Reactivatable set-inhibited cementitious compositions
AssigneeSociete Anonyme d'Explosifs et de Produits Chimiques
InventorsRobert H. Spensley, John Ellis
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Abstract
Aqueous grouting compositions based on high alumina cement have the onset of setting delayed for upwards of one month by the incorporation therein of a set-inhibiting agent such as boric acid or gluconic acid delta lactone and can then be rapidly reactivated for use by the incorporation therein of a reactivator, for example lithium carbonate, to produce a high strength hardened cementitious composition. The reactivated composition can advantageously be used to anchor a reinforcing element such as a rockbolt or dowel in a borehole and for this purpose the set-inhibited cementitious composition and the reactivator can be packaged in the separate compartments respectively of a dual-compartment frangible cartridge.
Claims9
A method of producing a hardened high alumina cement grouting composition which comprises forming a set- inhibited aqueous high alumina cement grouting composition essentially comprising high alumina cement, water and a set-inhibiting agent selected from boric acid and gluconic acid delta lactone, and thereafter, when the grouting composition is required for use, incorporating in the set- inhibited aqueous high alumina cement grouting composition a reactivator composition comprising a reactivator which will cause the grouting composition to set rapidly to a high strength hardened cementitious composition.
A dual-compartment frangible cartridge suitable for use in the anchoring of a reinforcing member in a borehole drilled in a rock formation, there being present in one compartment of the cartridge a set- inhibited aqueous high alumina cement grouting composition comprising high alumina cement, water and a set-inhibiting agent selected from boric acid and gluconic acid delta lactone, and in the other compartment a reactivator composition comprising a reactivator capable of causing the grouting composition to set rapidly to a high strength hardened cementitious composition when in use the reactivator composition is brought into contact with the set-inhibited composition.
Dependencies are inferred from the claim text.