The P2P Initiative Specifying Concrete for High Performance © National Ready Mixed Concrete Association All rights reserved

The P2P Initiative

Specifying Concrete for High Performance

© National Ready Mixed Concrete AssociationAll rights reserved

Announcement

This program is registered with the AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.

Introduction

Continuing education for engineers and architects Length of Presentation: 2 Hours Architects Earn 2 LUs Engineers Earn 2 PDHs NRMCA is an AIA/CES Registered Provider Records kept on file with NRMCA and AIA/CES Records

Outline

Prescriptive vs Performance Specifications What is a Prescriptive Specification? What is a Performance Specification? Laboratory Study Demonstrating the Advantages of

Performance-based Specifications ACI 318 Requirements for Durability Example Specification – ACI 318 Structures Example Specification – Non-ACI 318 Structures

Prescriptive vs Performance Specifications

Prescriptive Specifications Limit the types and quantities of ingredients Identify mixture proportions Detail construction means and methods

Performance Specifications Focus on performance and function Assignment of responsibility Flexibility to adjust mixture ingredients and proportions to

achieve consistent performance Measurable and enforceable

Encourages partnering within construction team:Leads to innovation and satisfied customers

11.3 k

22.0 k

21.1 k

19.9 k

20.5 k 15-0

Engineers and Architects

Contractors

Concrete Producers

Engineers and Architects are Experts in Design

Natchez Trace Bridge, Franklin, TN

Milwaukee Art Museum NBC Tower, Chicago

Contractors are Experts in Construction

High-rise

Tilt-up

Post-tension

Producers are Experts in Mix Design

Product Development

Testing Labs

Material Handling

Performance-based Specifications:Help Control Construction Cost

Innovative construction means and methods Improved construction schedules More efficient structural designs Simplified specifications and submittal process Optimized mix designs

Performance-based Specifications:Help Meet Greater Demands

High-Strength Concrete

High-Performance Concrete

Self- Consolidating Concrete

Performance-based SpecificationsImproves Quality Systems

Product Development

Testing Procedures

Material Handling

Performance-based Specifications:Encourages Training and Certifications

Plant and Truck Certification Plant Manager Certification Concrete Technologist Certifications Certified Delivery Professional (drivers) Concrete Certified Sales Professional Under development

Concrete technologist responsible for performance mixes

Concrete producer certification based on quality system

What is a Prescriptive Specification?

Details mixture proportions and construction means and methods

Do not always cover intended performance May conflict with intended performance

Example: Low w/c for durability could increase thermal and shrinkage cracking

Requirements are generally not directly enforceable Producer held responsible for performance and defects,

even though he lacks the freedom to make changes Prevents mixture optimization for performance No incentive for quality control / batch uniformity

Prescriptive Specification

Intended Performance Placing/Finishing Strength Min Shrinkage Resistance To:

Freeze-Thaw Corrosion Sulfate attack ASR Cracking Abrasion

Prescriptive Criteria Slump Max w/cm ratio Min cement content Min/max air Min/Max pozzolans/slag Blended cements Aggregate grading Source Limitations Chloride Limits

Prescriptive Specification

Intended Performance Placing/Finishing Strength Min Shrinkage Resistance To:

Freeze-Thaw Corrosion Sulfate attack ASR Cracking Abrasion

Prescriptive Criteria Slump Max w/cm ratio Min cement content Min/max air Min/Max pozzolans/slag Blended cements Aggregate grading Source Limitations Chloride Limits

Some prescriptive criteria are required by code but many are not

Prescriptive Specification Example

w/c ratio = 0.40 Min. cement = 600 pcy Strength = 3500 psi No SCM Aggregate grading 8 – 18% No reactive aggregate Low alkali cement Shrinkage = 0.04% max

No cracking No curling Slump 5 ± 1 inch Setting time 4 ± 0.5 hrs Max temp 85° F Impermeable Uniform color

Prescriptive requirementsShould be specified by contractorPerformance requirements

Example: Water Cement Ratio

Cement

Water

Air

Cement

Water

Air

Paste

w/cm alone does not control strength

0

1000

2000

3000

4000

5000

6000

7000

8000

0.40 0.45 0.5 0.55 0.6 0.70

Water-Cementitious Ratio (w/cm)

