Volume change behaviour of an expansive clay blended with lime and pond ash – controlling swell

2020 ◽  
Vol 54 (1) ◽  
pp. qjegh2020-046
Author(s):  
B. R. Phanikumar
Keyword(s):  
Pressure Coefficient ◽  
Swelling Pressure ◽  
Ash Content ◽  
Expansive Clay ◽  
Pond Ash ◽  
One Dimensional ◽  
Swell Index ◽  
Lime Content ◽  
Swell Potential ◽  
Compressibility Characteristics

This paper presents the influence of lime content on free swell index (FSI) of an expansive clay powder passing through a 425 µm sieve and on some significant swell-compressibility characteristics of oven-dry, expansive clay with grains of a size <4.75 mm. One-dimensional swell-consolidation tests were conducted on the expansive clay passing through a 4.75 mm sieve to which lime powder (CaOH2) was added at 0, 1, 2 and 4% by dry weight of the clay. Swell potential, swelling pressure, coefficient of compressibility (av), compression index (Cc) and linear shrinkage (LS) were evaluated. While av, Cc and LS decreased significantly with increasing lime content, swelling pressure increased. Heave and swell potential also decreased with increasing lime content but only up to 2% and were found to have increased at 4% lime content. The paper also compares the swell-compressibility behaviour of 2% lime-blended expansive clay lumps and powders. Heave and swell potential were higher for clay powder than for clay lumps at 2% lime. However, swelling pressure (ps) was found to be more for clay lumps than clay powder. Furthermore, the paper also presents the variation of FSI and swell-compressibility characteristics of another expansive clay powder (of different properties) blended with pond ash contents of 0, 5, 10, 15 and 20%. One-dimensional swell-consolidation tests were conducted on clay–pond ash blends in an oedometer. Swell potential and swelling pressure decreased up to 15% of pond ash content and increased thereafter, when pond ash content was increased to 20%. FSI of the ash-blended clay specimens was also determined. FSI continuously decreased with increase in pond ash content.

scholarly journals Swell and microstructural characteristics of high-plasticity clay blended with cement

2019 ◽  
Vol 79 (4) ◽  
pp. 2119-2130 ◽  
Author(s):  
S. J. Abbey ◽  
E. U. Eyo ◽  
S. Ng’ambi
Keyword(s):  
Structural Characteristics ◽  
Microstructural Analysis ◽  
Swelling Pressure ◽  
Plasticity Index ◽  
High Plasticity ◽  
Soil Particles ◽  
One Dimensional ◽  
Swell Potential ◽  
Dense Mass ◽  
The One

AbstractThis study presents the effect of high plasticity on swell potential, swelling pressure and micro-structural characteristics of kaolinite-bentonite mixed clays. Five different mix ratios of kaolinite bentonite mixture of 100:0, 90:10, 75:25, 50:50 and 25:75 in % by weight of dry kaolinite were used. All five synthesised soils were then mixed with 0%, 5% and 8% of cement by weight of dry soil, cured for 28 days and subjected to the Atterberg limit, one-dimensional oedometer and scanning electron microscope test. The inclusion of 5% and 8% cement reduces the plasticity index of the treated soils as the percentage of bentonite increases. The effects on plasticity of treatment with 5% and 8% cement after a 28-day curing period was evaluated, and the results show that reduction in plasticity index resulted in decreased swell potential and swelling pressure of the kaolinite-bentonite mixed clays. The results of microstructural analysis of 5% cement-treated soils show formation of flocculated fabric and cementation of soil particles, and filling with cementitious compounds of the voids of flocculated fabric in the soil. The reduction in swell can be attributed to the resulting compacted and dense mass of treated soils due to cementation of soil particles and cation exchange. The complex swell behaviour of high-plasticity kaolinite-bentonite mix is explained using the one-dimensional oedometer test, by further experimental study and examination of the microstructure of treated soils.

scholarly journals Reuse of Municipal Solid Waste from Incinerated Ash in the Stabilization of Clayey Soils

2020 ◽  
Vol 28 (4) ◽  
pp. 1-7
Author(s):  
B. J. S. Varaprasad ◽  
Jayaprakash Reddy Joga ◽  
Suryaprakash Reddy Joga
Keyword(s):  
Municipal Solid Waste ◽  
Solid Waste ◽  
Soil Stabilization ◽  
Sem Analysis ◽  
Primary Objective ◽  
Municipal Solid Wastes ◽  
Electron Microscopic ◽  
Swell Index ◽  
Swell Potential ◽  
Free Swell

AbstractA useful method for the disposal of waste from an incineration plant is to reuse it for geotechnical and civil engineering applications. The primary objective of this study concerns the reuse of local incinerated ash from municipal solid wastes in soil stabilization. Municipal Solid Waste Incinerated Ash (MSWIA) is blended with soil in various combinations and tested for its Atterberg limits, unconfined compressive strength (UCS), California Bearing Ratio (CBR), and Free Swell Index (FSI). A 1-D Consolidation Test was conducted, and changes in the soil during the test were examined by a scanning electron microscopic (SEM) analysis. The test results showed that there are increments in the UCS and CBR values with the reductions in the FSI, swell pressure, and swell potential of the treated soils.

