PROJECT REPORT ON FLY ASHB. S. Patel Polytechnic, Ganpat University, Gozariya Highway, Kherva, Mehsana. CERTIFICATE This is to certify that Mr. Patel Hardik R. in 5th semester student of Diploma in Civil Engineering, Reg. No. S012706040 has satisfactorily completed his seminar work titled Study of “Fly Ash” and submitted within four wall of B.S.Patel Polytechnic, Kherva. Shri B. S. Patel Polytechnic Date of Submission:Staff in-charge:Prof. G. K. Zala Head of Department:- Prof. V. M. Patel Acknowledgement We express our sincere thanks to all our guided professors as well as all the professors of our department. For their valuable guidance, constructive suggestions and affectionate care with which they have directed us in carrying out a work of the nature could not have been possible without the perpetual encouragement and meticulous attention they paid We give our kind thanks to our civil department and for giving us invaluable guidance. At all we can’t think to forget our parents, friends & all those persons who helped us directly or indirectly for our destiny to complete this seminar successfully and we gave our divine thanks to them. Prepared By: Registration No: Patel Hardik R. 012706040 Parekh Saurabh B. 012706030 Chaudhary Vipul D. 012706006 Dave Mehul D. SSSS-012706011 Patel Jaimin P. Chaudhary Alpesh K. Patel Chirag K. Makwana Dhaval S. 012706024 Patel Amit P. 012706031 Goswami Parth B. 012706017 Patel Manoj S. Patel Prakash R. Patel Kiran A. 012706069 S-012706043 S-012706002 S-012706034 SSSS-012706071 S-012706073 S- Index:i.Fly Ash in Cement. iii. Fly Ash in Mining Sector . v. ii. b. Introduction to Fly Ash What is Fly Ash? “Fly Ash” in Concrete Objectives of Fly Ash Fly Ash Used in Various Concrete Indian Scenario Fly Ash Generation & Utilization vii. Utilization Areas 2004-05 Fly Ash Used In Recent a. viii. iv. vi. Mortar & Concrete d. Roads and Embankments Fly Ash in Building Components c. Fly Ash Checklist: Increasing Concrete Performance . Others Products ix. How Fly Ash Contributes to Concrete Workability? xiv.e. Fly Ash in Agriculture f. Fly Ash Checklist: Enhancing Concrete Workability xvii. What Is Quality Concrete? xii. Fly Ash in Hydro Sector g. How Fly Ash Protects Concrete? How Fly Ash Reduces Heat of Hydration in Concrete? xvi. Summary of Utilization x. How Fly Ash Contributes to Concrete Durability and Strength? xiii. xv. Separation Technologies xi. xviii. Specifications of Fly Ash Specification of Fly Ash According to Indian Standard xx. xix. AAC: Autoclaved Aerated Concrete . is captured from the power plant's exhaust gases and collected for use. The difference between fly ash and Portland cement becomes apparent under a microscope. Instead of volcanoes. Fly ash particles are almost totally spherical in shape.300 years ago. alumina and iron. Those cements were made near the small Italian town of Pozzuoli .the mineral residue produced by burning coal . when mixed with lime and water. and one of the most commonly used. today's fly ash comes primarily from coal-fired electricity generating power plants. These power plants grind coal to powder fineness before it is burned.which later gave its name to the term "pozzolan. allowing them to flow and blend freely in mixtures." A pozzolan is a siliceous or siliceous / aluminous material that. glass powder recovered from the gases of burning coal during the production of electricity. forms a cementitious compound. Fly ash . pozzolans in the world.Introduction to Fly Ash:Fly ash closely resembles volcanic ashes used in production of the earliest known hydraulic cements about 2. Fly ash is the best known. Fly ash is a fine. . That capability is one of the properties making fly ash a desirable admixture for concrete. These micron-sized earth elements consist primarily of silica. The difference between fly ash and Portland cement becomes apparent under a microscope." A pozzolan is a siliceous or siliceous / aluminous material that. glass powder recovered from the gases of burning coal during the production of electricity. alumina and iron. . Fly ash . allowing them to flow and blend freely in mixtures.300 years ago.is captured from the power plant's exhaust gases and collected for use. Instead of volcanoes. These power plants grind coal to powder fineness before it is burned. Fly ash is the best known. forms a cementitious compound. when mixed with lime and water. These micron-sized earth elements consist primarily of silica. Fly ash is a fine. Fly ash particles are almost totally spherical in shape. today's fly ash comes primarily from coalfired electricity generating power plants. and one of the most commonly used.the mineral residue produced by burning coal . Those cements were made near the small Italian town of Pozzuoli .What Is Fly Ash? Fly ash closely resembles volcanic ashes used in production of the earliest known hydraulic cements about 2.which later gave its name to the term "pozzolan. That capability is one of the properties making fly ash a desirable admixture for concrete. pozzolans in the world. . Today only about 10% of available fly ash is used in concrete.