Suitability of Rupganj Soil for Earth Construction A thesis submitted by A.B.M. Fahimuzzaman (160051021) Sheikh Farhan Md Anam (160051009) Shah Al Fayed Afridi (160051023) In partial fulfillment of the requirement for the degree of BACHELOR OF SCIENCE IN CIVIL AND ENVIRONMENTAL ENGINEERING Under the supervision of Farnia Nayar Parshi Assistant Professor, CEE, IUT Department of Civil and Environmental Engineering Islamic University of Technology (IUT) Gazipur, Bangladesh February 2021 Suitability of Rupganj Soil for Earth Construction by A.B.M. Fahimuzzaman (160051021) Sheikh Farhan Md Anam (160051009) Shah Al Fayed Afridi (160051023) BACHELOR OF SCIENCE IN CIVIL AND ENVIRONMENTAL ENGINEERING Department of Civil and Environmental Engineering Islamic University of Technology (IUT) Gazipur, Bangladesh February 2021 ii | Page © 2021 Farnia Nayar Parshi A.B.M. Fahimuzzaman Sheikh Farhan Md Anam Shah Al Fayed Afridi ALL RIGHTS RESERVED iii | Page Suitability of Rupganj Soil for Earth Construction by A.B.M. Fahimuzzaman (160051021) Sheikh Farhan Md Anam (160051009) Shah Al Fayed Afridi (160051023) A thesis submitted to the academic faculty in partial fulfillment of the requirements for the degree of Bachelor of Science in Civil and Environmental Engineering Department of Civil and Environmental Engineering Islamic University of Technology February 2021 iv | Page Suitability of Rupganj Soil for Earth Construction v | Page vi | Page ACKNOWLEDGMENTS We are really grateful because we managed to complete our graduation thesis on ‘Suitability of Rupganj Soil for Earth Construction.’ Within the given time by the University. This undertaking couldn't be completed without the effort and cooperation of our group members. Who worked tirelessly through the unfortunate event of the Corona Virus Outbreak. We also thank our supervisor, Mrs. Farniya Nayar Parshi, for the guidance and encouragement in finishing this paper and also for teaching us the relevant courses. We also would like to acknowledge and thank the Prosoil Organization for their help by providing us with various data, which were indispensable for this paper. We also thank all of our teachers for the knowledge, support and encouragement they have given us for so long. We are forever indebted. Last but not the least we would like to thank our family and friends for their constant source of inspiration. vii | Page ABSTRACT In order to use the soil as a construction material for earth construction, we need to check the suitability of the said soil. For which, its geotechnical properties are required to be examined. The purpose of this study was to determine the suitability of Rupganj soil by reviewing previous studies on the suitability criteria and previously published similar soil samples. This study was conducted under the main reference of a previous review paper which compiled the necessary information and requirements for a soil to be deemed suitable for earth construction. We have conducted the study on 7 soil samples from different depths of the similar area and assessed them according to the chosen criteria. Five geotechnical properties were compiled and referred to and then analyzed. These properties are particle size distribution, specific gravity, maximum dry density, optimum moisture content and Atterberg limit. Based on the values of soil properties found on the literature review, and other recommendations from previous studies, analysis was carried out and recommendations were made for the suitability of different samples. We have also analyzed the cost and environmental impact produced by the suggested soil methods. viii | Page It was noted that some of the soil samples passed one set of criteria while failing the others. For this, stabilization techniques and materials were suggested. Finally, the study concludes whether the soil of said region is suitable for earth construction, and if not then what methods need to be applied. TABLE OF CONTENTS ACKNOWLEDGMENTS vi ABSTRACT vii LIST OF TABLES x LIST OF FIGURES xi LIST OF PICTURES 11 LIST OF ABBREVIATIONS xi CHAPTER 1 INTRODUCTION 1 Chapter 1.1 General 1 Chapter 1.2 Background 3 Chapter 1.3 Objectives 4 Chapter 1.4 Methodology 4 Chapter 1.5 Research Plan: 5 Chapter 2 LITERATURE REVIEW 6 CHAPTER 3 METHODOLOGY 9 Chapter 3.1 Introduction 9 Chapter 3.2 Outline of methodology 10 ix | Page Chapter 3.3 Selection of Site 10 Figure 3.3.d: Soil Texture map of Bangladesh 13 Chapter 3.4 Data collection 13 Chapter 3.5 Review of Previous Paper and Setting Criterias. 14 Chapter 3.5.1 Particle Size and Atterberg Limit 14 Chapter 3.5.2: Specific Gravity, Dry Density and Optimum Moisture Content 19 CHAPTER 4 RESULTS AND DISCUSSION 20 Chapter 4.1: Particle Size and Distribution 20 Table 4.1: Particle Size Distribution Table. 21 Chapter 4.2: Atterberg Limit 22 Chapter 4.3: Specific Gravity, optimum moisture content and maximum dry density 23 Chapter 4.4: Combined result: 25 Chapter 4.5: Cost Analysis 26 Chapter 4.6 Reduction of Carbon footprint: 28 CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS 29 Chapter 5.1 General 29 Chapter 5.2: Soil Review 29 Chapter 5.3: Future study and Suggestions 30 REFERENCES 32 APPENDIX Soil classification 37 x | Page LIST OF TABLES Table 3.5.1 Degree of Plasticity Index 18 Table 4.1 Particle Size Distribution Table 20 Table 4.2 Atterberg Limits and Plasticity Index Table 22 Table 4.3 Specific Gravity, Optimum Moisture Content and Maximum Dry Density Table 25 xi | Page LIST OF FIGURES Figure 3.2 Flow Chart of study outline 10 Figure 3.3a A sattelite view of Rupganj 11 Figure 3.3b Sattelite view of Jalshiri Abashan 12 Figure 3.3c Sattelite view of Boruna Bazar 12 Figure 3.3d Soil texture map of Bangladesh 13 Figure 3.5.1a Atterberg limits of soil suitibility 15 Figure 3.5.1b Granularity nomograms of suitable soil 16 Figure 3.5.1c Texture chart 17 Figure 4.1 Gradation curves of sample soils 20 Figure 4.5 Cost Comparision of different types of materials 27 Figure 4.6 Comparison of Carbon emission by different materials 