Assessing the Shrinkage Cracking Potential of Concrete Using Ring Specimens with Different Boundary Conditions

Table 3

Suggested cracking potential classification (based on the stress rate at cracking).

Net time-to-cracking, tcr, (days)	ASTM stress rate, S, (MPa/day) [7]	Suggested stress rate, S, (MPa/day)^a	Potential for cracking classification
0 < tcr ≤ 7	S ≥ 0.34	S ≥ 0.17	High
7 < tcr ≤ 14	0.17 ≤ S ≤ 0.34	0.11 ≤ S ≤ 0.17	Moderate-high
14 < tcr ≤ 28	0.10 ≤ S ≤ 0.17	0.05 ≤ S ≤ 0.11	Moderate-low
tcr > 28	S < 0.10	S < 0.05	Low

^asuggested values for the AASHTO ring setup.