Intro to Concrete Mix Design

Intro to Concrete Mix DesignNH Structural Engineers Association

American Society of Civil Engineers

September 22, 2009

Traditional Concrete Making

Materials

• Portland cement

• Coarse aggregate

• Fine aggregate

• Water

Modern Concrete Making

Materials

• Portland cement


• Fine aggregate

• Water

• Chemical admixtures

• SCM’s

• Other admixtures/additives

• Air entrainers, fibers,

pigments

Objective In Designing Concrete

Mixtures

To determine the most economical & practical combination

of readily available materials to produce a concrete that will

satisfy the performance requirements under particular

conditions of use

Designing Concrete MixturesFactors to be considered

• Workability

• Placement conditions

• Strength

• Durability

• Appearance

• Economy

Designing Concrete MixturesFactors to be considered

• Strength – important to the

design engineer

• Durability – important to the

owner

• Workability – important to

the contractor

• Economy – important to the

owner

Proportioning concrete is the art of optimizing

the mixture to meet these requirement

ProportioningAbsolute Volume Method

• ACI 211.1: Normal, Heavyweight & Mass

Concrete

• ACI 211.2: Lightweight Concrete

• ACI 211.3: No-Slump Concrete

• ACI 211.4R: High Strength w/Fly Ash

• ACI 211.5: Submittal of Concrete

Proportions

Absolute Volume

• Concrete mixture

proportions are usually

expressed on the basis of

the mass of ingredients

per unit volume1yd

1yd

1yd

weight

volume

Concrete is batched

by weight

Concrete is sold

by volume

Absolute Volume

Material Volume Density Mass

(yd3) (lb/ yd3) (lb)

Air 0.060

Water 0.150 1685 253

Cement 0.111 5319 590

Sand 0.245 4455 1095

Stone 0.434 4455 1937

Total 1.000 3875

Selecting Mix Characteristics

• Strength requirements

• Determine W/CM


requirements

• Air content

• Workability

• Water content

• Cement content

• Cement type

• Admixture effects

• Fine aggregate

requirements

• Moisture corrections

• Trial mixes

Determine Strength RequirementSpecified strength, f’c, is determine from:

• Structural design considerations

• Durability considerations (ACI 318)

• Although the durability of concrete is not directly

related to strength-strength is used as an indirect

means of assuring adequate durability

• Proper concrete construction

– Proper mix design

– Proper placement & consolidation

– Proper curing

• Moisture/Temperature/Time

Requirements of ACI 318

Building CodesMax W/CM Min. f’c

psi

Concrete intended to have low

permeability when exposed to water

0.50 4000

Concrete exposed to freezing &

thawing in a moist condition or to de-

icing chemicals

0.45 4500

Corrosion protection of reinforcement

in concrete exposed to chlorides

0.40 5000

Requirements For Sulfate

Exposure

Sulfate Exposure Max. W/CM Min. f’c

psi

Negligible ---- ----

Moderate 0.50 4000

Severe 0.45 4500

Very Severe 0.40* 5000

* - ACI 318 allows a W/CM of 0.45 & f’c= 4500 for this exposure

Determining Strength Requirement

• Probability that the average of three

consecutive tests(ave. of two cylinders) is

smaller than f’c is 1%

– f’cr = f’c + 1.34S

• Probability of an individual test being more

than 500 psi below f’c is 1%

– f’cr = f’c + 2.33S - 500

Select the higher value

Standard DeviationIf only 15 to 29 consecutive test are available-

multiply the standard deviation by the following modification

factors:

Number of Tests Modification Factor

Less than 15 ----

15 1.16

20 1.08

25 1.03

30 or more 1.00

Determine Required Water-

Cement RatioThe W/CM is determine from:

