It is about introduction to construction industry and methods of concrete specifications

1. Concrete Construction (CoTM 6022)
MSc Program in Construction Technology and Management
College of Engineering & Technology
Department of Construction Technology & Management,
Wachemo University
Behailu Z. (Ph.D. Candidate)
December, 2023

2. COURSE CONTENTS
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Behailu Z. (Ph.D. Cand.)
1 Methods of Specifying Concrete
2 Non Destructive Tests on Concrete
3 Cold & Hot Weather Concreting
4 High-performance Concrete
5 Special Types of Concrete

3. 1. Methods of Specifying Concrete
Concrete Construction (CoTM 6022)
MSc Program in Construction Technology and Management
College of Engineering and Technology, Wachemo University
Department of Construction Technology & Management
Behailu Z., (Ph.D. Candidate, BiT, BDU)
June, 2023

4. Engineers and Architects are Experts in Design
Natchez Trace Bridge, Franklin, TN
Milwaukee Art Museum, Wisconsin, USA
NBC Tower, Chicago, USA
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Methods of Specifying Concrete

5. Contractors are Experts in Construction
High-rise Tilt-up
Post-tension
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Methods of Specifying Concrete

6. Producers are Experts in Mix Design
Product Development
Testing Labs
Material Handling
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Methods of Specifying Concrete

7. Types of Specification
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1) Performance – based Specification
2) Prescription Specification
3) Mixed Specification
4) Proprietary Specification
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Methods of Specifying Concrete

8. • states requirements in terms of the required results with criteria
for verifying compliance, but without stating the methods for
achieving the required results to the contractor.
• the designer to describe what they need and the contractor to
determine the best way to get there.
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1. Performance – Based Specifications
Methods of Specifying Concrete

9.  It focuses on the outcome and shifts the selection of materials and
methods, as well as a portion of the design work, onto the shoulders of the
contractor.
 For example,
 if you're writing performance specifications for an office building, you
may include the intended height and width of the building, the expected
locations for utility connections and the materials you plan to use.
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1. Performance – Based Specifications
Methods of Specifying Concrete

10. 1. Performance – Based Specifications
 Focus on performance and function
 Assignment of responsibility
 Flexibility to adjust mixture ingredients and proportions
to achieve consistent performance
 Measurable and enforceable
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Methods of Specifying Concrete

11. Advantages
Innovative construction means and methods
Improved construction schedules
More efficient structural designs
Simplified specifications and submittal process
Optimized mix designs
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1. Performance – Based Specifications
Methods of Specifying Concrete

12. Help Control Construction Cost
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1. Performance – Based Specifications
Methods of Specifying Concrete

13. High-Strength Concrete
High-Performance Concrete
Self- Consolidating Concrete
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Help Meet Greater Demands
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1. Performance – Based Specifications
Methods of Specifying Concrete

14. Product Development
Testing Procedures
Material Handling
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Improves Quality Systems
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1. Performance – Based Specifications
Methods of Specifying Concrete

15. • 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
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Encourages Training and Certifications
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1. Performance – Based Specifications
Methods of Specifying Concrete

16. Behailu Z. (Ph.D. Cand.) 16
2. Prescription (Detailed – Design) Specifications
Types of Specification
 written documents that give details about the project's
materials and instructions for their installation.
 Architects and engineers usually determine prescriptive
specifications. Therefore, they are responsible for the
proper installation of materials, not the contractor.

17. Prescriptive specs put a greater burden on the
Engineer or Architect (as opposed to the
general contractor) to ensure proper
installation.
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2. Prescription (Detailed – Design) Specifications
Methods of Specifying Concrete

18. It usually involves three key components:
i. General provisions: requirements surrounding codes and standards
ii. Required products: the type of products required based on
performance and structural stipulations of each product
iii. Execution procedures: how to do the install and measure its
effectiveness
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2. Prescription (Detailed – Design) Specifications
Methods of Specifying Concrete

19. Prescriptive specifications are just recipes/guidelines/instructions: do
this, then do this, then do this, etc.
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2. Prescription (Detailed – Design) Specifications
 Limit the cost, types and quantities of ingredients
 Identify mixture proportions
 Detail construction means and methods
 Example,
 specifying 40 MPa as compressive strength for substructures in a salty
soil, perhaps in accordance with a ASTM or ACI.
Methods of Specifying Concrete

20.  Do not always cover intended performance, & may conflict with it.
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
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2. Prescription (Detailed – Design) Specifications
Methods of Specifying Concrete

21. W/c 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)
Compressive
Strength,
psi
Mix 1
Mix 2
Mix 3
Source: ACI 211
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2. Prescription (Detailed – Design) Specifications
Methods of Specifying Concrete

22. Initiative of the ready mixed industry
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
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3. Mixed (Performance & Prescriptive) specification
Methods of Specifying Concrete

23. 3. Mixed (Performance & Prescriptive) specification
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
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Methods of Specifying Concrete

24. Purchaser specifies:
• Compressive strength
• Cement content
• Admixture type and content
Concrete producer selects mix proportions.
Ready Mix Concrete: ASTM C 94
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3. Mixed (Performance & Prescriptive) specification
Methods of Specifying Concrete

25. 4. Proprietary specification
 Proprietary specifications are those that require the use of a single approved
product type for any particular installation or services.
 They are often used in two cases, where there is an existing equipment or
installations already on site. In these cases the owner may want to maintain
consistency of materials or possibly simply prefers a specific type of product.
 or, in highly complex installations where there is only one specific piece of
equipment that will accomplish a specified task, a proprietary specification is
required.
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Methods of Specifying Concrete

26. 4. Proprietary specification
Architects and engineers typically try to avoid utilizing proprietary
specifications except when absolutely necessary, and will usually allow the
contractor to select from a list of approved suppliers.
Requiring the use of one specific product type can lead to the perception of
favoritism towards a certain manufacturer and may eliminate competition
during the bid phase, which may increase the project cost.
A common example would be a specification by brand name, or for a patented
product, which excludes consideration of proposed “equals” or “equivalents”.
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Methods of Specifying Concrete

27. THANK YOU!
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