Abstract: A bituminous mixture of aggregate and a bituminous binder, especially for road construction or repair is prepared by mixing a batch of still moist aggregate with the bituminous binder in a pressurized mixing container. The gauge pressure in the mixing container is maintained at or just above the saturation pressure of the water adhering to the surfaces of the aggregate, at the desired mixing temperature. Upon completion of the mixing the pressure in the mixing container is reduced to below one bar whereby moisture is removed from the mixture. The present mixing apparatus is rotatable about a hollow axle through which a supply of heating gas is maintained during the mixing. During the removal of the mixture from the mixing container the heating gas may be circulated through the next batch of aggregate being prepared.