1、Designation: C806 04C806 12Standard Test Method forRestrained Expansion of Expansive Cement Mortar1This standard is issued under the fixed designation C806; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision.
2、 A number in parentheses indicates the year of last reapproval. Asuperscript epsilon () indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method covers the determination of length changes of expansive cement mortar, while under restraint, due to thedevelopment
3、 of internal forces resulting from hydration of the cement.1.2 The values stated in non-SIinch-pound units are to be regarded as the standard. When both the inch-pound units and the SIunits are present, the non-SI units are to be regarded as the standard. The values in SI units are approximate, are
4、listed forinformation only, and will likely provide different values than the inch-pound units.standard. The values given in parentheses aremathematical conversions to SI units that are provided for information only and are not considered standard.1.3 This standard does not purport to address all of
5、 the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatorylimitations prior to use. (WarningFresh hydraulic cement mixtures are caustic and may cause bu
6、rns to skin and tissue uponprolonged exposure.2)2. Referenced Documents2.1 ASTM Standards:3A307 Specification for Carbon Steel Bolts, Studs, and Threaded Rod 60 000 PSI Tensile StrengthC109/C109M Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2-in. or 50-mm Cube Specimens)C1
7、57/C157M Test Method for Length Change of Hardened Hydraulic-Cement Mortar and ConcreteC219 Terminology Relating to Hydraulic CementC305 Practice for Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic ConsistencyC490 Practice for Use of Apparatus for the Determination of Length Chan
8、ge of Hardened Cement Paste, Mortar, and ConcreteC670 Practice for Preparing Precision and Bias Statements for Test Methods for Construction MaterialsC778 Specification for SandC1005 Specification for Reference Masses and Devices for Determining Mass and Volume for Use in the Physical Testing ofHydr
9、aulic CementsF606 Test Methods for Determining the Mechanical Properties of Externally and Internally Threaded Fasteners, Washers, DirectTension Indicators, and Rivets3. Terminology3.1 Definitions of terms used in this test method are given in Terminology C219.4. Apparatus4.1 MoldsThe molds for cast
10、ing test specimens, when used in conjunction with the restraining cage described in 4.2, shallprovide for forming either 2 by 2 by 10-in. prisms having a 10-in. gage length, or 50 by 50 by 250-mm prisms having a 250-mmgage length. The molds shall otherwise conform to the requirements of Practice C49
11、0, except that the gage stud holder, gage studs,and spacer screws described in that specification will not be used.4.2 Restraining Cage, consisting of a threaded steel rod with steel end plates held in place by nuts as shown in Fig. 1. The rodshall be provided with cap nuts for prevention of corrosi
12、on. The rod shall conform to Specification A307 Grade A except, it shallsupport 1180-lbf (5249 N) proof load when tested in accordance with Method 1 of Test Methods F606.1 This test method is under the jurisdiction of ASTM Committee C01 on Cement and is the direct responsibility of Subcommittee C01.
