1、Standard Method of Test for Length Change of Hardened Hydraulic Cement Mortar and Concrete AASHTO Designation: T 160-17 Technical Section: 3c, Hardened Concrete Release: Group 1 (April 2017) ASTM Designation: C157/C157M-14 American Association of State Highway and Transportation Officials 444 North
2、Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-3c T 160-1 AASHTO Standard Method of Test for Length Change of Hardened Hydraulic Cement Mortar and Concrete AASHTO Designation: T 160-17 Technical Section: 3c, Hardened Concrete Release: Group 1 (April 2017) ASTM Designation: C157/C157M-14 1.
3、 SCOPE 1.1. This test method covers determination of the length changes that are produced by causes other than externally applied forces and temperature changes in hardened hydraulic-cement mortar and concrete specimens made in the laboratory and exposed to controlled conditions of temperature and m
4、oisture. 1.2. The values stated in either inch-pound or SI units are to be regarded separately as standard. An exception is with regard to sieve sizes and nominal size of aggregate, in which the SI values are the standard, as stated in specification ASTM E11. Within the text, the inch-pound units ar
5、e shown in parentheses. The values stated in each system are not exact equivalents; therefore, each system must be used independently of the other, without combining values in any way. 1.3. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is t
6、he responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 201, Mixing Rooms, Moist Cabinets, Moist Rooms, and Water Storage Tanks Used in
7、 the Testing of Hydraulic Cements and Concretes M 210M/M 210, Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and Concrete R 39, Making and Curing Concrete Test Specimens in the Laboratory R 60, Sampling Freshly Mixed Concrete T 106M/T 106, Compressive Stren
8、gth of Hydraulic Cement Mortar (Using 50-mm or 2-in. Cube Specimens) T 119M/T 119, Slump of Hydraulic Cement Concrete T 162, Mechanical Mixing of Hydraulic Cement Pastes and Mortars of Plastic Consistency 2.2. ASTM Standards: C125, Standard Terminology Relating to Concrete and Concrete Aggregates C1
9、43/C143M, Standard Test Method for Slump of Hydraulic Cement Concrete 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 160-2 AASHTO C511, Standard Specification for Mixing Rooms, Moist Cabinets, M
10、oist Rooms, and Water Storage Tanks Used in the Testing of Hydraulic Cements and Concretes C596, Standard Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement E11, Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves E337, Standard Test Method for Measuring Humidi
11、ty with a Psychrometer (the Measurement of Wet- and Dry-Bulb Temperatures) 3. TERMINOLOGY 3.1. DefinitionsThe terms used in this test method are defined in the terminology of ASTM C125. 3.2. Definition of Terms Specific to This Standard: 3.2.1. length changean increase or decrease in the length of a
12、 test specimen that has been caused to change by any factor other than externally applied forces and temperature changes. 4. SIGNIFICANCE AND USE 4.1. Measurement of length change permits assessment of the potential for volumetric expansion or contraction of mortar or concrete due to various causes
13、other than applied force or temperature change. The method is particularly useful for comparative evaluation of this potential in different hydraulic-cement mortar or concrete mixtures. 4.2. This test method provides useful information for experimental purposes or for products that require testing u
14、nder nonstandard mixing, placing, handling, or curing conditions, such as high product workability or different demolding times. Standard conditions are described in Section 5.4.1. 4.3. If conditions for mixing, curing, sampling, and storage other than those specified in this method are required, th
15、ey shall be reported but are not to be considered as standard conditions of this test method. Nonstandard conditions and the reasons for departure from standard conditions shall be reported clearly and prominently with comparator values. 5. APPARATUS 5.1. Molds and Length ComparatorThe molds for cas
16、ting test specimens and the length comparator for measuring length change shall conform to the requirements of M 210M/M 210. 5.2. TamperThe tamper shall be made of a nonabsorptive, nonabrasive material such as medium-hard rubber or seasoned oak wood rendered nonabsorptive by immersion for 15 min in
17、paraffin at approximately 200C (392F) and shall have a cross section of 13 by 25 mm (0.50 by 1 in.) and a convenient length of about 150 mm (6 in.). The tamping face of the tamper shall be flat and at right angles to the length of the tamper. 5.3. Tamping RodThe tamping rod shall be a straight steel
