AASHTO M 195-2011 Standard Specification for Lightweight Aggregates for Structural Concrete.pdf

1、Standard Specification for Lightweight Aggregates for Structural Concrete AASHTO Designation: M 195-11 (2015) ASTM Designation: C330-09 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001 TS-1c M 195-1 AASHTO Standard Spe

2、cification for Lightweight Aggregates for Structural Concrete AASHTO Designation: M 195-11 (2015) ASTM Designation: C330-09 1. SCOPE 1.1. This specification covers lightweight aggregates intended for use in structural concrete in which the prime considerations are reducing the density while maintain

3、ing compressive strength of the concrete. Procedures covered in this specification are not intended for job control of concrete. 1.2. The values stated in SI units are to be regarded as the standard. The values shown in parentheses are for information purposes only. 1.3. The text of this standard re

4、ferences notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the standard. Note 1This specification is regarded as adequate to ensure satisfactory lightweight aggregates for most concrete.

5、 It is recognized that it may be either more or less restrictive than needed for some conditions and for special purposes, such as fire resistance, fill, and concrete constructions, the use of which is based on load tests rather than conventional design procedures. 2. REFERENCED DOCUMENTS 2.1. AASHT

6、O Standards: M 6, Fine Aggregate for Hydraulic Cement Concrete R 39, Making and Curing Concrete Test Specimens in the Laboratory T 2, Sampling of Aggregates T 19M/T 19, Bulk Density (“Unit Weight”) and Voids in Aggregate T 21, Organic Impurities in Fine Aggregates for Concrete T 22, Compressive Stre

7、ngth of Cylindrical Concrete Specimens T 23, Making and Curing Concrete Test Specimens in the Field T 27, Sieve Analysis of Fine and Coarse Aggregates T 105, Chemical Analysis of Hydraulic Cement T 107M/T 107, Autoclave Expansion of Hydraulic Cement T 112, Clay Lumps and Friable Particles in Aggrega

8、te T 160, Length Change of Hardened Hydraulic Cement Mortar and Concrete T 161, Resistance of Concrete to Rapid Freezing and Thawing 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c M 195-2 AASHTO T

9、 198, Splitting Tensile Strength of Cylindrical Concrete Specimens T 248, Reducing Samples of Aggregate to Testing Size 2.2. ASTM Standards: C567/C567M, Standard Test Method for Determining Density of Structural Lightweight Concrete C641, Standard Test Method for Iron Staining Materials in Lightweig

10、ht Concrete Aggregates 2.3. ACI Standard: ACI 211.2, Standard Practice for Selecting Proportions for Structural Lightweight Concrete 3. GENERAL CHARACTERISTICS 3.1. Two general types of lightweight aggregates are covered by this specification, as follows: 3.1.1. Aggregates prepared by expanding, pel

11、letizing or sintering products such as blast-furnace slag, clay, diatomite, fly ash, shale, or slate; and 3.1.2. Aggregates prepared by processing natural materials, such as pumice, scoria, or tuff. 3.2. The aggregates shall be composed predominately of lightweight cellular and granular inorganic ma

12、terial. 4. CHEMICAL COMPOSITION 4.1. Lightweight aggregates shall not contain excessive amounts of deleterious substances, as determined by the following limits: 4.1.1. Organic ImpuritiesT 21. Lightweight aggregates that, upon being subjected to test for organic impurities, produce a color darker th

13、an the standard shall be rejected, unless it is demonstrated that the discoloration is due to small quantities of materials not harmful to the concrete. 4.1.2. StainingASTM C641. An aggregate producing a heavy stain index 60 or higher shall be rejected when the deposited stain is found upon chemical

14、 analysis to contain an iron content, expressed as Fe2O3, equal to or greater than 1.5 mg/200 g of sample. 4.1.3. Loss on IgnitionT 105. The loss on ignition of lightweight aggregates shall not exceed 5 percent. Note 2Some aggregates may contain carbonates or water of hydration that contribute to lo

15、ss on ignition, but may not affect the quality of the product. Therefore, when evaluating an aggregate, consideration should be given to the material characteristics that cause the ignition loss. 5. PHYSICAL PROPERTIES 5.1. Lightweight aggregate under test shall meet the following requirements: 5.1.

