Concrete in the 22nd Century

1
Concrete in the 22nd Century

• Ken Day
• Innovative Concrete Technologist
• Hon. Member, and founding committee member, of CIA

2
Is it Useful to Attempt Prediction?

• An accurate prediction of the situation 100yrs
  from now may seem unlikely
• But some of my concepts from the early 1950s
  are only now beginning to spread widely

3
Can We Influence the Future?

• Can we afford such delay?
• Why does it happen?
• Some things introduced 100 years from now may
  already be available, but struggling for
  acceptance

4
The Climate of Change

• There are huge changes due to admixtures,
  resource shortages, pollution considerations, and
  the computer revolution
• Concrete can be made without cement and
  reinforced without steel
• It can be a self-compacting fluid

5
What will concrete be like?

• Reactive Powder concrete essentially
  mortar, often with fibres, with strength of
  several hundred MPa has been produced
• Concrete of over 150MPa is now being used in
  precast bridges in USA (and we thought
  their technology lags!)

6
What will concrete be like?

• There is a rapidly increasing trend to Self-
  Compacting Concrete (SCC)
• This matches the reduced availability of
  skilled site personnel and the reduced tolerance
  for visual defects and for excessive noise and
  industrial injuries

7
Can We Cope with this?

• These new concretes rely heavily on chemical
  admixtures, pozzolans and other finely divided
  materials
• Concrete has become a high tech material and is
  becoming more so
• What is the significance of this?

8
Is Concrete Important?

• The production of concrete is used by some
  economists as a measure of a countrys economic
  strength
• even its degree of civilization
• Population is increasing worldwide but in some
  countries there is already a tax on carbon
  dioxide generation

9
How Much Concrete Can We Afford?

• Concrete is not just another material it
  is surpassed only by water as the
  most used material on earth
• So it has an enormous impact on the
  environment, on capital expenditure, on resource
  consumption, and on pollution

10
How Durable should Concrete be?

• Do we want our concrete to last 2000 years or
  20 years?
• The most expensive, most resource-consuming
  concrete is that which has to be replaced

11
What Resources will be available?

• Is there a limit to the resources available for
  the production of concrete?
• and will it all be Portland Cement concrete?

12
Is Concrete Eco-Friendly?

• Portland Cement production is already second
  only to the automobile as the major generator of
  carbon dioxide -greenhouse gas!
• What will the answer be?

13
Available Resources

• We cannot continue to throw away mountains of fly
  ash and slag
• But will there always be such mountains?

14
How Will We Use Them?

• If so, will we use them alkali-activated in
  geopolymer concrete, with no Portland Cement at
  all?
• Or will we use High Strength, High Durability
  concrete to make thinner, lighter structural
  members?

15
An Interesting Long-Shot

• Has basalt fibre reinforcement a future?
• (similar to glass fibre but much higher melting
  point)

16
Significance for Education in Concrete Technology

• Need for flexibility cannot teach ability to
  invent but must not stand in way
• New developments as likely to come from
  chemists, geologists, IT analysts etc, as from
  concrete technologists

17
Significance for Education in Concrete Technology

• Practitioners as well as students must learn
  how to keep up to date
• Continued Professional Development certainly
  required
• A qualification in structural design is an
  inadequate basis for specification and control

18
Significance for Education in Concrete Technology

• ill-informed specifiers have held back
  progress for decades, especially in USA
• There will be a legal requirement for an
  appropriate qualification before being allowed to
  specify or control concrete

19
Significance for Education in Concrete Technology

• Unfortunately neither CIA nor ACI ordinary
  membership provides this

20
Significance for Education in Concrete Technology

• Will there be an appropriate grade in future?
• A qualification such as that provided by the UK
  Institute of Concrete Technology is required

21
How will Concrete be Produced and Controlled?

• Still likely to be centrally mixed and delivered
  by truck
• High-tech heavily computerised plants providing
  the ultimate in QC

22
How will Concrete be Produced and Controlled?

• There will be well-proven, tightly controlled
  mixes with last minute adjustment for all
  available factors (slump, temperature and QC
  data on materials and concrete) (JIT!)

23
How will Concrete be Produced and Controlled?

• Trucks will have built-in devices to provide
  fine-tuned workability control
• (already available but rarely installed)

24
How will Concrete be Purchased?

• Via Internet (except large projects)
• Purchaser will nominate brief requirements
• Computer will offer nearest standard mix and
  state properties and price

25
How will Concrete be Purchased?

• If stated properties not acceptable, purchaser
  will tighten specification and Computer will
  offer revised mix (and revised price!)
• Regular and large customers will have code
  number to give agreed discount

26
Conclusions

• The fundamental things to learn are principles
  on which concrete technology is based

27
Conclusions

• Look for factors affecting actual durability,
  impermeability, dimensional stability, strength,
  environmental friendliness etc

28
Conclusions

• Rather than preconceived (and probably
  outdated) ideas of maximum or minimum contents of
  particular materials and of grading
  requirements.

29
Conclusions

• Critical knowledge is of
• what is involved in the realistic evaluation of
  mix proposals

30
Conclusions

• Critical knowledge is of
• what is possible in the way of testing accuracy

31
Conclusions

• Critical knowledge is of
• how to detect change in the quality of a
  continued supply of material and problems in the
  operation of a production facility

32
Conclusions

• WE MUST AVOID ERRORS OF THE PAST IN WHICH
  STUDENTS WERE TAUGHT ALREADY OUTDATED FACTUAL
  INFORMATION AND, SO EQUIPPED, WENT FORTH TO
  INHIBIT FUTURE DEVELOPMENT BEYOND THE NARROW
  CONFINES OF THE LITTLE THEY KNEW.

33
Conclusions

• IT IS NOT POSSIBLE FOR ANY INDIVIDUAL TO KNOW
  EVEN 10 OF THE TOTAL AVAILABLE KNOWLEDGE ABOUT
  CONCRETE

34
Conclusions

• BUT IT IS POSSIBLE TO LEARN HOW TO FUNCTION AS
  A FORWARD-LOOKING, RECEPTIVE, DISCRIMINATING, AND
  CONTRIBUTING MEMBER OF THE CONCRETE FRATERNITY