1、Standard Method of Test for Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate AASHTO Designation: T 104-99 (2011) American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1c T 104-1 AASHTO Standard Method
2、 of Test for Soundness of Aggregate by Use of Sodium Sulfate or Magnesium Sulfate AASHTO Designation: T 104-99 (2011) 1. SCOPE 1.1. This method covers the procedure to be followed in testing aggregates to determine their resistance to disintegration by saturated solutions of sodium sulfate or magnes
3、ium sulfate. This is accomplished by repeated immersion in saturated solutions of sodium or magnesium sulfate followed by oven drying to partially or completely dehydrate the salt precipitated in permeable pore spaces. The internal expansive force, derived from the rehydration of the salt upon re-im
4、mersion, simulates the expansion of water on freezing. This test method furnishes information helpful in judging the soundness of aggregates subject to weathering action, particularly when adequate information is not available from service records of the material exposed to actual weathering conditi
5、ons. Attention is called to the fact that test results by the use of the two salts differ considerably and care must be exercised in fixing proper limits in any specifications that may include requirements for these tests. 1.2. The values stated in SI units are to be regarded as the standard. 1.3. T
6、his standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety concerns associated with its use. It is the responsibility of the user of this standard to consult and establish appropriate safety and health practices and determine
7、the applicability of regulatory limitations prior to use. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 92, Wire-Cloth Sieves for Testing Purposes M 231, Weighing Devices Used in the Testing of Materials R 16, Regulatory Information for Chemicals Used in AASHTO Tests T 27, Sieve Analysis of Fine
8、and Coarse Aggregates 2.2. ASTM Standards: C670, Standard Practice for Preparing Precision and Bias Statements for Test Methods for Construction Materials E100, Standard Specification for ASTM Hydrometers 3. APPARATUS 3.1. SievesWith square openings of the following sizes conforming to M 92, for sie
9、ving the samples in accordance with Sections 5, 6, and 8: 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 104-2 AASHTO 4.75 mm (No. 4) 63 mm (21/2in.) 4.00 mm (No. 5) 50 mm (2 in.) 2.36 mm (No. 8
10、) 37.5 mm (11/2in.) 1.18 mm (No. 16) 31.5 mm (11/4in.) 600 m (No. 30) 25.0 mm (1 in.) 300 m (No. 50) 19.0 mm (3/4in.) 150 m (No. 100) 16.0 mm (5/8in.) 12.5 mm (1/2in.) 9.5 mm (3/8in.) 8.0 mm (5/16in.) 3.2. Containers for SamplesSieves 203.2 mm (8 in.) in diameter for each separate size fractions of
11、aggregate during test. Used, out-of-tolerance sieves according to M 92, in acceptable condition, may be used as containers (Note 1). 3.2.1. Coarse Aggregate2.36-mm (No. 8) Size. 3.2.2. Fine Aggregate250-m (No. 60) Size. Note 1Sieves 203.2 mm (8 in.) in diameter may be substituted with containers tha
12、t permit free access of solution to the sample and drainage of the solution from the sample without loss of aggregate. Substitution with such containers may affect results. Referee testing, comparison testing, or testing of aggregate to be used in critical applications must be performed using sieves
13、 203.2 mm (8 in.) in diameter. 3.3. Apparatus for Immersing Samples in Solution (optional)When necessary, apparatus for holding the sieves containing the sample for immersing into the solution shall be constructed in such a manner to permit free access of the solution to the sample and drainage of t
14、he solution from the sample. 3.4. Temperature RegulationSuitable means for regulating the temperature of the samples during immersion in the sodium sulfate or magnesium sulfate solution shall be provided. 3.5. ThermometerA thermometer covering the recommended temperature range for solutions during t
15、est and readable to 0.1C (0.2F). 3.6. Temperature RecorderA unit capable of recording solution temperature a minimum of once every 10 min for the duration of the test with an accuracy of 0.3C (0.5F). 3.7. BalanceThe balance shall have sufficient capacity, be readable to 0.1 percent of the sample mas
16、s, or better, and conform to the requirements of M 231. 3.8. Drying OvenThe oven shall be capable of being heated continuously at 110 5C (230 9F) and the rate of evaporation, at this range of temperature, shall be at least 25 g/h for 4 h, during which period the doors of the oven shall be kept close
17、d. This rate shall be determined by the loss of water from 1-L Griffin low-form beakers, each initially containing 500 g of water at a temperature of 21 2C (70 3F), placed at each corner and the center of each shelf of the oven. The evaporation requirement is to apply to all test locations when the