Co

mp

ress

ive

Str

eng

th,

psi

Mix 1

Mix 2

Mix 3

Source: ACI 211

w/cm alone does not control permeability

0

1000

2000

3000

4000

5000

6000

7000

8000

0.70 0.55 0.45

Ch

arg

e P

as

se

d,

Co

ulo

mb

s

Portland cement

SCM1

SCM2

Ternary Blend

Water-Cementitious Ratio (w/cm)

Source: ACI 232, 233, 234

Example Prescriptive Specification

Interior Building Column Maximum w/cm = 0.40 Minimum cementitious content = 640 lbs/yd3 Maximum fly ash = 15% by mass of cementitious f’c = 4,000 psi

Slump = 4 in. max.

Prescriptive Solution 1

Start with water Estimate 295 lbs/yd3 for target slump with local materials Use 740 lbs/yd3 to meet w/cm requirement Strength is probably over 7,000 psi High paste content leads to

High heat of hydration High shrinkage High creep

Mix will not be economical

Prescriptive Solution 2

Start with minimum cement content of 640 lbs/yd3

Use 250 lbs/yd3 to meet maximum w/cm requirement Based on water demand of local materials mix needs

High dosage of WR admixture, or HRWR admixture

This mix has lower paste content May not have proper consistency for placement Strength is probably 6,500 psi

Performance Solution

First requirement (engineer) = 4,000 psi at 28 days Second requirement (contractor) = 2,500 at 3 days Optimize mixture

Aggregate grading Minimize paste content Admixtures (possibly self-consolidating concrete)

Target average comp. strength = 4,600 psi Use 460 lbs/yd3 cementitious materials 25% fly ash This minimizes heat of hydration, shrinkage, and creep Results in better surface finish

What is a Performance Specification?

Performance requirements of concrete Hardened state for Service (meeting owner’s requirements) Plastic state for Constructability (meeting the contractor’s

requirements) Focus on performance and function Assignment of responsibility Flexibility to adjust mixture ingredients and proportions to

achieve consistent performance Changes in weather conditions Changes in materials

Measurable and enforceable Defined test methods and acceptance criteria

How does it work?

Qualification requirements would be established for producers

Performance criteria would be specified by the A/E Contractor would partner with producer to establish

constructability criteria Submittal will demonstrate compliance with specified

requirements Compliance through pre-qualification tests and limited

jobsite acceptance tests

The P2P Initiative

Stands for Prescription-to-Performance Initiative of the ready mixed industry through the NRMCA Coordinated by P2P Steering Committee under the

NRMCA Research, Engineering and Standards Committee

Members include technical representatives, product suppliers, contractors, engineers, and architects

P2P Goals

Allow performance specifications as an alternative to current prescriptive specifications

Leverage expertise of all parties to improve quality and reliability of concrete construction

Assist architects/engineers to address concrete specifications in terms of functional requirements

Allow flexibility on the details of concrete mixtures and construction means and methods

Better establish roles and responsibilities based on expertise Continue to elevate the performance level of the ready mixed

concrete industry Foster innovation and advance new technology at a faster pace

What are the Challenges?

Acceptance of Change Trust / Credibility Knowledge Level (training) Reference Codes and Specifications

Prescriptive limitations

Measurement and Testing Reliability of existing tests Reliability of jobsite tests

What Activities are Underway?

Communication Engineers, Architects, Contractors, and Producers Articles and presentations

Developing Producer Quality System / Qualifications Developing Model Spec / Code Revisions

Look at model codes from other countries (Canada, Europe, Australia) Look at similar initiatives in the US (FHWA and DOTs)

Documenting Case Studies Conducting Research

Test Methods for Performance Quantifying differences between prescriptive and performance mixes

Delivering Training Programs

Additional Resources

Visit www.nrmca.org/P2P Download Example Specifications Download P2P Articles Download Research Studies

