RH Test Hole Callout

[Ben]

I'm following the spec to put a test hole in the slab every 1000 sq ft after putting 3 test holes in the first 1000 sq ft. What is the rational for the 1000 sq ft callout?

[rthompson]

(09-26-2008 09:40 AM)Ben Wrote:  I'm following the spec to put a test hole in the slab every 1000 sq ft after putting 3 test holes in the first 1000 sq ft. What is the rational for the 1000 sq ft callout?

For the CaCl2 testing it is to establish a base line. I do not know why for the RH probes because they are calbrated and supposed to be maintained that way.
Rayt

[CMoore]

Ben,
I talked with someone that had this explained to him by a member of the ASTM committee in this way… three test holes in the first 1000 sq. ft. to better insure you’re getting a good RH reading in case one probe is on a piece of aggregate and won’t read correctly. A test hole in each additional 1000 sq. ft. is based on the amount a truckload typically carries to pour. This would help identify those mixes that vary with water to cement ratios.

[rthompson]

(09-26-2008 09:40 AM)Ben Wrote:  I'm following the spec to put a test hole in the slab every 1000 sq ft after putting 3 test holes in the first 1000 sq ft. What is the rational for the 1000 sq ft callout?

Ben,
The rational for testing for every 1,000 s/f is; it represents the amount of concrete per truck load. A truck load of concrete will cover approximately 800 - 1,000 s/f 4-inches thick.
Regards
Rayt