Influence of Multistage Target Temperature and Cyclic Loading/Unloading on the Permeability of Polypropylene Fiber Concrete

Table 3

Test results of unloading permeability of PPFRC under different temperatures.

State of stress	Difference of loading-unloading stress ratio	Permeability (kg/×10^−17 m^2)
		22°C	40°C	80°C	120°C	160°C	200°C	240°C	280°C
Graded cyclic unloading	0.07	1.82	2.27	7.86	28.77	117.27	360.32	482.18	499.47
	0.13	1.80	2.23	7.71	28.21	114.82	350.32	470.65	486.40
	0.20	1.76	2.19	7.55	27.62	109.76	337.75	450.97	466.54
	0.27	1.73	2.14	7.35	26.72	105.07	322.20	430.51	445.58
	0.34	1.69	2.08	7.16	25.97	101.81	311.33	419.32	432.05
	0.40	1.65	2.04	6.99	25.13	99.87	302.57	402.02	416.76
	0.47	1.63	2.01	6.90	24.72	98.74	291.30	391.50	401.42
Single unloading	0.47	1.71	2.12	7.25	26.54	111.92	330.70	417.15	426.99