• Durability

considerations

• Required strength

Requirements of ACI 318

Building CodesMax W/CM Min. f’c

psi


permeability when exposed to water

0.50 4000


thawing in a moist condition or to de-

icing chemicals

0.45 4500

Corrosion protection of reinforcement

in concrete exposed to chlorides

0.40 5000

Requirements For Sulfate

Exposure

Sulfate Exposure Max. W/CM Min. f’c

psi

Negligible ---- ----

Moderate 0.50 4000

Severe 0.45 4500

Very Severe 0.40* 5000

* - ACI 318 allows a W/CM of 0.45 & f’c= 4500 for this exposure

W/CM Required for Strength• Use data from field or trial mixes using same material

• Where no data is available use table from ACI 211

Required

Strength

f‖cr

W/CM

Non-air

W/CM

Air

7000 0.33 ----

6000 0.41 0.32

5000 0.48 0.40

4000 0.57 0.48

3000 0.68 0.59

2000 0.82 0.74

Coarse Aggregate Requirement

• Grading

• Nature of particles

– Shape

– Porosity

– Surface texture

Max Aggregate Size

• Cover between steel & form,

C: Dmax < 3/4C

• Spacing between bars, S: Dmax

< 3/4S

• Distance between forms, B:

Dmax < B/5

• Depth of slab, D: Dmax < D/3

Max Aggregate SizeFor pumped concrete

• Dmax < 1/3 diameter of

hose or 1-1/2 inch,

whichever is smaller

Fineness Modulus of Sand

• The FM is calculated from

particle size distribution of

the sand

• Values should range between

2.3 to 3.1

• Coarse sand has a higher FM

than fine sand

• FM influences the bulk

volume of coarse aggregate

Bulk Volume of Coarse Aggregate

Max Size

(in.)

-------- 2.40 2.60 2.80 3.00

3/8 0.50 0.48 0.46 0.44

½ 0.59 0.57 0.55 0.53

¾ 0.66 0.64 0.62 0.60

1 0.71 0.69 0.67 0.65

1½ 0.75 0.73 0.71 0.69

2 0.78 0.76 0.74 0.72

3 0.82 0.80 0.78 0.76

6 0.87 0.85 0.83 0.81

Bulk volume of dry-rodded coarse aggregate

per unit volume of concrete for different FM

of fine aggregate


• Values in table are based on aggregate in a dry-rodded condition(ASTM C-29)

• They are suitable for producing concrete with a moderate workability suitable for general concrete construction

• Less workable concrete(slip-form paving)-the bulk volume can be increased by10%

• For more workable concrete(pumping)-the bulk volume can be decreased by 10%

Air ContentThe amount needed depends on:

• Max aggregate size

– Less paste as size

increases

• Level of exposure

Effect of air content on water demand:

Rule of thumb-

Decrease water by 5lb/yd for each 1% air

Workability Requirements

• Concrete must always be

made with a workability,

consistency and plasticity

suitable for job

placement



Concrete Construction Slump

Max

Slump

Min

Reinforced walls & footings 3 1

Plain footings, caissons, and

Substructure walls

3 1

Beams & reinforced walls 4 1

Columns 4 1

Pavements and slabs 3 1

Mass concrete 3 1

Water ContentWater demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials content

• Temp

• Admixtures

– Water-reducing

– Mid & High range



• Aggregate size

• Aggregate shape

• Air content


• Temp

• Admixtures

– Water-reducing


•Water demand

•Cement content

•Paste content

•Cost

•Shrinkage

•Heat evolution



• Aggregate size

• Aggregate shape

• Air content


• Temp

• Admixtures

– Water-reducing




• Aggregate size

• Aggregate shape

• Air content


• Temp

• Admixtures

– Water-reducing




• Aggregate size

• Aggregate shape

• Air content


• Temp

• Admixtures

– Water-reducing




• Aggregate size

• Aggregate shape

• Air content


• Temp

• Admixtures

– Water-reducing




• Aggregate size

• Aggregate shape

• Air content


• Temp

• Admixtures

– Water-reducing


Water ContentWater requirement for Non-Air-Entrained

concrete:

Slump

Inches 3/8 1/2 3/4 1 1-1/2 2 3

1 to 2 350 335 315 300 275 260 220

3 to 4 385 365 340 325 300 285 245

6 to 7 410 385 360 340 315 300 270

Nominal Max Aggregate Size(inches)

Same chart for Air-Entrained concrete

Water Content

• Values shown are for

angular crushed stone.

