Experimental Study on Flexural Fatigue Properties of Reinforced Concrete Beams after Salt Freezing

Table 7

Damage criterion of the relative elastic modulus of the test beam after freezing and fatigue.

Freeze-thaw medium	Stress level	Freezing thawing times	Relative dynamic elastic modulus after freezing and thawing	Relative dynamic elastic modulus of fatigue at the second stage	Relative dynamic elastic modulus at the end of stage two of freezing-thawing + fatigue coupling	D limit value
Water	0.65	0	1.000	0.60	0.600	0.400
		50	0.975	0.61	0.595	0.405
		100	0.905	0.57	0.516	0.484
		150	0.819	0.58	0.475	0.525
NaCl		0	1.000	0.60	0.600	0.400
		50	0.969	0.63	0.610	0.390
		100	0.982	0.60	0.589	0.411
		150	0.957	0.54	0.517	0.483