13、13 on Special Cements.Current edition approved July 1, 2004Dec. 15, 2012. Published July 2004February 2013. Originally approved in 1975. Last previous edition approved in 19952004 asC806 95.C806 04. DOI: 10.1520/C0806-04.10.1520/C0806-12.2 Section of Safety, Manual of Cement Testing, Annual Book of
14、ASTM Standards, Vol 04.01.3 For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standa
15、rd and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases
16、only the current versionof the standard as published by ASTM is to be considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States14.3 Length ComparatorThe length comparator for measuring length shall conform to an
17、d be used in accordance with therequirements of Practice C490. If the terminals of the comparator are fitted with collars, they shall be such that the cap nuts onthe ends of the threaded rod of the specimen do not rest on the collar during measuring.4.4 TamperThe tamper shall be made of nonabsorptiv
18、e, nonabrasive material such as medium-hard rubber or seasoned oakwood, rendered nonabsorptive by immersion for 15 min in paraffin at approximately 392 F (200 C), and shall have a cross sectionof about 12 by 1 in. (13 by 25 mm) and convenient length of about 6 in. (150 mm). The tamping face of the t
19、amper shall be flatand at right angles to the length of the tamper.4.5 Apparatus for Demolding SpecimensApparatus similar to that described in the Apparatus section of Test MethodC157/C157M, may be found useful for demolding specimens.4.6 Weights and Weighing DevicesScales used shall comply with Spe
20、cification C1005.NOTE 1Generally defined, the sensibility reciprocal is the change in load required to change the position of rest of the indicating element or elementsof a nonautomatic-indicating scale a definite amount at any load.4.7 Glass Graduates,Graduate of suitable capacities (preferably lar
21、ge enough to measure the mixing water in a single operation)shall be made to deliver the indicated volume at 68 F (20 C). The permissible variation shall be 62 mL. These graduates shallbe subdivided to at least 5 mL, except that the graduation lines may be omitted for the lowest 10 mL for a 250-mL g
22、raduate andthe lowest 25 mL for a 500-mL graduate. The main graduation lines shall be circles and shall be numbered. The least graduationsshall extend at least one seventh of the waythat conforms to the requirements of Test Method C109/C109Maround, andintermediate graduations shall extend at least o
23、ne fifth of the way around4.8 Mixer, Bowl, and PaddleThe mixer shall be an electrically driven mechanical mixer of the type equipped with paddle andmixing bowl, as specified in the Apparatus section of Practice C305.4.9 TrowelThe trowel shall have a steel blade 4 to 6 in. (102 to 152 mm) in length,
24、with straight edges.5. Temperature and Humidity5.1 The temperature of the air in the vicinity of the mixing operation, the dry materials, mixing water, molds, base plates, mixingbowl, moist closet or moist room, and storage water shall not vary from 73.4 F (23 C) by more than 63 F (61.7 C).5.2 The r
25、elative humidity of the laboratory shall be not less than 50 %. The moist closet or moist room shall provide a relativehumidity of not less that 95 %.Dimension, in. (mm) Tolerance, in. (mm)A 1134 (300) .B 10 (250) 18 (3)C 2 (50) .D 1 (25) .E 13132 (49) 132 (1)F 6364 (24.5) .G 38 (10) .FIG. 1 Restrai
26、ning CageC806 1226. Graded Standard Sand6.1 Sand used shall comply with the graded sand requirement of Specification C778.Passing Sieve Percentage RetainedNo. 100 (150-m) 98 2No. 50 (300-m) 72 5No. 30 (600-m) 2 2No. 16 (1.18-mm) noneNOTE 1Segregation of Graded SandThe graded standard sand should be
27、handled in such a manner as to prevent segregation, since variations inthe grading of the sand cause variations in the consistency of the mortar. In emptying sacks of sand into bins or in scooping sand out of bins or sacks,care should be exercised to prevent the formation of mounds of sand or crater
28、s in the sand, down the slopes of which the coarser particles will roll. Binsshould be of sufficient size to permit these precautions. Devices for drawing the sand from bins by gravity should not be used.7. Test Specimen7.1 The test specimen shall be a 2 by 2 by 10-in. prism having a 10-in. gage len
29、gth, or a 50 by 50 by 250-mm prism havinga 250-mm gage length. At least two specimens shall be prepared for each test.8. Preparation and Assembly of Specimen Molds and Restraining Cage8.1 Install the cap nuts firmly in place on the ends of the restraining rods and measure the restraining rods for le
30、ngth while theyare at a temperature of 73.4 6 1 F (23.0 6 0.5 C).8.2 The edges of the end plates of the restraining cage that contact the sides and bottom of the mold shall be thinly covered witha heavy mineral oil or light cup grease such as petrolatum. After assembly of the molds, place a restrain
31、ing cage in eachcompartment. Seal the contact lines between the outer sides and base plate of the molds with paraffin or micro-crystalline wax.Thinly cover the interior faces of the molds with mineral oil and remove any oil or grease from the restraining cage rod and endplates.9. Proportioning and M
