Concrete_Mix_Specs.pdf

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Ratio

Location Location

I'C

(Min. 28~

Day Comp.

Strength)

(psi) (psi)

All interior.areas 3000

Concrete exposed to weather 4000

· sierra-Amy-Depot · Concrete Specifications

Maximum Nom'inal

Aggregate

(size No,) (Size No.)

Range Of Slump

(inches) (inches)

\'later Cement

(by 1·1eight) (by 1·1eight)

0.50

0,50

Air Entr, (percent) (percent)

Maximum· slump sho1m above may be increased 1 inch for methods of consolidation other than vibration. Slump may be increased to B inches \'I hen superplasticizero are used. , ·

Proportion concrete mixes for strength at 28 days.

2.3.1.1 Hix Proportions for Norrnal \'!eight Concrete

'l".rJ.al design batches, mixture proportioning studies 1 and testing requirernents for various classes and types of concrete specified are the responsibility of the Cohtractor. Base mixture proportions on compressive strength as determined by test specimens fabricated in accordance \·1ith ASTM c 192/C 192M and tested in accordance >iith ASTM c 39/C 39l4, Samples of all 1naterial$ used il'1 mixture proportioning studies must be representative of those proposed for use in the project and must be accompan.led by the manufacturer's or producer's test report indicating compliance with th_ese specific;;itions, Base trial mixtures havJ.ng proportions, consistencies, and suitable fol.~ the work on methodology described in ACI/MCP-1. J:n the trial mixtui·e, use at least thi;ee different water-cement ratios for each type of- mixture, \·1hich must produce a range of strength encompassing those required for each class and type of concrete required on the project. The maximum water-cement ratio required must be based on equivalent water-cement ratio calculations as determined by the conversion from the ~·1eight ratio of Nater to cement plus pozzolan, silica fume, and ground granulated blast-furnace slag by weight equivalency method. Design laboratory trial mixture for maximum permitted slump and air content. Each combination of material proposed for use must have separate trial mixture, except for accelerator or retarder use can be provided without separate trial mixture, Report the temperature of concrete ln each trial batch.· F'or each \·1ater-cement ratio, at least three test cylinders for each test age must be made and cured in acco)::'dance Hith ASTM c 192/C 192!4 and tested ln accordance. with l\STH c 39/C 39M for 7 and 28 days, Fxom these xesults, plot a· curve showing the relationship between water-cement ratio and strength for each set of trial mix studies, ln addition, plot a curve sbo1·1ing the relationship between. 7 and 28 day strengths.

2.3.:J.,2 Required Average Strength of Mix Design

The selected mixture must produce Gn average compressive strength exceeding the specified strength by the amount indicated in ACI/MCP-2, \'/hen a concrete production facility has a record of at least 15 consecutive tests, the standard deviation must be calculated and the required average compressive strength must be determined in accordance with ACI/MCP-2. tlhen a concrete production facility does not have a suitable record of tests to establish a standard deviation, the required average strength must follow ACl/MCP-2 requirements.

2.3.2 Ready-Mix Concrete

Provide concrete that meets the requirements of ASTH C 94/C 9,IM.

Ready-mixed concxete manufacturer rnust provide duplicate delivery tickets 1'1ith each load of concrete delivered. Provide dell.very tickets with the follol'ling information in addition to that required by ASTM C 94/C 941'1:

Type and brand cement

Cement content in.95~pound bags per cubic yard of concrete

Maximum size of aggregate

Amount and brand name of admixtures

Total water content expi:essed by \·later/cement ratio

2 , 3, 3 Concrete Curing Materials

2.3.3.1 llbsorptive Cover

Provide burlap cloth cover for curing concrete made from jute or kena£, ~·1eighing 10 ounces plus or minuspercent per square yard Nhen cloon and dry, conforming to AS'I'l>J c 171, Class 3; or cover may be cotton mats as ap.J?roved.

