The soaked engineering properties of soil-based foamed concrete
is dependent upon the state of water content and the decrease
of compressive strength [27]. Water absorption of soil-based
foamed concrete with different foam volume fractions is shown in
Fig. 5. For each mixture, water absorption increased remarkably
within 3 h of soaking time, then the absorption kept approximate
constant. This is in agreement with the results reported by Kampala
[28]. In addition, as the foam volume increased, water absorption of
soil-based foamed concrete increased sharply. This implies that
more pores are inter-connected in the foamed concrete with the
increase of stable foam. Fig. 6 shows the water resistance of soilbased
foamed concrete with different foam volumes. As shown in
Fig. 6, the RCS of soil-based foamed concrete decreased approximately
linearly with the increasing foam volume. As the water
absorption at 48 h increased from 13.1% to 69.1%, the RCS decreased
from 0.92 to 0.67, which indicates that the water resistance of soilbased
foamed concrete decreased.