“Fly Ash” in Concrete:Fly ash is a byproduct of coal burning: 600 million tons are produced per year and over 80% goes to the landfill. . Up to 50% of cement (by volume) can be replaced with fly ash (1535% is typical). We use 250 million MT coal every year for power generation. This figure likely will go up to 170 million MT by 2010. Improve long term concrete strength.Objectives of Fly Ash: In India 65% of the total installed power generation is coalbased. Increase corrosion resistance. . And therefore Ash Management would remain an important area of national concern. Indian coal has high ash content (30%–50%) and thus it contributes to large volumes of ash after combustion. Around 100 million MT of ash generated every year. Improve workability (better finish). Reduce environmental impact. The World Bank has cautioned India that by 2015. disposal of coal ash would require one square meter of land per capita. Current non coking coal reserve is 76 billion MT. India has a huge coal reserves. . . . fill materials. . . 6. 10. 1. .) 75 100 40 15 8 10 6 3 2 2 2 112 Ash Utilization % of Ash Production 65 45 85 50 60 85 75 85 100 100 100 38 Major Area of Utilization Cement. . . . 7. do . do . . . . fill material Cement. . . fill Material Blended cement.Fly Ash Used In Various Countries Sr. . . . . 5. do . . mine fill Cement. cement Cement. do . . concrete agriculture. concrete. . . . . . . . bricks. . . . 12. concrete. . fill material Concrete. . . fill material Cement. building materials . . . 9. . . . . bricks. . do . . fill materials. . . . 2. . . . . . . . . . . . . Country USA China Germany UK Japan Australia Canada France Denmark Italy Netherlands India Annual Ash Production (Million Tons. . . 11. . 3. . 8. 4. . . . . . No. 170 Million Tone FA Utilization --.112 Million Tone FA Utilization --.38% (42 Million Tone) 2012(Assumed):FA Generation --.3% (1.100% (Target) .40 Million Tone FA Utilization --.2 Million Tone) March 2005:FA Generation --.Indian Scenario Fly Ash Generation & Utilization:- 1994:FA Generation --. Utilization Areas 2004-05:- . Fly Ash Used In Recent:- . Roads and Embankments:- . Reduces excavation cost of borrow material. • • • • . Technical Advantages:• • • • • • Good compaction High range of OMC High internal angle of friction Free draining (less interruption due to rain) No large lumps to be broken (easy to spread) Light in weight (can be used on weak sub-grades) Economics Savings:No royalty to be paid as excavation of soil is eliminated. • Saving in ash management expenditure of thermal power plants. Excavated for getting soil. Normally reduces transportation cost. • Additional agricultural produce from the land which would otherwise have been. Easy and faster construction leads to reduction in construction cost. Used for fly ash disposal. Fly Ash in Building Components:- . • Plastering may be avoided or if it is to done. • Number of bricks required per unit volume of construction is less. . • Less consumption of mortar. Technical Advantages:• • • • • Better finish High strength Less water absorption No efflorescence Lower unit weight. • Less number of joints in case of blocks. the thickness of plaster required is less. less load on foundation Economic Savings:• Reduced Energy Consumption • Reduces excavation of clay • Lower cost of brick as compared to clay brick of same quality. Mortar & .Fly Ash in Concrete:- Cement. Fly Ash:• • • • • • Ordinary Concrete : 20-40% fly ash Roller Compacted Concrete : 60-70% fly ash Cellular Light Weight Concrete : 20-40% fly ash High Performance Concrete : 20-40% fly ash High Volume Fly Ash Concrete : 50-70% fly ash Fly Ash in Mortar : 20-40% Technical Advantages:• • • • • • • High long term strength Better workability Higher impermeability Less heat of hydration Corrosion resistance High resistance to aggressive environment More durability Economic Savings:• • • • Saves on clinker cost Reduce energy consumption Reduces raw material (lime stone. iron ore etc.) Cost Reduces overall consumption of cement . 5 lack m³ void capacity has been taken up for pond ash stowing at SCCL-Manuguru.Fly Ash in Mining Sector:Satisfied with the experience of demonstrations of Pond Ash stowing in underground mine fills the project for large scale adaptation of the technology at SCCL-Manuguru has started. . A similar large-scale project is being planned at WCLChandrapur also. A complete mine panel of 1. 