Quick lime, an effective cementitious material which can perform
the pozzolanic reactions, is often used for stabilizing soil
[25]. In this research, quick lime was used as the second binder
and replaced 5%, 10% and 15% of the cement (Table 2). Fig. 4 shows
the effects of the quick lime on the compressive strength and thermal
conductivity of soil-based foamed concrete. The compressive
strength and thermal conductivity both increased with the increasing
content of quick lime. When the foamed concrete consists of
15% quick lime, the 28-day compressive strength could reach to
28.2 MPa with the thermal conductivity increasing to 0.73 W/
m K. As shown in Table 2, although 60% foam was introduced in
the specimens for Series III, the density of soil-based foamed concrete
increased from 1047 kg/m3 to 1650 kg/m3 as the content of
quick lime increases from 5% to 15%. This implies that more foam
fractured with the increasing content of quick lime. As reported in
Ref. [26], the foam stability occurs on the premise of a small
amount of water absorbed on the surface of the foam (i.e. the stable
liquid membrane). During the mixing process, the reaction in
Eq. (3) occurs immediately and the water existing in the surface
of the foam can also be consumed by quick lime, which results in
the broken of foam and the increasing of the dry density.