CBR Value Of Soil Research Articles

The Effect of Addition of Bagasse Ash and Eggshell Powder on CBR Value of Clay Soil

In the construction of road construction, soil bearing capacity, such as the CBR value, needs to be considered. In clay soil, the CBR value of the soil is low, so that stabilization material can be added to its repair. In this study, the stabilization materials used were waste materials in the form of bagasse ash and eggshell powder. Variations in the mixture of bagasse ash mixture used in this study were 7%, 10%, and 13% plus 3% eggshell powder. Testing in this study includes testing moisture content, sieve analysis, specific gravity, consistency limits, compaction testing, and CBR. The soil classification system used is the Unified classification (USCS), a test guideline based on SNI. From the CBR soaked test, it was found that the CBR value of clay soil increased along with the increase in the percentage of bagasse ash plus 3% eggshell powder and the increase in collisions on the soil. The percentage increase in the CBR value of clay soil with a mixture of stabilization to clay soil is 92.303%. at 65 blow. So that bagasse ash and eggshell powder greatly affect the increase in the CBR value of clay soil.

A Review on Terrazyme as Pavement Enhancement Approach

During construction, Engineers often face difficulty related to the stability of soil with or on which the structure is being constructed as the unstable soil cannot not withstand the loads imposed over it. Since the layers of pavements distributes the load evenly over the subgrade, the design of pavement layer is very much dependent on the strength of the subgrade soil over which they are to be laid. So, there is an urgent need to improve the properties of subgrade. An effort to treat the earth with an enzyme that proves very much advantageous for engineering purposes. It is a natural solution which is generated by the enzymatic action on fruits, edibles, saccharine and water by means of fermentation. In this research, a bio-enzyme labelled as Terrazyme is being utilized that significantly improves the properties of soil. Terrazyme being cost effective, efficient, non-toxic, non-inflammable increases the stability by accelerating the enzymatic reactions between the argil and cations(organic) and accelerates the cationic interchange operation to lower down the diffused double layer thickness. The paper deals with all the information about terrazyme including its working mechanism and different properties of soil. It has been investigated that on incrementing the dosage of terrazyme in test sample, notable improvement in the value of UCS and CBR value of soil is observed.

A STUDY ON SOIL STABILIZATION USING FLY ASH

The objective of this paper is to determine the optimum fly ash content at which soil behavior is improved. Soil improvement is termed as soil stabilization. Soil stabilization depends on factors such as unconfined compression, cohesion, shear load, consolidation and permeability of soil and CBR value of soil. Fly ash is a thermal waste. Nearly half of the fly ash generated is not been used, hence usage of fly ash will reduce waste. Test conducted were sieve analysis, specific gravity, standard proctor compaction, unconfined compression, direct shear, free swell index, variable head permeability and consolidation for black cotton soil. Test also was conducted on soil replaced with fly ash in the level of 5%, 10% and 15%. Among the various replacement tried out, better results were observed for soil replaced with 10% of fly ash. Beyond the 10% level of replacement a reduction in performance was observed. Hence fly ash can be used for soil stabilization up to 10% replacement.

Impact of Volcanic Ash and Lime Adding on Expansive Soil for Subgrade Layer

Pavement performance is significantly affected by the mechanical properties and composition of soil subgrade. The mechanical properties of such soil are rigidity, strength, deformation and stability of subgrade material. Expansive clay is the soil with a low bearing capacity when used as the subgrade. The effort taken to improve the strength and rigidity of subgrade is represented by volcanic ash and lime stabilization. Volcanic ash is the non-widely used local material originated from Merapi and Kelud volcanoes. This research observes the value of subgrade rigidity and the changes in expansive soil morphology occurring due to the addition of volcanic ash and lime to increase the value of soil bearing capacity and stiffness. The tests are compaction, CBR, and SEM (Scanning Electron Microscopy) tests. The results show that, with the addition of volcanic ash and lime, there is an increase in the CBR value of soil, dry density and a decrease in optimum water content. The increased CBR value occurs due to the pozzolanic reaction between volcanic ash and lime and clay that results in mixed inter-particle bonding and changes in clay fraction morphology into the sand fraction, making sand stronger and more rigid.