28 xii | Page LIST OF ABBREVIATIONS IUT Islamic University of Technology Wp Plastic Limit Wl Liquid Limit Ip Plasticity Index RE Rammed Earth CEB Compressed Earth Blocks ADO Adobe Blocks OR Outside Recommendation GS Specific Gravity OMC Optimum Moisture Content MDD Maximum Dry Density 1 | Page CHAPTER 1 INTRODUCTION Chapter 1.1 General For shelter and alternative construction functions concrete is widely used round the world where industries hold no regard for the high costs of stuff, labor and transportation. As a low income country the people of Bangladesh will solely dream of building a good shelter for themselves at a low value. Therefore, a desire arises to search out possible alternative building materials that is not only regionally obtainable and economical, however is additionally a way towards property development. History always helps for developing new technology. So it is wise to look back. From primitive age man is dependent on housing. The history of civilization is synonymous to the history of housing. Ever since man learnt to build homes and cities around 10000 years ago, earth has undoubtedly been one of the most widely used construction materials in the world. Still today 50% of the population in developing countries, including the majority of the rural population and at least 20% of the urban and suburban population, live in earthen dwellings. (Houben H, 1994) 2 | Page Clay bricks are some of the oldest building materials to be manufactured and used by man. They are still popular as building materials mainly because of their structural properties, easy availability, relatively low cost and easy architectural workability. Traditionally, clay bricks are considered as solid and sustainable materials under normal weather conditions. Where clay deposit is available, bricks can be manufactured locally, which makes them easily available at relatively low cost (Chan, 2011). However, there are few undesirable properties like loss of strength once saturated with water, erosion because of wind or driving rain and poor dimensional stability. sturdiness and strength is also major downside. Another severe drawback is its vulnerability to earthquake loading. Various researches are dispensed round the world. These researchers have developed many solutions of structural reinforcement to earthen house. however most of the cases these solutions are neither low-cost nor straightforward to use in construction. Clays having low strength and high compressibility, can cause severe damage to civil engineering construction. Therefore, these soils must be treated before commencing the construction operation to achieve desired properties. Different methods are available to improve the engineering properties of problematic soils such as densification, chemical stabilization, reinforcement and techniques of pore water pressure reduction. People all over the world have been using various fiber with soil during earth construction. The chemical stabilization of clays using lime is also one of the commonest methods that can be used to upgrade the soils of poor properties to provide a workable platform to construction projects. 3 | Page But not all clayey soil can be directly used for such research. Thus the purpose of this particular paper was to test the different parameters of a regional soil and compare them with the idealistic values of workable soil and derive whether they are suitable or not. And to see if they can be made suitable using the guidelines found available through the review papers. So using the reviews and previous studies, this paper set to find out the suitability or how to make a certain area’s soil suitable for earthen work such as using it for compressed earth blocks or direct mud housing. We have also checked the impact towards the environment and the cost effectiveness of the above mentioned soil. Chapter 1.2 Background ● . Earth as a building material has low environmental impact and high availability. ● Utilization of locally available soil for the construction will optimize the cost and reduce the environmental impact. (Tharaka DGS, 2012) ● Earth building techniques are simple and easy to use, making it workable for local labors. (Ciancio D, 2013) ● Resources for concrete construction are slowly running out. ● Finding a new resource has become a new challenge and stable earth construction can solve that. (Laborel Préneron A, 2016) ● Naturally not all soil consists of suitable composition for building structures. ● Testing soil before using it as a construction material is necessary. (H. Danso, 2018) 4 | Page Chapter 1.3 Objectives ● Identify the soil properties ● Evaluating the acquired values for identifying the suitability of the soil ● Pointing out the stabilizers according to the lacking of particular soil. ● Assessing environmental impact. ● Alternative usage of soils which are not suitable for earth works. Chapter 1.4 Methodology This research work conducted in the following way: ● Study of referential papers: A total of 18 papers and 3 books and 5 websites were studied and taken reference of to find the ideal approach to judge the suitability of a certain soil. The research papers were properly reviewed and compared and one set of conclusion was chosen as the set answer. ● Selection of site and collection of data: The site selection was an important part of the research. Because, we needed to choose a site that had prior history of clay or mud housing, had accessible and abundance of samples to make use of, the soil was similar or at least look similar to the reviewed examples and finally a soil that has low microbial content. So Rupganj was selected as the study area. And the data was all collected from Prosoil foundation consultant. ● Study and analysis of the acquired data: 5 | Page The data collected were then put through the analysis as we compared and deduced whether the samples met the criteria. ● Recommendation of stabilizers After the analysis ended, the prior criteria were taken into account and proper