(gÉrÄ­l`É) [Span.,=little war], fighting by groups of irregular troops (guerrillas) within areas occupied by the enemy. When guerrillas obey the laws of conventional warfare they are entitled, if captured, to be treated as ordinary prisoners of war; however, they are often executed by their captors.
The Inside Story â Concrete Is Porous. Most people do not realize that concrete is porous â more porous than Swiss cheese! The pores constitute 12 â 18% or more of the concrete but they are invisible, much smaller than the diameter of human hair. After new concrete is poured, almost half of the water has to evaporate.
1 Check porosity by sprinkling a little water on the surface. 2  If it soaks in readily, paint will likely adhere to the surface after the necessary prep work is performed. 3  Note: Some concrete, especially in garages, is pre-finished with a glossy coating to make the surface more resistant to moisture penetration and stains.