1、Standard Practice for Sampling and Fabrication of 50-mm (2-in.) Cube Specimens Using Grout (Non-Shrink) or Mortar AASHTO Designation: R 64-171 Technical Section: 3b, Fresh Concrete Release: Group 1 (April 2017) American Association of State Highway and Transportation Officials 444 North Capitol Stre
2、et N.W., Suite 249 Washington, D.C. 20001 TS-3b R 64-1 AASHTO Standard Practice for Sampling and Fabrication of 50-mm (2-in.) Cube Specimens Using Grout (Non-Shrink) or Mortar AASHTO Designation: R 64-171Technical Section: 3b, Fresh Concrete Release: Group 1 (April 2017) 1. SCOPE 1.1. This practice
3、covers field sampling and fabrication and initial curing of 50-mm (2-in.) cube specimens of non-shrink grout or mortar materials, or both. 1.2. The values stated in either inch-pound or SI units shall be regarded separately as standard. The inch-pound units are shown in parentheses. The values state
4、d might not be exact equivalents; therefore, each system must be used independently of the other. Note 1“Unit weight” was the previous terminology used to describe the property determined by this practice, which is mass per unit volume. 1.3. The text of this practice references notes and footnotes t
5、hat provide explanatory information. These notes and footnotes (excluding those in tables) shall not be considered as requirements of this practice. 1.4. This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of thi
6、s standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. WarningFresh hydraulic cementitious mixtures are caustic and may cause chemical burns to skin and tissue upon prolonged exposure. 2. REFERENCED DOCUMENTS 2.1. AASHT
7、O Standard: R 60, Sampling Freshly Mixed Concrete 3. TERMINOLOGY 3.1. Definitions of Terms Specific to This Standard: 3.1.1. plastic mixmaterial viscous enough that an indentation will be left in the surface of the grout after tamping. 3.1.2. fluid mixmaterial fluid enough that little or no indentat
8、ion will be left in the surface after puddling. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b R 64-2 AASHTO 4. SIGNIFICANCE AND USE This practice provides standardized requirements for sampling,
9、fabrication, and curing of 50-mm (2-in.) cube specimens of non-shrink grout and mortar materials. 5. APPARATUS 5.1. Specimen Molds Including Cover Plate(s)The 50-mm (2 in.) cube specimen molds shall be tight-fitting and made of brass or other suitable material. This material shall not be susceptible
10、 to attack by the cement mortar. The mold portion shall have not more than three cube compartments and shall be separable into not more than two parts. The mold halves, when assembled, shall be positively held together. The working surface of the cover plate(s) shall be plane. The interior faces of
11、the molds shall conform to the tolerances of Table 1. Table 1Permissible Variations of Specimen Molds Parameter 50-mm Cube Molds 2-in. Cube Molds New In Use New In Use Planeness of sides 0.025 mm 0.05 mm 0.001 in. 0.002 in. Distance between opposite sides 50 mm 0.13 mm 50 mm 0.50 mm 2 in. 0.005 in.
12、2 in. 0.02 in. Height of each compartment 50 mm + 0.25 mm to 0.13 mm 50 mm + 0.25 mm to 0.38 mm 2 in. + 0.01 in. to 0.005 in. 2 in. + 0.01 in. to 0.015 in. Angle between adjacent facesa90 0.5 90 0.5 90 0.5 90 0.5 aMeasured at points slightly removed from the intersection. Measured separately for eac
13、h compartment between all the interior faces and the adjacent face and between interior faces and top and bottom planes of the mold. 5.2. TamperA nonabsorptive, nonabrasive, nonbrittle material such as a hard rubber compound having a Shore A durometer hardness of 80 10. The tamper shall have a cross
14、 section of about 13 mm by 25 mm (1/2in. by 1 in.) and a length of 125 to 150 mm (5 to 6 in.). The tamping face shall be flat and at right angles to the length of the tamper. 5.3. TrowelSteel bladed, 100 to 150 mm (4 to 6 in.) in length, with straightedges. 5.4. Other EquipmentRubber gloves, scoop,
15、clamps to secure the cover plate, light release oil for oiling the molds, small brush or lint-free cloth for applying and removing excess release oil, and burlap or wrapping cloth capable of retaining moisture. 6. SAMPLING 6.1. Samples shall be obtained in accordance with R 60 when the batch equals
16、or exceeds 1 m3(1 yd3). When the batch is less than 1 m3(1 yd3), sample from the batch after discharge. If remixing is required, sample after remixing. Begin molding the specimens within an elapsed time of not more than 21/2min from completion of the mixing. Note 2This practice is to be used only fo
17、r grouts with 100 percent passing the 9.5-mm (3/8-in.) sieve. 6.2. Obtain a representative sample of the mix. Samples shall be a minimum size of 2000 g (4 lb) for each set of three cubes to be fabricated. 2017 by the American Association of State Highway and Transportation Officials.All rights reser
18、ved. Duplication is a violation of applicable law.TS-3b R 64-3 AASHTO 7. PROCEDURE 7.1. Assemble both portions of the mold and the bottom cover plate. All joints shall be watertight. If not watertight, seal the surfaces where the halves of the mold join by applying a coating of light cup grease (non
19、water-soluble). The amount should be sufficient to extrude slightly when the halves are tightened together. Repeat this process for attaching the mold to the bottom cover plate. Remove any excess grease. Apply a thin coating of release agent to the interior faces of the mold and the bottom cover pla
20、te. Wipe the mold faces and base plate as necessary to remove any excess release agent and to achieve a thin, even coating on the interior surfaces. Adequate coating is that which is just sufficient to allow a distinct fingerprint to remain following light finger pressure. 7.2. Place a layer of grou