stabilization methods and stabilizers were commented and recommended for the soils that were outside the ideal criterion. Chapter 1.5 Research Plan: The following is the breakdown of the entire research project: a) Study of previous research to find the criteria defining a suitable soil. b) Gathering the data. c) Studying and analyze the acquired data. d) Compare and deduce the analyzed results and recommend proper stabilization. In this context, Chapter 2 includes the use of soil in infrastructure all over the world and recent relevant researches on soil as a building material. Also, the definition, classification, advantages, disadvantages of soil is explained. The methodology is discussed in Chapter 3. The physical properties of each type of soil are described here. The criteria of this study is shown here. The results of the experiments are mentioned in Chapter 4. Figures, graphs, and tables are used to discuss the outcomes of the test parameters. Regarding this study, Chapter 5 provides some recommendations. Finally, scopes for further research work are listed in the last portion. This is the concluding phase of this research project. 6 | Page Chapter 2 LITERATURE REVIEW A soil is a material that is widely available in almost everywhere in the world and can be used in many types of earth construction, such as cob, rammed earth or stabilized mud blocks (SSF soil testing manual, 2014). Major geotechnical problems in construction involving silty-clayey soils are due to their low strength, durability and high compressibility of soft soils, and the swell- shrink nature of the over-consolidated swelling soils (Stavridakis, 2006). The poor conditions of soils on their properties can often be a significant impediment to successfully implementing green infrastructure projects (United States Environmental Protection Agency, 2011). A major problem prior to the decision to use soil as the walling material on a construction project is to identify a sufficient supply of soil suitable for economic stabilization (AJ, 1988). Earthen construction has been one of the most largely used construction techniques in different historical ages (Parisi F, 2015). Earthen materials are still widely used worldwide because of their low-cost, abundance, availability and low environmental impact (Araya Letelier G, 2018). Earth as a building material is increasingly being studied for its low environmental impact and its availability (Laborel Préneron A, 2016). Utilization of locally available soil for the construction will optimize the cost and reduce the environmental impact (Tharaka DGS, 2012). The will of reducing environmental and social impact from the construction industry has led to a renewed interest in earth construction (Hamard E, 2016). Due to the ease and simplicity of earth building techniques, a local unskilled labour force can be readily employed, supplying job 7 | Page opportunities to remote communities and reduction in the cost of accommodation and transport of labour brought from distance (Ciancio D, 2013). Earth building techniques make use of raw earth as a material for constructing walls, and that evaluation of soils is a primary issue because not all soils are adequate in properties for earth buildings (Delgado MCJ, 2007). Geotechnical properties of soils influence the stability of civil engineering structures, and most of the geotechnical properties of soils influence each other (Roy S, 2017). Laborel Préneron et al. (Laborel Préneron A, 2016) reviewed the state of the art of research on the influence of various natural and renewable resources in unfired earth materials such as compressed earth blocks, plasters, and extruded and stabilized blocks based on 50 major studies. Their study included the characterization of the particles and treatments, recapitulative tables of the material compositions, the physical, mechanical, hygrothermal and durability performances of earth based materials. Danso et al. (Danso H, Performance characteristics of enhanced soil blocks: A quantitative review., 2015) reviewed 56 published studies on the effect of stabilization on the performance characteristics of soil blocks and found that few studies have been conducted on durability properties of enhanced soil blocks as compared with physicomechanical properties. Delgado and Guerrero (Delgado MCJ, 2007) reviewed more than 20 technical documents including standards from National Standards bodies, analyzed the provisions they offered concerning soil suitability for the use of unestablished earth and analyzed the different approaches and kinds of recommendation offered. Finally, Humphrey Danso (H, Experimental Investigation on the Properties of Compressed Earth Blocks Stabilised with a Liquid 8 | Page Chemical, 2017)analyzed the review work of more than 50 researchers and came up with a plausible way to find out the suitability of a soil, for using in earthen work. To check the suitability of soil to be used as a foundation or as construction materials, its properties are required to be assessed (www.ejge.com, n.d.). The evaluation of basic engineering properties of soils through laboratory testing is very important in understanding and interpreting how soils will behave in the field (Zhang J, 2018). The physical and engineering properties of existing soils are intrinsic and can be used as a frame of reference for the behavior of strength characteristics of soil (www.ijetsr.com, n.d.). Different kinds of soil exist worldwide with different characteristics which are likely to have effects on the performance of the structures that are constructed with the soil. It is imperative to identify the characteristics of any obtainable soil before using it for construction purposes. Natural soil exists in the distinct composition of sizes, for which certain proportions of these sizes can make a good material for building structures. This presents the need for testing any given soil before it is used in the construction industry as a filling or structural material. The issue is that, given the fact that not all soils are suitable, and some classes are better depending on the technique used, it is necessary to use some way for evaluating them (Delgado MCJ, 2007). This study, therefore, reviews and analyses soil properties of the collected sample data in order to determine their suitability for earthen construction using the preordained analysis data from the literature reviews. 