IMPROVEMENT OF SILTY SOIL AS SUBGRADE MATERIAL BY STABILIZATION WITH BITUMINOUS EMULSION A Dissertation Work Submitted to Osmania University in Partial Fulfillment of the Requirements for the Award of Degree of MASTER OF ENGINEERING IN CIVIL ENGINEERING (With Specialization in Transportation Engineering) BY PRUDHVI TEJA (1603-13-741-413)
Under the Supervision of Dr. MIR IQBAL FAHEEM Professor& Head of Civil Engineering Department
Department of Civil Engineering Deccan College of Engineering and Technology (Affiliated to Osmania University (A)) Darussalam, Hyderabad, Telangana State-500001 2014
DEPARTMENT OF CIVIL ENGINEERING DECCAN COLLEGE OF ENGINEERING AND TECHNOLOGY (Affiliated to Osmania University) Darussalam, Hyderabad, Telangana State- 500001
CERTIFICATE
This is to certify that the thesis Titled “Improvement of silty soil as subgrade material by stabilization with bituminous emulsion” submitted by Prudhvi Teja (160313741413) in partial fulfillment of the requirement for the award of degree of Master of Engineering in Civil Engineering (Transportation Engineering) to Osmania University (A), Hyderabad, Telangana state, during the academic year 2013-2015 was carried out under my supervision and that this work was not submitted elsewhere for the award of any other degree.
Dr. MIR IQBAL FAHEEM, M.Tech, Ph.D, FIE, FISCE Vice Principal, Professor & Head of Civil Engineering Dept. Department of civil Engineering Deccan college of Engineering and Technology Hyderabad, Telangana State - 500001
DECLARATION K.prudhvi teja (160313741413), student of M.E Civil Engineering, Transportation Engineering, Deccan college of engineering and Technology, declare that the project Titled “Improvement of silty soil as subgrade material by stabilization with bituminous emulsion” has been independently carried out under the guidance of Dr. Mir Iqbal Faheem, Professor & Head of Civil Engineering Department, Deccan College of Engineering and Technology. No part of the thesis is copied from books/journals/internet and wherever the portion is taken, the same has been duly referred in the text. The report is based on the project work done entirely by me and not copied from any other source.
Prudhvi teja
ABSTRACT Starting from the base, soil is one of nature’s most abundant construction materials. Almost all type of construction is built with or upon the soil. The most important part of a road pavement is subgrade soil and its strength. If strength of soil is poor, then stabilization is normally needed. Subgrade is sometimes stabilized or replaced with stronger soil material so as to improve the strength. Such stabilization is also suitable when the available subgrade is made up of weak soil. Increase in sub grade strength may lead to economy in the structural thicknesses of a pavement. Cement, fly ash, lime, fibres etc. are very commonly used for soil stabilization. The main objective of this experimental study is to improve the properties of the gravel soil by adding bitumen emulsion. An attempt has been made to use emulsion for improving the strength of gravel soil expressed in terms of CBR values which may prove to be economical. In this study, the whole laboratory work revolves around the basic properties of soil and its strength in terms of CBR. A little cement added to provide better soil strength. It is observed that excellent soil strength results by using cationic bitumen emulsion (CMS) with little quantity of cement used as filler. The appropriate mixing conditions for gravelly soil with CMS Bitumen emulsion have been first attempted. This is followed by deciding four particular material conditions to show the variation in dry density and CBR value to achieve the best possible strength properties of gravel soil. Keywords: Gravel soil, CBR, Bitumen Stabilization, bitumen emulsion
CHAPTER 1
INTRODUCTION 1.1 INTRODUCTION Eroded soil is due to strength of bindings among particles forming soil is unable anymore it hold pressures on it. The load can be in the form of striking and or sparkling of rains fall to the soil surface due to friction/erosion caused by water flow on soil surface in general the soil has an ability to hold/control the pressures on it but due to heterogenic soil characteristics there is type of soil which having insufficient ability. The minerals from soil consisting of elements and chemical compounds can react with other chemical substances mixed to it. For the soil which has in sufficient technical ability that has chemical potential the ability can be increased by adding chemical substances(chemical conservation). A lot of researches on soil stabilization with emulsion asphalt especially about construction have been done .For example (1-2-3-4-5-6-7-8-9-10-11) all find out that soil stabilization with emulsified asphalt can improve soil characteristics the aim of this study was to analyze the effect of soil stabilization with emulsified asphalt on soil characteristics that can increase its strength to reduce its erosion flow that is chemical bindings between soil minerals and emulsified asphalt, plasticity and shear strength of soil. 1.2 SOIL AS SUBGRADE MATERIAL Starting from the base, soil is a standout amongst the most abundant construction materials of nature. Just about all kind of construction is based with or upon the soil. Long term performance of pavement structures is altogether affected by the strength and durability of the subgrade soils. INsitu sub-grades frequently don't provide the support required to achieve acceptable performance under the traffic loading with increasing environmental demands. Despite the fact that stabilization is a well-known option for improving soil engineering properties yet the properties determined from stabilization shift broadly because of heterogeneity in soil creation, contrasts in micro and macro structure among soils, heterogeneity of geologic stores, and because of chemical contrasts in concoction interactions between the soil and utilized stabilizers. These properties require the thought of site-specific treatment alternatives which must be accepted through testing of soilstabilizer mixtures. Whether the pavement is flexible or rigid, it rests on a soil foundation on an embankment or cutting, normally that is known as subgrade. It may be defined as a compacted layer, generally occurring local soil just beneath the pavement crust, providing a suitable foundation
for the pavement. The soil in subgrade is normally stressed to certain minimum level of stresses due to the traffic loads. Subgrade soil should be of good quality and appropriately compacted so as to utilize its full strength to withstand the stresses due to traffic loads for a particular pavement. This leads the economic condition for overall pavement thickness. On the other hand the subgrade soil is characterized for its strength for the purpose of design of any pavement. Improvement of soil engineering properties is referred to soil stabilization. There are two primary methods of soil stabilization. One is mechanical method and the other one is chemical or additive methods. Soil is a gathering or store of earth material, determined regularly from the breakdown of rocks or rot of undergrowth that could be uncovered promptly with force supplies In the field or disintegrated by delicate reflex means in the lab. The supporting soil beneath pavement and its exceptional under course is called sub grade soil. Without interruption soil underneath the pavement is called regular sub grade. Compacted sub grade is the soil compacted by inhibited development of distinctive sorts of substantial compactors. Presently every road construction project will use one or both of these stabilization strategies. The most well-known type of mechanical soil stabilization is compaction of the soil, while the addition of cement, lime, bituminous or alternate executors is alluded to as a synthetic or added substance strategy for stabilization of soil. American Association of State Highway and Transportation Officials (AASHTO) classification system is a soil classification system specially designed for the construction of roads and highways used by transportation engineers. The system uses the grainsize distribution and Atterberg limits, such as Liquid Limits and Plasticity Index to classify the soil properties. There are different types of additives available. Not all additives work for all soil types. Generally, an additive may be used to act as a binder, after the effect of moisture, increase the soil density. Following are some most widely used additives: Portland cement, Quicklime or Hydrated Lime, Fly Ash, Calcium Chloride, Bitumen etc. But, mechanical soil stabilization alludes to either compaction or the introduction of sinewy and other Non-biodegradable reinforcement of soil. This practice does not oblige compound change of the soil and it is regular to utilize both mechanical and concoction intends to attain detailed stabilization. There are a few routines used to accomplish mechanical stabilization like compaction, combining, soil reinforcement, expansion of graded aggregate materials and mechanical remediation. Any land-based structure depends upon its foundation characteristics. For that reason, soil is a very critical element influencing the success of a construction project. Soil is the earliest
