Shotcrete Pre Con Panel

[specialinspector66]

When can the cores be taken out of the boundary areas of a pre-construction test panel of shotcrete? Is it at 28D? if so what code or specification can i find that in. The panel was shot on monday and the boss wants to remove cores at 7 days. I think that this is to green to core at this stage. Thanks in advanced.

 

[TXStructural]

This is a question for the shotcrete association. From shotcrete.org:
"ACI 506.4R-94 references under testing of shotcrete, ASTM C 1140-03 (Standard Practice for Preparing and Testing Specimens from Shotcrete Test Panels. Also ASTM C42/C 42M-03 (Standard Test Method for Obtaining and Testing Drilled Cores and Sawed Beams of Concrete. Standard 18"X18"X4" panels are typically made. ASTM C 1140-03 states a 24"X24"X4", cores are to be taken 1 core diameter plus one inch from any side of the test panel."