These estimates can be

reduced approximately:

• 20 lbs for sub-angular

• 35 lbs for gravel with

some crushed particles

• 45 lbs for rounded gravel

Water ContentEffects of admixtures

• Virtually all structural concrete is placed with a water-reducing admixture

• Typical effects

– Normal:5-10% reduction

– Mid:5-18% reduction

– High:12-30% reduction

• Adjusting slump

– Increase/decrease by add/delete 10lb/yd of water

Cement ContentCement Material Content= Water Content

W/CM• Minimum cement content may be

specified for the purpose of:

– Durability

– Finishability

– Wear resistance

– Appearance

• Excessively high cementitious contents should be avoided for:

– Economy

– Avoid adverse effects

• Workability

• Shrinkage

• Heat of hydration

Cement ContentGeneral recommendations(PCA):

• Cementitious material > 564lb/yd³ for severe

freeze-thaw, deicer, and sulfate exposures

• Cementitious material > 650lb/yd³ for

concrete to be placed under water(also

W/CM < 0.45)

Cement ContentGeneral recommendations(PCA):

• For workability, finishability, and durability

in flatwork cementitious material to follow

recommendations in table:

Max Aggregate

(inches)

Min Cement

(lbs)

1-1/2 470

1 520

3/4 540

1/2 590

3/8 610

Cement Content

• Quality depends mainly on w/cm & the water contentshould be held to a minimum to reduce cement content by using:

– Largest practical max aggregate size

– Optimum aggregate gradation

– Optimum ratio of fine to coarse aggregate

– Water-reducing & air-entraining admixtures

– SCM’s(fly ash & slag)

Cement Content







Cement Content







Aggregate Retained Chart

8 -18

Cement Content







% of total that is retained on 3/8 in. sieve and largerCoarseness Factor 100

% of total that is retained on the #8 sieve and larger

11.7% 25.0% 12.5% 10011.7% 25.0% 12.5% 7.1% 5.0%

49.2% 100

61.3%

80.3

Coarseness Factor

Cement Content







Workability Factor3

3

3

3

3

3

565 lb/ydWorkability Factor % of total that passes the #8 sieve 2.5

94 lb/yd

623 565 lb/yd 38.6% 2.5

94 lb/yd

58 lb/yd 38.6% 2.5

94 lb/yd

40.1

cm

Cement Content







Cement Content







Admixture EffectsThe use of admixtures may affect the water & air

content as follows:

• Water reducers typically decrease water by 5 to

10% and may increase air contents by up to 1%

• HRWR decrease water between 12 to 30% and

may increase air contents by up to 1%

• Calcium chloride-based admixtures reduce water

by about 3% and increase air by up to 0.5%

• Retarders may increase air contents

• Fibers will increase water demand

Cement Content







Cement Type

– Type I – Normal

– Type II – Some sulfate resistance

low heat

– Type III – High early strength

– Type IV – Low heat of hydration

– Type V – High sulfate resistance

05 US production- 93 million tons from 113 plants in 37 states

Cement Type

Sulfate

Exposure

Cement

Type

Negligible No special type required

ModerateII,MS,IP(MS),IS(MS),P(MS),

I(PM)(MS),I(SM)(MS)

Severe V(HS)

Very Severe V(HS)

Cement TypeThe use of fly ash, slag or blended cements should

be considered in conjunction with Portland cement

wherever possible for the purpose of:

• Improving economy

• Improving workability

• Reducing heat of hydration

• Increase long-term

strength

• Improve durability

– Reduced permeability

• Freeze/thaw & corrosion

– ASR

– Sulfate resistance

Fly Ash, Slag, Silica Fume,

and Natural Pozzolans

Also known as —

Supplementary Cementing Materials (SCMs)

— a material that, when used in conjunction

with Portland cement, contributes to the

properties of the hardened concrete through

hydraulic or pozzolanic activity, or both.

