Effect of Atmospheric Pressure on Performance of AEA and Air Entraining Concrete

Table 5

Surface tension and foaming property of AEA under different air pressures.

Sample	Atmospheric pressure (kPa)	Surface tension		Foaming ability
		Test value (mN·m^−1)	Growth rate (%)	Foaming capacity (ml)	Foaming capacity at 3 min (ml)	Foam stability (%)	Defoaming time (min)	Bubble shape
AEA A	101.1	29.4	100	Full	Full	100	≥72 h	Small, much even
	65.9	32.9	112	Full	Full	100	≥48 h	Big, little, sparse
	57.2	34.6	118	50	49	98	≥48 h
AEA B	101.1	31.9	100	38	36	95	≥36 h	Moderate, even
	65.9	34.2	107	32	30	94	≥24 h	Big, little, sparse
	57.2	36.3	114	29	26	90	≥24 h