Abstract: An apparatus for mixing a cementitious material, such as those quick-setting cementitious materials utilizing a volatile liquid, has a solid frame as the top of a mixing chamber. An inlet end of the solid frame is pivotably mounted on a vehicle. An auger or mixing screw is mounted in the frame, the auger being removable from the frame due to the mounting of one bearing in a removable plate member and the provision of a releasable flexible coupling between this end of the auger shaft and the drive motor. A low pressure gas may be inserted into the housing of the other bearing to prevent seepage of liquid or fumes into that bearing. A removable elastomeric trough forms the bottom of the mixing chamber and contains a discharge opening. A substantially dry material is inserted into the mixing chamber through an inlet hopper and a liquid injection arrangement introduces a liquid into the mixing chamber.