part of the foundation or one of the raw materials used in the whole construction process. Therefore the main thing related to us soil stabilization is nothing but the process of maximizing the CBR strength of soil for a given construction purpose. So many works have been done on cement, lime or fly ash stabilization. But very few works have been found on bitumen soil stabilization. 1.3 BITUMEN EMULSION FOR SOIL SATABILISATION OF SOIL SUBGRADE Emulsified Bitumen usually consists of bitumen droplets suspended in water. Most emulsions are used for surface treatments. Because of low viscosity of the Emulsion as compared to hot applied Bitumen, The Emulsion has a good penetration and spreading capacity. The type of emulsifying agent used in the bituminous emulsion determines whether the emulsion will be anionic or cationic. In case of cationic emulsions there are bituminous droplets which carry a positive charge and Anionic emulsions have negatively charged bituminous droplets. Based on their setting rate or setting time, which indicates how quickly the water separates from the emulsion or settle down, both anionic and cationic emulsions are further classified into three different types. Those are rapid setting (RS), medium setting (MS), and slow setting (SS). Among them rapid setting emulsion is very risky to work with as there is very little time remains before setting. The setting time of MS emulsion is nearly 6 hours. So, work with medium setting emulsion is very easy and there is sufficient time to place the material in proper place before setting. The setting rate is basically controlled by the type and amount of the emulsifying agent. The principal difference between anionic and cationic emulsions is that the cationic emulsion gives up water faster than the anionic emulsion. Over a time of time, which may of years, the asphalt stage will in the long run separate from the water. Asphalt is insoluble in water, and breakdown of the emulsion includes the combination of droplets. The asphalt droplets in the emulsion have a little charge. The wellspring of the charge is the emulsifier, and ionisable segments in the asphalt itself. However when two droplets do attain enough vitality to defeat this hindrance and approach nearly then they hold fast to one another. Over a time of time, the water layer between droplets in floccules will thin and the droplets will combine. Components which constrain the droplets together, for example, settlement under gravity, dissipation of the water, shear or solidifying will quicken the flocculation and mixture process. In this case mixing with soil slow setting bitumen emulsion is not so much effective and rapid setting is not easy to work with soil. So here I use medium setting emulsion as main stabilizing agent. Today the main utilization of bitumen is in the pavement industry for
construction and maintenance. Bitumen emulsions are a scattering of bitumen in a watery continuous stage, settled by the expansion of an emulsifier. They are ready as emulsions at high temperatures, however connected as robust scatterings at encompassing temperatures. In pavement engineering bitumen items are commonly added with aggregate. The solid adhesion that happens between the bitumen and mineral aggregate empowers the bitumen to go about as a binder, with the mineral aggregate providing mechanical quality for the way. From the review of present scenario bitumen emulsion acts as a key tool for mainly for road maintenance and construction. But effectively here emulsion is going to use as a soil stabilizing agent. 1.4 RESEARCH MOTIVATION Stabilization of soils to improve strength and durability properties often relies on cement, lime, fly ash, and asphalt emulsion. These materials are inexpensive, relatively easy to apply, and provide benefits to many different soil types. Most of the roads develop distress and failures like undulations, rutting and permanent deformation (rutting).The most common improvements achieved through stabilization include better soil gradation, reduction of plasticity index or swelling potential, and increases in durability and strength. In wet weather, stabilization may also be used to provide a working platform for construction operations. These types of soil quality improvement are referred to as soil modification. The strength and stiffness of a soil layer can be improved through the use of additives to permit a reduction in design thickness of the stabilized material compared with an unsterilized or unbound material. The design thickness strength, stability, and durability requirements of a base or sub base course can be reduced if further analysis indicates suitability. 1.5 RESEARCH GAP The work done on the subgrade with stabilizers was restricted due to its unavailability & the literatures for this study were mainly related to the performance characteristics of stabilized soil and different performance tests. Various experimental studies were conducted for performance evaluation of the pavement. The major work of most of the authors pertains to the improvement of soil characteristics using stabilizers. Least work has been done with Emulsion as binder to enhance the performance of Subgrade. The main contribution of this study is to improve the characteristics of soil for subgrade. Knowing these characteristics may induce ways to improve the performance of pavement by stabilizing the soil and its better optimization.
1.6 RESEARCH OBJECTIVES The main objective of this experimental study is to improve the properties of the gravely soil by adding bitumen emulsion as stabilizing agent. An attempt has been made to use emulsion for improving the strength and geotechnical properties of gravel soil. Very mostly, use of use of bitumen emulsion is environmentally accepted. To achieve the whole project some experimental investigation is needed in laboratory. The experiments which to be conducted are Specific Gravity of the soil sample, Grain size Distribution of soil sample and liquid limit plastic limit test to identify the material and Standard Proctor test to obtain maximum dry density and optimum moisture content of soil sample, CBR test of soil sample mixing with emulsion and cement. So the main objective is to maximize the CBR value by checking some conditions to increase the CBR value of soil subgrade. 1.7 RESEARCH SCOPE This discussion covers the determination procedure of optimum emulsion content to be used with silty soil type and procedures for determining a design treatment level with bituminous emulsion. A statistical analysis will be applied to identify the comparison between original soil and stabilized soil with bitumen which may show improvement in CBR, shear strength, maximum dry density and mechanical properties. The scope of this study is limited to understand various performance characteristics of stabilized soil with and without laboratory investigation. 1.8 ORGANIZATION OF STUDY This dissertation work is presented in 5 chapters including the introduction chapter Chapter 2: This chapter contains an overview of the literature on performance parameters, effect of compaction on performance and about different performance tests. It also provides a review on the experimental methodology for the present study. Chapter 3: This chapter explains the methodology followed in this study which includes the explanation of methodology followed for material collection, material characterization, preparation of test samples and performance testing
Chapter 4: This chapter discusses different tests and test results of stabilized soil. Performance of stabilized soil is compared with that of original soil. Chapter 5: This chapter deals with the validation of the obtained experimental results by ANNOVA test, regression equation and SPSS. Chapter 6: This final chapter summarizes the work accomplished in this study and suggests some directions for future research.