16、1. Clay Lumps and Friable ParticlesThe total amount of clay lumps and friable particles shall not exceed 2 percent by dry mass. 5.1.2. GradingThe grading shall conform to the requirements shown in Table 1. 2015 by the American Association of State Highway and Transportation Officials.All rights rese

17、rved. Duplication is a violation of applicable law.TS-1c M 195-3 AASHTO Table 1Grading Requirements for Lightweight Aggregates for Structural Concrete Nominal Size Designation Percentages (Mass) Passing Sieves Having Square Openings 25.0 mm (1 in.) 19.0 mm (3/4in.) 12.5 mm (1/2in.) 9.5 mm (3/8in.) 4

18、.75 mm (No. 4) 2.36 mm (No. 8) 1.18 mm (No.16) 300 m (No. 50) 150 m (No. 100) 75 m (No. 200) Fine aggregate: 4.75 mm to 0 100 85100 4080 1035 525 Coarse aggregate: 25.0 to 4.75 mm 95100 2560 010 010 19.0 to 4.75 mm 100 90100 1050 015 010 12.5 to 4.75 mm 100 90100 4080 020 010 010 9.5 to 2.36 mm 100

19、80100 540 020 010 010 Combined fine and coarse aggregate: 12.5 mm to 0 100 95100 5080 520 215 010 9.5 mm to 0 100 90100 6590 3565 1025 515 010 Note: Water demand of an approved mix may be influenced by a higher percentage of fines, thereby changing the plastic properties. Note 3The surfaces of pyro-

20、processed lightweight aggregate particles finer than 75-m (No. 200) sieves are not deleterious and may be moderately pozzolanic. 5.1.3. Uniformity of GradingTo ensure reasonable uniformity in the grading of successive shipments of lightweight aggregate, fineness modulus shall be determined on sample

21、s taken from shipments at intervals stipulated by the purchaser. If the fineness modulus of the aggregate in any shipment differs by more than 7 percent from that of the sample submitted for acceptance tests, the aggregate in the shipment shall be rejected, unless the supplier demonstrates that it w

22、ill produce concrete of the required characteristics. 5.1.4. Bulk Density (Dry Loose)The dry loose bulk density of the lightweight aggregates shall conform to the requirements shown in Table 2. Table 2Maximum Dry Loose Bulk Density Requirements of Lightweight Aggregates for Structural Concrete Size

23、Designation Maximum Dry Loose Bulk Density, kg/m3(lb/ft3) Fine aggregate 1120 (70) Coarse aggregate 880 (55) Combined fine and coarse aggregate 1040 (65) 5.1.5. Uniformity of Bulk Density (Dry Loose)The dry loose bulk density of lightweight aggregate shipments, sampled and tested, shall not differ b

24、y more than 10 percent from that of the sample submitted for acceptance tests, but the dry loose bulk density shall not exceed the limits in Table 2. 5.1.6. Density FactorWhen specified, the density factor shall be determined in accordance with Section 8.9. 5.2. Concrete specimens containing lightwe

25、ight aggregate under test shall meet the following requirements: 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c M 195-4 AASHTO 5.2.1. Compressive StrengthT 22, DensityASTM C567/C567M, and Splittin

26、g Tensile StrengthT 198. Compressive strength and density shall be an average of three specimens and the splitting tensile strength shall be the average of eight specimens. It shall be possible to produce structural concrete using the lightweight aggregates under test, so that from the same batch of

27、 concrete one or more of the compressive strength requirements and splitting tensile strength requirements in Table 3 will be satisfied without exceeding the corresponding maximum bulk density values. Table 3Compressive and Tensile Strength Requirements Calculated Equilibrium Density, max kg/m3(lb/f

28、t3) Average 28-day Splitting Tensile Strength, min MPa (psi) Average 28-day Compressive Strength, min MPa (psi) All Lightweight Aggregate 1760 (110) 2.2 (320) 28 (4000) 1680 (105) 2.1 (300) 21 (3000) 1600 (100) 2.0 (290) 17 (2500) Sand/Lightweight Aggregate 1840 (115) 2.3 (330) 28 (4000) 1760 (110)

29、2.1 (310) 21 (3000) 1680 (105) 2.1 (300) 17 (2500) Note 4Intermediate values for strength and corresponding density values shall be established by interpolation. Materials that do not meet the minimum average splitting tensile strength requirement may be used provided the design is modified to compe

30、nsate for the lower value. 5.2.2. Natural AggregatesNatural aggregates, when used to replace part or all of the lightweight-aggregate fines, shall comply with the applicable requirements of M 6. The test report shall record the proportion of all ingredients and the characteristics of the natural agg

31、regates to ensure compliance with these minimum requirements. 5.2.3. Drying ShrinkageThe drying shrinkage of concrete specimens prepared, cured, and tested in accordance with Section 8.4 shall not exceed 0.07 percent. 5.2.4. PopoutsConcrete specimens prepared as described in the method for preparati

32、on of sample for shrinkage of concrete and tested in accordance with T 107M/T 107 shall show no surface popouts. 5.2.5. Resistance to Freezing and ThawingWhen required, the aggregate supplier shall demonstrate by test or proven field performance that the lightweight aggregate when used in concrete,

33、had the necessary resistance to freezing and thawing to perform satisfactorily in its intended use. 6. SAMPLING 6.1. Sample lightweight aggregates in accordance with T 2. 6.2. Reduce sample to test size in accordance with T 248. 7. NUMBER OF TESTS 7.1. Tests on AggregateOne representative sample is

34、required for each test for organic impurities, staining, loss on ignition, grading, bulk density, and clay lumps. 2015 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c M 195-5 AASHTO 7.2. Tests on Concre

35、teAt least three specimens are required for each of the following tests of concrete: compressive strength, shrinkage, density, resistance to freezing and thawing, and presence of popout materials. At least eight concrete specimens are required for splitting tensile strength tests. 8. TEST METHODS 8.