32、ixing of Mortars9.1 Proportion the standard mortar by using one part of cement to 2.75 parts of graded standard sand by mass. Mix 800 g ofcement, 2200 g of graded standard sand, and 400 mL of water to produce a batch sufficient for two test specimens.9.2 Mix in accordance with the procedure for mixi
33、ng mortars given in Practice C305. Upon completion of mixing, shake themixing paddle into the mixing bowl to remove excess mortar.10. Molding Specimens10.1 Start molding specimens immediately after completion of mixing. Place the mortar in the mold in two layers with the firstlayer just covering the
34、 restraining rod and the second layer slightly overfilling the mold. Compact each layer by tamping. Workthe mortar into the corners, around the restraining rod, without striking the rod, and along the surfaces of the mold with the tamperuntil a homogeneous specimen is obtained. After the top layer h
35、as been compacted, strike-off the mortar flush with the top of themold, and smooth the surface with a few strokes of the trowel.11. Curing of Specimens11.1 Immediately after completion of molding, cover the specimens with a polyethylene sheet, or other suitable material forpreventing loss or gain of
36、 moisture, at the surface of the specimens. The cover should make contact with the surface of the mortar.Place the specimens in the moist room or moist cabinet.11.2 Remove the specimens from the molds at an age of 6 6 14 h after the addition of water to the cement during the mixingoperation (Note 32
37、). Particular care must be exercised in this operation in order not to damage the specimens because of their lowstrength at this age. It is preferable to use the demolding devices referred to in 4.5 for freeing specimens from the base and sideplates.NOTE 2At this time comparator readings may be made
38、. Although these readings may differ slightly from the initial reading made on the restrainingrod prior to molding the specimen, it can serve as a check on the initial reading which should be used as the basis for calculating the length change.11.3 Cure the specimens in lime-saturated water at 73.46
39、 3.0 F (23.0 6 1.7 C) until they have reached an age of 7 days 61 h, including the period in the molds, except that the temperature of the curing water shall be 73.4 6 1 F (23.0 6 0.5 C) forat least the last 15 min. At the end of this period, remove the specimens from the water one at a time, wipe w
40、ith a damp cloth,and immediately make comparator readings with the cap nuts in place.11.4 Return the specimens to curing in lime-saturated water at 73.4 6 3.0 F (23.0 6 1.7 C) until they have reached an ageof 28 days including the period in the molds. At the end of the curing period, make comparator
41、 readings immediately after thespecimens have been subjected to about 15 min of storage in water at 73.4 6 1.0 F (23.06 0.5 C) and in the same manner asdescribed in 11.3.C806 12312. Calculation12.1 Calculate the expansion or shrinkage at any age as follows:Ex 5 Lx 2Li10 250!3100 (1)where:Ex = expans
42、ion at x age, %,Lx = comparator reading of specimen at x age reference bar comparator reading, in. (mm), andLi = initial comparator reading of restraining rod reference bar comparator reading, in. (mm).13. Report13.1 Report the following information:13.1.1 Number of specimens for each condition and
43、date molded,13.1.2 Source and identification of cement.13.1.3 Age of specimen for each observation for length change,13.1.4 Length-change data, expressed as linear expansion or contraction based on the length of the specimen at time of moldingshall be reported as percent change dimension to the near
44、est 0.001 %, and13.1.5 Any other pertinent information.14. Precision and Bias414.1 Precision:14.1.1 Within Batch PrecisionThe standard deviation of two bars made from the same batch and tested together was foundto be 0.00276 %. Therefore two bars made from the same batch should not differ from each
45、other by more than 0.008 % lengthchange.514.1.2 Single Operator PrecisionThe single operator standard deviation has been found to be 0.0038 at seven and twenty eightdays age, based on the average of two bars. Therefore the results of two properly conducted tests by the same operator on the samemater
46、ial should not differ by more than 0.011 % length change.514.1.3 Multilaboratory PrecisionThe multilaboratory standard deviation has been found to be 0.0093 at seven and twentyeight days age, based on the average of two bars. Therefore the results of two properly conducted tests on the same material
47、 intwo different laboratories should not differ by more than 0.026 % length change.514.2 BiasA bias statement cannot be prepared due to the fact that absolute standards are not available.15. Keywords15.1 cement mortar; expansive cement; restrained expansionASTM International takes no position respec
48、ting the validity of any patent rights asserted in connection with any item mentionedin this standard. Users of this standard 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 sta
49、ndard is subject to revision at any time by the responsible technical committee and must be reviewed every five years andif 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, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your
