1、Designation: D6236 11Standard Guide forCoring and Logging Soil-Cement or Lime-Stabilized Soil1This standard is issued under the fixed designation D6236; 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 () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This guide covers obtaining cores of soil-cement orlime-stabilized soil for use in determining compressivestrength, lift thickness and
3、bond strength, and other physicalproperties. This guide is primarily for use in coring throughshallow (0.3 to 3 m (1 to 10 ft) thick) layers of cement orlime-stabilized soils containing particles 50 mm (2 in.) indiameter to the underlying foundation.NOTE 1This guide could be used for some Class C se
4、lf-cementing flyash materials, which may also stabilize soil.1.2 This guide does not cover material of less than 2100 kPa(300 psi) compressive strength such as cement-soil-bentonitemixtures or some controlled low strength materials (CLSM).1.3 All observed and calculated values shall conform to thegu
5、idelines for significant digits and rounding established inPractice D6026.1.4 The values stated in SI units are to be regarded as thestandard. Other values are examples or for information only.1.5 This standard does not purport to address all of thesafety concerns, if any, associated with its use. I
6、t is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. Specific precau-tionary statements are given in Section 8.1.6 This guide offers an organized collection of informationor
7、a series of options and does not recommend a specificcourse of action. This guide cannot replace education orexperience and should be used in conjunction with professionaljudgment. Not all aspects of this guide may be applicable in allcircumstances. This guide is not intended to represent orreplace
8、the standard of care by which the adequacy of a givenprofessional service must be judged, nor should this guide beapplied without consideration of a projects many uniqueaspects. The word “Standard” in the title of this documentmeans only that the document has been approved through theASTM consensus
9、process.1.7 The text of this standard references notes and footnoteswhich provide explanatory material. These notes and footnotes(excluding those in tables and figures) shall not be consideredas requirements of the standard.2. Referenced Documents2.1 ASTM Standards:2C51 Terminology Relating to Lime
10、and Limestone (as usedby the Industry)C219 Terminology Relating to Hydraulic CementD559 Test Methods for Wetting and Drying CompactedSoil-Cement MixturesD560 Test Methods for Freezing and Thawing CompactedSoil-Cement MixturesD653 Terminology Relating to Soil, Rock, and ContainedFluidsD1633 Test Meth
11、ods for Compressive Strength of MoldedSoil-Cement CylindersD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspection of Soil and Rock asUsed in Engineering Design and ConstructionD4220 Practices for Preserving and Transporting SoilSamplesD4452 Practice for X-Ray Radiog
12、raphy of Soil SamplesD5079 Practices for Preserving and Transporting RockCore SamplesD5102 Test Methods for Unconfined Compressive Strengthof Compacted Soil-Lime MixturesD5607 Test Method for Performing Laboratory DirectShear Strength Tests of Rock Specimens Under ConstantNormal ForceD6026 Practice
13、for Using Significant Digits in GeotechnicalData3. Terminology3.1 Definitions:3.1.1 Refer to Terminology C51 for terms relating to lime.3.1.2 Refer to Terminology C219 for terms relating tohydraulic cement.1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the di
14、rect responsibility of Subcommittee D18.15 on Stabilization WithAdmixtures.Current edition approved Jan. 1, 2011. Published February 2011. Originallyapproved in 1998. Last previous edition approved in 2004 as D623698(2004).DOI: 10.1520/D6236-11.2For referenced ASTM standards, visit the ASTM website,
15、 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.1*A Summary of Changes section appears at the end of this standard.Copyright ASTM International, 100 Barr Harbor Dri
16、ve, PO Box C700, West Conshohocken, PA 19428-2959, United States.3.1.3 Refer to Terminology D653 for terms relating to soil.4. Summary of Guide4.1 Core samples of soil-cement or lime-stabilized soil witha core diameter of 75- or 100-mm (3- or 4-in.) are obtainedthrough the entire thickness of a stab
17、ilized soil section orfacing using a rotary drill equipped with a diamond coring bit.To minimize the possibility of breakage or other internaldamage to the sample during coring operations, it is suggestedthat the stabilized soil have a minimum compressive strengthof 2100 kPa (300 psi) prior to corin