18. WCLChandrapur through Normal Surface Bunker & Katora Bunker. More than 12000 m³ pond ash stowed in panel Nos. Projects Undertaken:1. 17. 16.SP-1 Technical:• • • • • • Excellent flow characteristics Good load bearing capacity of ash fill No subsequent settlement Good water percolation rate Load on barricade is very low Fines escaping through barricade <1% Environmental:• • • • • • No excavation and transportation of scarce river bed sand Enormous reduction in water requirement Less water to be pumped out Discharged water is absolutely safe Large scale utilization of ash Release of coal stuck up in pillars . More than 10000 m³ pond ash stowed in panel No. SCCL.Manuguru. Durgapur Raitwari Colliery. PK-1 mine. 28 & 30 (6000 m³ pond ash & 6500 m³ pond ash mixed with sand) 2. Fly Ash in Agriculture:The produce as well as the biomass have been evaluated for toxicology. In some cases significant increase in minerals (iron and calcium) have been noticed which is beneficial. nutritional value as well as radioactivity and have been certified as good material for human and animal consumption. . P. Mo. Agriculture Applications:• • • • • • • • Improves soil texture Reduces bulk density of soil Improves water holding capacity Optimizes pH value Improves soil aeration Reduces crust formation Provides micro nutrients like Fe. Cu. Zn. B etc. Provides macro nutrients like K. Ca. etc Agriculture Related Application of Fly Ash:• • • • Field crops Forestry Floriculture Reclamation of Wasteland . . economical and environment friendly.Fly Ash in Hydro Sector:Fly ash not only provides solution to heat of hydration in mass concreting but also makes the concrete stronger. Thus. In Roller Compacted Concrete fly ash substitutes around 65 per cent of cement. durable and more impervious. in addition to faster construction it makes construction more durable. etc. . etc. fly ash bricks. aqueducts o Canal structures.Avenues of Fly Ash Utilization in Hydro Sector:• Mass Concrete o Conventional concrete with low ash content (10-15%) o Conventional concrete with medium ash content (30-35%) o Roller Compacted Concrete with high ash content (65-70%) • Tunnel Lining o Reinforced cement concrete works o Foundations o Super-structures o Pre-stressed concrete structure • Shotcrete / Gunite • Diaphragm walls for under seepage control • Canals o Canal lining : Insist concrete. CLC tiles o Pre-stressed concrete. fly ash pre-cast tiles. masonry. • Grouting • Gravity Dams • River banks • Concrete and Masonry Barrages • Office / Residential Complexes • Roads & Embankments • Development of Land and Horticulture. RCC o Super-passages. Others Products:Granite Substitute:• • • • • Fly ash content 60% Good finish. New Delhi Paint & Enamels:Fly ash exhibits better extending properties (less absorption) • Fly ash percentage 30-40% (in paints). 18-22% (in enamels) • Corrosion & abrasion resistant • Durable • Developed by RRL-Bhopal. properties comparable to natural granite Developed by BHEL Pilot production started Used at BHEL Corporate Office. • . In Crores) 100 30 25 15 100 15 100 >300 300 2500 50+Addn Coal 3000 75 Enormous Lands Would Be Recovered 5855 =1. 5. No.Summary of Utilization Area:Fly Ash Utilization Potential Sr. 2. Utilization Area Potential / Year Utilization (Million. Roads & Embankment Building Components Bricks / Blocks Cement Mine Fill Agriculture Reclamation Of Low Lying Areas Wasteland Development Total 15-20 Benefits (Rs.25 billion US$ . 6.) 1. Tons. 3. 4. The iron oxides are usually spherical magnetite. individual process separation circuits can be switched in sequence. Based on scanning electron microscope studies. 7]. and other common minerals in coal. low density silicates (cenospheres) and unburned carbons. a separation process has been designed and tested. The lower melting point of these high alkaline silicates may facilitate gas entrapment. The material left after these separations is designated as clean ash. This process consists of a gravitational separation process to separate the cenospheres. hematite. and limonite in the coal. Depending on user needs. or new circuits can be added.Separation Technologies:For a material to have reasonable commercial value. They are believed to be the melted products of clays. eliminated. It must also be available at consistent quality levels and in sufficient quantities to meet market demands. the major mineral components in fly ash can be categorized into silicates. calcite. siderite. Unburned carbons