Lab Study Demonstrating Advantages of Performance Specification

Case 1: Real Floor Specification from a Major Owner Case 2: Typical HPC Bridge Deck Specification Case 3: ACI 318 Chapter 4 Code – prescriptive durability

provisions

Fresh Concrete Tests

Fresh Concrete Properties Slump: ASTM 143 Air Content: ASTM C 231 Density: ASTM C 138 Temperature: ASTM C 1064 Initial Setting Time (Case 1): ASTM C 403 Finishability (Case 1): Subjective rating (5=Excellent to 1=Poor) Segregation (Case 1): Cylinders vibrated, density of top and

bottom half compared

Hardened Concrete Tests

Compressive Strength, ASTM C 39 Length Change, ASTM C 157

Durability Tests

Rapid Chloride Permeability Test (RCPT), ASTM C 1202 Rapid Migration Test (RMT), AASHTO TP 64 Sorptivity, ASTM C 1585 Bulk Diffusion, ASTM C 1556

Case 1 - Concrete Floor Specification

Prescriptive Performance

Specified = 4000 psi;

Average = 5200 psi

Specified = 4000 psi;

Average past records

Max w/c = 0.52, penalties, rejected -

No fly ash or slag SCMs may be used

Slump (max) = 4”, Non AE Slump = 4” – 6”, Non AE

Combined aggregate gradation

8% - 18%-

No HRWR -

- Shrinkage < 0.04% at 28 days

- Setting Time = 5 ± ½ hours

Specified by Contractor

Experimental Program (5 concrete mixtures)

One control (prescriptive) and 4 performance mixturesFS-1: CM = 611, w/cm = 0.49, 8-18% aggregate

FS-2: CM = 517, w/cm = 0.57, 8-18% aggregate

FS-3: CM = 530, 20% FA, w/cm = 0.57, 8-18% aggregate

FS-4: CM = 530, 20% FA with binary aggregates, w/cm = 0.53, #467 stone aggregate

FS-5: CM = 530, 20% SL, 15% FA with binary aggregates, w/cm = 0.54, #467 stone aggregate

Combined Aggregate Grading of FS Mixtures

Combined Aggregate Grading for FS Mixtures Relative to 8-18 criteria

0

5

10

15

20

25

2 1-1/2 1 3/4 1/2 3/8 #4 #8 #16 #30 #50 #100 #200Sieve Size

Ind

ivid

ual

Per

cen

t R

etai

ned

FS-1

FS-2

FS-3

FS-4

FS-5

Compressive Strength and Setting Time

Floor Slab Mixes

4:124:45

5:30 5:175:59

5,870

5,050 4,860 4,9804,720

0:00

2:00

4:00

6:00

8:00

10:00

12:00

FS-1 FS-2 FS-3 FS-4 FS-5

Initi

al S

et ti

me

0

1,000

2,000

3,000

4,000

5,000

6,000

7,000

28 d

ay C

om

pre

ssiv

e S

tren

gth

, psi

Segregation & Shrinkage

Segregation Index: Difference in the coarse aggregate content was consistently about 20% except for Mixture FS-5 which was about 15%

Shrinkage: All mixtures except FS-5 had 28 day shrinkage < 0.020%

Slab Finishability Test

All 5 concrete mixtures had a rating above 4.5 indicating excellent finishability

Durability

3050 3067

538635 584

0

500

1000

1500

2000

2500

3000

3500

FS-1 FS-2 FS-3 FS-4 FS-5

Mixture ID

RC

PT, C

oulo

mbs

Summary – Floor Slab Mixtures

All performance mixtures met performance requirements except Mixture FS-5

Strength over-design factor, limiting w/cm increased cement contents

Use of SCMs was beneficial Continuous aggregate grading mixtures did not impact

performance Performance mixtures had substantial material costs

savings

Case 2 - HPC Bridge Deck Specification

Prescriptive Performance

Specified 28 d strength=4000 psi; Average past records

Specified 28 d strength=4000 psi; Average past records

Max w/cm = 0.39 -

Total CM = 705.