18、 rod 10 mm (0.375 in.) in diameter and not less than 250 mm (10 in.) in length, having at least the tamping end rounded to a hemispherical tip of the same diameter. 5.4. Drying Room and ControlsA drying room with suitable racks shall be provided when storing specimens in air. The racks shall be desi
19、gned for free circulation of air around specimens, except for necessary supports, and shall be so situated with respect to the nearest wall or other obstruction that air circulation is not restricted in the intervening space. The supports shall be 2017 by the American Association of State Highway an
20、d Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 160-3 AASHTO horizontal and shall consist of two nonabsorptive members not deeper than 25 mm (1 in.) and having a bearing area of not more than 6 mm (0.25 in.) in width. Conditioned air shall be circ
21、ulated into and out of the room in a uniform manner so that the specified rate of evaporation is attained adjacent to all specimens. 5.4.1. The air in the room shall be maintained at a temperature of 23.0 1.7C (73.4 3.0F) and a relative humidity of 50 4 percent. The air movement past all specimens s
22、hall be such that the rate of evaporation is 77 30 mL/24 h from an atmometer or 13 15 mL/24 h from a 400-mL Griffin low-form beaker filled to 20 mm (0.75 in.) from the top. The temperature and relative humidity of the air in the room shall be measured with either a sling or Assmann psychrometer at l
23、east twice each working day. The psychrometer shall comply with ASTM E337, except that thermometers having an overall length of 250 mm (10 in.) and marked in subdivisions of 0.25C (0.5F) are permitted. The room shall be equipped with a means of measuring and recording wet- and dry-bulb temperatures
24、continuously. Correction factors as indicated by the sling or Assmann psychrometer shall be applied to the recorded data. The rate of evaporation within the room shall be determined daily by the use of the atmometer or by the loss of mass of water from a 400-mL Griffin low-form beaker filled initial
25、ly to 20 mm (0.75 in.) from the top. 5.5. AtmometerThe atmometer shall be constructed as shown in Figure 1. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 160-4 AASHTO Note: All parts are made o
26、f brass. Figure 1Atmometer 5.5.1. MountingFigure 2 shows a suggested arrangement for operating the atmometer. Punch a central hole 13 mm (0.50 in.) in diameter in a filter paper, place it on the atmometer, and secure it in place while dry, by turning the torque handle only, until it just starts to s
27、lip. Mount the atmometer on a stand with the filter paper in a horizontal position. Mount a 100-mL glass graduate so that the 100-mL mark is from 25 to 75 mm (1 to 3 in.) below the level of the filter paper. Stopper the graduate so that entrance is provided for two short glass tubes not extending to
28、 the water level and one long tube extending to the bottom of the graduate. Connect the glass tubing leading from the bottom of the graduate to the inlet of the atmometer by means of clear plastic tubing. Adjustable Torque HandleSet at 1.4 to 1.7 N-m12 to 15 lbf-in.32 mm1.25 in.8 mm0.31 in.3 mm0.125
29、 in.13 mm0.50 in.8 mm0.31 in.19 mm0.75 in.53 mm2.06 in.3 mm0.09 in.10 mm0.40 in.35 mm1.37 in.60 mm2.36 in.6 mm0.25 in.6 mm0.25 in.1.5 mm 0.0625 in. Drill through 11.5 mm 0.453125 in. CDrill32 mm 1.25 in. Deep Tap 12 mm 1.5 IMF 0.50 in.20 Thd19 mm 0.75 in. Deep 16 mm 0.625 in. CBore 6 mm 0.25 in. Dee
30、p5 mm 0.1875 in. Drill 3 mm 0.125 in. Deep 3 mm 0.125 in. CDrillat 60 as Shown through to Center Tapped HolePLAN VIEWWITHOUT CAP23-mm 0.87-in. Dia6-mm 0.25-in. Dia4-mm 0.15-in. Dia64-mm 2.50-in. Dia57-mm2.25-in. Dia52-mm2.06-in. Dia51-mm2.00-in. Dia4 mm0.56 in.38 mm1.50 in.Soft Solder4 Handles at 90
31、45 ChamferJam Nut 1.01.5 IMC0.375 in.16 N.C.10-mm Dia 1.5 IMC0.375 in.16 N.C. Thd12-mm Dia 1.5 IMF0.50 in.20 Thd 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 160-5 AASHTO Figure 2Suggested Arr
32、angement for Operating the Atmometer 5.5.2. OperationUse clear plastic tubing to connect a squeeze bottle containing distilled or deionized water to one of the short glass tubes into the graduate. Force water into the graduate until it is about half full and then close the remaining glass tube into
33、the graduate. Continue to force water through the graduate into the atmometer until the filter paper is saturated and there are no air bubbles in the system. Open the glass tube into the graduate and release pressure on the squeeze bottle gradually to avoid trapping air in the tube leading to the at
