The stability of conventional concrete mixture was investigated using an inclined plane method. The experiment consisted of two steps: first, the research was made to determine the influence of coarse aggregate content in aggregates mixture on the stability and sliding of concrete mixture, when the specimens of mixture are on the inclined plane without additional roughening of surface; second, the research was made to determine the influence of inclined plane surface roughening on the stability and sliding of concrete mixture. During the research the condition was checked: the concrete mixture on the sloping plane will be stable, if the yield stress τ0 is higher than the shear stress τ in. (τ 0 ≥ τ). The shear stresses and rheological property yield stresses of conventional concrete mixtures were calculated analytically by using an empirical formula. Test results showed that the increase of coarse aggregate (4/16 fraction gravel) content from about 417 to 1175 kg in concrete mixture is enough to achieve the stability of concrete mixture, when plane inclination angles are 25°, 35° and 45°, but not enough to stop sliding process. In this case, additional implements are needed to increase the adhesion of fresh concrete to the base. By using the inclined planes, which were coated with a special dimpled membrane and geotextile, the fresh concrete does not slide downwards by inclined plane.