# Introduction ly ash and Sand are very effectively used in various civil engineering projects. The quantity of ash produced depends upon the quality of coal and the method of burning of the coal. In India less than 20% of coal ash is used in the manufacture of brick, cement and other products. Coal fire power plants produce millions of tones of fly ash annually but only a small quantity is used. Consequently thermal power plant coal ash is "negative cost" material. Coal ash has many uses in civil engineering project. Sand is often angular sand and gravel size particles, are employed as aggregate in highway construction and icing control. The main disposal problem is with fly ash, the finer silt size fraction recovered from stack emissions. Fly ash is often a component in concrete mixtures, but it is also used in stabilized road and highway embankment, landfill linear and waste stabilizations. Fly ash and Sand was collected from Rihandnagar Thermal Power Project (U.P.) and has been used in present investigation. The fly ash and Sand were mixed in different proportions and their physical, chemical and geo-technical characteristics were investigated. Fly ash and Sand fulfill the technical properties required for various use. However experimental inadequate awareness among the user at various levels has resulted in limited use of fly ash and Sand material as fill. Environmentally safe disposal of large quantities of fly ash and Sand is not only tedious but also expensive. To reduce the problem of disposal of fly ash and Sand great efforts are being made to utilize fly ash and Sand. The properties of fly ash and Sand that is important for use in geotechnical engineering applications. # a) Fly Ash Fly ash obtained from thermal power station is a by-product available in abundant quantity and ought to be converted into meaningful and useful products. Fly ash is nothing but the finely divided residue resulting from the combustion of powdered coal Fly ash is the byproduct of coal combustion thermal power plant. Due to its pozzolonic nature it can be used effectively for variety of purpose. Coal Fly ash obtained as the by-product from pulverized coal consists of predominantly small spherical particle, which differs in shape and size due to its difference in degree of pulverization of coal and efficiency of collecting system. One of the major factors hindering the utilization of fly ash has been an economic system for collection, handling and transportation of fly ash at thermal power station and facilitate for handling and storage at the user end and its economics. Coal fly ash has been successfully used as highway road embankment fill material for highway construction projects in a number of different locations throughout the world. When compared with the conventional soil used as embankment. # b) Sand Sand is a common type of soil, which is having very fine particle size. The physical properties of sand include-It is made of silica, quartz with traces of other substances like titanium It is usually having irregular particle shape. Particle size is usually very small, but not so small that it can pass through a sieve. It is a loose granular substance yellowish brown in colour found from the erosion of siliceous and other rocks and forming a major constituent of beaches, river beds, the seabed, and deserts The engineering properties make sand is an ideal material in design construction of dam and for other civil engineering applications. Sand also exhibits a relatively high permeability and grain size distribution that allows the design engineer to use it in direct contact with impervious material. Sand proved to be an economical material because it has demonstrated to have not only good engineering property but also to have constructability benefits. c) Utilization of fly ash and Sand in India are ? Land Development ? Bricks ? Mine Filling ? Ash Dyke Raising Roads/Embankments ? Concrete ? Fill Matrix II. # Material Used a) Fly Ash For the present study the source of fly ash is Anpara Thermal Power Project, Anapara (U.P.). The total production of fly ash at Anpara Thermal Power Project is about 2.5 million tons per year. The Sand used in the study was locally available local sand. Preparation of Fly Ash and Sand Mixture The following procedure was adopted for preparation of fly ash and Sand mixtures in all tests. The materials were first dried for 24 hrs and brought to room temperature. Fly ash and Sand were then mixed together in the required proportions (by dry weight) in dry form. Different proportions of Rihandnagar fly ash and Sand and their mixed designation are given in table: 3. # Testing