CHAPTER 2 LITERATURE REVIEW
2.1 INTRODUCTION This chapter shows the previous work done on stabilization on soils with the author’s name and year. S.No 1 2
Author(s) Yuehuan et al Chinkulkijniwat and
3 4
Man-Koksung Razouki et al Michael
5
Paul et al
6
Marandi and Safapour
Year Name of the modifier 2010 Foamed bitumen 2010 Bitumen Emulsion 2002 Bitumen Emulsion 2006 Asphalt emulsion 2011 Asphalt binder 2012 Cement and Bitumen
Properties improved Strength and stiffness improves Improves pavement rutting resistance Improves water resistance Improved durability of roads Improved waterproofing of pavement Improved waterproofing of pavement Improvement in Tensile stress
7
Jones et al
2012 Asphalt emulsion
8
Cokca et al
2003 Bitumen Emulsion
9
Hussain
2008 Bitumen Emulsion
changes bearing ratio of soil and Plasticity index Improves bearing ratio of soil Immunity to Extreme weather
10
L. Lauren
2011 Polymer Emulsion
11
Martinet al.
2009 Foamed Bitumen
12
A. P. Chritz
2006 Bitumen Emulsion
13
Nikraz
2012 Bitumen -cement
14
Al-Khashab
2008 Emulsified Asphalt
15
Newman, K., Tingle, 2004 Emulsion polymer
of soil Improvement in shear strength of soil Improves Water resistance,
conditions Improves water resistance Improves indirect tensile strength Stabilization of Expansive Clayey Soil improves mechanical behavior
J.S.
Yuehuan et al. (2010) This paper investigates the merit of application worked on foamed bitumen stabilization for Western Australian Pavements. Currently, the popularity of soil cement stabilization had been challenged by a new Innovative soil improvement technique, known as foamed bitumen stabilization. Very few of Work have been done on it and application of this type of stabilization is currently applied in Flexible pavement subgrade stabilization. Numerous Australian roadway and way offices have Committed noteworthy investigation and stores to investigate this system so as to attain a more Adaptable and weakness safe balanced out material suitable for an extensive variety of pavement Conditions. Percent of froth bitumen utilized as 3 to 5 percent. It was one kind of mix design However here after the mix design process stabilization done and CBR quality tried. From those literature review part it can be observed that different types of work had been done previously on bitumen soil stabilization. But in India the number of work on it is very few. Actually in India there is no any appropriate code for bitumen soil stabilization. As from those Papers it is very difficult to get any actual idea about how to mix bitumen emulsion with soil and what will be its actual quantity. This experimental investigation is mainly to make a process for mixing bitumen emulsion with soil. Chinkulkijniwat and Man-Koksung (2010) This study investigates a test research on compaction aspects of non-gravel and gravelly Soils using a little compaction device. The standard delegate test has been broadly utilized and acknowledged for characterizing soil similarity for field compaction control. Here additionally indicates about the influence of gravel size and gravel content on standard delegate test results. In this study a relationship developed between the summed up optimum water substance of the fine division in the gravelly soil and the gravel content in standard molds using compaction results from the proposed little device.
Razouki et al. (2002) this paper investigates an experimental study on Granular Stabilized Roads. Bitumen was used as a stabilizing agent may act as a binder or as a water-proofing material. Soil bitumen systems had found the greatest used in road bases and surfaces. Michael (1993) had proposed about Bench-Scale Evaluation of Asphalt Emulsion Stabilization of Contaminated Soils. In this study, it was discussed about the application of ambient temperature asphalt emulsion stabilization technology and discussed to the environmental fixation of soils contaminated by organic contaminants. Paul et al. (2011) suggested an introduction to soil stabilization in pavement taking a mixture of bitumen and well-graded gravel or crushed aggregate. After compaction it gave an exceedingly Steady waterproof mass of subbase or base course quality. The fundamental system involved in asphalt stabilization of fine-grained soils is a waterproofing wonder. Soil particles or soil agglomerates were covered with asphalt that forestalls or abates the entrance of water which could regularly bring about abatement in soil quality. What's more, asphalt stabilization can enhance durability qualities by making the soil impervious to the unfavorable impacts of water, For example, volume. In non-iron materials, for example, sands and gravel, pounded gravel, and smashed stone, two fundamental systems are dynamic: waterproofing and adhesion. The asphalt Coating on the union less materials gives a film which anticipates or hinders the entrance of water; subsequently reducing the inclination of the material to lose quality in the vicinity of water. The second instrument had been distinguished as adhesion and characteristics of gravelly soils. Marandi and Safapour (2012) worked on Base Course Modification through Stabilization using cement and bitumen. The main objective of this research was to analyze the use of bitumen emulsion in base course stabilization. So that it was examined as replacement with conventional pavement in regions with low quality materials. Stabilization of soils and aggregates with bitumen shows it differs greatly from cement stabilization. The basic mechanism involved in bitumen stabilization was a waterproofing phenomenon.
Jones et al. (2012) conducted an experimental study on bitumen soil stabilization. Here asphalt Emulsion is a mix of asphalt binder, water, and emulsifying agent. In this case, a series of Indirect Tensile Strength (ITS), Unconfined Compressive Strength (UCS) and Marshal Tests were carried out. It is liquid at ambient temperature to facilitate handling at lower application temperatures. It accelerates breaking of the emulsion and for additional early strength to accommodate traffic during curing of the layer. Cokca et al. (2003) concentrated on the impacts of compaction dampness content on the shear quality of an unsaturated mud. In this study, the impacts of compaction dampness substance and soaking on the unsaturated shear quality parameters of mud were investigated. Experiments were carried out on specimens compacted at optimum dampness content, on the dry side of optimum and on the wet side. It was found that edge of erosion reductions quickly with increasing dampness substance, the union segment of shear quality attained its top worth at around optimum Moisture substance and afterward diminishes. Hussain (2008) did an excellent work to establish the correlation between CBR value and undrained shear strength value from Vane Shear Test. It was shown that un-drained shear strength value and CBR value increased with increasing plasticity index. Finally it was achieved that shear strength and CBR value is inversely proportional to the water content of that material. L. Lauren (2011) performed an experimental take a shot at soil stabilization products like the polymer emulsion for having all the earmarks of being the stabilization executors for what's to come. Every one of the three polymer-emulsions was utilized as a part of this testing project performed eminently making solid examples that all gave suitable CBR qualities to ways. The CBR test was utilized for this venture on the grounds that it has been effectively related with quality capability of the subgrade, subbase, and base course material for utilization in street and runway development.