15% FA plus 7% to 8% SFSCM required. Maximum amounts per

ACI 318 for deicer scaling

Air = 4% to 8% Air = 4% to 8%

RCPT < 1500 coulombs RCPT < 1500 coulombs

- Shrinkage < 0.04% at 28 days

Slump = 4” – 6” Slump = 4” – 6”

Specified by Contractor

Experimental Program (4 mixtures)

One control (prescriptive) and 3 performance mixturesBR-1: C = 550, Class F FA = 105, SF = 50; Total = 705

BR-2: C = 426, Class F FA = 150, SF = 24; Total = 600

BR-3: C = 300, SL = 300; Total = 600

BR-4: C = 426, Class F FA = 150, UFFA = 34; Total = 612

w/cm=0.39 for all mixtures except 0.36 for Mix 4

Strength

Compressive Strength: 28 day strengths were much higher than specified (6800 to 8970 psi)

RCPT (ASTM C 1202), RMT (AASHTO TP 64)

0

200

400

600

800

1000

1200

1400

1600

1800

2000

BR-1 BR-2 BR-3 BR-4

RC

PT

, Co

ulo

mb

s

0.000

0.004

0.008

0.012

0.016

0.020

0.024

0.028

RM

T, m

m/(

V-h

r)

RCPT@45D

RCPT@180D

RMT@60D

RMT@180D

Rapid Migration Test

FHWA Performance Grade (AASHTO TP 64) Grade 1: RCPT = 2000 to 3000; RMT = 0.024 to 0.034 Grade 2: RCPT = 800 to 2000; RMT = 0.012 to 0.024 Grade 3: RCPT < 800; RMT < 0.012

Drying Shrinkage (ASTM C 157)

Drying Shrinkage

0.043%

0.024% 0.025% 0.024%

0.000%

0.010%

0.020%

0.030%

0.040%

0.050%

BR-1 BR-2 BR-3 BR-4

Le

ng

th C

ha

ng

e, %

Summary – HPC Bridge Deck Mixtures

All performance mixtures met performance requirements Performance mixtures had similar or better performance

than Prescriptive mixtures Drying shrinkage, workability (stickiness), HRWR dosage,

strength, RCPT, RMT

Performance mixtures had substantial material cost savings

Case 3 - ACI 318 Chapter 4 Prescriptive durability provisions

Objective: Determine if w/cm is the best measure for durability (permeability).

Experimental Program (4 mixtures)

One control (prescriptive) and 3 performance mixtures318-1: 750 lbs Portland cement mixture

318-2: CM = 700; 25% FA (1.16% less paste)

318-3: CM = 564; 25% FA (7.24% less paste)

318-4: Same as #3 but yield adjusted largely by coarse aggregate

w/cm = 0.42 Slump = 3.75” – 6.5”; Air = 4.1% to 7.4%

Results

At same w/cm=0.42

Mix 318-1 318-2 318-3 318-4

Compressive Strength – 28 days, psi

5,440 5,950 5,670 5,600

Length Change – 180 days, %

0.064% 0.048% 0.037% 0.032%

RCPT – 180 days, coulombs

2772 608 533 457

RMT – 180 days, mm/V-hr

0.030 0.0077 0.015 0.0082

Summary – ACI 318 Mixtures

Code limitations on w/cm are no guarantee for high durability concrete

Considerable advances in the use of SCMs and chemical admixtures

Code durability provisions should be performance based

Conclusions

Prescriptive specs do not assure performance Performance mixtures achieved equal or better

performance Great opportunity for mixture optimization Producers compete on their knowledge, resources ACI 318 durability provisions needs to change

ACI 318 Requirements for Durability

Structural members not exposed to extreme conditions Most concrete for buildings falls in this category Few limits on materials or quantities

Structural members exposed to extreme conditions Follow ACI 318 Chapter 4 Most requirements are prescriptive

Slabs on grade (not part of structural system) and exterior flatwork (not part of structural system) do not need to meet requirements of ACI 318.

