max concrete temp at placement 2

[boffintech]

Most specs require concrete temp to be max 90F at time of placement.

Please remind me where in ACI this comes from. I looked all through 318 but couldn't find this info.

 

[JAE]

ACI 301 is the specification.

318 is the design code.

 

[henri2]

Also try IBC Section 1905.8.2 and or ACI 318 Section 5.8.2. Both sections refer to ASTM C 94 and C 685.

Both C 94 Section 11.8 and C 685 Section 9.2 state the max temp shall not exceed 90 deg F.

 

[boffintech]

ASTM C94 is a little cryptic on the subject: 11.8 The maximum temperature of concrete produced with heated aggregates, heated water, or both, shall at no time during its production or transportation exceed 90°F [32°C].

What if the concrete is produced with aggregate, water or both that is NOT heated?

ACI301 5.3.2.1.c Hot weather—The temperature of concrete
as placed shall not exceed 32°C (90°F) unless otherwise permitted.

I guess that by definition, hot weather is any weather that does not fall under the definition of cold weather described in 4.2.2.7.

 

[henri2]

You have a raised a valid point as the section pertains to cold weather concreting and the scenario you describe is something one has to contend with during hot weather.

The ACI guide for hot weather concrete is ACI 305. The copy I have is outdated. However, check this link

http://www.aci-int.org/FAQ/afmviewfaq.asp?faqid=17