1、Designation: D1635/D1635M 12Standard Test Method forFlexural Strength of Soil-Cement Using Simple Beam withThird-Point Loading1This standard is issued under the fixed designation D1635/D1635M; the number immediately following the designation indicates theyear of original adoption or, in the case of
2、revision, the year of last revision. A number in parentheses indicates the year of lastreapproval. A superscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope*1.1 This test method covers the determination of the flexuralstrength of soil-cement by the use of
3、a simple beam withthird-point loading.NOTE 1For methods of molding soil-cement specimens, see PracticeD1632.1.2 All observed and calculated values shall conform to theguidelines for significant digits and rounding established inPractice D6026 unless superseded by this standard.1.3 UnitsThe values st
4、ated in either SI units or inch-pound units are to be regarded separately as standard. Thevalues stated in each system may not be exact equivalents;therefore, each system shall be used independently of the other.Combining values from the two systems may result in non-conformance with the standard. T
5、he SI units are presented inbrackets.1.3.1 The gravitational system of inch-pound units is usedwhen dealing with inchpound units. In this system, the pound(lbf) represents a unit of force (weight), while the unit for massis slugs. The rationalized slug unit is not given, unless dynamic(F = ma) calcu
6、lations are involved.1.4 This 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 limitations prior t
7、o use.2. Referenced Documents2.1 ASTM Standards:2D653 Terminology Relating to Soil, Rock, and ContainedFluidsD1632 Practice for Making and Curing Soil-Cement Com-pression and Flexure Test Specimens in the LaboratoryD3740 Practice for Minimum Requirements for AgenciesEngaged in Testing and/or Inspect
8、ion of Soil and Rock asUsed in Engineering Design and ConstructionD6026 Practice for Using Significant Digits in GeotechnicalDataE4 Practices for Force Verification of Testing Machines3. Terminology3.1 For common definitions of terms in this standard, referto Terminology D653.4. Significance and Use
9、4.1 This test method is used to determine the flexuralstrength of soil-cement. Flexural strength is significant inpavement design and is used to determine slab thickness.NOTE 2The quality of the result produced by this standard isdependent on the competence of the personnel performing it, and thesui
10、tability of the equipment and facilities used. Agencies that meet thecriteria of Practice D3740 are generally considered capable of competentand objective testing/sampling/inspection/etc. Users of this standard arecautioned that compliance with Practice D3740 does not in itself assurereliable result
11、s. Reliable results depend on many factors; Practice D3740provides a means of evaluating some of those factors.5. Apparatus5.1 Testing MachineThe testing machine may be of anytype having sufficient capacity and control to provide the rateof loading (prescribed in 7.2). It shall conform to the requir
12、e-ments of Section 15 of Practices E4. The testing machine shallbe equipped with a spherically seated head block having abearing surface of at least 75 % of the width of the beam butnot greatly in excess of the width of the beam. The movableportion of this block shall be held closely in the spherica
13、l seat,but the design shall be such that the bearing face may berotated freely and tilted through small angles in any direction.5.2 The third-point loading method used in making flexuretests of soil-cement shall employ bearing blocks that willensure that forces applied to the beam will be vertical o
14、nly andapplied without eccentricity. A diagrammatic drawing of anapparatus that accomplishes this purpose is shown in Fig. 1.The apparatus shall be designed to incorporate the followingprinciples:1This test method is under the jurisdiction ofASTM Committee D18 on Soil andRock and is the direct respo
15、nsibility of Subcommittee D18.15 on Stabilization WithAdmixtures.Current edition approved May 1, 2012. Published June 2012. Originallyapproved in 1959. Last previous edition approved in 2000 as D163500(2006).DOI: 10.1520/D1635_D1635M-12.2For referenced ASTM standards, visit the ASTM website, www.ast
16、m.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 Drive, PO B
17、ox C700, West Conshohocken, PA 19428-2959, United States.5.2.1 The distance between supports and points of loadapplication shall remain constant for a given apparatus.5.2.2 The direction of the reactions shall be parallel to thedirection of the applied load at all times during the test.5.2.3 The loa
18、d shall be applied at a uniform rate and in sucha manner as to avoid shock.5.2.4 The directions of loads and reactions may be main-tained parallel by judicious use of linkages, rocker bearings,and flexure plates. Eccentricity of loading can be avoided byuse of spherical bearings.6. Test Specimens6.1
19、 The standard test specimens shall be beams 3 by 3 by1114 in. 76 by 76 by 290 mm, but a similar test method maybe used for testing specimens of other sizes. Test the specimenson their sides with respect to their molded position.6.2 Make flexural tests of moist cured specimens as soon aspracticable a