Water-cementitious material ratio

ACI 318 4.1 Maximum w/cm of 0.40 to 0.50 may be required for:

Freezing and thawing Sulfate soils or waters Corrosion protection To provide low permeability concrete

Corresponds to f’c of 5000 to 4000 psi respectively Specify w/cm and matching strength (per chapter 4)

w/cm is difficult to verify Strength is easy to verify

i.e. don’t specify f’c of 3000 psi and max w/cm of 0.40 Don’t specify w/cm for concrete without durability concerns

Freeze and Thawing Exposure: Air Content

• Tolerance on air content as delivered shall be +/- 1.5 %• For f’c > 5000 psi reduce air content by 1.0 percent shall be permitted

Freezing and Thawing Exposure:Low Permeability

Freezing and Thawing Exposure:Deicer Scaling

Sulfate Exposure

In addition, calcium chloride containing admixture shall not be used for severe and very severe sulfate exposure.

Corrosion Protection

Weathering Probability Map for Concrete2003 IBC

Proposed ACI 318 Exposure Classes

Exposure Category F – Exposure to freezing and thawing cycles

Exposure Category S – Exposure to water-soluble sulfates

Exposure Category P – Conditions that require low permeability concrete

Exposure Category C – Conditions that require additional corrosion protection of reinforcement

Exposure to freezing and thawing cycles

Exposure Category F – Exposure to freezing and thawing cycles

Class Description Condition

F0 Concrete not exposed to freezing and thawing cycles

F1 Moderate Occasional exposure to moisture

F2 Severe Continuous contact with moisture

F3 Very SevereContinuous contact with moisture and exposed to

deicing chemicals

Exposed to water-soluble sulfates

Exposure Category S – Exposure to water-soluble sulfates

Class DescriptionWater-soluble sulfate

(SO4) in Soil,

percent by weight

Sulfate (SO4) in

Water, ppm

S0 Negligible SO4 <0.10 SO4 <150 ppm

S1 Moderate 0.10≤ SO4 <0.20150≤ SO4 <1500 ppm

Seawater

S2 Severe 0.20≤ SO4 <2.00 1500≤ SO4 <10,000 ppm

S3 Very severe SO4 >2.00 SO4 >10,000 ppm

Conditions that require low permeability concrete

Exposure Category P – Conditions that require low permeability concrete

Class Condition

P0 Low permeability to water not applicable

P1 Concrete intended to have low permeability to water

Conditions that require additional corrosion protection of reinforcement

Exposure Category CConditions that require additional corrosion protection of reinforcement

Class Condition

C0Additional corrosion protection not a concern – for concrete that will be

dry or protected from moisture in service

C1Exposure to moisture but will not be exposed to external source of

chlorides in service

C2Exposure to moisture and an external source of chlorides in service –

from deicing chemicals, salt, brackish water, seawater, or spray from these sources

Requirements for Concrete - Exposure Class F

ExposureClass

Maxw/cm

Min f’c

psiAdditional Minimum Requirements

F0 - - -

F1 0.45 4500 Table 4.4.1 -

F2 0.45 4500 Table 4.4.1 -

F3 0.45 4500 Table 4.4.1 Table 4.4.2

TABLE 4.4.1—TOTAL AIR CONTENT FOR CONCRETE EXPOSED TO CYCLES OF FREEZING AND THAWING

Nominal maximum aggregate size, in.*

Air content, percent

Class F2 and F3 Class F1

3/8 7.5 6

1/2 7 5.5

3/4 6 5

1 6 4.5

1-1/2 5.5 4.5

2† 5 4

3† 4.5 3.5

TABLE 4.4.2—REQUIREMENTS FOR CONCRETE SUBJECT TO DEICING EXPOSURE CLASS F3

Cementitious materialsMaximum percent of total

cementitious materials by weight*

Fly ash or other pozzolans conforming to ASTM C 618

25

Slag conforming to ASTM C 989 50

Silica fume conforming to ASTM C 1240

10

Total of fly ash or other pozzolans, slag, and silica fume

50†

Total of fly ash or other pozzolans and silica fume

35†

Requirements for Concrete - Exposure Class S

ExposureClass

Maxw/cm

Min f’c


S0 - - -

S1 0.50 4000Cement Types II, IP(MS), IS(MS),

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

S2 0.45 4500Cement Type V

No calcium chloride admixtures

S3 0.45 4500Cement Type V + pozzolan‡

No calcium chloride admixtures

Requirements for Concrete - Exposure Class P

ExposureClass

Maxw/cm

Min f’c


P0 - - -

P1 0.50 4000 -

Requirements for Concrete - Exposure Class C

Exposure Class

Max w/cm

Min f’c psi

Max water-soluble chloride ion (Cl−) content in concrete, percent by weight of cement