9 | Page CHAPTER 3 METHODOLOGY Chapter 3.1 Introduction This chapter gives an outline of the research methods that were followed in the study. The systematic process from selecting the location of soil to analysis of the data. This study adopted the approach of the research of Humphrey Danso (H, Influence of compacting rate on the properties of compressed earth blocks. , 2016) as a base and worked its way up from there. As the papers reviewed had already given a certain direction to analyze the sample soil, the reviews and conclusions of previous studies were taken as reference points. And were used to derive the data of this study. The geotechnical properties of soil samples used in previous studies were compiled and compared with various criteria and requirements to ascertain their suitability for construction purposes. Eighty-nine (89) studies in all were consulted and useful data were found in fifty-two (52) of them. Five geotechnical properties of soil were compiled and analyzed. These properties are particle size distribution, Atterberg limits, specific gravity, maximum dry density and optimum moisture content. A wide range of properties exists for determining the characteristics of soil for construction purposes (Danso H, Performance characteristics of enhanced soil blocks: A quantitative review., 2015). However, these properties were selected because they are the main properties used in most previous studies to characterize the soil samples. 10 | Page Chapter 3.2 Outline of methodology Our paper being a referential study we went through different phases. These are as follows: 1. We initially went through various published papers in the related areas then selected one as a base for our paper. 2. Then we went and searched for suitable locations/sites for our paper and collected data sample from “Prosoil Foundation Consultant”. 3. After getting our desired data we went to study and analysis of our acquired data to get the required information for our study. 4. Then we determined the suitability of the soil for our required purposes. 5. We recommended various stabilizers for the soil depending on their characteristics. 6. Finally, we made different recommendations for making earth blocks using that soil. Here is a flow chart showing the progression of our study: Figure 3.2: Flow Chart of Study Outline 11 | Page Chapter 3.3 Selection of Site Bangladesh is blessed with soils of various types and many of them are suitable for construction, as seen prior in many research papers. And so to select the site we had taken help from a website called Banglapedia. (Banglapedia.com, n.d.).figure 3.3.d shows a soil texture map of Bangladesh. And finally after reviewing, we had chosen Rupganj as the study area. Because, ● It Falls under clayey soil region which is perfect for this study. ● Has prior history of mud construction. We have found out that there are signs of people living in mud houses in this area. ● Accessible to sample. There is abundance of soil which seem easy to be made use of. Figure 3.3.a: A Sattelite view of Rupganj 12 | Page An image of the Rupganj region is shown on figure (). From this region two spots were chosen to take data from. They were, Boruna Bazar and Jalshiri Abashan respectively. Figure 3.3.b: Satellite view of Jalshiri Abashan Figure 3.3.c: Satellite view of Boruna Bazar 13 | Page Figure 3.3.d: Soil Texture map of Bangladesh Chapter 3.4 Data collection 14 | Page Data were collected from Prosoil Foundation Consultant. The data came from two boreholes and they were directly used for the following study. Chapter 3.5 Review of Previous Paper and Setting Criteria. Many papers of prior research on similar subject were reviewed to find out the proper criteria to compare the found data on. Following are the set criteria based on our findings. Chapter 3.5.1 Particle Size and Atterberg Limit For particle size distribution and Atterberg limits of soil samples used in previous studies, their values and the techniques used were compiled in tables and then compared with the upper limits of various criteria and requirements. Out of the comparison, a suitable soil application technique of the soil samples based on the requirements were recommended. This helped in determining the suitability of the soil for earth construction. Figure 1 shows the upper limits of Atterberg limit values proposed as a guide to recommend soil samples used in previous studies for determining their suitability for earth construction based on different criteria by Doat et al. (Doat P, 1979), Spence and Cook (Spence RJS, 1983) and Delgado and Guerrero (Delgado MCJ, 2007) From Figure 3.5.1a, it can be seen that the study used upper limits of 50% and 30%, respectively for the liquid limit (WL) and plasticity index (PI). 