1、Standard Specification for Ready-Mixed Concrete AASHTO Designation: M 157-13 American Association of State Highway and Transportation Officials 444 North Capitol Street N.W., Suite 249 Washington, D.C. 20001TS-3b M 157-1 AASHTO Standard Specification for Ready-Mixed Concrete AASHTO Designation: M 15
2、7-13 1. SCOPE 1.1. This specification covers ready-mixed concrete manufactured and delivered to a purchaser in a freshly mixed and unhardened state as hereinafter specified. Requirements for quality of concrete shall be either as hereinafter specified or as specified by the purchaser. In any case wh
3、ere the requirements of the purchaser differ from those in this specification, the purchasers specification shall govern. This specification does not cover the placement, consolidation, curing, or protection of the concrete after delivery to the purchaser. 1.2. The values stated in SI units are the
4、preferred standard. The values given in parentheses are for information only. 1.3. As used throughout this specification the manufacturer shall be the contractor, subcontractor, supplier, or producer who furnishes the ready-mixed concrete. The purchaser shall be the specifying agency and designated
5、representatives thereof. The engineer shall be interpreted to mean the designated representative of the specifying agency. 2. REFERENCED DOCUMENTS 2.1. AASHTO Standards: M 6, Fine Aggregate for Hydraulic Cement Concrete M 80, Coarse Aggregate for Hydraulic Cement Concrete M 85, Portland Cement M 154
6、M/M 154, Air-Entraining Admixtures for Concrete M 194M/M 194, Chemical Admixtures for Concrete M 195, Lightweight Aggregates for Structural Concrete M 240M/M 240, Blended Hydraulic Cement M 295, Coal Fly Ash and Raw or Calcined Natural Pozzolan for Use in Concrete M 302, Slag Cement for Use in Concr
7、ete and Mortars M 307, Silica Fume Used in Cementitious Mixtures R 60, Sampling Freshly Mixed Concrete T 22, Compressive Strength of Cylindrical Concrete Specimens T 23, Making and Curing Concrete Test Specimens in the Field T 105, Chemical Analysis of Hydraulic Cement T 106 M/T 106, Compressive Str
8、ength of Hydraulic Cement Mortar (Using 50-mm or 2-in. Cube Specimens) T 119M/T 119, Slump of Hydraulic Cement Concrete T 121M/T 121, Density (Unit Weight), Yield, and Air Content (Gravimetric) of Concrete 2016 by the American Association of State Highway and Transportation Officials.All rights rese
9、rved. Duplication is a violation of applicable law.TS-3b M 157-2 AASHTO T 131, Time of Setting of Hydraulic Cement by Vicat Needle T 152, Air Content of Freshly Mixed Concrete by the Pressure Method T 196M/T 196, Air Content of Freshly Mixed Concrete by the Volumetric Method T 290, Determining Water
10、-Soluble Sulfate Ion Content in Soil 2.2. ASTM Standards: C567/C567M, Standard Test Method for Determining Density of Structural Lightweight Concrete C1157/C1157M, Standard Performance Specification for Hydraulic Cement C1602/C1602M, Standard Specification for Mixing Water Used in the Production of
11、Hydraulic Cement Concrete C1603, Standard Test Method for Measurement of Solids in Water D512, Standard Test Methods for Chloride Ion in Water E329, Standard Specification for Agencies Engaged in Construction Inspection, Testing, or Special Inspection 2.3. American Concrete Institute Standards: 211.