Programme Since fly ash generate in huge quantity from thermal power plants. mainly work has been done on fly ash not on Sand so in the project we want to investigate that what is the effect of engineering property on mixing of fly ash and Sand in different proportions and how Sand can be safely used with fly ash in geotechnical applications and other civil engineering projects. So following testing is done on fly ash and Sand and its mixtures in different proportions. ? Grain size analysis # Results and Discussion This investigation has been carried out to find the effect of fly ash and Sand mixture on optimum moisture content, maximum dry density, permeability, shear strength, particle size analysis and CBR values. In the present investigation fly ash and Sand has been taken from Rihandnagar Thermal Power Plant, Sonbhadra (U.P.) The results of these investigations have been presented in the form of tables and graphs in this chapter. Brief discussions on the laboratory test results are given below. The specific gravity was found out for fly ash, Sand, and fly ash and Sand mixtures in different proportions and it is presented in Table 10. The specific gravity of fly ash is 2.15 and for Sand it is 2.27. # a) Characteristics of Mix Proportion # Conclusions ? Maximum dry density of fly ash and Sand mixture decreases with increasing Sand content while optimum moisture content increases. ? The permeability of compacted coal ash sand mixtures was found to decrease slightly with increasing fly ash content. This may be due to the increasing specific surface with increasing content of the fines, which creates more resistance to flow of water through voids between their particles. Overall range of the values was similar to that of a fine sands/ silts mixture or silts. ? Permeability of fly ash and Sand is 5.570 x 10 -4 cm/sec and 7.68 x 10 -4 cm/sec, as such fly ash and sand mixtures can be used as a filling material in core of dyke and mixtures of fly ash and Sand in different proportions can be used in highway embankment as a fill matrix. ? Shear strength parameter of fly ash and Sand shows a variation in cohesion from 0.01 to 0.021 kg/cm 2 and angle of internal friction from 23 o to 34 0 in wet condition it can be safely used in construction of embankment and also body of dyke for water disposal. ? Sand exhibits lower density as compared to fly ash but strength characteristics is better than fly ash under as compacted. ? In soaked condition the CBR value of fly ash and Sand is 7.67 % and 23.15% respectively. While in 80%S+20%FA, 60%S+40%FA, 40%S+60%FA, 20%S+80%FA proportions CBR is 20.69%, 17.42%, 14.31% and 10.80% respectively. The recorded value of CBR for sub-base is 7-20 %. Therefore fly ash and Sand mixtures can be used as sub-base of road construction as well as fill materials for highway embankments. ? Based on the results obtained in this investigation, it is found that high volume coal fly ash mixtures are suitable for use in highway embankment; if proper design and construction procedures are follow. The coal fly ash and Sand mixtures can provide fill materials and fill matrix of comparable strength to most soils typically used as fill materials, while having the advantage of smaller dry unit weights. ? Sand alone or in combination with fly ash at equal or similar proportion can be used as construction material in most geotechnical application where borrow soil is presently used, thus solving an important environmental hazardous problem of disposal of coal fly ash to great extent. Further, this will help reducing degradation of valuable land affected by dumping of unutilized coal ash produced and mining of soil for geotechnical construction. 23456![Fig. 2 : Specific gravity of fly ash and Sand mixtures](image-2.png "Fig. 2 :Fig. 3 :Fig. 4 :Fig. 5 :Fig. 6 :") 789![Fig. 7 : CBR value of Fly Ash and Sand Mixtures in Unsoaked Condition](image-3.png "Fig. 7 :Fig. 8 :Fig. 9 :") 3ashColorGreyPhysical StatePowder with traces of unburnt carbonSp. Gravity2.12 4Rihandnagar fly ash 5ConstituentsPercentage (by weight)SiO 268.0Al 2 O 324.0Fe 2 O 3 + Fe 3 O 42.18TiO 22.64CaO1.49MgO0.06SO 4 --NilLoss on ignition1.63 3Mix Designation% of Fly Ash + % Sand0%FA+100% S0% Fly Ash + 100% Sand20% FA + 80% S20% Fly Ash + 80% Sand40% FA + 60% S40% Fly Ash + 60% Sand60% FA + 40% S60% Fly Ash + 40% Sand80% FA + 20% S80% Fly Ash + 20% Sand100% FA+0%S100% Fly Ash+ 0% SandIV. 5Mix designationMDDOMCCoefficient ofCohesion (c) Kg/cm 2Angle of shearingCBR ValueCBR Value(g / cc)(%)Permeabilityresistance (?)