Intro to Concrete Mix Design

(1)

Intro to Concrete Mix Design

NH Structural Engineers Association

American Society of Civil Engineers

(2)

Traditional Concrete Making

Materials

• Portland cement

• Coarse aggregate

• Fine aggregate

• Water

(3)

Modern Concrete Making

Materials

• Portland cement

• Coarse aggregate

• Fine aggregate

• Water

• Chemical admixtures

• SCM’s

• Other admixtures/additives

• Air entrainers, fibers,

(4)

(5)

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

(6)

Designing Concrete Mixtures

Factors to be considered

• Workability

• Placement conditions

• Strength

• Durability

• Appearance

• Economy

(7)

Designing Concrete Mixtures

Factors 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

(8)

Proportioning

Absolute 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

(9)

Absolute Volume

• Concrete mixture

proportions are usually

expressed on the basis of

the mass of ingredients

per unit volume

1yd 1yd

(10)

weight volume Concrete is batched by weight Concrete is sold by volume

(11)

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

(12)

Selecting Mix Characteristics

• Strength requirements

• Determine W/CM

• Coarse aggregate

requirements

• Air content

• Workability

• Water content

• Cement content

• Cement type

• Admixture effects

• Fine aggregate

requirements

• Moisture corrections

• Trial mixes

(13)

Determine Strength Requirement

Specified 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

(14)

Requirements of ACI 318

Building Codes

Max 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

(15)

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

(16)

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

(17)

Standard Deviation

If 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

(18)

Determine Required

Water-Cement Ratio

The W/CM is determine from:

• Durability

considerations

(19)

Requirements of ACI 318

Building Codes

Max 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

(20)

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

(21)

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

(22)

Coarse Aggregate Requirement

• Grading

• Nature of particles

– Shape – Porosity – Surface texture

(23)

Max Aggregate Size

• Cover between steel & form,

C: D

_max

< 3/4C

• Spacing between bars, S: D

_max

< 3/4S

• Distance between forms, B:

D

_max

< B/5

(24)

Max Aggregate Size

For pumped concrete

• D

max

< 1/3 diameter of

hose or 1-1/2 inch,

whichever is smaller

(25)

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

(26)

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

(27)

Bulk Volume of Coarse 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%

(28)

Air Content

The amount needed depends on:

• Max aggregate size

– Less paste as size increases

• Level of exposure

Effect of air content on water demand: Rule of

(29)

Workability Requirements

• Concrete must always be

made with a workability,

consistency and plasticity

suitable for job

(30)

(31)

Workability Requirements

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

(32)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

(33)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

– Mid & High range

•Water demand •Cement content •Paste content •Cost •Shrinkage •Heat evolution

(34)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

(35)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

(36)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

(37)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

(38)

Water Content

Water demand is influenced by:

• Slump requirement

• Aggregate size

• Aggregate shape

• Air content

• Cementing materials

content

• Temp

• Admixtures

– Water-reducing

(39)

Water Content

Water 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)

(40)

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

(41)

Water Content

Effects 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

(42)

Cement Content

Cement 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

(43)

Cement Content

General recommendations(PCA):

• Cementitious material > 564

lb/yd³

_{for severe}

freeze-thaw, deicer, and sulfate exposures

• Cementitious material > 650

lb/yd³

_for

concrete to be placed under water(also

W/CM < 0.45)

(44)

Cement Content

General 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

(45)

Cement Content

• Quality depends mainly on

w/cm & the water content

should 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)

(46)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

(47)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

Aggregate Retained Chart 8 -18

(48)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

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

% of total that is retained on the #8 sieve and larger 11.7% 25.0% 12.5% 100 11.7% 25.0% 12.5% 7.1% 5.0% 49.2% 100 61.3%             80.3 Coarseness Factor

(49)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

Workability Factor 3 3 3 3 3 3 565 lb/yd Workability 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  _    _ _        _ _       _ _   

(50)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

(51)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

(52)

Admixture Effects

The 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

(53)

Cement Content

• Quality depends mainly on

w/cm & the water content

should be held to a

minimum to reduce

cement content by using:

(54)

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

(55)

Cement Type

Sulfate Exposure

Cement Type

Negligible No special type required Moderate II,MS,IP(MS),IS(MS),P(MS),

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

Severe V(HS)

(56)

Cement Type

The 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

(57)

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.