36、1. Compressive StrengthT 22. Make test specimens in accordance with R 39. Unless otherwise specified, cure specimens in accordance with R 39 until the time of test. When specified, an alternative curing method is allowed. The alternative method shall be in accordance with R 39 for the first 7 days,

37、after which the specimens shall be removed from the moist curing and stored at 23 2C (73.5 3.5F) with a relative humidity of 50 5 percent until the time of test. 8.2. Splitting Tensile StrengthMake 152-by-305 mm (6-by-12 in.) cylindrical test specimens in accordance with R 39, cure, and test in acco

38、rdance with T 198. 8.3. Density of ConcreteASTM C567/C567M. Follow the procedures in ASTM C567/C567M. 8.4. Shrinkage of ConcreteT 160. Follow the procedures of T 160 with the following exceptions: 8.4.1. Prepare the concrete mixture using 335 kilograms of cement per cubic meter (564 pounds of cement

39、 per cubic yard), admixture (if any), and with an air content of 6 1 percent. Adjust the water content so as to produce a slump of 50 to 100 mm (2 to 4 in.). Thoroughly consolidate the concrete in steel molds not smaller than 50 by 50 mm (2 by 2 in.) nor larger than 100 by 100 mm (4 by 4 in.) in cro

40、ss section, and long enough to provide a 250-mm (10-in.) gauge length. The surface of the concrete shall be steel troweled. 8.4.2. CuringTo prevent evaporation of water from the unhardened concrete, cover the specimen with a nonabsorptive, nonreactive plate or sheet of tough, durable, impervious pla

41、stic or wet burlap. When wet burlap is used for covering, the burlap must be kept wet until the specimens are removed from the molds. (See Note 5.) Remove specimens from the molds not less than 20 nor more than 48 h after casting and store in a moist room maintained at 23 2C (73.5 3.5F) with a relat

42、ive humidity of not less than 95 percent. At the age of 7 days, remove the specimens from the moist room, measure for length, and store in a curing cabinet maintained at 37.8 1.1C (100 2F) with a relative humidity of 32 2 percent. Note 5Placing a sheet of plastic over the burlap will facilitate keep

43、ing it wet. Note 6The air immediately above a saturated solution of magnesium chloride (MgCl2) at 37.8C (100F) is approximately 32 percent relative humidity. 8.4.3. ReportAfter storage in the cabinet for 28 days, remove each specimen and within 15 s, determine its change in length to the nearest 0.0

44、1 percent of the effective gauge length. Report the change in length as the drying shrinkage of the specimen; report the average drying shrinkage of the specimens as the drying shrinkage of the concrete. 8.5. Test for Popout MaterialsPrepare concrete specimens for the test for popout materials as de

45、scribed in method for preparation of samples for shrinkage of concrete. Cure and autoclave the specimens in accordance with T 107M/T 107. Visually inspect the autoclaved specimens for the number of popouts that have developed on the surface. Report the average number of popouts per specimen. 2015 by

46、 the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-1c M 195-6 AASHTO 8.6. Test for Freezing and ThawingMake freezing and thawing tests of concrete, when required, in accordance with T 161, with the following mo

47、dification to the section on Test Specimens and on Procedure. Unless otherwise specified, remove the lightweight aggregate concrete specimens from moist curing at an age of 14 days and allow to air dry for another 14 days exposed to a relative humidity of 50 5 percent and a temperature of 23 2C (73.

48、5 3.5F). Then submerge the specimens in water for 24 h, prior to the freezing and thawing test. Table 4Mass of Sieve Test Sample for Fine Lightweight Aggregates Nominal Bulk Density (Loose) of Aggregate Mass of Test Sample, g kg/m3lb/ft380240 515 50 240400 1525 100 400560 2535 150 560720 3545 200 72

49、0880 4555 250 8801040 5565 300 10401120 6570 350 8.7. Bulk Density (Loose)T 19M/T 19. The aggregate shall be tested in an oven-dry condition utilizing the shoveling procedure. 8.8. Clay Lumps and Friable Particles in AggregatesShall be in accordance with T 112. 8.9. Density FactorDetermine the Density (“Specific Gravity”) Factor in accordance with ACI 211.