15 | Page Figure 3.5.1a: Atterberg limits for soil suitability. The particle size distribution test determines the amount, usually by mass, of the particles present in a soil sample (Jillavenkatesa A, 2001). Particle size distribution also known as grain size gives information on the soil’s ability to pack into a dense structure [26]. The particle sizes are classified as gravel, sand (fine and coarse), silt and clay. There are different recommendations for soil particle sizes that are suitable for different techniques of earth building. Five of these recommendations are put together in a nomogram (see Figure 2) by Delgado and Guerrero (Delgado MCJ, 2007). Compressed earth block (CEB) was recommended by Houben and Guillaud (Houben H, 1994), CRATerre EAG (CRATerre EAG , 1998) and AFNOR (XP, 2001). While Adobe was recommended by Houben and Guillaud (Houben H, 1994) and CRATerre EAG (CRATerre 16 | Page EAG , 1998), and rammed earth (RE) recommended by Houben and Guillaud (Houben H, 1994). Another source (Spence RJS, 1983) made a chart of soil particle size as shown in Figure 2. The shaded portion of the chart shows the recommended particle size suitable for soil stabilisation, which is in the range of 0% to 25% for clay, 0% to 25% for silt and 60 to 90% for sand constituents. In addition, a study by Bengtsson and Whitaker (Bengtsson LP, 1986) made recommendations for various techniques of soil particle sizes suitable for construction. Figure 3.5.1b: Granularity nomograms of Suitable Soils 17 | Page Figure 3.5.1c: Texture chart The plasticity index (PI) is a measure of the plasticity of a soil. The plasticity index is the size of the range of water contents where the soil exhibits plastic properties. The PI is the difference between the liquid limit and the plastic limit (PI = LL-PL). Soils with a high PI tend to be clay, those with a lower PI tend to be silt, and those with a PI of 0 (non-plastic) tend to have little or no silt or clay. (Sowers, 1979.) Water loss also contributes to the shrink of the clay fraction. For low clay mineral content (index plasticity below 20%), drying shrinkage showed a steady increase with the increase of clay content, but for a plasticity index beyond 25–30%, drying shrinkage increased rapidly as the clay content also increased. Soil with a plasticity index <20% is good for cement stabilization with cement content 10%. And, the commonly used drying shrinkage limit is from 0.008% to 0.10% . (F.V. Riza, 2015) 18 | Page Sand as part of the mix seems to have significant influence in shrinkage, although sand content does not significantly affect the compressive strength as stated by Guettala (Guettala et al., 2002). However, (F.V. Riza, 2015) found out it can decrease plasticity, linear shrinkage and warping. On the other hand, (Food and Agricultural Organization of the United Nations, n.d.) referred Plasticity Index on the basis of the liquid limit and the plastic limit. As the plasticity index (PI) can be defined as the numerical difference between them: PI = LL - PL The plasticity index is expressed in percent of the dry weight of the soil sample. It shows the size of the range of the moisture contents at which the soil remains plastic. In general, the plasticity index depends only on the amount of clay present. It indicates the fineness of the soil and its capacity to change shape without altering its volume. A high PI indicates an excess of clay or colloids in the soil. Its value is zero whenever the PL is greater or equal to the LL. For this study the following chart will be referred to. Plasticity Index (PI) Degree of Plasticity 0-1 Non- Plastic 1-5 Slight Plasticity 5-10 Low Plasticity 10-20 Medium Plasticity 20-35 High Plasticity 35> Very High Plasticity Table 3.5.1: Degree of plasticity through Plasticity Index. 19 | Page Chapter 3.5.2: Specific Gravity, Dry Density and Optimum Moisture Content Similarly, specific gravity, maximum dry density and optimum moisture content of soil samples used in previous studies were also compiled and analyzed based on the various requirements and closely related spacing of the values of the soil properties. FM5- 472 [24] provides a different range of specific gravity values for different types of soil. It, however, provides a specific gravity of 2.00 and 2.80 for the lowest and highest, respectively for all types of soils. Therefore, the study adopted 2.00 and 2.80 as the lower and upper limits, respectively for the suitable specific gravity of soil samples for earth construction. There are no known criteria for acceptable optimum moisture content and maximum dry density for soil suitability for earth construction, therefore, the study considered values that are closely related as suitable optimum moisture content and maximum dry density. 20 | Page CHAPTER 4 RESULTS AND DISCUSSION Chapter 4.1: Particle Size and Distribution Theoretically having higher clay content in soil with medium to high plasticity should be able to be used for earthen work if applied with high compaction pressure. As the clay particle’s, inter particle cohesive bond acts as electrical charges of different intensities, depending on the inter particle distance. With a low humidity content clays form a coherent solid with high densities. [l] So by checking the grading curves on the Particle Size curve, we will be able to determine the suitability of the samples for earthen work by judging the clay amounts. Figure 4.1 : Gradation Curves of the Sample Soils 21 | Page Table 4.1: Particle Size Distribution Table. 22 | Page Chapter 4.2: Atterberg Limit The Atterberg limits are a basic measure of the critical water contents of a fine-grained soil: its shrinkage limit, plastic limit, and liquid limit. Depending on its water content, a soil may appear in one of four states: solid, semi-solid, plastic and liquid. It can provide a way to identify a soil for a particular area objectively and generally. The determination of the liquid and plastic limits is sufficient for construction purposes. The plastic limit can be defined as the moisture content at which, when rolled into a thread, a soil will begin to crumble. The thread is roughly 3mm in diameter. The liquid limit is the moisture content at which the soil transitions and starts to flow from plastic into liquid states. The difference between the plastic limit and the liquid limit is the plasticity index. Table 4.2: Atterberg Limits and Plasticity of the Sample Soil 23 | Page Here, we have about 7 soil samples with their liquid limit, plastic limit and plasticity index. According USCS we have categorized all the samples into high plasticity and low plasticity. When the liquid limit is higher than 50, we considered it having high plasticity and when the liquid limit is lower than 50, we considered it having low plasticity. From the table, we see [3.0,6.0,7.0] have low plasticity and [1.0,2.0,4.0,5.0,] have high plasticity. [1.0,2.0,4.0,5.0] these soils have high amount of clay. Since clay ties the larger particles together, the clay content in the soil is a significant factor in earth building. Here these soils have more than 30 per cent clay. So they have ability to absorb moisture, have a very high shrinkage and swelling effect, which can result in the creation of cracks in the end product. So in order to use them in building structure we need to use stabilizers. On the other hand, a relatively low amount of clay is present in the soil sample [3.0,6.0,7.0]. They will lead to weak bonding of other particles, which can lead to bonding failures in the final product. Therefore, in order to make them suitable for building purposes, soils with very low or very high content of clay and often silt may require the addition of stabilizers. Chapter 4.3: Specific Gravity, optimum moisture content and maximum dry density The specific gravity of a soil is the ratio of the mass of soil solids to the mass of an equal volume of water which provides an idea about the suitability of the soil as a construction material (Oyediran, 2011) and (Jain, 2002). Specific gravity (GS) of a solid 24 | Page substance is the ratio of the weight of a given volume of material to the weight of an equal amount of water at 20 oC (www.globalsecurity.org, n.d.). In simple language, the specific gravity of soil tells how much heavier or lighter in weight the soil is than water. In many situations during construction processes, it is necessary for the soil to be compacted to its maximum dry density (Ren XC, 2015). Compaction is the process of mechanically densifying a soil by pressing the soil particles together into a closed state of contact so that the entrapped air can be expelled from the soil mass (www.bits.de, n.d.) and (H, Influence of compacting rate on the properties of compressed earth blocks. , 2016). The optimum moisture content (OMC) of soil is the water content at which a maximum dry unit weight can be achieved after a given compaction effort (en.wikipedia.org, n.d.). Maximum Dry density (MDD) of soil is the density that occurs at optimum moisture content. The tables given below presents the data collected from the soil tests conducted by “Prosoil” a foundation consultant company for their project at Rupganj, Naraynganj. Forty-eight (48) data samples were collected from their tests which reported the values of specific gravity of soil. Table shows that all the samples have a specific gravity value of 2.725 which is within the recommended range of 2.00 to 2.80. Tables also shows the optimum moisture content (OMC) values of the samples are mostly within the recommended range of 9.00 to 29.80 other than three exceptions. Of 33.98, 45.19, 30.11 values 45.19 is way out of recommendation. Also the tables provide the data of Maximum Dry Density (MDD) of the collected samples which are between 10.52 KN/m3 to 20.1 KN/m3. Critical observation of the values shows close relative spacing. Therefore, this provides the basis for recommendation for all the 25 | Page maximum dry density values in the table. Considering the results of the specific gravity, optimum moisture content and maximum dry density of the soil samples, it can be said that the influence of these are less in determining the suitability of the soil for earth construction compared to the particle size distribution and Atterberg limits. Table 4.3: Specific Gravity, Optimum Moisture Content and Maximum Dry Density Chapter 4.4: Combined result: Stabilization of soil is an essential step in any construction project. In order to make our soil samples suitable for earth construction work we need to use various stabilizers such as cement, lime and fly ash etc. Criteria that are considered for the selection of suitable stabilizers are as follows- Cement Stabilizer: Suitable for under 30% of clay amount, high control of moisture content although this method is not economic. 26 | Page Lime Stabilizer: Clayey soil, high amount of clay, plasticity index around 10 but this method can have impact on the environment and isn’t suitable for the stabilization of silty soil. Fly ash: For low moisture content, for coarse grain soil/sandy soil and must be used with cement. From the above mentioned qualities we have recommended the stabilization methods of our soil samples: Cement stabilization- [6.0] Lime stabilization- [2.0], [4.0] Fly ash with cement stabilization- [1.0], [3.0], [5.0] Among our sample data some of the soil some soil properties are unsuitable for earth construction works but are rather suitable for other works such as pottery and use in concrete mix etc. We found that among our sample data [7.0], have high content of silt and clay as such these type of soil is very suitable for making earthen wears and pottery. Chapter 4.5: Cost Analysis Below shows the comparative cost analysis for the proposed stabilized earth blocks using the Rupganj Soil. Compressed Stabilized Earth Blocks: BDT 35/unit (8% cement) Unit Dimensions: (7 inch x 14 inch x 4 inch) = 0.227 cu ft. Therefore, 1 cubic ft. = 154.18 BDT 27 | Page Fire Clay Brick: BDT 10.5/unit Unit Dimensions: (10 inch x5 inch x3 inch)” = 0.087 cu ft. Therefore, 1 cubic ft. = 120.68 BDT Price of concrete ranges depending on the PSI 1 cubic ft. = BDT 230 - BDT 300 So considering the price and environmental effects we can consider Compressed Stabilized Earth Blocks as a viable alternative to traditional building materials. Figure 4.5: Cost comparison of different types of material 28 | Page Chapter 4.6 Reduction of Carbon footprint: Below shows the amount of carbon emission reduction due to choosing earth as a material, 60-70% less energy consumption compared to traditional burnt clay brick For one unit (0.227cft) of earth block, considering 8% cement, We know, 0.01816 cft cement produces 0.667 kg of CO2 Similar unit of concrete would emit about 1.52544 kg of CO2 So we can see the reduction of carbon= {(1.5254-0.667)/1.5254} *100% =56.26% Figure 4.6: Comparison of carbon emission by different materials. 