are generally chars with irregular shapes and wide range of particle sizes. a magnetic separation process to separate the iron oxide spheres. Based on these characterization results. feldspars. They are believed to be derived from pyrite. Characterization of fly ash obtained from various sources shows that the mineral components of the ashes are similar. A schematic flow sheet of the separation process is shown in Figure. The silicates are usually present as spherical particles. Low density silicates are frequently high alkaline silicates which entrapped gas to yield hollow spherical particles. Variations in fly ash bulk chemistry are usually due to the changes of ratios of these mineral components. iron oxides. This offers great flexibility for meeting varying . even though the bulk chemistry of these ashes may vary widely. quartz. and a froth flotation process to separate the unburned carbon [6. this material must be well defined and be able to meet industrial specifications. For plastic filler applications. For example. where they were skimmed off. the slurry was conditioned with an oil collector at a dosage of 2 lb/ton.40%. from a fuel switch in a power plant) and markets. greatly reduced from the 21.requirements due to changes in ash (e. a hydro cyclone circuit would need to be included in order to separate out the appropriate fine particle fraction. Fly ash was mixed with water at 20% solids content in a pilot plant operation running at 200 lb/hr. During flotation. A typical operation showed the carbon (LOI) content in the clean ash to be only 0.g. Table 1 shows the results of separation for an AEP low NOx fly ash sample. The magnetic concentrate contained 77. This clean ash was then filtered and dried. The carbon fraction was transferred to another flotation cell and re-floated to upgrade the carbon content in the carbon concentrate. After magnetic separation. This flotation operation left the clean ash in the cell. . This caused the carbon particles to float to the top of the flotation cell.70%. The slurry was then fed into a flotation machine where air was bubbled through it. The slurry was fed into a tank where the cenospheres were skimmed off from the top since these cenospheres have a density less than that of water. a froth flotation circuit may be all that is needed for ash processing if the material is to be used only for cement replacement.70% carbon content of the as-received fly ash. the rising air bubbles collided with the oil coated carbon particles and attached themselves to these particles due to a hydrophobic interaction. The oil has an affinity for carbon and is preferentially adsorbed onto the carbon particles. The carbon concentrate had a carbon content of 67. But magnetic separation would have to be included if the cleaned ash is to be used for refractory applications.18% iron oxide. The reject from the carbon-refloat operation was then returned to the first flotation cell. Then the slurry was fed into a magnetic drum separator to recover the magnetic spheres. 03 0.4 -1. Note that clean ash with less than 1% carbon content can always be obtained.28 .26 57.6 19.22 0.2 9.02 0.09 0.71 77.40 67.11 0.00 58.35 3.8 4.38 99.38 0.05 0. Virginia Power.5 1.2 0.58 14.32 0.92 29.86 1. Table 2 shows typical results obtained on these ashes.03 0.5 CaO 0.45 Na2O 0. Consumers Power.42 0.40 29.33 0.04 K2O 2.02 0.16 0.38 0.4 Total 98.83 100.11 1.01 0.04 3.57 8. 01: Separation Products From An AEP Low NOx Sample Clean Cenospher Magnetic As-Rec’d Carbon Ash e s SiO2 44. Figure of Fly Ash Separation Process Table No.43 TiO2 1. Baltimore Gas and Electric.7 2. American Electric Power.91 0.84 100. Nevada Power.This process has been applied to many different fly ash samples obtained from various power companies including Detroit Edison.89 100.30 5.7 0.35 0.5 0.31 P2O5 0.85 0.01 0.70 0.01 MnO 0.2 Fe2O3 5.34 Al2O3 22.06 LOI 21.76 0.18 MgO 0.23 0. 90 C 4. which essentially consists of two components: aggregates and cementitious paste. The result is that excess voids often exist between the aggregate particles that must now be filled by paste and air.25 0. so that the largest practicable rock fills the majority of the volume.35 0. Concrete is a composite material. In real life. Clean Ash F (#1) 21. . To produce exceptional concrete. while the progressively smaller rock and sand fill the voids left between the larger particles).96 What Is Quality Concrete? To fully appreciate the benefits of fly ash in concrete. 