Additional Requirement

Reinforced Concrete

C0 - - 1.00 -

C1 - - 0.30 -

C2 0.40 5000 0.15 Min. Cover

Prestressed Concrete

C0 - - 0.06 -

C1 - - 0.06 -

C2 0.40 5000 0.06 Min. Cover

Future Specification for Concrete

Concrete for parking garage slabs and beams shall meet the following requirements:

Specified compressive strength, f’c = 5,000 psi

Maximum aggregate size = ¾” Exposure class F3, S0, P1, C2

Example SpecificationACI 318 Structures

Interior slabs and beams Interior columns Footings Parking garage slabs, beams, and columns Parking garage slab-on-grade and foundation walls.

Recommendations

Comply with ACI 318 Avoid details of mixture proportions (where durability is

not a concern) Avoid details of construction means and methods State the required performance in measurable terms that

are enforceable Avoid the use of specific brands of products, especially

when reference standards are available. Avoid making acceptance criteria more restrictive than

industry practice

Quality Assurance

Installer Qualifications: On-site supervisor of the finishing crew who qualified as ACI Certified

Concrete Flatwork Technician for flatwork placing and finishing.

Flatwork finisher certification is important for constructing slabs General standard of care of concrete construction is addressed in

this certification program

Quality Assurance (cont’d)

Manufacturer Qualifications: NRMCA Certified Ready Mixed Concrete Production Facility NRMCA Concrete Technologist Level 2

NRMCA certified concrete production facilities demonstrate compliance with requirements of ASTM C 94

Includes an annual certification of delivery vehicles The NRMCA Concrete Technologist Level 2 Certification validates

personnel’s knowledge of fundamentals of concrete technology including mixture proportioning.

Certification is obtained by passing a 90 minute exam administered by NRMCA with ACI Grade 1 Field Testing Technician Certification as the prerequisite.

Details available at www.nrmca.org/certifications .


Testing Agency Qualifications: Meet the requirements of ASTM C 1077. Field testing: ACI Concrete Field Testing Technician Grade I. Lab testing: ACI Concrete Strength Testing Technician or ACI Concrete

Laboratory Testing Technician – Grade I. Test results for the purpose of acceptance shall be certified by a

registered design professional employed with the Testing Agency.

Concrete testing is very sensitive to the way specimens are collected, cured, and tested. Proper field and lab procedures are essential to achieving meaningful results.


Pre Installation Conference: Require representatives of each entity directly concerned with cast-in-

place concrete to attend, including: Architect Structural Engineer Contractor Installer (Concrete Contractor) Pumping Contractor Manufacturer (Ready-mixed concrete producer) Independent testing agency

NRMCA and American Society of Concrete Contractors has a document titled Checklist for the Concrete Pre-Construction Conference that can be used as a guide

Concrete Materials

Cementitious Materials: Use materials meeting the following requirements with limitations

specified in Section 2.12. Hydraulic Cement: ASTM C 150 or ASTM C 1157 or ASTM C 595 Fly Ash: ASTM C 618 Slag: ASTM C 989 Silica Fume: ASTM C 1240

Avoid listing brand names for most materials in this section if a standard for the product already exists.

Many existing standards are performance-based. Avoid limiting the type or quantities of cementitious materials that

can be used unless required for certain performance attributes as listed in Section 2.12 Concrete Mixtures.

Concrete Materials (cont’d)

Normalweight Aggregate: ASTM C 33 Water: ASTM C 1602 Fibers: ASTM C 1116

Concrete Materials (cont’d)

Chemical Admixtures: Air Entraining: ASTM C 260 Water reducing, accelerating and retarding: ASTM C 494 Admixtures for flowing concrete: ASTM C 1017 Admixtures with no standard designation shall be used only with the

permission of the design professional when its use for specific properties is required.

Avoid limiting the type of admixtures that can be used unless there is a specific reason (eg. Chloride based admixtures for corrosion).