29 | Page CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS Chapter 5.1 General Our research has finally led us to a conclusion that the soil properties of Rupganj soil are ideal for earthen construction. We can see that it is suitable for such construction based on the obtained values from various experiments and collected data. We were also able to identify specific stabilizers for the lack of a specific soil component. We also discovered soil's other uses. We also looked at the soil's impact on the environment. Chapter 5.2: Soil Review We discovered that the soil is mostly clay, with some sandy soils thrown in for good measure. One advantage that should be mentioned is that there was no organic material. In comparison to traditional burnt clay bricks, 60 percent to 70 percent less energy is consumed here. As a result, it is both cost-effective and environmentally friendly. Unfortunately, the amount of data collected was insufficient for a conclusive study like the one we conducted here. We couldn't possibly consider all possible construction methods. We were only able to collect data from two locations, which we considered to be ideal samples. The use of the soil directly is limited because our research is based on referential papers. It can, however, be used as a reference point. As a result, other researchers can use our findings to determine the suitability of local soil. Future research can be based on our findings, and the interaction between fiber and various earth block materials can be easily determined. 30 | Page Finally, but certainly not least, we attempted to use our findings as a foundation for any future research or work, so that it can be used to determine the suitability of the soil and to compare it to other studies in order to better understand its characteristics. Chapter 5.3: Future study and Suggestions Evaluation of soil quality may be one of the soil science community's most contentious topics ever debated. Our goal is to examine the current status and potential of the assessment of soil quality as a tool for monitoring the physical, chemical and biological effects of management decisions that may affect soil and water resources on the soil. Differences are identified and discussed between inherent and dynamic soil quality and different approaches for evaluation. In our research we got the value of particle size of soil, plastic limit, liquid limit, plasticity index, specific gravity, optimum moisture content, maximum dry density. From these values we can do the following future evaluation: ● For earthblock construction purpose it will help to compare between different soils of Bangladesh. ● Further research can be conducted on the soil that we tested as the values we got are suitable for construction. ● Similar research can be done on a bigger scale regarding different types of soil from different region. ● Research on fiber interaction can also be done as we have good data of soil investigation. We can do improvement also according to necessity. ● It will be beneficial on deciding to how to choose and use soil economically. ● A huge threat to our environment which is Carbon emission can be controlled by gaining knowledge from this research. ● It will help us by providing alternatives regarding building purpose also. 31 | Page ● Energy saving. The main manufacturing cost of the block involves only the cost of conveying the earth to the site, a routine procedure since earth is a material within easy reach of most building sites. Furthermore, if the earth comes from the excavation work on the site itself, two birds are killed with one stone, compounding the savings.Technically, moreover, it is a very advantageous material with great energy-saving potential in heating and cooling terms. ● The cheapness of the material will help to reduce homelessness. A study can be conducted on the population with a poorer income and find out if using earthen houses can be a solution to their predicament. 32 | Page REFERENCES (n.d.). Retrieved from www.ejge.com: http://www.ejge.com/2012/Ppr12.261alr.pdf (n.d.). Retrieved from www.globalsecurity.org: https://www.globalsecurity.org/military/library/policy/army/fm/5- 472/ch2part2.pdf (n.d.). Retrieved from www.globalsecurity.org: https://www.globalsecurity.org/military/library/policy/army/fm/5- 472/ch2part2.pdf (n.d.). Retrieved from www.bits.de: http://www.bits.de/NRANEU/others/amd-us- archive/fm5_410(97).pdf (n.d.). Retrieved from en.wikipedia.org: https://en.wikipedia.org/wiki/Optimum_water_content_for_tillage#:~:text=The% 20Optimum%20Water%20Content%20of,want%20to%20get%20it%20wet. (n.d.). Retrieved from article.sapub.org: http://article.sapub.org/10.5923.j.re.20170704.03.html#:~:text=Specific%20gravit y%20is%20the%20ratio,an%20equal%20volume%20of%20water.&text=It%20gi ves%20an%20idea%20about,strength%20for%20roads%20and%20foundations (n.d.). Retrieved from www.ijetsr.com: http://www.ijetsr.com/images/short_pdf/1503855009_874-886- AJ, B. (1988). Bryan AJ (1988) Criteria for the suitability of soil for cement stabilization. Building and Environment , 23(4): 309-319. 