20、fter removing them from the moist room, andduring the period between removal from the moist room andtesting keep the specimens moist by a wet burlap or blanketcovering.NOTE 3Other conditioning procedures, such as soaking in water, airor oven drying, alternate wetting and drying or alternate freezing
21、 andthawing, may be specified after an initial moist curing period. Curing andconditioning procedures shall be given in detail in the report.6.3 Check the smoothness of the side faces of the beams atthe points where loads will be applied with a straightedge. Ifnecessary, cap the faces to meet the re
22、quirements of Section 15of Practice D1632.7. Procedure7.1 Turn the specimen on its side with respect to its moldedposition and center it on the lower half-round steel supports,which have been spaced apart a distance of three times thedepth of the beam. Place the load-applying block assembly incontac
23、t with the upper surface of the beam at the third pointsbetween the supports. Carefully align the center of the beamwith the center of thrust of the spherically seated head block ofthe machine. As this block is brought to bear on the beam-loading assembly, rotate its movable portion gently by hand s
24、othat uniform seating is obtained.7.2 Apply the load continuously and without shock.Ascrewpower testing machine, with the moving head operating atapproximately 0.05 in./min 0.02 mm/s when the machine isrunning idle, may be used. With hydraulic machines adjust theloading to such a constant rate that
25、the extreme fiber stress iswithin the limits of 100 6 5 lbf/in.2/min 690 6 39 kPa/min.Record the total load of failure of the specimen to the nearest10 lbf 40 N.8. Measurement of Specimens After Test8.1 Make measurements to the nearest 0.01 in. 0.25 mm todetermine the average width and depth of the
26、specimens at thesection of failure.9. Calculations9.1 If the fracture occurs within the middle third of the spanlength, calculate the modulus of rupture as follows:R 5PLbd2FIG. 1 Diagrammatic View of Suitable Apparatus for Flexure Test of Soil-Cement by Third-Point Loading MethodD1635/D1635M 122wher
27、e:R = modulus of rupture, lbf/in.2MPa,P = maximum applied load, lbf N,l = span length, in. mm,b = average width of specimen, in. mm, andd = average depth of specimen, in. mm.NOTE 4Mass of the beam is not included in the above calculation.9.2 If the fracture occurs outside the middle third of the spa
28、nlength by not more than 5 % of the span length, calculate themodulus of rupture as follows:R 53Pabd2where:a = distance between line of fracture and the nearestsupport, measured along the center line of the bottomsurface of the beam, in. mm.9.3 If the fracture occurs outside the middle third of the
29、spanby more than 5 % of the span length, discard the results of thetest.10. Report10.1 The report shall include the following:10.1.1 Specimen identification number,10.1.2 Average width and depth at section of failure to thenearest 0.01 in. 0.25 mm,10.1.3 Maximum load, to the nearest 10 lbf 40 N,10.1
30、.4 Modulus of rupture, calculated to the nearest 5lbf/in.20.05 MPa,10.1.5 Defects, if any, in specimen,10.1.6 Age of specimen, and10.1.7 Details of curing and conditioning periods, and watercontent at time of test.11. Precision and Bias11.1 PrecisionThe precision of this test method has notbeen esta
31、blished by an interlaboratory test program. However,based on test data that are available, the following may serve asa guide to the variability of flexural strength test results.11.1.1 Tests were performed in a single lab on a silt loamsoil with 92 % passing the No. 200 75-m sieve. Liquid limitand p
32、lasticity index of soil were 26 and 7, respectively. Theseries of tests consisted of 24 specimens, 12 at 6 % cement, 12at 14 % cement. The specimens were cured in a moist room at73 F 23 C for 28 days. Results3of the tests are given inTable 1.11.2 BiasThere is no accepted reference value for this tes
33、tmethod, therefore, bias cannot be determined.12. Keywords12.1 flexural strength; soil-cement; soil stabilizationSUMMARY OF CHANGESCommittee D18 has identified the location of selected changes to this test method since the last issue,D163500(2006), that may impact the use of this test method. (Appro
34、ved May 1, 2012)(1) Revised the standard as a combined units test method withSI units presented in brackets, including revision to Fig. 1.ASTM International takes no position respecting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this st
35、andard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical committee and must be reviewed every five years a
36、ndif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,
37、 which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-29
38、59,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org). Permission rights to photocopy the standar
39、d may also be secured from the ASTM website (www.astm.org/COPYRIGHT/).3Felt, E. J., Abrams, M. S., Strength and Elastic Properties of CompactedSoil-Cement Mixtures, ASTM STP 206, ASTM, 1957.TABLE 1 PrecisionAverage flexuralstrength, lbf/in.2MPaStandarddeviation,lbf/in.2MPaCoefficient ofvariation, %Specimens with 6 % cement 94 0.65 6 0.04 6.4Specimens with 14 % cement 157 1.08 9 0.06 5.7D1635/D1635M 123