Supplementary Cementitious

Materials (SCMs)

From left to right:

• Fly ash (Class C)

• Metakaolin (calcined clay)

• Silica fume

• Fly ash (Class F)

• Slag

• Calcined shale

Why Use SCM’s

• Lower heat of hydration

• Improved workability(silica fume???)

• ASR resistance

• Higher strength

• Lower permeability

• Better concrete at lower cost

Alkali-Silica Reaction

Why Do SCM’s Work in

Concrete• Have the same basic

minerals as in portland cement

– CaO

– SiO2

– Al2O3

• Different proportions than Portland cement

• Possibly different mineral phases

Secondary Cementitious

Materials

• Cementitious Materials

– Fly Ash

– Ground Slag

– Silica Fume

• Chemically react with cement and water to make more―glue‖

• Lower early strength,higher later strength

• Better quality concrete


MaterialsCautions

• Less controlled than cement

• Composition depends on

origin

• Can change the properties of

the concrete(setting, water

demand,admixture behavior)

Cement Hydration Process

Cement + Water CSH + CaOH

Cement Hydration Process

Cement + Water CSH + CaOH

SCMs + CaOH more CSH


Materials• Fly ash

– By-product of coal burning industry

– Finer than cement – round shape

• Easier to pump

• Reduces the amount of mixing water

• Fly ash bleeds less, improves finishing

• Sets slower – lower heat of hydration

• Less expensive than Portland cement


Materials

• Fly ash

– Does not lose slump as rapidly

– May be harder to entrain air

– Chemical composition varies

– Flowable fill market

Specifications and Classes of Fly Ash

• Class F—Fly ash with pozzolanic properties

• Class C—Fly ash with pozzolanic and cementitious properties

ASTM C 618 (AASHTO M 295)

Fly Ash

SEM Micrograph of

Fly Ash Particles


Materials• Ground Slag

– By-product of the

iron making process

– Produces strong and

durable concrete

– Sets slower

– Lower early

strength but much

higher 28 day

strengths

Specifications and Grade of Ground

Granulated Iron Blast-Furnace Slags

• Grade 80

Slags with a low activity index

• Grade 100

Slags with a moderate activity index

• Grade 120

Slags with a high activity index

ASTM C 989 (AASHTO M 302)

SEM Micrograph of

Slag Particles


Materials• Silica Fume

– By-product of electric furnaces in silicon metal

production

– 100 times smaller than a cement particle

– Used in structures

where durability is

important

– Very low addition rate

10% by weight of

cement or less

– Expensive – limited

supply

Specification for Silica Fume

ASTM C 1240

Silica Fume—finely divided residue

resulting from the production of

silicon, ferro-silicon, or other

silicon-containing alloys that is

carried from the burning surface area

of an electric-arc furnace by exhaust

gases.

SEM Micrograph of

Silica Fume Particles

Typical Amounts of SCM

in Concrete by Mass of

Cementing Materials• Fly ash

– Class C 15% to 40%

– Class F 15% to 25%

• Slag 20% to 70%

• Silica fume 5% to 10%

• Calcined clay 15% to 35%

– Metakaolin 10%

• Calcined shale 15% to 35%

Effects of SCMs on Freshly Mixed Concrete

Water requirements

Workability

Bleeding & segregation

Air content

Heat of hydration

Setting time

Finishability

Pumpability

Plastic shrinkage cracking

Fly ash SlagSilica

Fume

Reduced no/little effect

Increase varies

Effects of SCMs on Hardened Concrete

Strength gain

Abrasion resistance

Freeze thaw/scaling resistance

Drying shrinkage

Permability

Alkali silica reactivity

Chemical resistance

Carbonation

Concrete color

Fly ash SlagSilica

Fume

Reduced no/little effect

Increase varies

Effect On Reducing ASRASTM C 441

• Type F Ash:

– 15% replacement: 47%



• Type C Ash:




Concrete can play a major role in

attaining LEED certification

LEED version 2.1

Materials & Resource category

•Credit 4-Recycled Content: up to 2 points for using building

products that incorporate recycled content materials

•Masonry products are ideal candidates for incorporating recycled

materials because of the inert nature

•SCMs such as fly ash, slag cement, silica fume are considered

post-industrial material

•Glass, slag, recycled concrete masonry, or other recycled materials

as aggregate are considered post-consumer material

LEED version 2.1

Materials & Resource category

•Credit 5-Local/Regional Materials: up to 2 points for using

building products that incorporate materials produced locally.

•Selecting materials & products from local manufacturers to a job

site supports the regional economy.In addition, selecting local

vendors minimizes fuel & handling cost for shipping products

•1 point earned for using a minimum of 20% of building materials

produced regionally within a radius of 500 miles

•Additional 1 point added if 50% of building materials produced

regionally within a radius of 500 miles

Cement TypeThe use of fly ash or slag impact the mix proportions

in a number of ways including:

• Changes in water demand

– Fly ash reduces

– Slag has minimal effect

– Silica fume increases

• Changes in volume due to different

specific gravities(Portland cement =

3.15)

– Fly ash = 1.9 to 2.8

– Slag = 2.85 to 2.95

– Silica fume = 2.25

• Changes relationship between w/cm

& strength

Cement TypeACI 318 Building Code also places limits on the

maximum amount of SCM allowed in concrete

exposed to de-icing salts as follows:

• Slag < 50%

• Fly ash < 25%

• Silica fume < 10%

• Total SCM in concrete

with slag < 50%

• Total SCM in concrete

without slag < 35%

Fine Aggregate Requirements

• Convert to volumetric proportions using appropriate material density

• Calculate the volume of sand required to make up a unit volume(1yd³)

• Convert volume of sand to mass quantity using appropriate density

Mass Proportions(lb/yd³)

• Cement content

• Water content


Already determined

Moisture Corrections

• Mix proportions are calculated in a SSD state

• But corrections to free water in both fine & coarse aggregate are needed to maintain proper design volume

• Total free water from aggregates is than subtracted from total batch water

• Most ready mix facilities now have moisture probes and moisture adjustments are done continuously

Trial Mixes

• Trial batches are performed to determine whether the slump, air content and strength are as required

• If not, modifications to the mix are made and further trials are performed until all properties are met

Absolute Volume ExampleConditions & Specifications

• Concrete pavement

• 8 inches thick

• Exposed to moisture

& deicer salts in

severe freeze-thaw

environments

• Slump 0f 3 in. +/- 1 in.

• No statistical data


• Fine aggregate

– Natural sand

– S.G. = 2.64(SSD)

– Fineness modulus, FM

= 2.70

– Absorption, abs. =

0.9%

– Moisture content, mc =

3.5%


– Well graded gravel w/ some crushed particles

– 1 in. nominal max size

– S.G. = 2.68(SSD)

– Dry-rodded bulk density = 2700lb/yd³

(100lb/ft³)

– Absorption, abs. = 0.5%

– Moisture content, mc = 2.0%


• Admixtures

– Water-reducer:

• 7% water reduction at 5.5 fl. Oz. Per 100 lb of cement

• S.G. +/-= 1.0

– Air-entraining admixture

• Manufacturer recommends 1.0 fl. Oz. Per 100 lb of cement for

6% air

• S. G. +/-= 1.0

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

From this information a trial mixture is

proportioned to meet the conditions and

specifications

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Specified strength for design = 3500 psi

Note requirements of ACI 318 Building Code

Max

W/CM

Min. f’c

psi


permeability when exposed to

water

0.50 4000


thawing in a moist condition or

to de-icing chemicals

0.45 4500

Corrosion protection of

reinforcement in concrete

exposed to chlorides

0.40 5000

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Specified strength for design = 3500 psi