Effect of Addition of Waste Tyre Crumb Rubber on Weak Soil Stabilisation

Objectives : In this work, the possibility of using crumb rubber powder was an additive to improve the strength of soft soil was investigated. Methods: Two types of problematic clay soils are stabilised with the various percentages of crumb rubber (5, 10, 15 and 20%). The strength properties of stabilized soils were improved by increasing percentages of crumb rubber up to 10% is studied by the CBR tests. In addition to strength development, the influences of this stabilizer type and different quantities on drainage characteristics are also studied. Findings: Addition of crumb rubber in both the soils shows desirable changes in permeability. With the addition of crumb rubber of 10% shows the improvement in CBR value of soil is 161% and 130 % in soil A1 and A2. The results obtained shows that both strength and permeability modification results in the better stabilization for clayey soil. Applications: Increase in CBR value of stabilized soil can significantly reduce the overall thickness of the pavement and hence the total cost involved in the construction of road

Effect of Random Inclusion of Palm Fibers on Strength Characteristics of Shanghai Cohesive Soil

Abstract This paper presents the effect of random inclusion of palm fibers on strength characteristics of Shanghai cohesive soil. Locally available cohesive soil (CL) is used as medium and palm fibers with three lengths (l = 6, 12 and 18 mm) are used as reinforcement. Soil is compacted with standard Proctor’s maximum density with low percentage of reinforcement (0–1% by weight of oven-dried soil). Direct shear tests, unconfined compression tests and CBR tests were conducted on un-reinforced as well as reinforced soil to investigate the strength characteristics of fiber-reinforced soil. The test results reveal that the inclusion of randomly distributed palm fibers in soil increases peak and residual shear strength, unconfined compressive strength and CBR value of soil. It is noticed that the optimum fiber content for achieving maximum strength is 0.6–0.8% of the weight of oven-dried soil for fiber length 12 mm.

Application of Jute Fiber for the Improvement of Subgrade Characteristics

Improvement in subgrade has always been an area of concern to highway and geotechnical engineers. In case of a highway, a weak subgrade results in greater thickness of pavement layer which increases the cost of pavement construction. To strengthen the subgrade soil, the use of jute fiber is advantageous because they are cheap, locally available, biodegradable, and eco-friendly. Jute fiber mixed randomly with subgrade soil has significant impact on the improvement of subgrade characteristics over the last decade. Keeping this in view an experimental study was conducted on locally available soil reinforced with jute fiber. In this study the soil samples were prepared at its maximum dry density corresponding to optimum moisture content in the CBR mold with and without reinforcement. The percentage of jute fiber by dry weight of soil was taken as 0.3%, 0.6%, 0.9%, and 1.2%. In the present investigation the length of fiber was taken as 15 mm and 30 mm, and two different diameters (4 mm and 8 mm) were considered for each fiber length. From the laboratory tests the effect of jute fiber content on density of soil (optimum moisture content and maximum dry density) was observed for each length and diameter of jute fiber. It was observed that the optimum moisture content increases and the maximum dry density decreases with the increase in jute fiber content for each length and diameter of jute fiber. The laboratory CBR values of soil and soil reinforced with fiber were determined. The effects of aspect ratio (length/diameter ratio) of jute fiber on CBR value of soil were also investigated. Test results indicate that CBR value of soil increases with the increase in length of jute fiber. It was also observed that increasing the diameter of jute fiber further increases the CBR value of reinforced soil, and this increase is substantial at fiber content of 1.2% for aspect ratio of 3.75 (length = 30 mm, diameter = 8 mm).

Effect of Random Inclusion of Polypropylene Fibers on Strength Characteristics of Cohesive Soil

This paper presents the effect of random inclusion of polypropylene fibers on strength characteristics of soil. Locally available cohesive soil (CL) is used as medium and polypropylene fibers with three aspect ratios (l/d = 75, 100 and 125) are used as reinforcement. Soil is compacted with standard Proctor’s maximum density with low percentage of reinforcement (0–1% by weight of oven-dried soil). Direct shear tests, unconfined compression tests and CBR tests were conducted on un-reinforced as well as reinforced soil to investigate the strength characteristics of fiber-reinforced soil. The test results reveal that the inclusion of randomly distributed polypropylene fibers in soil increases peak and residual shear strength, unconfined compressive strength and CBR value of soil. It is noticed that the optimum fiber content for achieving maximum strength is 0.4–0.8% of the weight of oven-dried soil for fiber aspect ratio of 100.