scholarly journals Effect of clay content on strength and permeability of plastic loess-cement

2019 ◽  
Vol 48 (2) ◽  
pp. 25-30
Author(s):  
Boriana Tchakalova

Plastic soil-cement is a type of soil stabilization used for the treatment of natural soil to improve its engineering properties. It is a hardened material prepared by mixing soil and Portland cement at a water content higher than optimum, usually near the liquid limit, without compaction at optimum water content to maximum dry density. In Bulgaria, this soil stabilization technique has been applied in foundation works in collapsible loess ground in order to replace a part of the collapsible layer, to increase the bearing capacity of the soil base and/or to isolate the geoenvironment from migration of pollutants. The aim of the current paper is to examine the effect of the clay content of the loess soil on the strength and permeability of plastic loess-cement. Results from the investigation indicate that the mechanical and hydraulic properties of the plastic loess-cement highly depend on the presence of clay fraction.

2021 ◽  
Vol 6 (2) ◽  
pp. 044-050
Author(s):  
Tsion Mindaye ◽  
Emer Tucay Quezon ◽  
Temesgen Ayna

Expansive soil swells when it is wet, and it will shrink when it dries. Due to this behavior of the soil, the strength and other properties of soil are inferior. To improve its properties, it is necessary to stabilize the soil with different stabilizers. Soil stabilization is a process to treat the soil to maintain, alter, or improve expansive soil performance. In this study, the potential of 'Fino' as stabilizing additive to expansive soil was investigated for the improving engineering properties of expansive soil to be used as subgrade material. The evaluation involved the determination of the Free Swell test, CBR test, Atterberg's limits, and the Proctor test of expansive soil in its natural state as well as when mixed with varying proportions of 'Fino.' The practices were performed on six proportions 5%, 10%, 15%, 20%, 25% and 30 % with expansive soil. The research result indicated a considerable reduction in Swelling, and the Maximum dry Density of soil was improved. Optimum moisture content decreased in increasing 'Fino.' At 30% of 'Fino,' the CBR values of expansive soil increased from 1.06% to 5.94%, Liquid Limit decreased from 95.2% to 29.4%, plasticity index decreased from 57.24% to 17.82% and the degree of expansion of the natural subgrade soil has reduced from "very high to medium." Hence, it is concluded that the 'Fino' at 30% has shown significant improvement in the expansive soil's engineering properties meeting the ERA and AASHTO Standard specifications requirements for road subgrade material.


2021 ◽  
Author(s):  
Emer Tucay Quezon ◽  
Tsion Mindaye

Expansive soil swells when it is wet, and it will shrink when it dries. Due to this behavior of the soil, the strength and other properties of soil are inferior. To improve its properties, it is necessary to stabilize the soil with different stabilizers. Soil stabilization is a process to treat the soil to maintain, alter, or improve expansive soil performance. In this study, the potential of 'Fino' as stabilizing additive to expansive soil was investigated for the improving engineering properties of expansive soil to be used as subgrade material. The evaluation involved the determination of the Free Swell test, CBR test, Atterberg's limits, and the Proctor test of expansive soil in its natural state as well as when mixed with varying proportions of 'Fino.' The practices were performed on six proportions 5%, 10%, 15%, 20%, 25% and 30 % with expansive soil. The research result indicated a considerable reduction in Swelling, and the Maximum dry Density of soil was improved. Optimum moisture content decreased in increasing 'Fino.' At 30% of 'Fino,' the CBR values of expansive soil increased from 1.06% to 5.94%, Liquid Limit decreased from 95.2% to 29.4%, plasticity index decreased from 57.24% to 17.82% and the degree of expansion of the natural subgrade soil has reduced from "very high to medium." Hence, it is concluded that the 'Fino' at 30% has shown significant improvement in the expansive soil's engineering properties meeting the ERA and AASHTO Standard specifications requirements for road subgrade material.


2018 ◽  
Vol 162 ◽  
pp. 01020 ◽  
Author(s):  
Nahla Salim ◽  
Kawther Al-Soudany ◽  
Nora Jajjawi

All structures built on soft soil may experience uncontrollable settlement and critical bearing capacity. This may not meet the design requirements for the geotechnical engineer. Soil stabilization is the change of these undesirable properties in order to meet the requirements. Traditional methods of stabilizing or through in-situ ground improvement such as compaction or replacement technique is usually costly. Now a safe and economic disposal of industrial wastes and development of economically feasible ground improvement techniques are the important challenges being faced by the engineering community. This work focuses on improving the soft soil brought from Baghdad by utilizing the local waste material for stabilization of soil, such as by using “Nylon carry bag’s by product” with the different percentage and corresponding to 1 %, 3% and 5% (the portion of stabilizer matters to soil net weight) of dried soil. The results indicated that as Nylon’s fiber content increases, the liquid limit decreases while the plastic limit increases, so the plasticity index decreases. Furthermore, the maximum dry density decreases while, the optimum moisture content increases as the Nylon’s fiber percentage increases. The compression index (decreases as the Nylon’s fiber increases and provides a maximum of 43% reduction by adding 5% nylon waste material. In addition, the results indicated that, the undrained shear strength increases as the nylon fiber increases.


