AASHTO PP 92-2018 Standard Practice for Preparation of Test Specimens Using the Plastic Mold Compaction Device.pdf

1、Standard Practice for Preparation of Test Specimens Using the Plastic Mold Compaction Device AASHTO Designation: PP 92-181Tech Section: 1b, Geotechnical Exploration, Instrumentation, Stabilization, and Field Testing Release: Group 3 (August) American Association of State Highway and Transportation O

2、fficials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1b PP 92-1 AASHTO Standard Practice for Preparation of Test Specimens Using the Plastic Mold Compaction Device AASHTO Designation: PP 92-181Technical Section: 1b, Geotechnical Exploration, Instrumentation, Stabilization, and

3、 Field Testing Release: Group 3 (August) 1. SCOPE1.1. This standard practice covers the use of the plastic mold compaction device (PM device) toprepare cylindrical test specimens with an approximate 2:1 height-to-diameter aspect ratio for usein a variety of mechanical property testing (e.g. compress

4、ive strength, elastic modulus, tensilestrength). This practice is intended for chemically stabilized soil materials (e.g. soilcement). Thisstandard practice can be performed in a laboratory, or, if performed at a construction site, mayproduce comparable properties.1.2. The values stated in SI units

5、are to be regarded as the standard.2. REFERENCED STANDARDS2.1. AASHTO Standards: M 205, Molds for Forming Concrete Test Cylinders Vertically T 99, MoistureDensity Relations of Soils Using a 2.5-kg (5.5-lb) Rammer and a 305-mm(12-in.) Drop T 134, MoistureDensity Relations of SoilCement Mixtures T 180

6、, MoistureDensity Relations of Soils Using a 4.54-kg (10-lb) Rammer and a 457-mm2.2. (18-in.) Drop ASTM Standards: E11, Standard Specification for Woven Wire Test Sieve Cloth and Test Sieves 3. SIGNIFICANCE AND USE3.1. This standard practice provides procedures to compact chemically stabilized soil

7、materials intoplastic cylinder molds for the purpose of fabricating a test specimen with a height-to-diameteraspect ratio of approximately 2:1. Methods of compaction are designed to achieve a targetspecimen density which is typically determined using T 134.3.2. Practical uses for this practice inclu

8、de utilizing the PM device to produce laboratory testspecimens for design purposes and utilizing the same method of specimen compaction duringconstruction operations as part of a quality control program. 2018 by the American Association of State Highway and Transportation Officials. All rights reser

9、ved. Duplication is a violation of applicable law.TS-1b PP 92-2 AASHTO 3.3. This standard practice is limited to chemically stabilized soil materials where approximately 90 percent passes the 4.75-mm (No. 4) sieve and 100 percent passes the 9.5-mm sieve. Soils meeting M 145 designation A-2-4 are ide

10、ally suited for this method. 4. APPARATUS 4.1. Plastic Mold Device Assembly (Split-Mold, Collar, and Base Plate)The PM device shall be made of solid metal and manufactured with dimensions and capacities shown in Annex A. The PM device shall have a collar approximately 50.8-mm (2.000-in.) in height t

11、o permit preparation of specimens of the desired height and volume. The split-mold component shall be constructed so that it can be fastened firmly to the base plate during operation. Figure 1 shows a manufactured PM device. Figure 1PM Device 4.2. RammerA manual metal rammer conforming to criteria s

12、pecified in T 180. 4.3. Cylindrical Plastic Mold (Mold, Plastic Lid, and Plastic Plug)76.2-mm (3.000-in.) diameter by 152.4-mm (6.000-in.) tall plastic cylinder mold conforming to M 205. The bottom of the standard plastic mold is sanded smooth and a hole cut in the center to aid specimen extraction.

13、 The plastic plug from the cutting process is retained for plastic mold assembly. The plastic lid is used to cover the top surface of the specimen after compaction. The cylindrical plastic mold can be seen in Figure 2. Figure 2Plastic Mold (Bottom View) with Aluminum Plate (Section 4.4) 2018 by the

14、American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1b PP 92-3 AASHTO 4.4. Aluminum PlateA 75.8-mm (2.984-in.) diameter aluminum plate with a thickness of 1.59-mm (1/16th-in.). The diameter of the aluminum plate cor

15、responds to the inside diameter at the bottom of the plastic mold, and the plate is utilized for the plastic mold assembly. 4.5. Plastic Mold AssemblyThe plastic mold assembly used in conjunction with the PM device consists of the modified cylindrical plastic mold, aluminum plate, and plastic plug.

16、The aluminum plate is placed inside the plastic mold and allowed to rest at the bottom of the mold. The plastic plug is taped to the outside bottom surface of the plastic mold to give the mold assembly an even bottom surface for compaction. 4.6. Sample ExtruderA jack, lever, frame, or other device a

17、dopted for the purpose of extruding compacted specimens from the plastic mold assembly. The plastic plug is removed and the jack presses against the aluminum plate to facilitate extruding the specimen with no damage. 4.7. StraightedgeA hardened-steel straightedge at least 250 mm (10 in.) in length.