Consider specifying or allowing the use of admixtures which do not have a specific ASTM designation with appropriate documentation indicating beneficial use to concrete properties.

These include colors, viscosity modifying admixtures, hydration stabilizing admixtures, pumping aids, anti-freeze admixtures, etc.

Concrete Mixtures (cont’d)

Table 2.12 Concrete Mixtures

Application Exposure ƒ΄c

Nom. Max. Agg. Size1

Air Content

Max. w/cm by weight

Cement-itious Materials

Admix.

Max. water sol. Cl ion in conc., % by

wt of cement

Interior Slabs and beams

None 4,000 psi 3/4” N/A2 N/ASee section

2.5 ASee section

2.5 D1.00

Interior Columns


2.5 ASee section

2.5 D1.00

FootingsSulfate

(moderate)4,500 psi 1-1/2” N/A2 0.45

Limits on cement4

No calcium chloride

admixtures0.30

Parking Garage Slabs, Beams, and

Columns

Freeze/Thaw,Deicing

Chemicals5,000 psi 3/4” 6%3 0.40

Limits on cement4,

fly ash, slag, and silica

fume5

See section 2.5 D

0.15

Parking Garage Slabs on

grade, Foundation

walls

Freeze/Thaw,Deicing

Chemicals,Sulfate

(moderate)

4,500 psi 1-1/2” 5-1/2 %3 0.45

Limits on cement4,


fume5

No calcium chloride

admixtures0.30

Interior Slabs, Beams and ColumnsNo Exposure


Application Exposure ƒ΄cNom. Max. Agg. Size1

Air Content

Max. w/cm by weight

Cement-itious

MaterialsAdmix.


wt of cement

Interior Slabs and beams


2.5 ASee section

2.5 D1.00

Interior Columns


2.5 ASee section

2.5 D1.00

Few limits on materials for class 1 and 2 since durability is not a concern No maximum water-cement ratio or minimum cement content Compressive strength based on structural design requirements Maximum aggregate size controlled by ACI 318 – 3.3 Aggregates

1/5 narrowest dimension of forms 1/3 slab depth 3/4 minimum clear spacing between reinforcement (governs)

Maximum chloride ions controlled by ACI 318 – 4.4 for corrosion protection of reinforcement that will be dry or protected from moisture in service

FootingsExposed to Sulfates



Air Content

Max. w/cm by weight

Cement-itious

MaterialsAdmix.


wt of cement

FootingsSulfate

(moderate)4,500 psi 3” N/A2 0.50

Limits on cement4

No calcium chloride

admixtures0.30

Compressive strength, cement type, maximum w/cm, and restriction on using calcium chloride admixtures are based on ACI 318 4.3 – Sulfate exposure Type II, IP(MS), IS(MS), P(MS), I(PM)(MS), I(SM)(MS)

Parking Garage SlabExposed to Freeze-Thaw and Deicing Chemicals



Air Content

Max. w/cm by weight

Cement-itious

MaterialsAdmix.

Max. water sol. Cl ion in conc.,

% by wt of cement

Parking Garage Slabs,

Beams, and Columns

Freeze/Thaw,Deicing

Chemicals5,000 psi 3/4” 6%3 0.40

Limits on cement4,fly ash,

slag, and silica fume5

See section

2.5 D0.15

Compressive strength, air content, maximum w/cm based on ACI 318 4.2 Freezing and thawing exposure.

Limits on SCMs based on ACI 318 4.2.3 for concrete exposed to deicing chemicals: Fly ash, 25% max Slag, 50% max Silica fume, 10% max Total of fly ash, slag, and silica fume, 50% max Total of fly ash and silica fume, 35% max

Exterior Slabs on Grade and Foundation WallsExposed to Freeze-Thaw and Sulfates



Air Content

Max. w/cm by weight

Cement-itious

MaterialsAdmix.

Max. water sol. Cl ion in

conc., % by wt of cement

Parking Garage Slabs on

grade, Foundation

walls

Freeze/Thaw,Deicing

Chemicals,Sulfate

(moderate)

4,500 psi 1-1/2” 5-1/2 %3 0.45

Limits on cement4,


fume5

No calcium chloride

admixtures0.30

Compressive strength, air content, maximum w/cm based on ACI 318 4.2 Freezing and thawing exposure.