2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Sara Mansouri ◽  
Mehran Nasiri ◽  
Amir Modarres

Many pozzolans are waste products from industrial processes. Every year a huge amount of coal waste is gathered from the coal washing plant in the Hyrcanian forests of Iran. These materials can be used for soil stabilization in construction and maintenance projects of forest roads. This paper aims to (a) investigate the role of coal waste (CW) as a soil stabilizer and (b) determine the changes in soil specification regarding the environmental pollution in different combinations of materials (soil, lime (4 and 6%) and CW (3, 6, 9 and 12%)). For this purpose, different technical and environmental analysis and laboratory tests were performed. Technical tests showed that the soil liquid limit and maximum dry density decreased with an increase in lime and CW contents. Addition of CW could increase the soil CBR, UCS and OMC. According to XRD test, the addition of CW and lime can increase the size of crystals in stabilized soil samples. Environmental analysis showed that the use of stabilizer significantly reduced the concentration of heavy metals such as Cd, Cr and Pb. Also, all of the metal concentrations leached from samples satisfied the required criteria, but the addition of lime and CW increased the concentration of N, P, and K. These changes can increase the invasive species consistent with calcareous soil conditions along the roads. According to the results, the combination of coal waste and lime can be one of the best methods for in situ remediation. It would, however, be better to use a minimum amount of stabilizer in pavement layers of access roads due to environmental sensitivity.


2012 ◽  
Vol 512-515 ◽  
pp. 1905-1918
Author(s):  
Yu Xian Shao ◽  
Bin Shi ◽  
Chun Liu ◽  
Lei Gao

Temperature significantly influences the engineering properties of clayey soil and this temperature effect usually depends on soil type. In this investigation, laboratorial experiments were conducted on three soils to evaluate the adsorbed water content, Atterberg limits, swelling, shear strength and permeability under different temperatures (5-50°C). The results indicate that liquid limit decreases, swelling increases, permeability increases with increasing temperature. It is fundamentally due to the change of adsorbed water content. Hydrophilic minerals, which contain large amounts of adsorbed water, play an important role in the temperature effect. With the increase of hydrophilic minerals, the temperature effect on liquid limit increases and the effect on swelling ratio decreases. The hydrophilic minerals content also has significant impact on the temperature effect of permeability. With increasing temperature, the adsorbed water is transformed to free water, and then the permeability may increase significantly. The shear strength of clayey soils with higher content of hydrophilic mineral is more sensitive to temperature variation. The cohesive force mainly changes linearly with the temperature. Different phenomena, i.e. thermal-hardening or thermal-softening, was observed on strength behaviour due to different hydrophilic mineral content, moisture content and dry density of sample.


Soil Stabilization is one of the modern techniques for modification of soil which are using in our daily life in construction. Due to increase in population land is also getting scarce so we need to build in the available area. So this technique we use is called Soil stabilization or modification of soil. As we know that some of the soils are not useful for construction. As a result while constructing pavements like national highways (NH) we should definitely build the pavement on soils like black cotton soil by improving its strength because the original nature of the soil will have poor bearing capacity and less strength. So by adding admixtures from Industrial wastes such as Ground granulated blast furnace slag(GGBS) which is the waste of iron ore i.e., in powder form and Lime which will increase the bearing strength of the soil, So that it will also increase the pavement design over long period of time which is the ultimate goal for the design of the pavement or any other construction purpose. So by adding these admixture using the industrial waste which is available in a low cost so that we can easily improve the strength of the soil because of the availability of admixtures in economy. After adding the admixtures Soil should be tested by some basic tests of U.C.C (Unconfined Compressive Strength) and also California bearing test (CBR) and also some basic tests like MDD (Maximum Dry Density) & OMC (Optimum Moisture Content), Plasticity index and liquid limit etc.., should be carried out in order to test the improved strength of the soil.


2018 ◽  
Vol 1 (March 2018) ◽  
Author(s):  
O.M Osuolale ◽  
A.A Raheem ◽  
J.R Oluremi ◽  
A.K Adeosun