02: Carbon Removal by Froth Flotation Ash Type LOI. The challenge becomes producing an appropriate amount of the best possible quality paste.61 F+C 4. so that the resulting hardened paste will fill the excess voids with durability and strength approaching that of the aggregates. it is best to have as much volume as possible filled with strong. AsReceived LOI. the basics of producing exceptional concrete must be understood.40 F (#2) 7. Also. a good mix of particle sizes.70 0. it is extremely important to have a smooth gradation of material from rock down to the finest particles (in other words. durable aggregate particles. Ideally. though.Table No.00 0. voids should not be present in the paste unless they are specifically provided as microscopic entrained air bubbles to provide durability in freeze-thaw environments. economics and local aggregate sources dictate the quality of materials used. with enough paste (comprised of as much CSH and as little lime as possible) to coat every particle. thus the reasoning behind specifications normally requiring determination of 28-day strengths as a standard. Durability is the ability to maintain integrity and strength over time. resistance to chemical attack.How Fly Ash Contributes to Concrete Durability and Strength? Most people don’t realize that durability and strength are not synonymous when talking about concrete. it reacts with fly ash. and substantially higher strength within a year’s time. equal strength at 28 days. As lime from cement hydration becomes available (cements tend to vary widely in their reactivity). concrete made with fly ash will be slightly lower in strength than straight cement concrete up to 28 days. resistance to cracking and general deterioration over time — all of which are important to durability. Conversely. Typically.000 psi at 28 days can vary widely in their permeability. . Two concrete mixes with equal cylinder breaks of 4. this lime would remain intact and over time it would be susceptible to the effects of weathering and loss of strength and durability. in straight cement concrete. Strength is only a measure of the ability to sustain loads at a given point in time. Cement normally gains the great majority of its strength within 28 days. . Efflorescence is caused by the face of the concrete being wetted and dried repeatedly or by the movement of water vapor from the damp side of the concrete to the dry side through the capillaries (voids). The result is concrete that is less permeable. drawing out the water soluble lime from the concrete. thereby closing off the capillaries that allow the movement of moisture through the concrete. At full hydration. Most people have seen concrete or masonry walls or slabs with the white. assuming average quality aggregates are used. chalky surface coating or streaks called efflorescence. block or mortar. . as witnessed by the reduction in efflorescence. A typical 5 sack concrete mix having 470 pounds of cement per cubic yard has the potential of producing 118 pounds of lime. Fly ash chemically reacts with this lime to create more CSH. concrete made with typical cements produces approximately 1/4 pound of non-durable lime per pound of cement in the mix.As previously described. the paste is the key to durable and strong concrete. the same “glue” produced by the hydration of cement and water. lower water demand.5 sacks (7. reduced heat of hydration and its fine particle size are crucial to making high-strength concrete (8.000 psi to over 20. .000 years and is still intact. over 170 years ago.C. It features a cast concrete dome 124 feet in diameter and was the world’s largest domed structure until modern times. in a town named Cosa. where a mixture of natural pozzolans (volcanic) were combined with lime to produce concrete that has withstood waves and attack from seawater for over 2.000 psi). – The Pantheon in Rome is a pozzolan and lime concrete structure built around 300 B. and still stands today. above which the psi per pound of cement strength contribution in a concrete mix diminishes rapidly. Cement was invented in 1824. The tallest concrete structures in the world are made with concrete where fly ash is a necessary component. Its ability to contribute to additional CSH.5 x 94# sack = 705#) when using 1" maximum size aggregate.Other evidence of the contribution fly ash makes to strength and durability includes: Cement has an upper limit of roughly 7. There are examples on the west coast of Italy. How Fly Ash Contributes to Concrete Workability? . the amount of sand proportioned into the mix can be reduced. Typically. The spherical shape of fly ash particles and its dispersive ability provide water-reducing characteristics similar to a water reducing admixture. Slip form pavers eliminate rock pockets and voids in an otherwise harsh. depending on a number of factors including