(58)

Supplementary Cementitious

Materials (SCMs)

From left to right:

• Fly ash (Class C)

• Metakaolin (calcined clay)

• Silica fume

• Fly ash (Class F)

• Slag

(59)

Why Use SCM’s

• Lower heat of hydration

• Improved

workability(silica

fume???)

• ASR resistance

• Higher strength

• Lower permeability

• Better concrete at lower

cost

(60)

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

(61)

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

(62)

Secondary Cementitious

Materials

Cautions

• Less controlled than cement

• Composition depends on

origin

• Can change the properties of

the concrete(setting, water

demand,admixture behavior)

(63)

Cement Hydration Process

(64)

Cement Hydration Process

Cement + Water CSH + CaOH

SCMs + CaOH more CSH

(65)

Secondary Cementitious

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

(66)

Secondary Cementitious

Materials

• Fly ash

– Does not lose slump as rapidly

– May be harder to entrain air

– Chemical composition varies

– Flowable fill market

(67)

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)

(68)

SEM Micrograph of

Fly Ash Particles

(69)

Secondary Cementitious

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

(70)

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

(71)

SEM Micrograph of

Slag Particles

(72)

Secondary Cementitious

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

(73)

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.

(74)

SEM Micrograph of

Silica Fume Particles

(75)

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%

(76)

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 _Slag Silica Fume Reduced no/little effect

(77)

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 _Slag Silica Fume Reduced no/little effect

(78)

Effect On Reducing ASR

ASTM C 441

• Type F Ash:

– 15% replacement: 47% – 25% replacement: 66% – 35% replacement: 81%

• Type C Ash:

– 15% replacement: 3% – 25% replacement: 14% – 35% replacement: 20%

(79)

Concrete can play a major role in

attaining LEED certification

(80)

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

(81)

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

(82)

Cement Type

The 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

(83)

Cement Type

ACI 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%

(84)

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

• Coarse aggregate

Already determined

(85)

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

(86)

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

(87)

Absolute Volume Example

Conditions & 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

(88)

Absolute Volume Example

Conditions & Specifications

• Fine aggregate

– Natural sand – S.G. = 2.64(SSD) – Fineness modulus, FM = 2.70 – Absorption, abs. = 0.9% – Moisture content, mc = 3.5%

• Coarse aggregate

– 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%

(89)

Absolute Volume Example

Conditions & Specifications

• 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

(90)

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

(91)

Specified strength for design = 3500 psi

Note requirements of ACI 318 Building Code

Max 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

(92)

Specified strength for design = 3500 psi

Note requirements of ACI 318 Building Code 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

(93)

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

(94)

W/CM required for durability

Note requirements of ACI 318 Building Code Max

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 W/CM = 0.34 is to be used

(95)

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

0.68 2.70

(96)

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

(97)

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.)

(98)

(99)

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

(100)

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)

(101)

Cement Content Requirements

Cement content = Water content W/CM

Cement content = 242 0.34

(102)

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

(103)

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

(104)

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

(105)

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

(106)

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

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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

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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

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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)

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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

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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 Moisture Corrections M_batch = M_SSD X 1 + mc 1 + abs

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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 Moisture Corrections M_batch = M_SSD X 1 + mc 1 + abs Coarse Aggregate M_batch = 1845 X 1.020 = 1873 lb/yd³ 1.005 Fine Aggregate M_batch = 1130 X 1.035 = 1159 lb/yd³ 1.009

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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 Moisture Corrections W_corr = M_SSD X (abs – mc) 1 + abs

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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 Moisture Corrections W_corr = M_SSD X (abs – mc) 1 + abs Coarse Aggregate W_corr = 1845 X (.005 - .020) = -28 lb/yd³ 1.005 Fine Aggregate W_corr = 1130 X (.009 - .035) = -29 lb/yd³ 1.009

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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

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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.

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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

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