12、1, Standard Practice for Selecting Proportions for Normal and Heavyweight and Mass Concrete 211.2, Standard Practice for Selecting Proportions for Structural Lightweight Concrete 305R, Hot Weather Concreting 306R, Cold Weather Concreting 2.4. U.S. Government Printing Office: “Test for Variability of
13、 Constituents in Concrete.” Designation 26, Bureau of Reclamation Concrete Manual, 7th Edition 3. TERMINOLOGY 3.1. For the purpose of this specification, ready-mixed concrete is hydraulic cement concrete manufactured for delivery to a purchaser in a plastic state and delivered as hereinafter specifi
14、ed. 3.2. The volume of freshly mixed and unhardened concrete in a given batch shall be determined from the total mass of the batch divided by the actual mass per cubic foot of the concrete. The total mass of the batch shall be calculated either as the sum of the masses of all materials, including wa
15、ter, entering the batch or as the net mass of the concrete in the batch as delivered. The mass per cubic foot shall be determined in accordance with T 121M/T 121 from the average of at least three measurements, each on a different sample using a 14-L (1/2-ft3) container. Each sample shall be taken f
16、rom the midpoint of each of three different truck loads by the procedure outlined in R 60. Note 1It should be understood that the volume of hardened concrete may be, or appear to be, less than expected due to waste and spillage, overexcavation, spreading forms, some loss of entrained air, or settlem
17、ent of wet mixtures. 4. MATERIALS 4.1. Storage and facilities satisfactory to the engineer shall be provided at the batching plant to permit proper sampling, testing, and control of materials prior to and during use. The following specifications shall apply: 2016 by the American Association of State
18、 Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b M 157-3 AASHTO 4.1.1. CementCement shall conform to M 85 for hydraulic cement, M 240M/M 240 for blended hydraulic cement, or ASTM C1157/C1157M for blended hydraulic cement. The engineer shal
19、l specify the type or types required. If no type is specified, the requirements of Type 1 as specified in M 85 shall apply. These different cements will produce concrete of different properties and should not be used interchangeably. Cement from different sources shall not be used interchangeably wi
20、thout approval of the engineer. 4.1.2. Other Cementitious MaterialsCementitious materials other than cement shall meet the requirement of the following specification unless specified otherwise by the purchaser: Fly AshM 295 Ground Granulated Blast Furnace SlagM 302 Silica FumeM 307 4.1.3. Aggregates
21、Coarse aggregates shall conform to M 80. Fine aggregates shall conform to M 6. Lightweight aggregates shall conform to M 195. 4.1.4. WaterWater shall be clear and free from injurious amounts of oil, acid, alkali, organic matter, or other deleterious substance. It shall not be salty or brackish. It s
22、hall be tested in accordance with ASTM C1602/C1602M. Water of questionable quality shall be subject to the acceptance criteria of Tables 1 and 2 or as designated by the purchaser. Table 1Acceptance Criteria for Questionable Water Supplies Limits Test Method Compressive strength, min percent control
23、at 7 days 90 T 106M/T 106aTime of set, deviation from control From 1:00 earlier to 1:30 later T 131aa Comparison shall be based on fixed proportions and the same volume of test water compared to control mix using water or distilled water. Table 2Chemical Limitations for Mixing Water Limits Test Meth
24、od Chemical requirements, maximum concentration Chloride as C11expressed as a percent by weight of cement when added to the C11in the other components of the concrete mixture shall not exceed the following levels: 1. Prestressed concrete 0.06% ASTM D512 2. Conventionally reinforced concrete in a moi
25、st environment and exposed to chloride 0.10% 3. Conventionally reinforced concrete in a moist environment but not exposed to chloride 0.15% 4. Above ground building construction where the concrete will stay dry No limit for corrosion Sulfate as SO4ppma3000 T 290 Alkalis as (Na2O + 0.658 K2O), ppm 60
26、0 T 105 Totals, solids, ppm 50000 ASTM C1603 aWash water reused as mixing water in concrete may exceed listed concentrations of sulfate if it can be shown that the concentration calculated in the total mixing water, including mixing water on the aggregate and other sources, does not exceed the state
27、d limits. 4.1.4.1. Wash water from mixer washout may be used only with the purchasers approval. When wash water is permitted, the producer will provide satisfactory proof or data of nondetrimental effects if potentially reactive aggregates are to be used. Use of wash water will be discontinued if un
28、desirable reaction with admixtures or aggregates occurs. 4.1.5. AdmixturesWhen air entrained concrete is specified and an admixture is used to secure the desired air content, the admixture shall meet the requirements of M 154M/M 154. Where it is 2016 by the American Association of State Highway and
29、Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b M 157-4 AASHTO desired to use admixtures for purposes other than entrainment of air, the admixture shall conform to the requirements of M 194M/M 194. 5. QUALITY OF CONCRETE 5.1. The mix design may be spe
30、cified by the engineer or submitted to the engineer by the contractor for approval, or a performance based specification can be used. When specified by the engineer, it shall include the following: 5.1.1. Each cementitious materials content in kg/m3(lb/yd3) of concrete, or equivalent units; 5.1.2. D
31、esignated size, or sizes, and amount by mass of aggregates; 5.1.3. Maximum water to cementitious materials ratio where water includes surface moisture and water in the admixture but excludes the absorption water of the aggregates; 5.1.4. Consistency desired at the point of delivery (see Section 6.1.
