1、Designation: E 2277 03Standard Guide forDesign and Construction of Coal Ash Structural Fills1This standard is issued under the fixed designation E 2277; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A n
2、umber in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This guide covers procedures for the design and con-struction of engineered structural fills using coal fly ash,bottom ash, or ponded a
3、sh.1.2 The utilization of coal ash under this guide is a compo-nent of a pollution prevention program; Guide E 1609 de-scribes pollution prevention activities in more detail. Utiliza-tion of coal ash in this manner conserves land, naturalresources, and energy.1.3 This guide applies only to fly ash a
4、nd bottom ashproduced primarily by the combustion of coal.1.4 The testing, engineering, and construction practices forcoal ash fills are similar to generally accepted practices fornatural soil fills. Coal ash structural fills should be designedusing generally accepted engineering practices.1.5 Laws
5、and regulations governing the use of coal ash varyby state. The user of this guide has the responsibility todetermine and comply with applicable requirements.1.6 The values stated in inch-pound units are to be regardedas the standard. The SI units given in parentheses are forinformation only.1.7 Thi
6、s standard does not purport to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory requirements prior to use.2. Referenced Documen
7、ts2.1 ASTM Standards:2C 150 Specification for Portland CementC 188 Test Method for Density of Hydraulic CementC311 Test Methods for Sampling and Testing Fly Ash orNatural Pozzolans for Use as a Mineral Admixture inPortland-Cement ConcreteC 595 Specification for Blended Hydraulic CementsD75 Practice
8、for Sampling AggregatesD 420 Guide to Site Characterization for Engineering, De-sign, and Construction PurposesD 422 Test Method for Particle-Size Analysis of SoilsD 653 Terminology Relating to Soil, Rock, and ContainedFluidsD 698 Test Method for Laboratory Compaction Character-istics of Soil Using
9、Standard Effort (12 400 ft-lbf/ft3(600kN-m/m3)D 854 Test Method for Specific Gravity of SoilsD 1195 Test Method for Repetitive Static Plate Load Testsof Soils and Flexible Pavement Components, for Use inEvaluation and Design ofAirport and Highway PavementsD 1196 Test Method for Nonrepetitive Static
10、Plate LoadTests of Soils and Flexible Pavement Components, for Usein Evaluation and Design of Airport and Highway Pave-mentsD 1452 Practice for Soil Investigation and Sampling byAuger BoringsD 1556 Test Method for Density and Unit Weight of Soil InPlace by the Sand-Cone MethodD 1557 Test Methods for
11、 Laboratory Compaction Charac-teristics of Soil Using Modified Effort (56 000 ft-lbf/ft3(2700 kN-m/m3)D 1586 Test Method for Penetration Test and Split-BarrelSampling of SoilsD 1883 Test Method for CBR (California Bearing Ratio) ofLaboratory-Compacted SoilsD 2166 Test Method for Unconfined Compressi
12、ve Strengthof Cohesive SoilD 2167 Test Method for Density and Unit Weight of Soil inPlace by the Rubber Balloon MethodD 2216 Test Method for Laboratory Determination of Water(Moisture) Content of Soil and RockD 2435 Test Method for One-Dimensional ConsolidationProperties of Soils1This guide is under
13、 the jurisdiction ofASTM Committee E50 on EnvironmentalAssessment and is the direct responsibility of Subcommittee E50.03 on PollutionPrevention, Reuse, Recycling, and Environmental Efficiency.Current edition approved May 10, 2003. Published July 2003.2For referenced ASTM standards, visit the ASTM w
14、ebsite, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United S
15、tates.D 2850 Test Method for Unconsolidated, Undrained Com-pressive Strength of Cohesive Soils in Triaxial Compres-sionD 2922 Test Methods for Density of Soil and Soil-Aggregate in Place by Nuclear Methods (Shallow Depth)D 3080 Test Method for Direct Shear Test of Soils UnderConsolidated Drained Con
16、ditionsD 3550 Practice for Ring-Lined Barrel Sampling of SoilsD 3877 Test Methods for One-Dimensional Expansion,Shrinkage, and Uplift Pressure of Soil-Lime MixturesD 4253 Test Methods for Maximum Index Density and UnitWeight of Soils Using a Vibratory TableD 4254 Test Method for Minimum Index Densit
17、y and UnitWeight of Soils and Calculation of Relative DensityD 4429 Test Method for Bearing Ratio of Soils in PlaceD 4643 Test Method for Determination of Water (Moisture)Content of Soil by the Microwave Oven MethodD 4959 Test Method for Determination of Water (Moisture)Content of Soil by Direct Hea
18、ting MethodD 4972 Test Method for pH of SoilsD 5084 Test Method for Measurement of Hydraulic Con-ductivity of Saturated Porous Materials Using a FlexibleWall PermeameterD 5239 Practice for Characterizing Fly Ash for Use in SoilStabilizationE 1527 Practice for Environmental Site Assessments: PhaseI E