F’c = 4500 psi

Since less than 15 consecutive test are available

Specified Strength

F’c (psi)

Required Average

Strength F’cr (psi)

Less than 3000 F’c + 1000

3000 to 5000 F’c + 1200

Over 5000 1.10 F’c + 700

F’cr = 4500 + 1200 = 5700 psi

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

W/CM required for strength

Required

Strength

f‖cr

W/CM

Non-air

W/CM

Air

7000 0.33 ----

6000 0.41 0.32

5000 0.48 0.40

4000 0.57 0.48

3000 0.68 0.59

2000 0.82 0.74

5700 0.34

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

W/CM required for durability


Max

W/CM

Min. f’c

psi


permeability when exposed to

water

0.50 4000


thawing in a moist condition or

to de-icing chemicals

0.45 4500

Corrosion protection of

reinforcement in concrete

exposed to chlorides

0.40 5000

W/CM = 0.34 is to be used

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials


Max Size

(in.)

-------- 2.40 2.60 2.80 3.00

3/8 0.50 0.48 0.46 0.44

½ 0.59 0.57 0.55 0.53

¾ 0.66 0.64 0.62 0.60

1 0.71 0.69 0.67 0.65

1½ 0.75 0.73 0.71 0.69

2 0.78 0.76 0.74 0.72

3 0.82 0.80 0.78 0.76

6 0.87 0.85 0.83 0.81

Bulk volume of dry-rodded coarse aggregate

per unit volume of concrete for different FM

of fine aggregate

0.68

2.70

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Mass of Coarse Aggregate

Oven dry mass = bulk volume X bulk density

Oven dry mass = 0.68 X 1650 = 1836 lbs

Coarse Aggregate Content(SSD) = 1845 lbs

absorption

Mass in SSD = 1836 X 1.005

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Specified Air Contents (tolerance +/- 1.5%)

Exposure

-------- 3/8 1/2 3/4 1 1-1/2 2 3

Mild 4.5 4.0 3.5 3.0 2.5 2.0 1.5

Moderate 6.0 5.5 5.0 4.5 4.5 4.0 3.5

Severe 7.5 7.0 6.0 6.0 5.5 5.0 4.5

Nominal Maximum Aggregate Size(in.)

Air required = 6.0% +/- 1.5%

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Slump specified at 3 in. +/- 1 in.

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Water Requirements(lbs/yd³) for air-entrained concrete

Slump

Inches 3/8 1/2 3/4 1 1-1/2 2 3

1 to 2 305 295 280 270 250 240 205

3 to 4 340 325 305 295 275 265 225

6 to 7 365 345 325 310 290 280 260

Nominal Max Aggregate Size(inches)

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Water Requirements(lbs/yd³) for air-entrained concrete

295 - 35 = 260

260 - 18 = 242

(from table) (for rounded gravel

with some crushed

particles)

(7% reduction for water

Reducing admixture)

Water content = 242 lb/yd³

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Cement Content Requirements

Cement content = Water content

W/CM

Cement content = 242

0.34

Cement content = 712 lb/yd³

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Cement Type Requirement

No special requirements

Type I (ASTM C 150)

Use either

Type GU (ASTM C 1157)

Note: if SCM are used ensure that proportions do

Not exceed limits of ACI 318 Building Codes for

Concrete exposed to deicer salts

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Admixture Requirements

Water-reducer dose

Air-entrainment dose

5.5 fl. oz. / 100 lb X 712 lb/yd³ = 39.0 fl. oz./yd³

1.0 fl. oz. / 100 lb X 712 lb/yd³ = 7.0 fl. oz./yd³

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Sand Requirements

Material

Mass

(yd³)

Density

(lb/ yd³)

Volume

(yd³)

Cement 712 5308

Water 242

Stone

(SSD) 1845

Air

6% by

volume

Total

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Sand Requirements

Material

Mass

(yd³)

Density

(lb/ yd³)

Volume

(yd³)