Martinet al. (2009) developed a paper deals with foam bitumen stabilization. Foamed bitumen is a mixture of bitumen, air and water. Here 2 percent of cement and 3.5 percent of bitumen foam was used. From here it has been found that Rehabilitation using foamed bitumen had proved to be successful because of its ease and speed of construction, its compatibility with a wide range of aggregate types and its relative immunity to the effects of weather. A. P. Chritz (2006) discussed about performance evaluation of mixed in place bituminous stabilized shoulder gravel. Here it was showed an economical maintenance of gravel shoulders, a very common problem is facing by highway agencies. Nikraz (2012) worked on Bitumen-cement Stabilized Layer in Pavement Construction Using Indirect Tensile Strength (ITS) Method. In this study, the goal was to mix and blend Portland concrete and bitumen emulsion with soil for upgrading the quality, strength and durability of the dirt. So as to upgrade the soil quality and decrease its weakness to water, soil stabilization is obliged to be connected to the soil. In accordance with this, enhanced burden exchange was added to the asphalt establishment by having the bond impact which really supports the firmness and Bitumen emulsion impacts which enhance versatility and soil penetrability of the settled layer. Yuehuan et al. (2010) worked on foamed bitumen stabilization for Western Australian pavements. Currently, the popularity of soil cement stabilization had been challenged by anew innovative soil improvement technique, known as foamed bitumen stabilization. Very few of work have been done on it and application of this type of stabilization is currently applied in flexible pavement subgrade stabilization. Numerous Australian roadway and way offices have committed noteworthy investigation and stores to investigate this system so as to attain a more adaptable and weakness safe balanced out material suitable for an extensive variety of pavement conditions. Percent of froth bitumen utilized as 3 to 5 percent. It was one kind of mix design however here after the mix design process stabilization done and CBR quality tried.
From those literature review part it can be observed that different types of work had been done previously on bitumen soil stabilization. But in India the number of work on it is very few. Actually in India there is no any appropriate code for bitumen soil stabilization. As from those papers it is very difficult to get any actual idea about how to mix bitumen emulsion with soil and what will be its actual quantity. This experimental investigation is mainly to make a process for mixing bitumen emulsion with soil.
CHAPTER 3 MATERIAL AND METHODS
3.1 SOIL STABILIZATION PROCESS The method involves on site soil improvement by applying stabilizing agent without removing the bulk soil. This technology offer benefit of improving soils for deep foundations, shallow foundations and contaminated sites. Planning of the design mix involves the selection and assessment of engineering properties of stabilized soil and improved ground. The purpose is to determine the dimensions of improved ground on the basis of appropriate stability and settlement analyses to satisfy the functional requirements of the supported structure (Keller Inc.). The technology can be accomplished by injection into soils a cementitious material such cement and lime in dry or wet forms. The choice to either use dry or wet deep mixing methods depend among other things; the in-situ soil conditions, in situ moisture contents, effectiveness of binders to be used, and the nature of construction to be founded. Depending on the depth of treatment, the in situ stabilization may be regarded as either deep mixing method or mass stabilization. Mechanical stabilization: Mechanic stabilization is accomplished by mixing or blending soils of two or more gradations to obtain a material meeting the required specification. The blended material is then spread and compacted to required densities by conventional means. Addictive Stabilization: It is achieved by the addition of proper percentages of bituminous emulsion materials to the silty soil the selection of type and determination of the percentage of additive to be used is dependent upon the soil classification and the degree of improvement in soil quality desired generally small amount of additives are required when it is simply desired to modify soil properties such as gradation workability and plasticity. When it is desired to improve the strength and durability significantly larger quantities of additives are used after the additive has been mixed with silty soil, spreading and compaction are achieved by conventional means. Modification method: Modification refers to the stabilization process that results in improvement in some property of the soil but doesn’t by design result in a significant increase in silty soil strength and durability.
3.1.1 CURRENT STABILIZING TECHOLOGY The soil stabilization includes multiple alternatives.one choice involves the pulverization and homogenization of existing material in-place without the addition of an additive to change or improve the characteristics of the material this technique is typically performed when the in-situ material is suitable and when FDR (FULL DEPTH RECLAMATION) can create a new stabilized base of sufficient thickness and strength for the intended traffic loads. Of course, a surface of some type must be placed over the stabilized base to protect it. A second technique of soil stabilization includes the addition of single addictive such as lime, cement or bitumen. Less common additives include fly ash and mineral filters. Addition of this stabilization agent was historically done dry. In recent years emphasis on environmental conditions has led to more frequent utilization of liquid slurry additive applications. The dry stabilization agent is premixed with water to form slurry which has water content at or slightly below the optimal moisture content for the material being stabilized. Not only does the use of slurry dramatically reduce the occurrence of dust during the mixing process and it also permit more accurate and uniform application and the blending of the addictive into the material being stabilized. When the stabilizing agent is able to be added during the pulverization pass of the stabilizer, a corresponding reduction in production costs and time can also be reduced. The deep mixing method involves the stabilization of soils at large depth. It is an in situ ground modification technology in which a wet or dry binder is injected into the ground and blended with in situ soft soils (clay, peat or organic soils) by mechanical or rotary mixing tool. Depending on applications, the following patterns may be produced (Figure 4); single patterns, block patterns, panel pattern or stabilized grid pattern. Note that, the aim is to produce the stabilized soil mass which may interact with natural soil and not, to produce too stiffly stabilized soil mass like a rigid pile which may independently carry out the design load. The increased strength and stiffness of stabilized soil should not, therefore, prevent an effective interaction and load distribution between the stabilized soil and natural soil .Thus the design load should be distributed and carried out partly by natural soil and partly by stabilized soil mass (column).
3.2 STABILISATION WITH LIME Experience shows that lime will react with many medium-, moderately fine-, and fine-grained soils to produce decreased plasticity, increased workability, reduced swell, and increased strength. Soils classified according to the USCS as CH, CL, MH, ML, OH, OL, SC, SM, GC, GM, SW-SC, SPSC, SM-SC, GWGC, GP-GC, ML-CL, and GM-GC should be considered as potentially capable of being stabilized with lime. Lime should be considered with all soils having a PI greater than 10 and more than 25 percent of the soil passing the No. 200 sieve. 3.2 STABILISATION WITH CEMENT Portland cement can be used either to modify and improve the quality of the soil or to transform the soil into a cemented mass with increased strength and durability. Cement can be used effectively as a stabilizer for a wide range of materials; however, the soil should have a PI less than 30. For coarse-grained soils, the amount passing the No. 4 sieve should be greater than 45 percent. The amount of cement used depends on whether the soil is to be modified or stabilized. The soil stabilized with cement is known as soil cement. The cementing action is believed to be the result of chemical reactions of cement with siliceous soil during hydration reaction. The important factors affecting the soil-cement are nature of soil content, conditions of mixing, compaction, curing and admixtures used. The appropriate amounts of cement needed for different types of soils may be as follows: Gravels – 5 to 10%, Sands – 7 to 12%, Silts – 12 to 15%, and Clays – 12 – 20% The quantity of cement for a compressive strength of 25 to 30 kg/cm2 should normally be sufficient for tropical climate for soil stabilization. If the layer of soil having surface area of A (m2), thickness
H (cm) and dry density rd(tonnes/m3), has to be stabilized with p percentage of cement by weight on the basis of dry soil and, the amount of cement required for soil stabilization is given by Amount of cement required, in tonnes. Lime, calcium chloride, sodium carbonate, sodium sulphate and fly ash are some of the additives commonly used with cement for cement stabilization of soil.