18、g, cores are retrieved,labeled, and logged. Coring may be repeated at other times ifspecified by the engineer. Retrieve, label, and log the cores.Retrieved cores are tested as specified by the engineer. Testscommonly requested include unconfined compressive strengthin accordance with Test Methods D1
19、633 and D5102, durabilityin accordance with Test Methods D559 and D560, bondstrength in accordance with Test Method D5607 and unifor-mity and possible voids in accordance with Test MethodsD4452.5. Significance and Use5.1 Coring is performed to evaluate construction control andphysical properties of
20、stabilized soil.5.2 Coring is conducted to determine the quality and thetotal thickness of the stabilized soil and to evaluate bondingbetween lifts.5.3 Coring stabilized soil before it has cured to at least 2100kPa (300 psi) compressive strength can cause excessive break-age in the core.5.4 If lab-c
21、ured specimens are prepared, samples may becored to correlate with specified break intervals of the lab-cured specimens. Typical curing time intervals are 7, 28, 60, or90 days or combinations thereof after placement. Twenty-eight(28) days after placement is the most common time interval forfirst dri
22、lling cores.NOTE 2The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesuitability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective tes
23、ting/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable results. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.6. Interferences6.1 Failure to adequately stabi
24、lize the drill and drill standduring coring can cause excessive breakage in the core.6.2 Failure to set up the drill and drill stand perpendicular tothe surface of the stabilized soil will cause error in determiningthe thickness of the stabilized material.7. Apparatus7.1 Drill and Drill StandA rotar
25、y drill capable of drilling100-mm (4-in.) diameter core samples to the required depth(generally 0.3 to 1.2 m (1 to 4 ft). The drill must be capable ofdrilling holes perpendicular to the face of the stabilized soil.The drill should be mounted and the drill stand anchored sothat the drill and stand ar
26、e stable during the drilling process.7.2 Core BarrelsDiamond surface set or diamond impreg-nated core bits, 75- or 100-mm (3- or 4-in.) inside diameter, ofsufficient length to penetrate the full vertical depth of thestabilized material.7.3 AdaptersRemovable extension adapters and exten-sions rods co
27、mpatible with drill and core barrels.7.4 WaterWater supply for drilling to remove cuttings andcool drill bits.7.5 GeneratorPortable electric generator suitable for sup-plying electric power to drill.7.6 Percussion DrillRotary percussion drill or other suit-able device holes for anchor bolts.7.7 Anch
28、orsAnchors and bolts adequate for securing thedrill stand to the stabilized material.7.8 Core Retrieval BarrelsWorn 75- or 100-mm (3- or4-in.) diameter core bits with cutting edge removed and slottedon the drilling end for retrieving core samples (Fig. 1).7.9 Pry BarMetal bar suitable for breaking c
29、ore from thebottom of the hole.7.10 ContainersContainers shall be in accordance withPractices D5079 or D4220.7.11 Grouting MaterialsPotable water, concrete premix,bagged cement, or grout premix for back filling drill holes.7.12 Miscellaneous EquipmentAssorted tools necessaryfor drilling operations,
30、chain tongs and pipe wrenches forinstalling and removing core barrels, and water proof markersfor labeling core samples.8. Hazards8.1 Safety Hazards:8.1.1 Safety hazards may be involved in the use of the rotarydrill. Refer to the manufacturers handbook before operatingthe drill.8.1.2 Ensure that ele
31、ctrical supply lines are well insulatedand connections kept dry to prevent electrical shock.8.1.3 Use caution when refilling gasoline tanks on electricalgenerators.8.1.4 Drilling equipment and core samples are heavy andawkward. Use care when lifting or transporting equipment orsamples.8.1.5 Drilling
32、 operations often take place on sloped sur-faces. Adequate safety shoes or safety boots should be worn toprevent slipping into machinery or down the slope.8.1.6 Wear safety glasses and hard hat.8.1.7 Use of a respirator may be necessary.8.2 Technical Hazards:8.2.1 Because of low early compressive st
33、rength, it may bedifficult to obtain representative intact core samples until thestabilized soil has reached a compressive strength of 2100 kPa(300 psi).9. Procedure9.1 Record all data on an appropriate log form.9.2 CoringCoring is done when the strength of thestabilized soil has reached an estimate
34、d minimum compressivestrength of 2100 kPa (300 psi). Time to reach this strength willvary depending on mix design. Time interval after placementuntil sample is cored should be coordinated with specifiedbreak intervals of lab-cured specimens if such were prepared,D6236 112or as specified by an engine