34、mometer. Adjust the level of water in the graduate to approximately the 100-mL mark. If the atmometer is to be used under variable temperature conditions, disconnect the squeeze bottle after filling the graduate to avoid the possibility of additional water being forced into the graduate. Permit evap
35、oration of water from the filter paper for 1 h before recording the time and initial reading of the graduate. It is not permitted to omit the waiting period during subsequent use of the atmometer provided the filter paper does not become dry. Change the filter paper whenever it shows signs of contam
36、ination but not less frequently than once every 2 weeks. 5.6. Filter PaperThe filter paper to be used with the atmometer shall be white with a smooth surface texture. It shall be 152 mm (6 in.) in diameter and 1.27 0.08 mm (0.050 0.003 in.) thick and shall have a cotton fiber content of not less tha
37、n 75 weight. The density shall be between 0.400 and 0.425 g/cm3. The Mullen bursting strength shall not be less than 345 kPa (50 psi). Note 1E and D filter paper No. 625 has been found suitable.15.7. Apparatus for Demolding SpecimensIt is useful to construct an apparatus for demolding specimens mold
38、ed in double molds as detailed in Figure 3 or to a different design that serves the same purpose. When this device is to be used, the center side plate of the double mold must be appropriately drilled and tapped to receive the 8-32 (4.5-0.75 IMC) machine screw of the demolding thumb screw. Figure 4
39、shows the details of a suitable apparatus for demolding specimens molded in single molds. 25 to 75 mm1 to 3 in.AtmometerFilter PaperWood Block34.8 mm 1.37 in.SqueezeBottle100-mLGraduate100-mLLevel 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Dup
40、lication is a violation of applicable law.TS-3c T 160-6 AASHTO Figure 3Device for Detaching 25-mm (1-in.) Square by 285-mm (11.25-in.) Bars from Center Side Plate of Double Molds 10 mm 0.375 in.6 mm0.25 in.13 mm 0.50 in.6-mm 0.25-in. DiaSteel Rod4.50.75 IMC x 16 mm8-32 x 0.625 in.Mach Screw6 cm2.375
41、 in.3 cm1.1875 in.25 mm1in.12.5 mm0.50 in.Drill Cl. Hole for4.50.75 IMC 8-32Mach ScrewBraze All AroundInstructions for Use: Remove end and outer side plates leaving base,center side plate, and gauge stud holders in place.Engage machine screw in drilled and tapped endof center side plate. Turn thumb
42、screw to loose bars. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 160-7 AASHTO Note: Dimensions shown are appropriate for one design of mold for 8-cm (3-in.) square specimens. Change dimension
43、s are required for other molds. Figure 4Device for Demolding Specimens from Single Molds 6. SAMPLING 6.1. Take samples according to the applicable provisions of R 39 from batches of hydraulic-cement mortar or concrete made in the laboratory (Note 2). Note 2When collecting samples in nonstandard cond
44、itions, such as field concrete, it is suggested that R 60 be followed. Field-cast specimens can show up to twice as much drying shrinkage as laboratory-cast specimens from the same materials and proportions. 7. TEST SPECIMENS 7.1. MortarThe test specimen for mortar shall be a prism of 25-mm (1-in.)
45、square cross section and approximately 285 mm (11.25 in.) in length. Three specimens shall be prepared for each test condition. 7.2. ConcreteThe test specimen for concrete, in which all of the aggregate passes a 50-mm (2-in.) sieve, shall be a prism of 100-mm (4-in.) square cross section and approxi
46、mately 285 mm (11.25 in.) long. However, a prism of 75-mm (3-in.) square cross section may be used if all of the aggregate passes a 25.0-mm (1-in.) sieve. Three specimens shall be prepared for each test condition. Since length change is capable of being influenced by the size of the specimen, specim
47、ens to be compared shall have the same dimensions and any specification limit based upon this method shall be applied to a specified size of specimen. 13 cm 5 in. 8 cm 0.568 kg/m 3 in. 4.1 lb Channel33 cm 13 in. 2 cm 0.75 in.142.0 IMC 0.50 in.12 Thd10 cm4in.5cm2in.5cm2in.2 cm 0.75 in.2 cm0.75 in.Fil
48、let Weld 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3c T 160-8 AASHTO 8. PROCEDURE FOR MIXING MORTARS AND CONCRETE 8.1. If the mortar or concrete to be tested is made in accordance with requireme
49、nts other than those given in one of the following paragraphs, samples shall be taken and specimens molded as described in the sections on sampling and on molding specimens. 8.2. Bring all materials to a temperature between 18 and 24C (65 and 75F) before using to make mortar or concrete. Proportion solid materials by mass (that is, not by volume). It is permitted to batch water and liqu