32、1 for acceptable tolerances); 5.1.5. The range of air content of the concrete when air-entraining cement or an air-entraining admixture is specified. The air content shall be determined on samples taken at the point of placement; and 5.1.6. The type and amounts of admixture other than air-entraining
33、 agents when such admixtures are specified. 5.2. When submitted by the contractor for approval by the engineer, the mix design shall be within the limitation specified for: 5.2.1. Minimum cement content, 5.2.2. Maximum amount of water, 5.2.3. Range for air content, 5.2.4. Range for consistency, and
34、5.2.5. Maximum aggregate size. 5.3. When a performance-based specification is used, the engineer shall specify the desired fresh and hardened concrete properties and permit the contractor to design the mixture. The specifying agency may specify the design method to be used by the contractor. The con
35、tractor will demonstrate through trial mixtures that the mix designs will provide the specified fresh and hardened properties. Selection of slump for placement shall be the responsibility of the contractor. The contractor shall make trial placements to demonstrate that concrete can be placed without
36、 any segregation and without any difficulty in consolidating and finishing. 6. TOLERANCES IN SLUMP 6.1. Unless other tolerances are included in the project specifications, the following shall apply: 6.1.1. When the project specifications for slump are written as a “maximum” or “not to exceed” requir
37、ement, see Table 3. This option is to be used only if one addition of water is permitted on the 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b M 157-5 AASHTO job provided such addition does not in
38、crease the water-cement ratio above the maximum permitted by the specifications. Table 3Specified Slump If 76 mm (3 in.) or Less If More Than 76 mm (3 in.) Plus tolerance 0 0 Minus tolerance 38 mm (11/2in.) 63 mm (21/2in.) 6.1.2. When the project specifications for slump are not written as a “maximu
39、m” or “not to exceed” requirement, see Table 4. Table 4Tolerances for Nominal Slumps For Specified Slump of Tolerance 51 mm (2 in.) and less 13 mm (1/2in.) More than 51 to 102 mm (2 through 4 in.) 25 mm (1 in.) More than 102 mm (4 in.) 38 mm (11/2in.) 7. AIR-ENTRAINED CONCRETE 7.1. The purchaser sha
40、ll specify or approve the design total air content of the concrete. 7.2. The air content of air-entrained concrete, when sampled from the transportation unit at the point of placement, shall be within the purchaser specified tolerances. Where it is not practical to test at this point, comparison of
41、values measured at the point of placement and the nearest practical location shall be established. 8. MEASURING MATERIALS 8.1. Except as otherwise specifically permitted, cementitious material shall be measured by mass. When supplementary cementitious materials are specified in the mix design, they
42、may be weighed cumulatively with cement. Cement and other cementitious material shall be weighed on a scale and in a weigh hopper, which is separate and distinct from those used for other materials. Cement shall be weighed before other cementitious material. When the quantity of cementitious materia
43、l exceeds 30 percent of the full capacity of the scale, the quantity of cement, and the cumulative quantity of cement plus supplementary cementitious material, shall be within 1 percent of the required mass. For small batches to a minimum of 1 m3(1 yd3), the quantity of cement, and the quantity of c
44、ement plus supplementary cementitious material used, shall not be less than the required amount nor more than 4 percent in excess. Under special circumstances, approved by the purchaser, cement may be measured in bags of standard mass (Note 2). No fraction of a bag of cement shall be used unless wei
45、ghed. Note 2In the United States, the standard mass of a bag of portland cement is 42.6 kg (94 lb) 3 percent. 8.2. Aggregate shall be measured by mass. Batch mass shall be based on dry materials and shall be required mass of dry materials plus the total mass of moisture (both absorbed and surface) c
46、ontained in the aggregate. The quantity of aggregate used in any batch of concrete as indicated by the scale shall be within 2 percent of the required mass when weighed in individual weigh batchers. In a cumulative aggregate weigh batcher, the cumulative mass after each successive weighing shall be
47、within 1 percent of the required cumulative amount when the scale is used in 2016 by the American Association of State Highway and Transportation Officials.All rights reserved. Duplication is a violation of applicable law.TS-3b M 157-6 AASHTO excess of 30 percent of its capacity. For cumulative mass
48、 for less than 30 percent of scale capacity, the tolerance shall be 0.3 percent of scale capacity or 3 percent of the required cumulative mass, whichever is less. 8.3. Mixing water shall consist of water added to the batch, ice added to the batch, water occurring as surface moisture on the aggregate
49、s, and water introduced in the form of admixtures. The added water shall be measured by mass or volume to an accuracy of 1 percent of the required total mixing water. Added ice shall be measured by weight. In the case of truck mixers, any wash water retained in the drum for use in the next batch of concrete shall be accurately measured; if this proves impractical or impossible, the wash water shall be discharged prior to loading the next batch of concrete. Total water (includ