Limits on SCMs based on ACI 318 4.2.3 for concrete exposed to deicing chemicals: Fly ash, 25% max Slag, 50% max Silica fume, 10% max Total of fly ash, slag, and silica fume, 50% max Total of fly ash and silica fume, 35% max

Limits on cement type, calcium chloride admixtures, strength, and w/cm are based on ACI 318 4.3 Sulfate exposure.

Type II, IP(MS), IS(MS), P(MS), I(PM)(MS), I(SM)(MS)

Possible additional requirements for parking garage concrete

In addition to the requirements in table 2.12, concrete mixtures proposed for parking garage slabs, beams, and columns shall meet the following criteria:

RCPT (ASTM C 1202) 1500 coulombs 28 days (7 days moist plus 21 days in 100°F

water) for mixture qualification Criteria for acceptance samples should be more lenient

80% below 1500 coulombs, or 95% below 2000 coulombs

Shrinkage (ASTM C 157) 0.06% (7-d moist cure, 28-d drying for mixture qualification

Possible additional requirements for parking garage concrete

Determine if the aggregate is reactive: Fails either ASTM C 1260 (14 day exp. < 0.10%) or C 1293 (1

years exp.< 0.04%) Has a history

If reactive: Use job materials and have producer demonstrate C 1567 (14

day expansion < 0.10%)

Concrete Mixtures (cont’d)

The installer and manufacturer shall coordinate to establish properties of the fresh concrete to facilitate placement and finishing with minimal segregation and bleeding. Factors shall include but are not limited to slump or slump flow, set time, method of placement, rate of placement, hot and cold weather placement, curing, and concrete temperature.

Bridge DeckFreeze Thaw, Deicing Chemicals, Seawater




Air Content

Cement-itious

Materials

Admix.

AdditionalRequirements

Bridge Deck

Freeze/Thaw,Deicing

Chemicals

5,000 psi

3/4” 6 %

Limits onfly ash,

slag, and silica fume

See section

2.5 D

Additional testing required

Limits on SCMs: Fly ash, 25% max Slag, 50% max Silica fume, 10% max Total of fly ash, slag, and silica fume, 50% max Total of fly ash and silica fume, 35% max

Additional Requirements

In addition to the requirements in table 2.12, concrete mixtures proposed for bridge decks shall meet the following criteria:




Shrinkage (ASTM C 157) 0.06% (7-d moist cure, 28-d drying for mixture qualification






Loading Dock Wall (marine)

Mass Concrete Freeze Thaw Deicing Chemicals Seawater Concerns

Mass concrete – minimize cement content and maximize SCM to reduce temperatures

Marine – maximize SCM and minimize w/cm for corrosion protection

Salt scaling – limit SCM dosage Strength – is not an issue Cementitious Material – enough to fill all the spaces around the

aggregate, 450 pcy for 1-1/2” aggregate

Loading Dock Wall - Mass Concrete, Freeze Thaw, Deicing Chemicals, Seawater




Air Content

Cement-itious

Materials

Admix.

AdditionalRequirements

Loading Dock Wall

Mass Concrete,

Freeze/Thaw,Deicing

Chemicals, Seawater

4,000 psi

1-1/2” 5-1/2 %Limits on Cements

See section

2.5 D

Additional testing required

Limits on hydraulic cement – Portland Cement Type I (although seawater is considered to have moderate sulfates, corrosion is more critical so use Type I with SCMs)

No limits on SCMs


In addition to the requirements in table 2.12, concrete mixtures proposed for loading dock wall shall meet the following criteria:









Additional Requirements (cont’d)

During placement of the loading dock wall concrete, the maximum differential temperature between the internal concrete (center of wall) and the surface (2” below surface) shall be 35 °F through the use of insulation blankets, cooling the concrete, or other method.

Minimum 7 day insulation blanket curing. Alternatively, the contractor may submit an alternative

temperature control plan.

The P2P Initiative

Specifying Concrete for High Performance

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The P2P Initiative Specifying Concrete for High Performance © National Ready Mixed Concrete Association All rights reserved