19、nvironmental Site Assessment ProcessE 1528 Practice for Environmental Site Assessments:Trans-action Screen ProcessE 1609 Guide for the Development and Implementation of aPollution Prevention ProgramE 2201 Terminology for Coal Combustion ProductsG51 Test Method for pH of Soil for Use in CorrosionTest
20、ingG57 Test Method for Field Measurement of Soil ResistivityUsing the Wenner Four-Electrode Method2.2 AASHTO Standards:3T 288 Determining Minimum Laboratory Soil ResistivityT 289 Determining pH of Soil for Use in Corrosion TestingT 290 Determining Water Soluble Sulfate Ion Content inSoilT 291 Determ
21、ining Water Soluble Chloride Ion Content inSoil3. Terminology3.1 DefinitionsFor definitions related to Coal CombustionProducts, see Terminology E 2201. For definitions related togeotechnical properties see Terminology D 653.3.2 Definitions of Terms Specific to This Standard:3.2.1 internal erosionpip
22、ing; the progressive removal ofsoil particles from a mass by percolating water, leading to thedevelopment of channels.4. Significance and Use4.1 General:4.1.1 Coal ashes are suitable materials for the constructionof engineered, structural fills. Coal ashes may be used as:structural fill for building
23、 sites and foundations; embankmentsfor highways and railroads, dikes, levees; and in any otherapplication requiring a compacted fill material. Their low unitweight, relatively high shear strength, ease of handling, andcompaction all make coal ashes useful as fill material. Coalashes may be a cost-ef
24、fective fill material in many areasbecause they are available in bulk quantities, conserve naturalresources, and reduce the expenditures required for the pur-chase, permits, and operation of a soil borrow pit. Coal ashoften can be delivered at near optimum moisture content.4.1.2 This guide describes
25、 the unique design and construc-tion considerations that may apply to structural fills constructedof coal ash. The requirements for specific structural fills mayvary due to local site conditions or the intended use of thestructural fill, or both.4.2 Regulatory Framework:4.2.1 FederalThe U.S. Environ
26、mental Protection Agency(USEPA) has completed a study of coal combustion by-products for the U.S. Congress and has issued a formalregulatory determination (1, 2).4USEPA “encourages theutilization of coal combustion by-products and supports Stateefforts to promote utilization in an environmentally be
27、neficialmanner” (3). USEPA subsequently ruled that national regula-tion of most beneficial uses of coal ash, including structuralfills, is not warranted (4).4.2.2 State and LocalLaws and regulations regarding theuse of coal ash vary by state and locality.4.3 Economic BenefitsCoal ash can be a cost-e
28、ffective fillmaterial. In many areas, it is available in bulk quantities at areasonable cost. Use of coal ash conserves natural resourcesand reduces the expenditures for the purchase, permits, andoperation of a soil borrow pit.5. Engineering Properties and Behavior5.1 GeneralFly ash and bottom ash e
29、xhibit distinct engi-neering properties and behavior as described below. Theengineering properties and behavior of ponded ash may besimilar to fly ash or bottom ash, depending on the ratio of eachin the ponded ash.5.2 Unit WeightMany coal ashes have relatively low unitweights. The low unit weight of
30、 these materials can beadvantageous for some structural fill applications. The lighterweight material will reduce the load on weak layers or zones ofsoft foundation soils such as poorly consolidated or landslide-prone soils.Additionally, the low unit weight of these materialswill reduce transportati
31、on costs since less tonnage of materialis hauled to fill a given volume.5.3 Strength:5.3.1 Shear StrengthFor non-self-cementing fly ash andbottom ash, shear strength is derived primarily from internalfriction. Typical values for angles of internal friction fornon-self-cementing fly ash are higher th
32、an many naturalfine-grained soils. These ashes are non-cohesive and although3Interim Specifications for Transportation Materials and Methods of Samplingand Testing, Part II, AASHTO, 444 North Capitol St., N.W., Suite 225, Washington,DC 20001.4The boldface numbers in parentheses refer to the list of
33、references at the end ofthis standard.E2277032the ash may appear cohesive in a partially saturated state, thiseffect is completely lost when the material is either completelydried or saturated.5.3.1.1 Due to its angular shape, the shear strength ofbottom ash is typically greater than fly ash and is
34、similar to theshear strength of natural materials of similar gradation. How-ever, friable bottom ash may exhibit lower shear strength thannatural materials of similar gradation.5.3.2 Compressive StrengthSelf-cementing fly ash expe-riences a cementing action that increases with time. Becausethe hydra
