Location: New York Athletic Club, 59th & 7th Avenue – 180 Central Park South
Topic: 90 Minutes to Discharge a Concrete Truck Is This an Outdated Requirement?
Most specifications require a ready mix truck to discharge the concrete within 90 minutes after the
cement had been mixed with water. This requirement is given in ASTM C-94, the standard for ready mix concrete.
This standard has existed for over 30 years. Concrete technology has changed significantly over these years.
The cement of today is not the cement we had 30 years ago. Today, we have admixtures that can delay the
cement hydration process for hours, and we have admixtures that can extend the desired slump life of a concrete mix.
The issue of how much time should be allowed to discharge a truck is not a simple answer, like 90 minutes.
This seminar will present:
The latest in concrete technology to extend the working time for a concrete mix;
Test data on plastic and hardened concrete that was not discharged in 90 minutes;
What others are specifying as a required time or criteria to discharge concrete.
Cas Bognacki will be the seminar moderator. There will be three presenters
- Dr. Mohamed Mahgous
- Dr. Charles Nmai, PE, M.ASCE
- Henry Prenger
Click here to register.