3.3 STABILISATION WITH BITUMEN Most bituminous soil stabilization has been performed with asphalt cement, cutback asphalt, and asphalt emulsions. Soils that can be stabilized effectively with bituminous materials usually contain less than 30 percent passing the No. 200 sieve and have a PI less than 10. Soils classified by the USCS as SW, SP, SW-SM, SP-SM, SW-SC, SP-SC, SM, SC, SM-SC, GW, GP, SW-GM, SP-GM, SW-GC, GP-GC, GM, GC, and GM-GC can be effectively stabilized with bituminous materials, provided the above-mentioned gradation and plasticity requirements are met. 3.3.1 ADDICTIVE SELECTION Anionic Emulsions: The term anionic is derived from the migration of particles of asphalt under an electric field. The droplets migrate toward the anode (positive electrode), and hence the emulsion is called anionic. In an anionic emulsion, there are “billions and billions” of asphalt droplets with emulsifying agent at the water asphalt interface. The tail portion of the emulsifying agent aligns itself in the asphalt while the positive portion of the head floats around in the water leaving the rest of the head negatively charged and at the surface of the droplet. This imparts a negative charge to all the droplets. Since negatives repel each other, all the droplets repel each other and remain as distinct asphalt drops in suspension. A typical anionic emulsifying agent is shown below along with a diagram showing the orientation of the agent at the asphalt-water interface and the negative charge imparted to each drop.
Cationic Emulsions: The term cationic is derived from the migration of particles of asphalt under an electric field also. The droplets migrate toward the cathode (negative electrode), and hence the emulsion is called cationic. The cationic emulsifying agent functions similarly to the anionic; the negative portion of the head floats around in the water leaving a positively charged head. This imparts a positive charge to all the droplets. Since positives repel each other, all the droplets repel each other and remain as distinct asphalt drops in suspension. A typical cationic emulsifying agent is shown below along with a diagram showing the orientation of the agent at the asphalt-water interface and the positive charge imparted to each drop. 3.3.2 USE OF MULTIPLE ADDICTIVES Combination stabilization is specifically defined as lime-cement, lime-asphalt, and LCF stabilization. Combinations of lime and cement are often acceptable expedient stabilizers. Lime can be added to the soil to increase the soil’s workability and mixing characteristics as well as to reduce its plasticity. Cement can then be mixed into the soil to provide rapid strength gain. Combinations of lime and asphalt are often acceptable stabilizers. The lime addition may prevent stripping at the asphalt-aggregate interface and increase the mixture’s stability. Can be added to it to help with water absorption till the amendments into the soil. If the procedure is conducted in the fall, the improvements should be apparent by the following spring. 3.4 STABILIZATION WITH FLY ASH Fly ash, when mixed with lime, can be used effectively to stabilize most coarse- and medium grained soils; however, the PI should not be greater than 25. Soils classified by the USCS as SW, SP, SP-SC, SW-SC, SW-SM, GW, GP, GP-GC, GW-GC, GP-GM, GW-GM, GC-GM, and SC-SM can be stabilized with fly ash. 3.5 STABILIZATION WITH CHEMICALS Calcium chloride being hygroscopic and deliquescent is used as a water retentive additive in mechanically stabilized soil bases and surfacing. The vapor pressure gets lowered, surface tension increases and rate of evaporation decreases. The freezing point of pure water gets lowered and it results in prevention or reduction of frost heave.
The depressing the electric double layer, the salt reduces the water pick up and thus the loss of strength of fine grained soils. Calcium chloride acts as a soil flocculent and facilitates compaction. Frequent application of calcium chloride may be necessary to make up for the loss of chemical by leaching action. For the salt to be effective, the relative humidity of the atmosphere should be above 30%. Sodium chloride is the other chemical that can be used for this purpose with a stabilizing action similar to that of calcium chloride. Sodium silicate is yet another chemical used for this purpose in combination with other chemicals such as calcium chloride, polymers, chrome lignin, alkyl chlorosilanes, siliconites, amines and quarternary ammonium salts, sodium hexametaphosphate, phosphoric acid combined with a wetting agent.
CHAPTER 4 EXPERIMENTAL PROGRAMME
4.1 INTRODUCTION This chapter explains the methodology used find the performance of the properties of materials as well as the emulsion mix have very much importance in the design and construction of a long lasting pavement. The experimental methodology used for the study starts with the first step of selection of materials and extends to the different tests conducted on the emulsion and the soil. The tests are conducted according to the standards specified in the relevant codes. Silt soil is finer than sand, but still feels gritty. Silt is commonly found in floodplains and is the soil component that makes mud. Soils with a lot of silt make excellent farm land, but erode easily. This is the soil blown away in dust storms and carried downstream in floods.
4.2 SITE DETAILS The site was located between cities Rajahmundry and Kakinada which connects NH-5 to the Kakinada city with a corridor of 60.6 kms along with irrigation canals on both sides (7-8 feet) below the ground water table elevation. The entire site is situated on dredge spoil area which includes variety of material s like clay, silt, sand and organic matter.
4.3 DATA COLLECTION Material collection is the primary step for the subsequent steps to be carried out accordingly. The materials to be collected are 1. Additive: Emulsion slow setting (Ss1). 2. Soil: Soil samples are collected all along the project corridor.
Soil: Silty soil sample was taken from Rajahmundry village as can be seen in fig .4.1 Soil sample was taken in its original and distributed forms. Sample of original soil was taken by using pipe of diameter 7.5 cm with length 30 cm. Distributed soil sample was taken at the depth of 0 to 50 cm.
Cationic Emulsion: Emulsion type SS1 used especially for soil stabilization was obtained from Silica manufacturers Fig 4.2. The concentrations of emulsified asphalt used in this study were 1.5%, 3% and 4.5% respectively toward dry soil weight. The term cationic is derived from the migration of particles of asphalt under an electric field also. The droplets migrate toward the cathode (negative electrode), and hence the emulsion is called cationic. The cationic emulsifying agent functions similarly to the anionic; the negative portion of the head floats around in the water leaving a positively charged head. This imparts a positive charge to all the droplets. Since positives repel each other, all the droplets repel each other and remain as distinct asphalt drops in suspension. A typical cationic emulsifying agent is shown below along with a diagram showing the orientation of the agent at the asphalt-water interface and the positive charge imparted to each drop.