Application of Terzaghi's consolidation theory to nearly saturated soils

1994 ◽  
Vol 31 (2) ◽  
pp. 311-317 ◽  
Author(s):  
Hans H. Vaziri ◽  
Harold A. Christian
Keyword(s):  
Unsaturated Soils ◽  
Measured Data ◽  
One Dimensional ◽  
Deformation Response ◽  
Consolidation Theory ◽  
Modified Equations ◽  
Consolidation Coefficient ◽  
Soil Skeleton ◽  
Oedometer Tests ◽  
Compressibility Characteristics

Terzaghi's one-dimensional consolidation theory is modified to account for the compressibility of fluid and solid phases. The proposed modified equations can be used to analyze the consolidation response of unsaturated soils over the saturation range where the gases remain in an occluded form (generally within a range between 80 and 100aturation); however, such applications are subject to the same limitations and idealizations implicit in Terzaghi's classical consolidation theory. The purpose of this note, therefore, is to offer a simple solution and not to unravel the complexities involved in general analysis of flow and deformation response of unsaturated soils. The proposed approach involves defining the consolidation coefficient, and hence the time factor, in terms of an equivalent fluid compressibility. This equivalent fluid is assumed to represent the compressibility characteristics of all the compressible phases that constitute the soil skeleton. The proposed generalized form of Terzaghi's consolidation equations is shown to qualitatively capture the consolidation behaviour of unsaturated soils. To test the validity of the formulations presented, one-dimensional oedometer tests were performed on specimens of Lantz clay that had been prepared at different saturation levels; satisfactory agreement was achieved between the theoretical and measured data at two states of saturation. Key words : consolidation, theoretical solutions, oedometer test, compressible fluid, occluded gas.

scholarly journals Swelling phenomena and effective stress in compacted expansive clays

2016 ◽  
Vol 53 (1) ◽  
pp. 134-147 ◽  
Author(s):  
David Mašín ◽  
Nasser Khalili
Keyword(s):  
Pore Water ◽  
Effective Stress ◽  
Pore Water Pressure ◽  
Water Pressure ◽  
Swelling Pressure ◽  
Constitutive Modelling ◽  
Dry Density ◽  
Expansive Clay ◽  
Experimental Database ◽  
Clay Aggregates

The central aim of this paper is to discuss the applicability of the effective stress principle as defined by Terzaghi (total stress minus pore-water pressure) to predict the behaviour of expansive clay aggregates. Phenomena occurring between individual clay minerals are reviewed first at the molecular level obtained in the colloid science research. In particular, it is noted that, for interparticle distances higher than approximately 1.5 nm, the pore-water pressure in the bulk equilibrium solution forms an additive component of the interparticle disjoining pressure. It is concluded that for these distances Terzaghi’s effective stress principle should be adequate to describe the clay behaviour. To support these developments, an extensive experimental database of nine different sodium and calcium bentonites available in the published literature was analysed. With the aid of double structure constitutive modelling, procedures were developed to extract information about the behaviour of clay aggregates from the experimental measurements. It was then shown that unconfined water retention curves, swelling pressure tests, swelling under constant load tests, and mechanical unloading tests are all uniquely related in terms of the dependency of dry density (or void ratio) of clay aggregate versus mean effective stress. By considering reversibility of aggregate behaviour and full saturation of aggregates, this implies that the effective stress principle is a valid way of predicting expansive clay aggregate volumetric deformation.

scholarly journals Estimation of Free Swell and Swelling Pressure using Genetic Programming

2019 ◽  
Vol 8 (12) ◽  
pp. 4718-4720
Keyword(s):  
Genetic Programming ◽  
Regression Models ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Expansive Clay ◽  
Undisturbed Soil ◽  
Geotechnical Parameters ◽  
Theory Of Evolution ◽  
Free Swell ◽  
Problematic Soil

Regression models by genetic programming are useful in establishing relationships among various parameters using Darwin’s theory of evolution. Geotechnical parameters have been used in this model for the dataset obtained from literature. Genetic Programming is the automatic creation of computer programs to perform a selected task using Darwinian natural selection. The datasets for the expansive soil contain all the 3 expansive clay minerals – montmorillonite, illite and kaolinite. The origin for this problematic soil in Tabuk region, Saudi Arabia is due to the presence of Hanadir shale. Consolidometer was used in determining free swell for the undisturbed soil.