33 | Page Araya Letelier G, C. R. (2018). Influence of natural fiber dosage and length on adobe mixes damagemechanical behaviour. Construction and Building Materials , 174: 645-655. Bengtsson LP, W. J. (1986). Farm structures in tropical climates. Rome, Italy: FAO/SIDA Cooperation Programme, . bjyus. (n.d.). Retrieved from byjus.com: https://byjus.com/chemistry/soil-pollution/ Ciancio D, J. P. (2013). Advances on the assessment of soil suitability for rammed earth. Construction and Building Materials , 42:40-47. CRATerre EAG . (1998). Compressed earth blocks. Standards-Technology series, no. 11. Brussels, CDI. Danso H, M. B. (2015). Performance characteristics of enhanced soil blocks: A quantitative review. Building Research & Information , 43(2): 253-262. Danso H, M. B. (2015). Performance characteristics of enhanced soil blocks: A quantitative review. Building Research & Information , 43(2): 253-262. Delgado MCJ, G. I. (2007). The selection of soils for unstabilised earth building: A normative review. . Construction and Building Materials , 21(2): 237-251. DEM, G. (1993). Soil testing for soil-cement block preparation. . Development Technology Unit working paper, , volume 38. Doat P, H. A. (1979). Construire en Terre. Paris. : CRATerre. Encyclopedia Britanica. (n.d.). Retrieved from cdn.britannica.com: https://cdn.britannica.com/18/204718-050-F6177E8B/pollution-kinds-air-land- water-environment-society.jpg 34 | Page enva corporation. (2020). Retrieved from enva.com: https://enva.com/case- studies/contaminated-soil-treatment-methods Environmental pollution centers. (n.d.). Retrieved from https://www.environmentalpollutioncenters.org/: https://www.environmentalpollutioncenters.org/water/ F.V. Riza, I. R. (2015). In Eco-Efficient Masonry Bricks and Blocks. Food and Agricultural Organization of the United Nations. (n.d.). Retrieved from www.fao.org: http://www.fao.org/tempref/FI/CDrom/FAO_Training/FAO_Training/General/x6 706e/x6706e08.htm H, D. (2016). Influence of compacting rate on the properties of compressed earth blocks. . Advances in Materials Science and Engineering. H, D. (2017). Experimental Investigation on the Properties of Compressed Earth Blocks Stabilised with a Liquid Chemical. Advances in Materials, 6(6): 122-128. Hamard E, C. B. (2016). A vernacular earth construction process in the context of modernsustainable building. Building and Environment , 106: 103-119. Houben H, G. H. (1994). Earth construction: A comprehensive guide. . London. : Intermediate Technology Publications. Irena Twardowska, J. S. (2004). Solid Waste: Assessment, Monitoring and Remediation. Waste Management Series. Jain, S. P. (2002). Engineering Soil Testing. Nem Chand & Bros, Roorkee. Jillavenkatesa A, D. S. (2001). Particle size characterization. . NIST Special Publication, , pp. 960-961. . 35 | Page jkahbskjdhkal. (2099). skjdks. dsasad. Laborel Préneron A, A. J. (2016). Plant aggregates and fibers in earth construction materials: A review. . Construction and Building Materials , 111: 719-734. Mateo-Sagasta, J. (2018). More people, more food, worse water? the Food and Agriculture Organization of the United Nations. Muhammad Aqeel Ashraf, M. J. (2013). Soil Contamination, Risk Assessment and Remediation. Murray, A. G. (2018). Encyclopedia of Geochemistry. Springer, Cham. Nathanson, J. A. (2019). Environmental pollution. Oyediran, A. a. ( 2011). Variability in the geotechnical properties of some residual clay soils from south western Nigeria. 2 (9), 1-6. Parisi F, A. D. (2015). Experimental characterization of Italian composite adobe bricks reinforced with straw fibers. Composite Structures , 122: 300-307. Rebecca George, V. J. (n.d.). Treatment Methods for Contaminated Soils - Translating Science into Practice . Coimbatore, Tamil Nadu, India. Ren XC, L. Y. (2015). Test method for determination of optimum moisture content of soil and maximum dry density. KSCE Journal of Civil Engineering , 19(7): 2061- 2066. Roy S, B. S. (2017). Role of geotechnical properties of soil on civil engineering structures. . Resources and Environment , 7(4): 103-109. Sheppard, C. (2019). World Seas: an Environmental Evaluation. Academic Press. Sowers. (1979.). Introductory Soil Mechanics and Foundations: Geotechnical Engineering, 4th Ed. New York: Macmillan. 36 | Page Spence RJS, C. D. (1983). Building materials in developing countries. Chichester, England.: Wiley. SSF soil testing manual. (2014). Retrieved from smartshelterfoundation.com: https://www.smartshelterfoundation.org/wp-content/uploads/2014/07/SSF-soil- testing-manual.pdf Stavridakis, E. I. (2006). A Solution to the problem of predicting the suitability of silty- clayey materials for cement-stabilization. Geotechnical & Geological Engineering, 24. Tharaka DGS, M. W. ( 2012). Suitability of cohesionless soil as a highway construction material. civil engineering research exchange symposium (p. 6). Sri Lanka: Faculty of Engineering University of Ruhuna,. United States Environmental Protection Agency. (2011). Evaluation of Urban Soils: Suitability for Green Infrastructure or Urban Agriculture. Cleveland, Ohio: EPA. XP, A. (2001). Compressed earth blocks for walls and partitions: Definitions- Specifications-Test methods-Delivery acceptance conditions . Saint-Denis La Plaine Cedex. Zhang J, W. X. (2018). Strength and water stability of a fiberreinforced cemented loess. Journal of Engineered Fibers and Fabrics, 13(1): 72-83. 37 | Page APPENDIX Soil classification USCS Soil Classification System For fine grained soil (≥50% passing #200 sieve 38 | Page Plasticity Chart for USCS Grain size Analysis Bore Hole: SW-BH-103 Location: Boruna Bazar, Narayanganj Depth (m): 4.0 Sample Type: Disturbed Date: 28-Sep Liquid and Plastic Limit Test Soil Classification by Cassagrande’s chart ACKNOWLEDGMENTS ABSTRACT LIST OF TABLES LIST OF FIGURES LIST OF ABBREVIATIONS CHAPTER 1 INTRODUCTION Chapter 1.1 General Chapter 1.2 Background Chapter 1.3 Objectives Chapter 1.4 Methodology Chapter 1.5 Research Plan: Chapter 2 LITERATURE REVIEW CHAPTER 3 METHODOLOGY Chapter 3.1 Introduction Chapter 3.2 Outline of methodology Chapter 3.3 Selection of Site Figure 3.3.d: Soil Texture map of Bangladesh Chapter 3.4 Data collection Chapter 3.5 Review of Previous Paper and Setting Criteria. Chapter 3.5.1 Particle Size and Atterberg Limit Chapter 3.5.2: Specific Gravity, Dry Density and Optimum Moisture Content CHAPTER 4 RESULTS AND DISCUSSION Chapter 4.1: Particle Size and Distribution Table 4.1: Particle Size Distribution Table. Chapter 4.2: Atterberg Limit Chapter 4.3: Specific Gravity, optimum moisture content and maximum dry density Chapter 4.4: Combined result: Chapter 4.5: Cost Analysis Chapter 4.6 Reduction of Carbon footprint: CHAPTER 5 CONCLUSIONS AND RECOMMENDATIONS Chapter 5.1 General Chapter 5.2: Soil Review Chapter 5.3: Future study and Suggestions REFERENCES REFERENCES APPENDIX Soil classification