A good understanding of the engineering properties of lateritic soil is highly essential for effective use of the soil for highway pavement construction. The alarming rate of highway pavement failures within the study area has been attributed to paucity of information on the properties of the soil within the study zone. Therefore, the lateritic soils along selected locations along Ibadan – Oyo were characterised for their suitability for highway construction. Ten (10) lateritic soil samples were collected and they were labelled Trial Pit (TP) 1 to 10. The samples were subjected to the following laboratory tests: Sieve analysis, Liquid Limit (LL), Plastic Limit (PL), and Shrinkage Limit (SL), British Standard (BS), West African Standard (WAS), Modified AASHTO compaction and California bearing ratio. The samples were classified using AASHTO classification system. The results of the sieve analyses for percentage passing the 75 m ranged from 15.6 – 33.7%, LL, PL and SL ranged from 30.1 – 39.2%, 2.6 – 23.1%, and 2.1 – 9.3%, respectively. The maximum dry density (MDD) and optimum moisture content (OMC) for British, West African and Modified AASHTO compaction ranged from (1.48 – 1.94 g/cm’ and 10.40 – 16.40%), (1.69 – 2.40 g/cm’ and 9.60-14.40%) and (1.79 – 2.60 g/cm’ and 6.60- 11.60%), respectively. The ten samples are classified as A-2-6 soil. Based on the characterisation, all the samples are only suitable for fill and subgrade except sample TP2 that is also suitable for subbase and base course construction in highway pavement.


Soil stabilization is the process which involves enhancing the physical properties of the soil in order to improve its strength, durability etc. by blending or mixing with additives. The different types of method used for soil stabilization are: Soil stabilization with cement, Soil stabilization with lime, Soil stabilization using bitumen, Chemical stabilization and a new emerging technology of stabilization by Geo textiles and Geo synthetic fibres. In this study, we are making use of Jute and Coir fibre as geo synthetic material for stabilization of soil. With the introduction of Jute and Coir fibres to the soil the CBR values will improve and thickness of pavement layer also gets reduced. It also reduces the intensity of stress on subgrade. Jute and Coir fibres are such a geo synthetic material which is easily available, eco friendly and also cost-effective. With the application of soil stabilization method in construction the overall cost gets reduced when compared to the ordinary method of construction. To determine the Liquid limit using Casagrande Method, Plastic limit by rolling the sample to 3mm diameter thread, Optimum Moisture Content and Maximum Dry Density using Standard Proctor Test, Unconfined compression test and also California Bearing Ratio by conducting CBR test.


2021 ◽  
Vol 24 (2) ◽  
pp. 123-129
Author(s):  
Kamal Ahmed Rashed ◽  
Nihad Bahaaldeen Salih ◽  
Tavga Aram Abdalla

Soil’s characteristics are essential for the successful design of projects such as airports runway and flexible pavement. CBR (California Bering Ratio) is one of the significant soil characteristics for highways and airports projects. Thus, the CBR property can be used to determine the subgrade reaction of soil through correlations. Many of the soil geotechnical parameters such as compaction characteristics (Maximum Dry Density, MDD; Optimum Moisture Content, OMC), and consistency parameters (Liquid Limit, LL; Plastic Limit, PL; Plasticity Index, PI) can be in charge of changes that happen in soil CBR value. Soaked and/or non-soaked conditions of soils also affect CBR value. Hence, testing soils in a laboratory for CBR calculation is time-consuming that needs notable effort. Therefore, this study aims to generate some useful correlations for soil’s CBR with compaction and consistency parameters for 85 samples of fine-grained soils. The study trials were applied on natural soil samples of various places in Sulaimani Governorate, Northern Iraq. Statistical analysis has been carried out by using SPSS software (Version 28). Soaked CBR is counted, which is important for conditions such as rural roads that remain prone to water for few days. Based on the statistical analysis, there is a significant correlation between LL, PL, PI, MDD, and OMC with CBR as the dependent variable as a single variable equation with R2 of  0.7673, 0.5423, 0.5192, 0.6489, and 0.51, respectively. In addition, the highest value of R2 correlation was obtained between CBR value with consistency and compaction properties as a multiple regression equation with R2 of 0.82. The obtained equations for correlation purposes are successfully achieved and can be used, notably, to estimate CBR value.


2019 ◽  
Vol 803 ◽  
pp. 331-337 ◽  
Author(s):  
Hengchhorn Phai ◽  
Amin Eisazadeh

Bangkok clay (BC) is notorious for its poor engineering properties in Thailand and world-widely. In terms of workability, it is significant to modify its naturally weak properties. Nowadays, humans are overusing Earth’s resources and generating so much waste. In consequence, eco-friendly and cost cutting improvements are appreciated in geotechnical field. At the same time, Rice Husk Ash (RHA) is a cheap potential material for soil improvement. Lime is also known as a common material used in soil stabilization both solely and mixed with other materials. An inevitable step to every soil stabilization is to perform compaction tests that gives basic notions to treat soil. In this experimental study, compaction tests were proceeded with soil mixed with 0%, 10%, 20%, 30%, 50% of Rice Husk Ash (RHA) by dry soil mass in replacement manner and added 0%, 4%, 8%, 12% of lime. Overall, the more RHA and lime amount is mixed with soil, the higher Optimum Moisture Content (OMC) gets. This means that when replacement/stabilizers are added more and more, the soil needs more water to reach its Maximum Dry Density (MDD). Unlike OMC, MDD reduces when quantity of additives is increased.


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