Patent attributes
Bonded aggregate compositions such as concrete, concrete repair products, high temperature refractories, high temperature insulation and fire resistant insulation are made from an aqueous solution of phosphoric acid and a separate, storable dry mixture of suitable aggregate, monocalcium phosphate, and calcium in the form of calcium aluminate cement or calcium oxide. The proportion of wet to dry constituents is variable so as to select the working time and strength of the aggregate composition, typically on the order of ten to fifteen minutes. The mixture of the preferred dry constituents, and the binder to be mixed with the aggregate to yield the preferred dry mixture, are also disclosed. The binder system is particularly advantageous in that the same set of binder constituents can readily be employed with a variety of aggregates, reducing the cost of providing a variety of aggregate compositions due to the ready availability of the raw materials and obviating the need to stock different binders for different aggregate compositions. Cost is additionally reduced through the use of less purified, and therefore less expensive constituents.