35、er. Common curing time intervalsare 7, 28, 60, and/or 90 days. If coring is repeated, subsequentholes should be immediately adjacent to the previous holes.9.2.1 Core drill hole locations and depths are based on thedesign of the stabilized soil-lime or soil-cement structure.General hole locations and
36、 core diameters required for testingshould be determined prior to the start of construction. Coresshould also be obtained in any area of questionable stabilizedsoil quality.9.2.2 Anchor the drill stand in a manner which effectivelystabilizes the drill and drill stand during drilling and allows forco
37、ring and core retrieval to be perpendicular to the placementlifts.NOTE 3Core barrels should remain perpendicular to the face of thestabilized soil, and the drill and stand should be stable while drilling toprevent core from binding in the barrel.9.2.3 As required, install a 75- or 100-mm (3- or 4-in
38、.)inside diameter core barrel of sufficient length to penetrate thefull vertical depth of the stabilized material facing.9.2.4 In one continuous operation, drill through the entiredepth of the stabilized soil to the embankment or foundationcontact.NOTE 4Drilling should be performed at a slow rotatio
39、nal speed, withconstant feed pressure, such that the core is not damaged during thedrilling operations. Because of the great variation in strength of thematerial, depending on mix design and time of sampling, no one rotationalFIG. 1 Core Retrieval Barrel Made From Worn Diamond Studded Core BarrelD62
40、36 113speed or feed rate can be specified. However, note that the material maybe fragile and can easily be damaged in drilling.9.2.4.1 If the core has broken and is binding in the corebarrel, stop drilling, remove the core barrel, and retrieve anybroken pieces of core remaining in the hole with the
41、coreretrieval barrel before continuing.9.2.4.2 If the depth of the stabilized material exceeds themaximum length of the core barrel, remove the core barrel andretrieve the core with the core retrieval barrel. Add anextension rod and continue drilling to embankment or founda-tion contact.9.2.5 Remove
42、 the core barrel, and install a core retrievalbarrel of sufficient length to remove the core in one piece.9.2.6 Retrieve the core in one operation by inserting the coreretrieval barrel over the full length of core and extracting bothfrom the hole. As soon as the core retrieval barrel and core areout
43、 of the hole, place a cover over the hole to prevent the corefrom falling back into the hole.9.2.6.1 WarningTake care when handling recoveredsamples to minimize disturbance, which can affect test resultsstrength and permeability.9.2.7 Remove the core retrieval barrel from the drill, andcarefully rem
44、ove the core from the barrel by pushing the coreout the top. Immediately place the core in a shipping box in theexact order that it was retrieved.9.3 Logging CoreLog each core as it comes from theretrieval barrel and is placed in the shipping box.9.3.1 Immediately label the core by hole number and i
45、tsposition in the hole from top to bottom. Indicate the directionof top on each piece of core.9.3.2 Identify, place core samples in shipping boxes, andcover immediately after retrieval to minimize moisture loss inaccordance with Practices D4220 and D5079.9.3.3 To prevent moisture loss, place the sam
46、ples in airtightplastic bags prior to placing in shipping container. Keepsamples out of direct sunlight.9.3.4 Immediately After Logging, carefully and securelypack each section of core in the shipping box in accordancewith Practice D5079 to prevent moisture loss and damageduring transport to laborat
47、ory for testing.9.4 Refilling HolesRefill all core holes with grout, con-crete premix slurry, or stabilized soil mixed to original place-ment specifications.10. Report: Data Form10.1 The methodology used to specify how data are re-corded on the data forms is covered in 1.3.10.2 Report the following
48、information:10.2.1 A log for each hole drilled and completed,10.2.2 At a minimum note the following:10.2.2.1 Drilling method10.2.2.2 Drill run intervals10.2.2.3 Depth at which breaks occur in the core10.2.2.4 Lift contacts10.2.2.5 Embarkment or foundation contact10.2.2.6 Bonding agent used (if any),
49、 and10.2.2.7 Condition of bond.10.2.3 Include any other pertinent information, such as spuncore, loose material, surface appearance, poor compaction,clayballs, unhydrated lime concentrations, fractures, lack ofbonding, etc.10.2.4 Location and condition (backfilled, capped, etc.) ofdrill hole, and10.2.5 Disposition of core samplesNOTE 5Examples of soil-cement and soil-lime logs are shown in Figs.2 and 3.11. Precision and Bias11.1 This guide provides qualitative and general informa-tion only. Therefore, a precision and bias statement is notapplicable.12. Keywor