18、It shall have one beveled edge, and at least one longitudinal surface (used for fine trimming) shall be plane within 0.250 mm per 250 mm (0.01 in. per 10 in.) (0.1 percent) of length within the portion used for trimming the soil. 4.8. Locking PliersA pair of locking pliers (e.g. vise grips) or clamp

19、ing tool capable of fastening together the split-mold component of the PM device during compaction. 4.9. Sieve4.75-mm (No. 4) sieve conforming to the requirements of ASTM E11-15. 4.10. Miscellaneous ToolsTape, scoops, calipers, scarifying tool, and labeling materials. 5. PROCEDURE 5.1. Insert the pl

20、astic mold assembly into the split-mold component of the PM device and clamp the PM Device together with a pair of locking pliers. Place the collar on top of the device. The PM device shall rest firmly on a dense, uniform, and stable foundation or base during compaction. 5.2. Select a representative

21、 sample of chemically stabilized soil to fabricate a test specimen. 5.3. Form a specimen by compacting the sampled soil into the plastic mold assembly in three approximately equal layers. Compact each layer by five uniformly distributed blows from the rammer dropping free from a height of 457 mm (18

22、 in.) above the elevation of the stabilized soil. Use a scarifying tool to scarify the top surface of layers one and two before compacting subsequent layers to prevent compaction planes within the specimen. After compaction, approximately 6.4-mm (0.250-in.) of compacted material should extend above

23、the top of the plastic mold. 5.4. Compaction approach presented is intended to produce test specimens with appropriate specimen density (typically determined via T 99). In the case of soil materials with approximately 90 percent passing the 4.75-mm (No. 4) sieve, 5 blows per layer with the T 180 ram

24、mer yielded specimen densities approximately equal to target density. If desired, more or less than five blows can be used per layer, but if the number of blows per layer differs from five, this value must be reported. 5.5. Place the plastic lid on top of the specimen. 5.6. Label with appropriate in

25、formation and allow the specimen to cure inside the plastic mold for at least 24 h before extruding the test specimen. Curing conditions should be reported (e.g. on lab bench at room temperature, at project site, etc.). 2018 by the American Association of State Highway and Transportation Officials.

26、All rights reserved. Duplication is a violation of applicable law.TS-1b PP 92-4 AASHTO 5.7. Once extruded, remove the aluminum plate from the bottom of the specimen. Measure specimen mass and volume (with calipers), and use the mixed moisture content to calculate dry density. The specimen is now rea

27、dy for additional curing and/or mechanical property testing. 6. REPORTING 6.1. Report the number of blows per layer used, curing conditions during the 24-h period, specimen moisture content, and specimen dry density. 7. KEYWORDS 7.1. Compaction; plastic mold compaction device; PM device; plastic mol

28、d; soilcement. ANNEX APM DEVICE DRAWINGS (Mandatory Information) A1. DRAWINGS Figures A.1 through A.5 contain the drawings needed to produce the PM device. Notes: 1. Hinges, latches, and stationary support tube half are welded as shown. 2. Hinges (two required) are McMaster Part No. 1071A22, and are

29、 welded to support tube halves. Figure A.1PM Device Assembly: Overall View Mounting Plate3.2-mm GapMovable SupportTube HalfStationary SupportTube HalfHinges1.59 cm3.2-mm GapLatch3.2 mm7.78 cm0.8 mm 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. D

30、uplication is a violation of applicable law.TS-1b PP 92-5 AASHTO Notes: 1. Support tube halves are made from steel tubing 9.53 cm O.D. and 7.62 cm I.D. 2. Cut tubing into two pieces along 15.49-cm length. 3. Support tube stationary half is welded to PM mounting plate. 4. Support tube movable half is

31、 shortened by 0.1 cm from 8.10 cm I.D. end. Figure A.2PM Device Assembly: Support Tube SupportTubeStationary HalfSupportTubeStationary HalfSupportTubeMovable HalfSupportTubeMovable HalfCross Section ViewCross Section ViewPlan View3.2 mm9.53 cm8.10 cm (+0.025, 0.000)15.49 cm (+0.025, 0.000)15.39 cm8.

32、10 cm (+0.025, 0.000) 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1b PP 92-6 AASHTO Notes: 1. Mounting plate thickness is 12.7 mm. 2. Weld support tube stationary half as shown. 3. Break all shar

33、p edges. 4. One mounting plate required. Figure A.3PM Device Assembly: Mounting Plate and Support Tube Stationary Half SupportTubeStationary HalfPM Mounting Plate12.7 mm9.5-mm DIA(6 Holes)4.76-cmRadius6.35 cm3.81 cm12.7 mm2.54 cm15.24 cm7.62 cm6.35 cm 2018 by the American Association of State Highwa

34、y and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1b PP 92-7 AASHTO Notes: 1. Weld inner and outer tubes together as shown (one required). 2. Latch consists of two halves: threaded (one required) and non-threaded (one required). 3. UNF = unified fin

35、e thread. Figure A.4PM Device Assembly: Guide Collar and Latch Inner TubeSectionA-APlan ViewLatch ThreadedLatch Non-ThreadedInner TubeOuter TubeCross Section View7.62 cm5.08 cm9.53 cm2.54 cm2.54 cm11.43 cm O.D. 9.53 cm I.D.12.7 mmAA2.54 cm6.4 mm2.54 cm6.35 mm12.7 mm12.7 mm12.7 mm12.7 mm9.5-mm DIA Ho

36、leDRILL for and TAP5/16in. - 24 UNF 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.TS-1b PP 92-8 AASHTO Notes: 1. Holes are symmetrical. 2. Plate thickness is 12.7 mm. Figure A.5PM Device Compaction Base Plate 1This provisional standard was first published in 2018. PM-P Base Plate 28.9 cm24.1 cm7.14 cm8.10 cm3.81 cm6.35 cm3.81 cm 2018 by the American Association of State Highway and Transportation Officials. All rights reserved. Duplication is a violation of applicable law.