(Unsoaked(Soaked(cm/sec)DryWetDryWetCondition) %Condition) %100% FA1.4018.565.570×10 -40.2050.0125.7 023.0 015.757.6780% FA +20% S1.34220.906.115×10 -40.2550.02633.4°32.0°18.1010.8060% FA +40% S1.29623.126.60×10 -40.2500.0434.4°31.5°22.0514.3140% FA +60% S1.22325.967.10×10 -40.2300.02130.2°29°.24.2117.4220% FA +80% S1.15228.977.410×10 -40.2200.00531.7°26.5°27.1120.69100% S1.08132.017.68×10 -40.2050.02136.2°34.0°29.6123.15100100% FA908080% FA+Percentage Finer30 40 50 60 7020% S 60% FA+40% S 40% FA+60%20S 20%10FA+80%0S 100% S0.0010.010.1110Grain Size (mm)Fig.1: Grain Size distribution curve of Fly Ash and Sand mixtures 10Ash and Sand © 2014 Global Journals Inc. (US) Some Geotechnical Properties of Coal Fly Ash and Sand Mixtures with Different Ratio using in Highway & Embankments * Geotechnical Properties of Fly Ash and Bottom Ash Mixtures in Different Proportions DilipKumar NeeteshKumar AshishGupta International Journal of Science and Research (IJSR) 3 9 2014 * Coal Combustion Products Production and Uses RSKalyoncu Geological Survey 4 2005 * Performance evaluation of silty sand sub-grade reinforced with fly ash and fiber MSChauhan SMittal BMohanty Geotextiles and Geomembranes 26 2008 * Use Of Class C Fly Ashes for the Stabilization -of an Expansive Soil ErdalCokca Journal of Geotechnical and Geoenvironmental Engineering 127 2001. July * Geotechnical Properties of Fly and Sand Mixtures for Use in Highway EmSnkments BKim MPrezzi RSalgado J. Geo, Geoenv 7 2005 ASCE * Soil Stabilization And Drying Using Fly Ash HAAcosta TBEdil CHBenson Geo Engg. Report 2005 * Effect of Fly Ash on Engg. Property of Expansive Soil BRPhani R SSharma J. Geo, Geoenv 7 2004 ASCE * Evaluation of the Properties of Fly Ash for its Use in Geotechnical Applications JPPrashanth 1998 IISC. Bangalore Ph.D Thesis * A critical review of the applicability of conventional test methods and materials specifications to the use of coal associated waste in pavement construction MAUsmen 1977 West Virginia Univ., Morgantown. W. Va PhD dissertation * NSPandian KCKrishna BLeelavathamma Effect of Fly Ash on the CBR Behaviour of Soils, Indian Geotechnical Conference Allahabad 2002 1 * Densification of Pond Ash By Blasting SRGandhi AKDey SSelvam J.Geo. Geoenv 125 10 1999 * Engineering properties of pond ash and pond ash sand mixtures NBhatta July 2008 Indian Highways * Behavior of Compacted Soil-Fly Ash-Carbide Lime Mixtures NCConsoli PD MPrietto JA HCarroro KSHeineck J. Geo. Geoenv 127 9 2001 ASCE * Lime Stabilization and Low Cost Road Construction WDDocky DE HManigault 1947 90 Road and Street * Properties and Use of Fly Ash for EmSnkments JPMartin RACollins JSBrowning FJBiehl Journal of Energy Engg 116 2 1990 ASCE * Geotechnical Characteristics of Fly Ash Soil Mixture SRKaniraj VGHavangi Geotechnical Engg. Journal 30 2 1999. August * Use of Fly Ash in Soil Stabilization for Road VirendraSingh NarendraKumar & Devendra Mohan Proceeding of Indian Geotechnical Conference, 96, Madras eeding of Indian Geotechnical Conference, 96, Madras 1996 * Cementitious binder from fly ash and other industrial wastes Singh (M) & Garg (M.) 3. 1999 29 309 Cement & Concrete Research * Analysis of ash from United States coals WASelvig FHGibson Bulletin 567 1956 * A study on flexible pavement performance with reinforced fly-ash sub base DS VPrasad International Journal of Earth Sc. and Engg 0974-5904 4 6 2011 * Sand: An engineering material RKSeals LKMoulton BERuth J. Soil Mech. Found. Div 98 4 1972 * The use of Sand in highway emSnkments sub grade, and sub Sse HWHuang Joint Highway Research Project 1990 Purdue Univ., W. Lafayette Report Ind * Design and construction of reinforced approach embankment using pond ash SMathur UK GVittal VHavangi AKSinha CBIP-3 rd International Conference on Fly Ash Utilization and Disposal New Delhi 2003 * Determination of Specific Gravity-Fine-grained soils IS: 2720-Part-3-1980 * Determination of Water Content-Dry Density Relation using Heavy Compaction IS:2720-Part-8-1983 * Laboratory Determination of Permeability of Granular Soils (Variable Head IS: 2720-Part-37-1975 * Direct Shear Test for Soils containing gravel IS: 2720-Part-39-1977 Laboratory Test * Geotechnical characterization of pond ash, Ash Ponds and Ash Disposal systems NA SSridharan CPandian Rajasekhar V. S. Raju et.al Eds 1996 Narosa Publishing House New Delhi * Use of fly ash in soil stabilization for roads VirendraSingh NarendraKumar DevendraMohan Proceedings of IGC-96 IGC-96Madras 1996 * Effect of fly ash on engineering properties of expansive soils PhaniKumar SRSharma RS J. Geotech. Geoenviron. Eng 130 7 2004 * Geotechnical Properties of Tanjung Bin Coal Ash Mixtures for Backfill Materials in Embankment Construction AminatonAbdul Rahim Awang Marto Ahmad Mahir Makhtar 16 2011 EJGE