3.4 RESEARCH PROCESS (FLOW CHART)
Selection of material and methodology Specific gravity, Grain size distribution and other soil property testing Prepare sample for CBR Test in different conditions
Modified proctor test to identify maximum dry density and optimum moisture content Stabilization with bitumen emulsion and check Yd variation in different conditions A comparative study and analysis of results, Conclusions
Fig. 4.3 Methodology flow chart
3.5 METHODS OF STABILIZATION The two general methods of stabilization are mechanical and additive. The effectiveness of stabilization depends upon the Ability to obtain uniformity in blending the various materials. Mixing in a stationary or traveling plant is preferred; however, other means of mixing, such as scarifies, plows, disks, graders, and rotary mixers, have been satisfactory. The method of soil stabilization is determined by the amount of stabilizing required and the conditions encountered on the project. An accurate soil description and classification is essential to the selection of the correct materials and Procedures.
3.5.1 Mechanical method MECHANICAL METHOD Mechanical stabilization is accomplished by mixing or blending soils of two or more gradations to obtain a material meeting the required specification. The soil blending may take place at the construction site, at a central plant, or at a borrow area. The blended material is then spread and compacted to required densities by conventional means. ADDITIVE METHOD Additive refers to a manufactured commercial product that, when added to the soil in the properquantities, will improve the quality of the soil layer. Thischapter is directed towards the use of portland cement,lime, lime-cement-fly ash, and
bitumen, alone or incombination, as additives to stabilize soils. Theselection and determination of the percentage of additives depend upon the soil classification and the degree of improvement in soil quality desired.Generally, smaller amounts of additives are required to alter soil properties, such as gradation, workability, and plasticity, than to improve the strength and durability sufficiently to permit a thickness reduction design. After the additive has been mixed with the soil, spreading and compacting are accomplished by conventional means.
Table 4.1 Determination of cumulative % wt. of passing.
% wt. Wt. Of
Of
size(mm retaine retaine si.no
)
d
d
(gm.)
Cumulativ e% wt.
Cumulati ve wt
retained
passing
1
4.75
7
7
0.7
99.3
2
2
12
19
1.9
98.1
3
0.425
103
122
12.2
87.8
4
0.075
104
226
22.6
77.4
Gravel (%): 0.7 Sand (%): 21.9 Silt/Clay: 77.4 4.1.1 Conclusion remarks From the result we get that the taken soil is well graded
4.2 Compaction test using water To determine the optimum moisture content and corresponding maximum dry density of a taken soil using standard proctor test
Table 4.2 Determination of Dry density using water
Modified Proctor Compaction Test Mould weight
4303
Trail No
1
Mould wet soil
gm
1000
2
3
4
5
6165
6264
6314
6358
6351
wt. of wet soil
gm
1862
1961
2022
2055
2048
wet density
gm/cc
1.862
1.961
2.022
2.055
2.048
45
40
23
31
17
con no Con wt.
gm
46.58
48.94
43.83
44.48
46.53
con+wet soil
gm
192.00
212
186
200.41
200.36
con+dry soil
gm
183.25
199.64
172.86
183.21
181.00
water
gm
8.75
12.36
13.14
17.20
19.36
Dry soil
gm
136.67
150.70
129.03
138.73
134.47
Moisture content
%
6.4
8.2
10.18
12.4
14.4
Dry density
gm/cc
1.750
1.812
1.835
1.828
1.790
Bulk density =
gm/c.c
W = water content V= wt. of mould Dry density (g/cc)
volume
Dry density
Graph 4.1The graph between optimum moisture content and maximum dry density
4.2.1 Observations Moisture content (%) Bulk density (
=
= 2.022 gm/c.c
Water content (W) =
Dry density =
*100
= 1.835 gm/c.c
4.2.2 Conclusion remarks
A compaction curve is plotted between the water content and corresponding dry density as ordinate. The dry density goes on increase as water content is increased till max density is reached. The water content corresponding to max density is called optimum moisture content.
the optimum moisture content is 10.18% Maximum dry density is 1.835 gm./c.c
4.3 compaction test with bituminous emulsion To determine the optimum bituminous emulsion content and corresponding maximum dry density of a taken soil using standard proctor test
Table 4.3 Determination of dry density using bituminous emulsion
Modified Proctor Compaction Test Mould weight Trail No Mould+wet soil wt. of wet soil wet density gm/cc con no con wet
gm gm gm
gm
con+wet soil
gm
con+dry soil water
gm gm
Dry soil gm Moisture content % Dry density gm/cc
4303 1 6165 1874 1.874 25 48.73 140.0 0 134.6 7 5.33 85.94 6.2 1.765
volum e 2 6264 1995
3 6314 2052
4 6358 2061
5 6351 2043
1.995 22 46.97
2.052 68 44.95
2.061 49 51.68
162 153.0 9 8.91 106.1 2 8.4 1.840
173 160.8 3 12.17 115.8 8 10.50 1.857
182 167.4 2 14.58 115.7 4 12.6 1.830
2.043 6 45.47 168.0 0 152.2 0 15.80 106.7 3 14.8 1.780
1000 cc
Dry density
Bituminous content (%) Results
MDD: 1.857 g/cc
OBC: 10.50 %
Graph 4.2 Graph between optimum bituminous emulsion content and maximum dry density
4.3.1 Observations Bulk density (γ) = gm./cc W = water content V=wt. of mold Bulk density = = 2.052 gm. /cc. Water content (w) = Dry density =
* 100
= 1.857 gm./cc.
4.3.2 Conclusion remarks A compaction curve is plotted between the bituminous content and corresponding dry density as ordinate. The dry density goes on increase as bituminous content is increased till max density is reached. The bituminous content corresponding to max density is called optimum bituminous content.
