sdz
Structural
- Dec 19, 2001
- 567
We recently had a job where some concrete returned quite low strengths. A check showed the members were adequate for strength but are there any other provisions that might limit the minimum strength. My check found -
Clause 1.1.1 specifies a minimum strength of 17MPa
Chapter 4 contains durability provisions which apply in certain circumstances, viz;
Clause 4.2 Freezing and thawing
Clause 4.2.2 Special exposure conditions including salt
Clause 4.3 Sulphate exposure
Clause 4.4 Chloride ion content
Clause 7.7 specifies concrete cover, unrelated to concrete quality except;
Clause 7.7.5 - Corrosive environments contains a general statement that in corrosive environments concrete quality and cover should be appropriate to the environment.
Conclusion: unless there is a corrosive environment or freeze-thaw, ACI 318 contains no specific provisions for minimum concrete strength other than Clause 1.1.1
Is this conclusion correct or are there any other clauses we should refer to?
Clause 1.1.1 specifies a minimum strength of 17MPa
Chapter 4 contains durability provisions which apply in certain circumstances, viz;
Clause 4.2 Freezing and thawing
Clause 4.2.2 Special exposure conditions including salt
Clause 4.3 Sulphate exposure
Clause 4.4 Chloride ion content
Clause 7.7 specifies concrete cover, unrelated to concrete quality except;
Clause 7.7.5 - Corrosive environments contains a general statement that in corrosive environments concrete quality and cover should be appropriate to the environment.
Conclusion: unless there is a corrosive environment or freeze-thaw, ACI 318 contains no specific provisions for minimum concrete strength other than Clause 1.1.1
Is this conclusion correct or are there any other clauses we should refer to?