18、oven is empty except for the beakers of water. 3.9. Specific Gravity MeasurementHydrometers conforming to the requirements of ASTM E100, or a suitable combination of graduated glassware and balance, capable of measuring the solution specific gravity within 0.001. 2015 by the American Association of
19、State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 104-3 AASHTO 4. SPECIAL SOLUTIONS REQUIRED 4.1. Prepare the solution for immersion of test samples from either sodium or magnesium sulfate in accordance with Section 4.1.1 or 4.1.2 (N
20、ote 2). The volume of the solution shall be at least five times the solid volume of all samples immersed at any one time. Note 2Some aggregates containing carbonates of calcium or magnesium are attacked chemically by fresh sulfate solution, resulting in erroneously high-measured losses. If this cond
21、ition is encountered or is suspected, repeat the test using a filtered solution that has been used previously to test the same type of carbonate rock, provided that the solution meets the requirements of Sections 4.1.1 and 4.1.2 for specific gravity. 4.1.1. Sodium Sulfate SolutionPrepare a saturated
22、 solution of sodium sulfate by dissolving a reagent grade of the salt in water (Note 5) at a temperature of 25C (77F) minimum. Add sufficient salt (Note 3) of the anhydrous (Na2SO4) form to ensure not only saturation but also the presence of excess crystals when the solution is ready for use in the
23、tests. Thoroughly stir the mixture during the addition of the salt and stir the solution at frequent intervals until used. To reduce evaporation and prevent contamination, keep the solution covered at all times when access is not needed. Allow the solution to cool to 20.3 to 21.9C (68.5 to 71.5F). A
24、gain stir, and allow the solution to remain at the designated temperature for at least 48 h before use. Prior to each use, break up the salt cake, if any, in the container, stir the solution thoroughly, and determine the specific gravity of the solution. When used, the solution shall have a specific
25、 gravity not less than 1.154 nor more than 1.171. Discard a discolored solution, or filter it and check for specific gravity. Note 3For the solution, 215 g of anhydrous salt per liter of water is sufficient for saturation at 22C (71.6F). However, because this salt is not completely stable and becaus
26、e it is desirable that an excess of crystals be present, the use of not less than 225 g of the anhydrous salt per liter of water is recommended. 4.1.2. Magnesium Sulfate SolutionPrepare a saturated solution of magnesium sulfate by dissolving a reagent grade of the salt in water (Note 5) at a minimum
27、 temperature of 25C (77F) (Note 4). Add sufficient salt (Note 4) of either the anhydrous (MgSO4) or the crystalline (MgSO47H2O) (Epsom salt) form, to ensure saturation and the presence of excess crystals when the solution is ready for use in the tests. Thoroughly stir the mixture during the addition
28、 of the salt and stir the solution at frequent intervals until used. To reduce evaporation and prevent contamination, keep the solution covered at all times when access is not needed. Allow the solution to cool to 20.3 to 21.9C (68.5 to 71.5F). Again stir, and allow the solution to remain at the des
29、ignated temperature for at least 48 h before use. Prior to each use, break up the salt cake, if any, in the container, stir the solution thoroughly, and determine the specific gravity of the solution. When used, the solution shall have a specific gravity not less than 1.297 nor more than 1.306. Disc
30、ard a discolored solution, or filter it and check for specific gravity. Note 4For the solution, 350 g of anhydrous salt or 1230 g of the heptahydrate per liter of water is sufficient for saturation at 23C (73.4F). However, because these salts are not completely stable, with the hydrous salt being th
31、e more stable of the two, and because it is desirable that an excess of crystals be present, it is recommended that the heptahydrate salt be used and in an amount of not less than 1400 g/L of water. When preparing the saturated solution of magnesium sulfate, the salt crystals will dissolve more read
32、ily if the crystals are added in small amounts and the water temperature is higher than 35C (95F) due to the chemical cooling effect during preparation. Note 5Distilled water shall be used in referee or comparison testing. 4.2. Barium Chloride SolutionA 0.2 molar solution of barium chloride (41.6 g
33、of BaCl2per liter of solution) to determine the presence of sodium or magnesium sulfate in the wash water. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 104-4 AASHTO 5. SAMPLES 5.1. Fine Aggreg