The optimum bituminous content is 10.50% Maximum dry density is 1.857 gm./c.c
4.4 CALIFORNIA BEARING RATIO TEST WITH WATER4. To determine the strength of the taken silty soil Table 4.4Details of CBR test results using water
CALIFORNIA BEARING RATIO No.of Blows Description:
[IS:2720 Part (XVI)]
10
Before soaking
Volume of mould Wt. Of the mould (m1) Mass of Mould+compcted soil in gms(m2) Mass of compacted soil in gms m3=(m2-m1)
Wet Density, gm/cc γb=m3/v Container No. Mass of Container, (w1)gm. Mass of Container & Wet Soil (w2) gms. Mass of Container & Dry Soil (w3) gms. water content
Dry Density (gm/cc) γd= γb/(1+w/100)
2250 6850 11536 4686 2 12 46 180 165 13 1.840
No.of Blows
Before soaking
Penetration (mm)
1 2 3 4
0.5 1.0 1.5 2.0
5
2.5
6 7 8 9 10
3.0 4.0 5.0 7.5 10.0 CBR @ 2.5mm in %
Mould No
16
4.37
No.of Blows
65
Before soaking
2250 6529 11576 4726 2 16 44 160 147 12 1.868
Proving Ring Dial Readings Proving ring capacity:30KN factor:4.243 16 Mould No Mould No S.NO
35
2250 6911 11344 4815 2 20 46 156 144 13 1.896
Proving ring 17
Mould No
18
Dial Gauge Reading
Unit Load(k g)
Dial Gauge Reading
Unit Load(k g)
Dial Gauge Reading
Unit Load(k g)
6.5 9.4 11.8 13.2 14.1 15.1 15.9 16.7 17.4 18.1
27.5 39.9 50 55.8 59.9 63.9 67.3 71 73.9 76.9
7.8 10.9 13.4 15.5 16.9 18.1 18.9 19.7 20.3 20.7
32.9 46.3 56.8 65.8 71.9 76.8 80.4 83.4 86 87.9
6.3 12.0 15.3 17.2 18.4 19.5 20.6 21.4 22.1 22.8
26.8 51 65 72.9 77.9 82.9 87.6 90.6 93.6 96.9
CBR @ 5.0 mm in %
3.45
Remark s:
CBR value:
5.10 %
17 18
5.25 5.69
4.06 4.41
Graph 4.3 A CBR load-penetration curve using water.
4.4.1 Observations =
*100=5.10%
4.4.2 Conclusion remarks
The CBR value calculated at 5mm penetration is constantly found to be more than the CBR value calculated at 5.0mm.for flexible pavement design purpose. If the CBR calculated at 5.0mm penetration is constantly more than the value at 2.5mm penetration. The CBR at 5.0mm should be taken as the design value.
Hence we repeat the test for three times the obtain CBR values at 2.5mm are 4.37%,5.25%,5.69% from this values we take the average value from graph as 5.1%
4.5 CALFORNIA BEARING RATIO TEST WITH BITUMINOUS EMULSION To determine the strength of the taken silty soil by bituminous emulsion
Table 4.5 Details of CBR test results using bituminous emulsion
CALIFORNIA BEARING RATIO No.of Blows Description:
[IS:2720 Part (XVI)]
10
Before soaking
Volume of mould Wt. Of the mould (m1) Mass of Mould+compcted soil in gms(m2) Mass of compacted soil in gms m3=(m2-m1)
Wet Density, gm/cc γb=m3/v Container No. Mass of Container, (w1)gm. Mass of Container & Wet Soil (w2) gms. Mass of Container & Dry Soil (w3) gms. water content
Dry Density (gm/cc) γd= γb/(1+w/100)
2250 7089 11105 4016 1.785 11 38.15 143.93 132.75 11.92 1.596
No.of Blows
Penetration (mm)
1 2 3 4
0.5 1.0 1.5 2.0
5
2.5
6
3.0
7
4.0
8
5.0
9
7.5
10
10.0 CBR @ 2.5mm in %
Mould No
16 17
6.19 7.43
No.of Blows
65
Before soaking
2250 6750 11228 4478 1.990 17 38.49 159.89 146.65 12.15 1.774
Proving Ring Dial Readings Proving ring capacity:30KN factor:4.243 16 Mould No Mould No S.NO
35
Before soaking
2250 6899 11584 4684 2.082 41 37.66 143.07 132.08 11.95 1.860
Proving ring 17
Mould No
18
Dial Gauge Reading
Unit Load(k g)
Dial Gauge Reading
Unit Load(k g)
Dial Gauge Reading
Unit Load(k g)
5 10 14 17
21.2 42.4 59.4 72.1
8 14 18 21
5 11 17 23
20
84.9
24
22
93.3
26
33.9 59.4 76.4 89.1 101. 8 110. 3
25
106. 1
29
123
36
29
123
31
21.2 46.7 72.1 97.6 118. 8 131. 5 152. 7 169. 7 190. 9 195. 2
152. 7 165. 5
36 39 CBR @ 5.0 mm in %
5.98 6.89
36 41 Remark s:
131. 5 152. 7 173. 9
28 31
40 45 46 CBR value:
8.10 %
18
8.67
8.26
Graph 4.4 A CBR load-penetration curve using bituminous emulsion.
4.5.1 Observation
=
*100=8.10%
4.5.2 Conclusion Remarks
The CBR value calculated at 2.5mm penetration is constantly found to be more than the CBR value calculated at 5mm.for flexible pavement design purpose.
If the CBR calculated at 5mm penetration is constantly more than the value at 2.5mm penetration. The CBR at 5mm should be taken as the design value.
Hence we repeat the test for three times the obtain CBR values at 5.0mm are 6.19%, 7.43%, 8.69% from this values we take the average value 8.10%.
4.6
Falling head with water
4.6.1 To determine the coefficient of permeability of given soil by falling head method
The constant head permeability test is used for course grained in a given time. However the falling head test is used for relatively less permeable soils where the discharge is small.
Table 4.6 Details of permeability test results using water. K(Cm/Sec)*
Initial
Final
Time't's
Head
Head
Sino
ec
H1cm
H2cm
H1\H2
H2
1
40.1
100
50
2
0.301
1.794
2
20
50
20
2.5
0.397
4.745
3
23
100
60
1.66
0.22
2.286
4
47
60
5
12
1.079
5.488
5
9.37
100
70
1.428
0.154
3.92
6
27
70
40
1.75
0.243
2.151
7
54.4
100
40
2.5
0.397
1.744
8
73
100
30
3.33
0.5224
1.711
4.6.2Observations K=
K=coefficient of permeability.
Log10h1\
A=area of stranded pipe.
L=length of specimen.
=head at time
.
=head at time
.
A=cross sectional area of specimen. T= ~
K=
in sec.
*0.397 =1.794*
4.6.3 Conclusion Remarks
The average value of coefficient of permeable of silty soil sample by variable head method is k=2.979*
cm/sec., obtained at 95% of MMD
4.7 Falling head with bituminous emulsion
4.7.1 To determine the coefficient of permeability of given soil by falling head
method
The constant head permeability test is used for course grained in a given time. However the falling head test is used for relatively less permeable soils where the discharge is small.
Table 4.7Details of test results using bituminous emulsion Initial
Final K(Cm/Sec)*
Time Head
Head
S.N
'T'
o.
Sec
Cm.
Cm.
1
39
100
70
1.428
0.154
0.944
2
30
70
50
1.4
0.146
1.163
3
56
50
25
2.5
0.3
1.283
4
43
25
10
2.5
0.39
2.168
5
15
100
85
1.176
0.07
1.115
6
42
85
45
1.88
0.27
1.532
7
57
45
10
4.5
0.65
2.726
8
5
10
5
2
0.301
1.09
4.7.2 Observation K=
*0.154=9.44*
cm/sec.
