Abstract: A method of mixing particulate cement and water in a primary mixing vessel to form a slurry batch, includes introducing a measured quantity of water into the vessel, introducing a measured quantity of particulate cement into the vessel, agitating the water and cement in the vessel to form a slurry, and while continuing such agitating, pumping slurry from the lower interior extend of the vessel and delivering the pumped slurry to the upper interior of the vessel, at high velocity, removing slurry from the vessel for flow to an auxiliary mixing vessel for mixing with aggregate, and employing wash water to wash remanent slurry from surfaces in the primary mixing vessel for flow to the auxiliary vessel.

Abstract: A method for forming foam, useful in mixing with concrete at a batching plant, includes the steps:(a) supplying a synthetic resinous foaming agent, in liquid form,(b) combining the foaming agent with water, to form a liquid mix, and pressurizing the mix,(c) adding pressurized gas to the mix,(d) sub-dividing the mix into droplets, in a confined flowing stream,(e) reducing the stream confinement,(f) whereby the droplets expand as foam, typically consisting of individual, gas filled bubbles.

Abstract: An improved cement for making concrete and mortar comprises a blend of ground calcium carbonate or Portland cement kiln dust, or both, and ground, granulated blast furnace slag. While its physical and chemical characteristics differ from Portland cement, it is a functional substitute for Portland cement and may be used in combination with Portland cement in a wide range of proportions. The hardening and other characteristics of this slag-dust cement can be improved by the addition of SO.sub.3, ordinarily by adding ground gypsum and by the use of accelerators and high-range water reducing formaldehyde compounds.