Review of Oedometer Method for Predicting Heave on the Expansive Soil

2020 ◽  
Vol 11 (2) ◽  
Author(s):  
Willis Diana ◽  
◽  
Agus Setyo Muntohar ◽  
Anita Widianti ◽  
◽  
...  
Keyword(s):  
State Of The Art ◽  
Expansive Soil ◽  
Swelling Pressure ◽  
Foundation Design ◽  
Swelling Properties ◽  
One Dimensional ◽  
Testing Procedures ◽  
Frequent Use ◽  
The One ◽  
Heave Prediction

In foundation design on an expansive soil, the most critical step is to quantify accurately the magnitude of heave and swelling pressure due to change in moisture content. The one-dimensional oedometer has been widely accepted method to determine the heave and swelling pressure of expansive soil. Its simplicity, suitability, and the availability were the reasons for the frequent use of oedometer swell testing technique, but many procedures were identified to measure the swelling properties. Each testing procedures were not unique and resulted different swelling properties and heave prediction. Then, this paper provides an overview of various existing heave prediction by oedometer methods and evaluate common practices of this methods. The techniques were reviewed systematically and summarized. The study summarized a state-of-the-art heave prediction based on the oedometer methods. Various equations forms to predict heave based on the oedometer method have been presented, but the fundamental principles were the same to propose the equation of heave prediction. The differences in these methods were related to the procedures in which the heave index parameter were determined. The three main procedures of oedometer test, i.e. consolidation swell (CS), constant volume CV, and swell overburden (SO), have been summarized. Most of the heave prediction uses the parameter from CS and CV methods. Several reports have shown that the closest estimates of field heave were predicted based on CV method.

Analysis of a New Expansive Soils Stabilization Method Made from Eco-Cement and Fiber Reinforcement

2013 ◽  
Vol 649 ◽  
pp. 217-222
Author(s):  
Mircea Aniculaesi ◽  
Anghel Stanciu ◽  
Irina Lungu
Keyword(s):  
Portland Cement ◽  
Expansive Soils ◽  
Expansive Soil ◽  
Fiber Reinforcement ◽  
Synthetic Fiber ◽  
Expansive Clay ◽  
Swelling Potential ◽  
Stabilization Method ◽  
Swell Potential ◽  
Main Factor

The main factor that governs the shrink-swell behavior of expansive soils is the change in water content and the amount and type of clay size in the soil. In this paper, the research made are focused in reducing the swell potential of the studied clay by improvement in two ways: first by stabilization with a combination of eco-cement and Portland cement (1:1 ratio), and second by synthetic fiber reinforcement. A series of laboratory tests were performed on synthetic fiber reinforced expansive soil to determine the potential for using synthetic fiber reinforcement to reduce swell potential of soils. Specimens tested were prepared at two different synthetic fiber dosages 0.2% and 0.4%. The treatment of expansive clay with 5% eco-cement and 5% Portland cement revealed a better improvement of the swelling potential. The synthetic fiber reinforcement of the expansive soil doesn’t lead to a significant improvement of the soil.

Measurement of swelling pressure: direct method versus indirect methods

2011 ◽  
Vol 48 (3) ◽  
pp. 354-364 ◽  
Author(s):  
Kamil Kayabali ◽  
Saniye Demir
Keyword(s):  
Expansive Soils ◽  
Direct Method ◽  
Swelling Pressure ◽  
Expansive Clay ◽  
Swelling Properties ◽  
Indirect Methods ◽  
Natural Soils ◽  
Considerable Research ◽  
Free Swell ◽  
Swell Pressure

Light structures including highways and railroads built over potentially expansive clay soils may suffer damage from swelling. Considerable research has been done in an attempt to characterize swelling properties of expansive soils. Although direct measurement of swelling pressure is relatively straightforward, it has not drawn much interest. The present study attempts to measure swelling pressure directly. We call experimental techniques for swelling pressure other than this direct method the indirect methods. Some indirect methods require more than one soil sample and that all samples be identical. However, natural soils may not always provide identical samples. Therefore, reconstructed identical soil samples produced from natural soils were used in the present study. For comparison, the restricted swell, swell-consolidation, double oedometer, and zero swell tests were employed as indirect methods. While the restricted swell test slightly underestimated swell pressure, swell-consolidation and zero swell tests overestimated it. The double oedometer test did not provide swell pressures correlatable with those found using the direct method. Free swell data correlated reasonably well with swell pressure data from the direct method, so an empirical form was established from which swell pressure can be easily estimated.

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