the amount used and class of fly ash. reducing the sand means the paste available can more efficiently coat the surface area of the aggregates that remain? Evidence of the contribution fly ash makes to workability includes: • Lightweight concrete including fly ash is much easier to pump. and by its shape and dispersive action makes the paste more “slippery”. the better lubricated the aggregates are and the better concrete flows. water demand of a concrete mix with fly ash is reduced by 2% to 10%. Since sand has a much greater surface area than larger aggregates and therefore requires more paste. Because fly ash creates more paste. Second. fly ash reduces the amount of water needed to produce a given slump. which means that on a pound for pound basis. fly ash produces more cementitious paste. fly ash contributes roughly 30% more volume of cementitious material per pound versus cement. • Finishers notice the “creamier” texture when working. no-slump paving mix . The greater the percentage of fly ash “ball bearings” in the past. They also see reduced “bug holes” and segregation when stripping forms. fly ash reduces the amount of sand needed in the mix to produce workability. It has a lower unit weight. Third.First. Gypsum is a material that has greater volume than the calcium hydroxide and sulfates that combine to form it.How Fly Ash Protects Concrete? An extremely important aspect of the durability of concrete is its permeability. the chemistry of Class F ashes has proven to be more effective in mitigating sulfate and alkalisilica expansion and deterioration in concrete. fly ash can reduce the rate of ingress of water. which combines with sulfates to produce gypsum. Fly ash concrete is less permeable because fly ash reduces the amount of water needed to produce a given slump. and through pozzolanic activity. • Aluminates in the cement also combine with sulfates to form expansive compounds. At this point a distinction between Class C and Class F fly ashes needs to be made. Fly ash also increases sulfate resistance and reduces alkali-silica reactivity. By decreasing concrete permeability. While both improve the permeability and general durability of concrete. Some Class C fly ashes have been used to mitigate these reactions. the amount of . corrosive chemicals and oxygen — thus protecting steel reinforcement from corrosion and its subsequent expansive result. Fly ash improves corrosion protection. but must be used at higher rates of cement replacement. creates more durable CSH as it fills capillaries and bleeds water channels occupied by watersoluble lime (calcium hydroxide). causing damaging expansion. By replacing cement. Fly Ash in concrete can reduce sulfate attack in two additional ways: • Fly ash reduces calcium hydroxide. This natural heating of the aggregates. Heat is generated very quickly. In these applications. leading to reduced concrete strength and durability. Replacing 20% to 35% of the cement for “everyday” concrete in warm conditions will help reduce thermal cracking and provide the time needed to obtain the desired finish. For most concrete installations. warm weather concreting and the risk of thermal cracking is a problem that exists today for all concrete. coupled with solar heating at the construction site. causing the concrete temperature to rise and accelerating the setting time and strength gain of the concrete. thereby potential for this type of expansive reaction. lowering the How Fly Ash Reduces Hydration in Concrete? Heat of The hydration of cement is an exothermic reaction. While the first structures to apply this concept in earnest were hydroelectric dams built in the 1930s and 1940s with 40% to 50% cement replacement. many applications exist where the rapid heat gain of cement increases the chances of thermal cracking. the heat generation is not detrimental to its long-term strength and durability. replacing large percentages of cement with fly ash (fly ash generates only 15 to 35 percent as much heat as compared to cement at early ages) can reduce the damaging effects of thermal cracking. Warm weather will naturally raise the temperature of concrete aggregates. which make up the majority of the mass in concrete.available aluminates is reduced. However. . can cause even thin concrete slabs to suffer the damaging effects of thermal cracking. along with finishing difficulties caused by rapid uncontrolled setting. Reduced Segregation: Improved cohesiveness of fly ash concrete reduces segregation that can lead to rock pockets and blemishes. clear architectural definition is easier to achieve. Reduced Bleeding: Fewer bleed channels decrease permeability and chemical