34、ateFine aggregate for the test shall be passed through a 9.5-mm (3/8-in.) sieve. The sample shall be of such size that it will yield not less than 100 g of each of the following sizes, expressed in terms of the following sieves: Passing Sieve Retained on Sieve 9.5 mm (3/8in.) 4.75 mm (No. 4) 4.75 mm
35、 (No. 4) 2.36 mm (No. 8) 2.36 mm (No. 8) 1.18 mm (No. 16) 1.18 mm (No. 16) 600 m (No. 30) 600 m (No. 30) 300 m (No. 50) 5.1.1. Should the sample contain less than 5 percent of any of the sizes specified in Section 5.1, that size shall not be tested. 5.2. Coarse AggregateCoarse aggregate for the test
36、 shall consist of material from which the sizes finer than the 4.75-mm (No. 4) sieve have been removed. The sample shall be of such a size that it will yield the amounts indicated in Table 1. Table 1Coarse Aggregate Sample Sieve Size Mass, g 63 mm to 37.5 mm (21/2in. to 11/2in.) 5000 300 Consisting
37、of: 50-mm to 37.5-mm (2-in. to 11/2-in.) material 2000 200 63-mm to 50-mm (21/2-in. to 2-in.) material 3000 300 37.5 mm to 19.0 mm (11/2in. to 3/4in.) 1500 50 Consisting of: 25.0-mm to 19.0-mm (1-in. to 3/4-in.) material 500 30 37.5-mm to 25.0-mm (11/2-in. to 1-in.) material 1000 50 19.0 mm to 9.5 m
38、m (3/4in. to 3/8in.) 1000 10 Consisting of: 12.5-mm to 9.5-mm (1/2-in. to 3/8-in.) material 330 5 19.0-mm to 12.5-mm (3/4-in. to 1/2-in.) material 670 10 9.5 mm to 4.75 mm (3/8in. to No. 4) 300 5 5.2.1. Should the sample contain less than 5 percent of any of the sizes specified in Section 5.2, that
39、size shall not be tested. When a combination of sizes is specified for the test portion and one of the sizes specified is less than 5 percent of the sample, reduce the test portion by the applicable mass specified in Section 5.2 for the size not available. 5.2.2. When testing large rock (broken ston
40、e, ledge rock, cobbles, and boulders for use as riprap, channel lining, etc.), obtain the test portion by crushing, splitting, or sawing the larger sample pieces. Test only those pieces in the 37.5- to 19.0-mm (11/2to 3/4-in.) and 63- to 37.5-mm (21/2- to 11/2-in.) size fractions when size reduction
41、 is by crushing or splitting. Test pieces in the 63- to 37.5-mm (21/2- to 11/2-in.) size fraction when size reduction is by sawing. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c T 104-5 AASHTO No
42、te 6When the rock contains bedding planes, crushing or splitting will usually cause the rock to break on those bedding planes. Sawing will usually leave the bedding planes intact, and thus more likely to split the particles due to growth of the salt crystals in the soundness test. 5.2.3. When testin
43、g large rock (to evaluate a potential source) that will be subsequently crushed to produce aggregate, obtain the test portion by crushing the larger sample pieces. Test pieces only in those sizes that will be included in the produced aggregate, but ignoring any material finer than the 4.75-mm (No. 4
44、) sieve or coarser than the 63-mm (21/2-in.) sieve. 5.2.4. When the finished aggregate material will contain particles coarser than 63 mm (21/2in.), such as aggregate for use in mass concrete, crush the material coarser than 63 mm (21/2in.) and distribute the material among that in the range of the
45、63-mm (21/2-in.) to 4.75-mm (No. 4) sieves. Discard material finer than the 4.75-mm (No. 4) sieve. 5.3. When an aggregate to be tested contains appreciable amounts of both fine and coarse material, having a grading more than 10 percent coarser than the 9.5-mm (3/8-in.) sieve and, also, more than 10
46、percent finer than the 4.75-mm (No. 4) sieve, test separate samples of the minus 4.75-mm (No. 4) fraction and the plus 4.75-mm (No. 4) fraction in accordance with the procedures for fine aggregate and coarse aggregate, respectively. Report the results separately for the fine aggregate fraction and t
47、he coarse aggregate fraction, giving the percentages of the coarse and fine size fractions in the initial grading. 6. PREPARATION OF TEST SAMPLE 6.1. Fine AggregateThoroughly wash the sample of fine aggregate on a 300-m (No. 50) sieve, dry to constant mass at 110 5C (230 9F), and separate into the d
48、ifferent sizes by sieving, as follows: Make a rough separation of the graded sample by means of a nest of the standard sieves specified in Section 5.1. From the fractions obtained in this manner, select samples of sufficient size to yield 100 g after sieving to refusal. (In general, a 110-g sample w
49、ill be sufficient.) Do not use fine aggregate sticking in the meshes of the sieves in preparing the samples. Weigh samples consisting of 100 0.1 g out of each of the separated fractions after final sieving, record the masses of the test samples, and place in separate containers for the test. 6.2. Coarse AggregateThoroughly wash and dry the sample of coarse aggregate to constant mass at 110 5C (230 9F) and separate it into the different sizes shown in Section 5.2 b