35、tion of dry self-cementing fly ash commences imme-diately upon exposure to water, higher compressive strengthswill be attained when the fly ash is placed and compactedimmediately following addition of water. If too much timelapses, the fly ash particles can become cemented in a loosestate, reducing
36、the compacted density and strength.5.4 Consolidation CharacteristicsStructural fills con-structed of fly ash typically exhibit small amounts of time-dependent, post-construction consolidation. This is becauseexcess pore water pressures dissipate relatively rapidly, andthus, most of the embankment se
37、ttlement or deformationoccurs due to elastic deformation of the material, rather than byclassical consolidation. Most deformation due to the mass ofthe fill or structure thereon generally occurs during construc-tion.5.4.1 Bottom ash is usually a free-draining material that canbe compacted into a rel
38、atively dense, incompressible mass. Forthese reasons structural fills constructed of bottom ash alsotypically exhibit small amounts of time-dependent, post-construction consolidation or deformation, with most deforma-tion occurring during construction.5.4.2 Self-cementing fly ash typically exhibits
39、minimalpost-construction consolidation or deformation due to cement-ing and solidification of the fly ash.5.4.3 Some self-cementing fly ash may swell with time.Section 6.3.8 provides guidance on evaluating the swellingpotential of self-cementing fly ash.5.5 PermeabilityThe permeability of non-self-c
40、ementingfly ash is similar to values observed for natural silty soils.5.5.1 Self-cementing fly ash is relatively impermeable, withpermeability values similar to natural clays.5.5.2 Bottom ash is typically as permeable as granular soilsof similar gradation.5.6 Liquefaction and Frost HeaveFine-grained
41、, non-cohesive materials such as fly ash are susceptible to liquefac-tion and frost heave when saturated. For this reason, fly ash fillsare designed to be well drained or are located in areas wherethey are not subject to saturation or infiltration by surface orground water. Self-cementing fly ash is
42、 not susceptible toliquefaction.5.6.1 Bottom ash is not typically susceptible to eitherliquefaction or frost heave. However, some of the finer bottomash materials may behave quite similarly to fly ash and wouldrequire the same consideration for design as fly ash fills.6. Testing Procedure6.1 General
43、Testing requirements are determined basedon site conditions, knowledge of the coal ash, intended use ofthe fill, and local requirements.6.2 SamplingPractice D75 or Test Method C311 asappropriate, and Guide D 420 with sample extraction con-ducted in accordance with Practice D 1452, Test MethodD 1586,
44、 or Practice D 3550, as appropriate.6.3 Physical and Engineering Characteristics:6.3.1 Grain-Size DistributionTest Method D 422. For flyash, a substantial portion of the material will be finer than theNo. 200 sieve and hydrometer analyses will also be required.Use distilled water in the hydrometer t
45、est with a deflocculatingagent added to prevent fly ash from forming flocs. Self-cementing fly ashes may require use of alcohol or othernonreactive solution in place of the standard solution used. Flyash often has a relatively uniform particle size and precautionsagainst overloading sieves are warra
46、nted. Specimen lossthrough dusting can also be a problem. Specific gravity mayvary with particle size. Specific gravity values used in hydrom-eter analyses should be appropriate to the portion of the samplebeing tested.6.3.2 Specific GravityTest Method D 854. For some flyash, a significant portion o
47、f the particles may have a densityless than water and float.Agitation of the slurry may be neededto keep the particles in suspension so that the average specificgravity can be obtained. Alternately for this ash and self-cementing fly ash, Test Method C 188, which uses kerosene asthe fluid, may be us
48、ed.6.3.3 Water ContentTest Method D 2216. For self-cementing fly ash consider lowering the drying temperature to140F (60C) to avoid driving off the water of hydration.6.3.4 Compaction:6.3.4.1 Fly AshTest Method D 698 or D 1557. For dryself-cementing fly ash, the time interval between wetting andcomp
49、action in the laboratory should be similar to that antici-pated during construction to account for the influence of therate of hydration on compaction characteristics.6.3.4.2 Bottom AshTest Methods D 4253 and D 4254 maybe used for the determination of maximum and minimumdensity of coarse-grained bottom ashes that do not exhibit amoisture-density relationship.6.3.5 Strength:6.3.5.1 Shear StrengthTest Method D 3080. This test ispreferred because it models the drained conditions that typi-cally exist in a structural fill constructed of coal ash. Themethod is modif