21、t about 25 mm (1 in.) (approximately one half of the depth of the mold) in all of the cube compartments. Consolidate according to the consistency (plastic or fluid) of the mix. 7.2.1. For plastic mixes, tamp the lift in four rounds of 8 tamps for a total of 32 tamps with the rubber tamper in 10 s. S
22、ee Figure 1 for tamping sequence of each round. Rounds 1 and 3 and Rounds 2 and 4 shall be the same. Figure 1Tamping Sequence 7.2.2. For fluid mixes, puddle the lift five times with a gloved finger. See Figure 2 for puddling sequence. Figure 2Puddling Sequence 7.3. Place the second lift in each of t
23、he cube compartments, slightly overfilling each compartment. Consolidate the material in the same fashion as the first lift with the additional requirement that, during consolidation of the second lift, any grout forced out onto the top of the mold after each round will be pushed back onto the compa
24、rtment by means of the tamper or gloved fingers, or Rounds 1 and 312345678Rounds 2 and 412345678 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b R 64-4 AASHTO both, before the next consolidation ro
25、und. When consolidation of the grout is completed, material should extend slightly above the top of the mold. After the last round, push any grout forced onto the top of the mold back into the compartment with the trowel. 7.4. Smooth off the cubes by drawing the flat side of the trowel (with the lea
26、ding edge slightly raised) once across the top of each cube at right angles to the length of the mold. Then, for the purpose of leveling the mortar and making the mortar that protrudes above the top of the mold of more uniform thickness, draw the flat trailing edge of the trowel (with leading edge s
27、lightly raised) once lightly along the length of the mold. Cut off the mortar to a plane surface flush with the top of the mold by drawing the straightedge of the trowel (held nearly perpendicular to the mold) with a sawing motion over the length of the mold. The material shall be flush with the top
28、 of the mold. 7.5. Immediately secure the top cover plate to the cube mold. 7.6. Initial CuringImmediately after securing the top cover plate to the cube mold, the specimens shall be stored in a secure, level location away from vibration, and remain undisturbed for a period of 24 to 28 h. Maintain t
29、he specimens in one of the following conditions: 7.6.1. Standard Controlled CuringAfter initial curing, place specimens in a controlled environment capable of producing a temperature range from 16 to 27C (60 to 80F) and preventing moisture loss from the specimens unless stipulated otherwise by the s
30、pecifier of tests. Various procedures are capable of being used during the initial curing period to maintain the specified moisture and temperature conditions. An appropriate procedure or combination of procedures shall be used (Notes 3 and 4). Shield all specimens from direct sunlight and, if used,
31、 radiant heating devices. The storage temperature shall be controlled by the use of heating and cooling devices, as necessary. Record the temperature using a maximumminimum thermometer. 7.6.2. Field Controlled CuringAfter initial curing, place specimens as close as possible to the structure for init
32、ial curing. Cover with wet burlap, towels, or rags; seal it in a plastic sack out of direct sunlight; and record the time. Provide the same temperature protection as provided for the structure. Note 3A satisfactory moisture environment can be created during the initial curing of the specimens by one
33、 or more of the following procedures: (1) store in properly constructed wood boxes or structures, (2) place in damp sand pits, (3) cover with removable lids, (4) place inside plastic bags, or (5) cover with plastic sheets or nonabsorbent plates if provisions are made to avoid drying and damp burlap
34、is used inside the enclosure, but the burlap is prevented from contacting the concrete surfaces. Note 4A satisfactory temperature environment can be controlled during the initial curing of the specimens by one or more of the following procedures: (1) use of ventilation, (2) use of ice, (3) use of th
35、ermostatically controlled heating or cooling devices, or (4) use of heating methods such as stoves or light bulbs. Other suitable methods may be used if the requirements limiting specimen storage temperature and moisture loss are met. 7.7. At the end of the initial curing period as required by the a
36、gency, either: 7.7.1. Place the sealed molds into a watertight container. Transport the cube samples immediately to the location of final curing. During transport, the cube samples shall be protected from jarring, freezing, and moisture loss; or 7.7.2. Disassemble the mold and carefully remove the c
37、ube samples. Using a permanent marker, identify the cube samples. Handling the cube samples very carefully, wrap them in wet burlap or wet towels and place them into a watertight container. Transport the cube samples immediately to the location of final curing. During transport, the cube samples sha
38、ll be protected from jarring, freezing, and moisture loss. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b R 64-5 AASHTO 7.8. Final curing shall consist of removing the samples from the transport c
39、ontainer and immersing the cube samples in a lime-saturated water storage tank maintained at a temperature of 23.0 2.0C (73.5 3.5F). They are to remain in the storage tank until time of test. (Curing cube samples of material other than hydraulic cement shall be in conformance with the manufacturers
40、recommendations.) The storage tank shall be made of noncorroding materials. 8. KEYWORD 8.1. Grout. 1Formerly AASHTO Provisional Standard TP 83. First published as a full standard in 2014. 2017 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.
