density and optimum moisture content. The fine particles have engineering defect and its CBR value is low. This paper presents the effect of fine particles on CBR value. For the laboratory investigation, specimens were fabricated at optimum moisture content and maximum dry density by heavy compaction with varying proportion of sand, silt-clay and fine gravel mixtures. The samples were soaked in water for four days to simulate highly unfavorable condition. Correlation coefficient between fine particles and laboratory CBR values are obtained. Various linear relationships between index properties and CBR of the samples are investigated using linear regression analysis. Analysis of the experimental data indicated that there exist a good correlation among the measured value and predicted value of CBR


The presents study showed the effect of open dumping on soil characteristics and biodegradation settlement analysis of soil in non-engineered landfill. The contaminated soil is referred to as waste soil which has different settlement rates due to the various categories and complex characteristics of waste. The degradation of waste causing percolation of leachate into soil affecting the strength and stability of soil. This paper includes the analysis of geotechnical properties and settlement analysis of waste soil and its comparison was done with natural soil. The geochemical analysis was carried out by Energy Dispersive X- Ray Spectroscopy (EDX) and Scanning Electron Microscopy (SEM). The elemental analysis of soil exhibited presence of high oxygen and silica content in uncontaminated soil. The analysis depicted that specific gravity, maximum dry density (MDD), permeability and California bearing ratio (CBR) showed decreasing trend variation for polluted soil. It was observed that cohesion for contaminated soil was found to be increased thereby increasing the shear strength of soil. Additionally, temperature, pH and moisture content hold a significant position for assessing the settlement. The settlement of soil due to biodegradation of MSW is estimated using empirical mathematical model for dump site depending upon pH, moisture content and temperature. Additionally, settlement is evaluated keeping in view the settlement due to biodegradation of MSW on soil, which further helped in determination of the suitability of the site for the construction and other recreational purposes.


2018 ◽  
Vol 6 (1) ◽  
pp. 78
Author(s):  
Layade Gideon Oluyinka ◽  
Ogunkoya Charles Olubunmi

Lateritic soils that overburden Mohammad Buhari Estate in Abeokuta area of Ogun State, Nigeria is in great use for road construction. However, little is known of their geotechnical properties and suitability as base, sub-based and sub-grade materials for road construction. This study is aimed at utilizing in accordance with regulatory standards of Nigeria, the geotechnical techniques to investigate the properties of this lateritic soil. The samples were collected at 0. 25m deep at different locations and were subjected to the following laboratory test; Particle size analysis, Atterberg limits test, Compaction test, Californian Bearing Ratio test, Moisture content and Specific gravity test. The result shows un-soaked CBR test from 12.52-55.84 %. The specific gravity results range from 2.57-2.89 while the optimum moisture content and maximum dry density range from 18.20-28.30% and 1.48-1.81mg/m3 respectively. The liquid limit, plastic limit and plastic index ranges from 12.0 to 40.1%, 10.0 to 22.0% and 2.8 to 20.4% respectively. This implies that lateritic soil present throughout the study area is suitable for use as sub-base and base materials since the geotechnical properties are fairly within the regulatory standards of Nigeria.


2018 ◽  
Vol 1 (March 2018) ◽  
Author(s):  
S.I Adedokun ◽  
J.R Oluremi ◽  
N.T Adekilekun ◽  
O.V Adeola

This paper investigated the effect of cement kiln dust (CKD) on the geotechnical properties of clay. Soil sample was collected from clay deposit at Ede North Local Government Area, Osun State, which lies within the geographical coordinates of 7N and 4E, was treated with up to 10% CKD. Sieve analysis, specific gravity, consistency limits, compaction (British Standard Light, BSL and West African Standard, WAS) and California Bearing Ratio (CBR) tests were carried out on both treated and untreated soil samples. Results showed that Ede clay is an A-7- 6 soil. Specific gravity increased from 2.61 to 2.91 with increase in CKD from 0 to 10%, maximum dry density (MDD) of the natural soil sample increased from 1.72 and 1.76 g/m’ to 1.84 and 1.85 g/m’ at 8% CKD for BSL and WAS, respectively. The unsoaked CBR of the specimen increased from 17 to 35% for 0-10% addition of CKD, and a similar trend was observed for the 24 hours soaked CBR values. This study indicated that CKD, though regarded as waste material, can be used to improve the geotechnical properties of Ede clay.


2010 ◽  
Vol 173 (3) ◽  
pp. 368-379 ◽  
Author(s):  
Amir Hossein Alavi ◽  
Amir Hossein Gandomi ◽  
Ali Mollahassani ◽  
Ali Akbar Heshmati ◽  
Azadeh Rashed

2020 ◽  
Vol 8 (2) ◽  
pp. 35
Author(s):  
Thompson Henry Tolulope Ogunribido ◽  
Tunde Ezekiel Fadairo

Twenty soil samples collected from the failed portions in the study area were air dried for two weeks before analyses. Each soil samples were subjected to eight engineering tests which include: natural moisture content, atterberg limit, specific gravity, compaction, unconfined compressive strength, California bearing ratio, grain size and hydrometer analysis. Results showed that the natural moisture content ranged from 17.7% to 37.8%, liquid limit from 48.5% to 62.4%, plastic limit from 18.3% to 26.8%, plasticity index from 25.7% to 37.7%, shrinkage limit from 5.8%-12.5%, optimum moisture content from 14.2% to 32.4%, maximum dry density from 1301 Kg/rn3 to 2002 Kg/rn3. Soaked California bearing ratio ranged from 5% to 17%, unsoaked from 15% to 38%, specific gravity from 2.5 to 2.68, unconfined compressive strength r from 112.8 Kpa to 259.7 Kpa, shear strength from 56.4 Kpa to 129.9 Kpa and hydrometer analysis from 48.5% to 72.1%. Based on the Federal Government specifications for pavement construction, for the soil to be suitable, stabilization with bitumen, Portland cement, lime, coal fly ash, and saw dust should be done. Road pavement failure along Arigidi – Oke Agbe road was due to poor engineering geological condition of the sub-grade soils and poor drainage systems.  


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