Cement 712 5308

712

5308

Water 242

Stone

(SSD) 1845

Air

6% by

volume

Total

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Sand Requirements

Material

Mass

(yd³)

Density

(lb/ yd³)

Volume

(yd³)

Cement 712 5308

712

5308 0.134

Water 242

Stone

(SSD) 1845

Air

6% by

volume

Total

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Sand Requirements

Material

Mass

(yd³)

Density

(lb/ yd³)

Volume

(yd³)

Cement 712 5308

712

5308 0.134

Water 242 1685

242

1685 0.143

Stone

(SSD) 1845 4516

1845

4516 0.409

Air

6% by

volume

6

100 0.060

Total

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Sand Requirements

Material

Mass

(yd³)

Density

(lb/ yd³)

Volume

(yd³)

Cement 712 5308

712

5308 0.134

Water 242 1685

242

1685 0.143

Stone

(SSD) 1845 4516

1845

4516 0.409

Air

6% by

volume

6

100 0.060

Total 0.746

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Sand Requirements

Volume of sand = 1.000 – 0.746 = 0.254 yd³

Mass of sand = volume X density

Mass of sand = 0.254 X 4448 = 1130 lb(SSD)

Fine Agg. Content(SSD) = 1130 lb/yd³

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Mixture Proportions

Material Content

(lb/yd³)

Cement 712

Water 242

Coarse Agg.(SSD) 1845

Fine Agg.(SSD) 1130

Total Mass. 3929

WRA 39 fl.oz./yd³

AEA 7 fl.oz./ yd³

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials


Mbatch = MSSD X 1 + mc

1 + abs

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials


Mbatch = MSSD X 1 + mc

1 + abs

Coarse Aggregate

Mbatch = 1845 X 1.020 = 1873 lb/yd³

1.005

Fine Aggregate

Mbatch = 1130 X 1.035 = 1159 lb/yd³

1.009

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials


Wcorr = MSSD X (abs – mc)

1 + abs

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials


Wcorr = MSSD X (abs – mc)

1 + abs

Coarse Aggregate

Wcorr = 1845 X (.005 - .020) = -28 lb/yd³

1.005

Fine Aggregate

Wcorr = 1130 X (.009 - .035) = -29 lb/yd³

1.009Total water correction = 28 + 29 = 57 lb/yd³

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Mixture Proportions

Moisture Batch

Corrections Proportions

Cement 712 lb/yd³ 712 lb/yd³

Water 242 lb/yd³ -57 185 lb/yd³

CA(SSD) 1845 lb/yd³ +28 1873 lb/yd³

FA(SSD) 1130 lb/yd³ +29 1159 lb/yd³

Total Mass 3929 lb/yd³ 3929 lb/yd³

WRA 39 fl.oz./yd³ 39 fl.oz./yd³

AEA 7 fl.oz./yd³ 7 fl.oz./yd³

OK

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Trial Batch

For a 2 cubic foot (0.074 yd³) batch:

Batch

Quantities

Cement 712 lb/yd³ X 0.074 52.688 lb

Water 185 lb/yd³ X 0.074 13.690 lb

C.A. 1873 lb/yd³ X 0.074 138.602 lb

F.A. 1159 lb/yd³ X 0.074 85.766 lb

Total Mass 3929 lb/yd³ X 0.074 290.746 lb

WRA 39 fl.oz./yd³ X 0.074 2.89 fl.oz.

AEA 7 fl.oz./yd³ X 0.074 0.51 fl.oz.

11.0 Moisture

1.0 Strength

2.0 W/CM

3.0 Stone

4.0 Air

5.0 Slump

6.0 Water

7.0 Cement

8.0 Type

9.0 Admixture

10.0 Sand

12.0 Trials

Trial Batch

Trial batches tested for:

• Slump

• Air Content

• Strength

Adjustments made:

• Water Content

• Admixture Dose

• Cement Content

• Sand Content

Thank You

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http://www.portcement.org/

http://www.concrete.org/

Documents

Intro to Concrete Mix Design