attack. Ease of Pumping: Pumping requires less energy and longer pumping distances are possible. Improved Finishing: Sharp. with less worry about in-place integrity. . Bleed streaking is reduced for architectural finishes. responding better to vibration to fill forms more completely.Fly Ash Checklist: Concrete Workability Enhancing Workability: Concrete is easier to place with less effort. Fly Ash Checklist: Concrete Performance Increasing Higher Strength:Fly ash continues to combine with free lime. Fly ash concrete is also more resistant to attack by sulfate. increasing compressive strength over time. results in fewer bleed channels and decreases permeability. mild acid. and seawater. soft (lime hungry) water. where destructive action is lessened. Decreased Permeability:Increased density and long term pozzolanic action of fly ash. Reduced Sulfate Attack:Fly ash ties up free lime that can combine with sulfates to create destructive expansion. Increased Durability:Dense fly ash concrete helps keep aggressive compounds on the surface. and dense concrete holds efflorescence producing compounds on the inside. . Reduced Efflorescence:Fly ash chemically binds free lime and salts that can create efflorescence. which ties up free lime. Reduced Heat of Hydration:The pozzolanic reaction between fly ash and lime generates less heat. . The lubricating action of fly ash reduces water content and drying shrinkage. resulting in reduced thermal cracking when fly ash is used to reduce Portland cement. causing destructive expansion. Reduced Shrinkage:The largest contributor to drying shrinkage is water content. Reduced Alkali Silica Reactivity:Fly ash combines with alkalis from cement that might otherwise combine with silica from aggregates. Specifications:ASTM (West Conshohocken. ASTM C 1240: Standard Specification for Silica Fume for Use in Hydraulic-Cement Concrete and Mortar. of Trans. ASTM E 1861: Standard Guide for Use of Coal Combustion By-products in Structural Fills. PA USA):• • • • • • • ASTM C 618: Standard Specification for Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use as a Mineral Admixture in Portland Cement Concrete. ASTM C 311: Standard Test Methods for Sampling and Testing Fly Ash or Natural Pozzolans for Use as a Mineral Admixture in Portland-Cement Concrete. ASTM E 850: Standard Practice for Use of Inorganic Process Wastes as Structural Fill.01: Special Provision for Fly Ash Stabilized Soil Mixture Sub base Special Provision for Cement-Fly Ash-Aggregate Mixture (CFAM) Base Course Special Provision for Pozzolanic Base Course. Type A . IDOT (Illinois Dept. Springfield. ASTM D 5370: Standard Specification for Pozzolanic Blended Materials in Construction Applications. ASTM D 5239: Standard Practice for Characterizing Fly Ash for Use in Soil Stabilization. IL USA):• • • • 306.01: Special Provision for Fly Ash Modified Soils 308. C.• Special Provision for Use of Fly Ash in P. Pavement. Base Course Widening.C. Base Course. . silica fume) Allowed in Concrete.S. A. BS EN 450 European Standard for Fly Ash.AASHTO:• AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing.1-1991 and Ground Granulated Blast Furnace Slag -AS 3582. . 1129 Fly Ash Specification. BS EN 197 European Standard for Multiple Binders ( fly ash.5-97 Canadian Specification for Supplementary Cementing Materials (includes fly ash). Fly ash -AS 3582. Australia:• • • • Portland Cement -AS 3972-1991. European Standards:• • • BS 3892 Part 1 Fly Ash standard. Canada:• CAN/CSA A23. Part 2 Fly Ash for Use as a Type II Addition. cement.2. Teil 2: Bestimmung der Feinheit durch Naßsiebung Netherlands:• NEN 3550 Dutch cement standard.Germany (Deutsches Normung-Berlin):• • • • • • • Institute for • • • DIN 1164-1 German Cement standard DIN 1045 Reinforced Concrete Structures. Herstellung. Demands and Quality control ENV 206:1990 (CEN/TC 104) Beton . Anforderungen und Güteüberwachung EN 451-1:1994 (CEN/TC 104) Prüfverfahren für Flugasche Teil 1: Bestimmung des freien Calciumgehalts EN 451-2:1994 (CEN/TC 104) Prüfverfahren für Flugasche .Eigenschaften. . Design and Construction DIN EN 450 Fly Ash In Concrete-Definition. Verarbeitung und Gütenachweis EN 445:1996 (CEN/TC 104) Einpreßmörtel für Spannglieder .Einpreßverfahren EN 447:1996 (CEN/TC 104) Einpreßmörtel für Spannglieder Anforderungen für üblicheSn Einpreßmörtel EN 450:1994 (CEN/TC 104) Flugasche für Beton Definitionen.Prüfverfahren EN 446:1996 (CEN/TC 104) Einpreßmörtel für Spannglieder . .United Kingdom (British Standards Institution. 6610 Pozzolanic pulverized fuel ash cement. 6588 Blended cement containing PFA. B.S.S.London):• • • B.S. 3892 PFA as a separate constituent in OPC. B.