4.7.3 Conclusion Remarks
The average value of coefficient of permeable of silty soil sample by variable head method is k=1.502*
cm/sec.
Decease in permeability (% ) = =52%
*100
CHAPTER 5 CONCLUSIONS
5.1 CONCLUSION
Advantages and uses of using cationic bituminous emulsion. For stabilization subgrade soil gives good strength Increasing of CBR value gives good strength, stiffness and cohesiveness to subgrade soil. Decreasing of permeable value gives good permeability
to the sub grade soil Test results with water and bituminous emulsion Optimum moisture content(OMC) is 10.18% Maximum dry density (MDD) is 1.835gm/cc. Optimum bituminous content(OBC) is 10.5% Maximum dry density(MDD) is 1.850gm/c
Table 5.1Comparing of OMC and MDD using water and bituminous emulsion values Soil admixture with water
Soil admixture with bituminous emulsion
Optimum moisture content(OMC) is Optimum bituminous content(OBC) 10.18%
10.5%
Maximum dry density (MDD) is
Maximum dry density(MDD) is
1.835gm/cc.
1.850gm/cc
[email protected] is 5.10%
is
CBR@ 5mm is 4.98% After trail we take CBR@ 2.5mm is 5.10%
[email protected] 8.10% CBR@5mm is 7.65% After trial and zero correction we take
[email protected] is 8.10%
Table 5.2 comparing of CBR values using water and bituminous emulsion Soil admixture with using water
Soil admixture using bituminous emulsion
[email protected] is 5.10%
[email protected] 8.10%
CBR@ 5mm is 4.98%
CBR@5mm is 7.65%
After trial we take CBR@ 2.5mm is After trial and zero correction we take 5.10%
Percentage increase of CBR value =
[email protected] is 8.10%
=58.82%
The silty soil strength has been increasing by about 58.2% due to using bituminous emulsion at Optimum content as 8.10 %. From the above results it is concluded that stabilization with bituminous emulsion will increase strength and durability of subgrade soil.
The rate of permeability of silty soil decreased by using bituminous emulsion and the following summary of the test details indicate the same.
Table 5.3 comparing of permeable values using water and bituminous emulsion Soil admixture with water
Soil admixture with bituminous emulsion
The avg.coefficient of permeability
The avg. Coefficient of permeability is
Is 2.979*
1.502*
cm/sec, obtained at
cm/sec.
95% of MMD .
Permeability test results with water The average coefficient of permeable k=2.297*
cm/sec.
Permeable test with bituminous emulsion The average coefficient of permeable k=1.502*
cm/sec
From above values 2.297*
1.502*
= 1.477*
Decease in permeability (%) =
*100
=52%
Economic analysis of the bituminous emulsion stabilization of the soil is compared with the conventional soil water stabilization and it is found that the construction cost of construction also decreased. The following are the details of the economic comparison made with and without using bituminous emulsion.
5.2Cost analysis
[email protected] is 5.10% CBR@ 5mm is 4.98%
After trail we take
[email protected] is 5.10% Traffic volume= 2msa ,
Bituminous surface 75mm Base of gravel (WBM) 100mm
subgrade 100mm
a)
Bituminous surface= 3.75*0.05*1000
= 187*5
= 3.75*0.025*1000
= 93.75
1
dense bitumen macadam=Rs5221.79
Therefore 187.5*5221.79= Rs979085.62
1
bitumen concrete=Rs6356.21.
Therefore 93.75*6356.21=595894.68
Bituminous surface cost=1574980.305
Base of gravel(water bond macadam) = 3.75*0.1*1000
b)
= 375
1
cost = Rs1030.43.
Therefore 375*1030.43 = Rs386411.25. c)
Granular sub-base = 3.75*0.1*1000 = 375
1
cost = Rs982.72
Therefore 375*982.7 = Rs368520 d)
The total road cost for 1KM is Rs2329911.55
[email protected] is 8.10% CBR@5mm is 7.65% After trial we take CBR@ 5mm is 8.10%
,
Bituminous surface 75mm
Base of gravel(WBM) 160mm
a)
Bituminous surface= 3.75*0.05*1000 = 187*5 = 3.75*0.025*1000 = 93.75
1
dense bitumen macadam = Rs5221.79
Therefore 187.5*5221.79 = 979085.62
1
bitumen concrete = Rs6356.2
Therefore 93.75*6356.21 = 595894.68
Bituminous surface cost = 1574980.305
Base of gravel(water bond macadam)=3.75*0.16*1000
b)
=600
1
cost = Rs1030.43.
Therefore 600*1030.43 = Rs618258. c)
The cost of cationic bituminous emulsion for 550 liters is Rs23500
The total road cost for 1KM is Rs2219088.305
d)
At final the cost will decrease while applying cationic bituminous emulsion.
The decreasing cost is = 2329911.55-2219088.305 = Rs113173.245 Therefore, the Advantage of using bituminous emulsion per 1 KM is Rs113173.245
5.3 Scope of future work
Occurrence of the silty soils are commonly available type of soil in around the study of sieve analysis,compaction,CBRand permeable can also be done for other type soils which are available at different locations where roads are to be laid.
The silty soil stabilization with bituminous emulsion is also being done with foamed bituminous emulsion, lime, fly ash, cement, cinder and combinations.
`
References 1. Dense-Graded
Mixtures
Using
Asphalt
Emulsions,
AEMA
Recommended
Performance Guidelines 2nd Edition, pp71-76. 2. GEMS – The Design and Use of Granular Emulsion Mixes, SABITA (South African Bitumen and Tar Association), Manual 14. 3. A Basic Emulsion Manual No.19, 3rd Edition, AEMA. 4. Ballantine RW and Rossouw AJ 1989. Stabilization of soils. PPC Lime Handbook. Johannesberg. 5. Brown S and Needham A. 2000. A study of cement modified bitumen emulsion mixtures. 6. Proceedings of the Association of Asphalt paving Technologists, AAPT, vol.69, Reno. USA. 7. Giuliani F. 2001. X-Ray Diffraction method for studying cement-modified bitumen-emulsion
8. Mixtures in asphalt pavement cold recycling. 1st International symposium on sub-grade 9. Stabilization and in-situ pavement recycling using cement, Salamanca, Spain. October. 10.Hodgkinson A L. 2003. Investigation into the role of cementitious binders when recycling with foamed bitumen or bitumen emulsion. MSc. (Applied Sciences) project report. University of Pretoria. 11.Liebenberg J J E. 2003. A structural design procedure for emulsion treated pavement layers. Masters dissertation. Faculty of Engineering. University of Pretoria. April. 12.Muthen K M. 1998. Foamed asphalt mix design procedure. Report No CR-98/077. CSIR Transportek. Pretoria. 13.Sabita Manual 21. 1999. The design and use of emulsion–treated bases. Cape Town.