2.3.3.2 Moisture··Retaining Cover

Provide waterproof paper cover for curing concrete conforming to l\S'l1M C 171, regular or t1hite, or polyethylene sheeting conforming to ASTM C 171, or polyethylene-coated bul'lap consisting of a laminate of burlap and a 1·1hite opaque polyethylene film permanently bonded to the burlap; burlap must conform to l\STM C 171, Class 3, and polyethylene film must conform to ASTM c 171, When tested for 1·1ater retention J.n accordance with ASTM C 156, 1·1eight of water lost 72 hours after appliaation of moisture retaining covering material· must 11ot exceed 0. 039 gram per square centimeter Of the mortar specimen sur·face.

2.3.3.3 Mernbrane-b'orming Curing Compound

Provide liquid type compound conforming to l\STl1 c 309, Type 1, clear, Type lb ~1ith fugitive dye for interior work and Type .2, white, pigmented for extel:ior \'lork.

2 , 4 MATERIALS

2.4.1 Cement

l\STM c 150/C lSOM, Typ<> II, 101·1 alkali except as modified herein, Provide blended cement that consists of a mixture of AS'l'M c 150/C lSOM, Type II

J?age H

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cement and one of the follo1·1ing materials I AS'l'M C 618 pozzolan or fly ash, AS'l'M C 969. For portland cement manufactured in a kiln fueled by hazardous \·1ast81 maintain a record of source for each batch. _For exposed concrete, use one manufacturer for each type of cement and fly ash.

2.4.1.1 Fly Ash ai\d Pozzolan

ASTM c 618, '\'ype F. The maximum all01·1able loss on ignition must be 6 percent for Type F. Add 1·1ith cement. The use of class F Fly ash is mandatory to mitigate the potential of Alkali Silica Reactivity (l\SR) in concrete, Fly· ash shall be used at a rate between 15 and 35 percent of the total cementitious material by weight.Fly ash content must be a minimum of 15 percent by weight of cementitious material, provided the fly ash does

-not .reduce the amount of cement in the concrete mix belo\'1 the mini1nurn requirements of local building codes. Where the use of fly ash cannot meet the minimum. level, provide the maxill\um amount of fly ash permittable that meets the code r·equirements for cement content, Report the cliell\ical analysis of the fly ash in accordance 1·1ith i\STM C 311. Evaluate and classify fly aSh in accordance with ASTt·1 D 5759, High contents of supplementary cemantitious materials can have some detrimental effects on the _concrete_ properties, suoh a~ slo~·1ing excessively the strength gain rate, and delaying and increasing the difficulty of finishing, The recommended maximum content (by weight of the total ce1nentitious material) for these materials are:

1. For fly ash or natural pozzolan: 35 percent (25 percent in cold climates)

2.4.1.2 Portland Cement

Provide cement that con.forms to ASTM C 150/C 150M, Type .t, IA, lI, or .r:rA, Use one brand and type of cement for formed concrete having exposed-to-view finished surfaces.

2.4.2 Water

Minimize the amount of water in the mix. The amount of \·1at_er must not exceed 45 percent by 1·1eight of cementitious materials (cement plus pozzolans), and in general, improve workability by adjusting the grading .

rathei' than by adding water. Plater must be fresh, clean, and potable; free from injurious amounts of oils, acids, alkalis, salts, organic materials, or other substances deleterious to concrete. · ·

2.4.3 Aggregates

ASTM C 33/C 33M, except as modifiad herein, Furnish aggregates for e~posed concrete surfaces fi:om one source. Provi(j.e aggregatel'J that do not contain any substance ;1hich may be deleteriously ·reactive 1-lith the alkalies in the cement.

2.4.3,1 Aggregates/Combined Aggregate Gradation (Floor Slabs Only)

ASTM C 33/c 33M, uniformly graded and as follows: Nominal maximum . aggregate size of 1 inch.