By preparing a raw material mixture comprising CaO raw material, SiO.sub.2 raw material and waste material, and having a content of Al.sub.2 O.sub.3 after heating at 1000 C. of 5.0 mass % or less, and calcining at a calcination temperature of 1350 C. to 1600 C., it is possible to efficiently use waste materials as a part of raw materials, and to obtain a calcined product that comprises almost an equivalent amount of -2CaO.Math.SiO.sub.2 as conventional can be obtained.

Devices and methods of recycling cement waste. A cement waste recycling device (1) comprising a heater (2) with an inlet (3) for cement waste and an outlet (4) for processed cement waste, wherein the heater (2) is configured for transporting cement waste in a cement waste transportation direction from the inlet (3) to the outlet (4) while transporting heated gas in countercurrent with the cement waste transportation direction.

Systems and methods of the present invention include a method for the treatment of drilling wastes and coal combustion residues, comprising combining at least a first drilling waste with coal combustion residues to form a paste, combining at least a second drilling waste with coal combustion residues to form a compactable fill, and placing the paste and the compactable fill in a landfill. Other embodiments include a method of treating drilling wastes and coal combustion residues, comprising combining at least one drilling waste with a coal combustion residue to form a paste. Further embodiments include containing the paste within at least one geotextile container. Still further embodiments include placing the geotextile container in a landfill.

A cementitious composition including: a binder containing (a) 60-94%, by weight, of at least one pozzolanic material; (b) at least 0.5% calcium sulfoaluminate (CSA), by weight; (c) 1.2-11% by weight, expressed as SO.sub.3, of at least one inorganic sulfate selected from the group of sulfates consisting of a calcium sulfate hemihydrate, an anhydrous calcium sulfate, a calcium sulfate dihydrate, a sodium sulfate, and a sodium calcium sulfate; and (d) a total sulfate content of at least 3%, by weight, expressed as SO.sub.3, the cementitious composition including, at most, 3% natural lime, the cementitious composition including, at most, 10% alumina cement, the contents of the composition being calculated on a dry, aggregateless basis.

A method for the manufacture of a high alumina hydraulic binder comprising hydrating a source of aluminium ions with a source of calcium ions in the presence of water to form mineral hydrates and subsequently heating said mineral hydrates to form said high alumina hydraulic binder.

A method for the manufacture of a high alumina hydraulic binder comprising hydrating a source of aluminium ions with a source of calcium ions in the presence of water to form mineral hydrates and subsequently heating said mineral hydrates to form said high alumina hydraulic binder.

A viscosity reducer for asphalt recycled material is provided by this disclosure. The viscosity reducer for asphalt recycled material includes 10% to 40% by weight of a surface active dispersant, 20% to 40% by weight of a penetrant, 1% to 5% by weight of a plasticizer, 0% to 5% by weight of a emulsifier and the remaining proportion is a diluent. In addition, a method of preparing a viscosity reducer for asphalt recycled material is also disclosed in this disclosure. Besides, a method for applying a viscosity reducer for asphalt recycled material to recycled asphalt concrete material is also disclosed in this disclosure.

A viscosity reducer for asphalt recycled material is provided by this disclosure. The viscosity reducer for asphalt recycled material includes 10% to 40% by weight of a surface active dispersant, 20% to 40% by weight of a penetrant, 1% to 5% by weight of a plasticizer, 0% to 5% by weight of a emulsifier and the remaining proportion is a diluent. In addition, a method of preparing a viscosity reducer for asphalt recycled material is also disclosed in this disclosure. Besides, a method for applying a viscosity reducer for asphalt recycled material to recycled asphalt concrete material is also disclosed in this disclosure.

A method for preparing a general-purpose cement by chlorination roasting of aluminosilicates is provided, in which a mixture of aluminosilicates and sodium chloride is roasted in a steam atmosphere to obtain a roasted slag. The roasted slag is mixed with a material containing calcium oxide and magnesium oxide and ground to prepare a raw meal powder. The raw meal powder is subjected to oxidative calcination at a temperature not lower than 1240 C., followed by rapid cooling to obtain a calcined slag. The calcined slag is mixed with 0-3% by weight of caustic alkali and ground to obtain the general-purpose cement.

Method for producing a supplementary cementitious material from concrete waste and similar materials, supplementary cementitious material obtainable by the method, use of the supplementary cementitious material for making hydraulic building materials and alkali activated binders, method for manufacturing alkali activated binders, composite binders and alkali activated binders comprising the supplementary cementitious material, and use of the composite binder for making hydraulic building materials.