W. R. Grace Co.-conn.

Paul C Scheiner

Charles G Carter

Ellis M Gartner

Joseph A Cogliano

Leslie A Jardine

Ahmad Arfaei

Narender P Luthra

Heyman C Duecker

Ismail Abdelrazig

Hydraulic cement set-accelerating admixture compositions; cement compositions containing such admixtures; and methods for preparing said cement compositions. The admixture compositions comprise one or more nitroalcohols present in an amount effective to increase the set acceleration of a hydraulic cement composition. The invention further relates to a method of making a hydraulic cement composition comprising adding to a cement composition comprising a hydraulic cement binder, a nitroalcohol component in an amount effective to increase the set-acceleration of the binder, and to a cement composition comprising a hydraulic cement binder and a nitroalcohol set-accelerating agent.

Hydraulic cement set accelerators based on nitroalcohols

A method for making, clean, bughole-free hardened cement structural units, including the steps of a) applying a release agent to the surface of a form; b) preparing a cement composition; c) adding to the cement composition a water-soluble polymer dispersant and a solution viscosity-reducing agent; d) placing the cement composition of step c) into the form, e) curing the cement composition of step c) to form a hardened structural unit, and f) removing the structural unit from the form.

Method for making bughole-free hardened cement structural units using

The present invention relates to the use of .alpha., .beta.-amino alcohols as a cement admixture to inhibit drying shrinkage of resultant cement compositions.

Low shrinkage cement composition

A method of reclaiming unset cement compositions by mixing a polymethoxy polyphosphonate to the unset composition to cause long-term retardation of cement hydration and subsequently treating the composition with a set accelerator to reinitiate hydration.

Hydration retarder

Aqueous-based microsilica slurries having resistance to gelling and settlement of solids are provided. The slurries contain amino alcohols as stabilizing agents, the amino alcohols having the formula ##STR1## wherein R.sup.1 and R.sup.2 are each individually hydrogen or a linear or branched alkyl group containing 1 to 6 carbon atoms; R.sup.3 is a linear or branched alkylene group containing 1 to 8 carbon atoms; and R.sup.4 and R.sup.5 are each individually hydrogen, a linear or branched alkyl group containing 1 to 8 carbon atoms, or a linear or branched hydroxyalkyl group containing 1 to 8 carbon atoms. Also provided are hydraulic cement compositions comprising a hydraulic-cement binder, microsilica, and an amino alcohol of the invention.

Growing community of inventors

Maynard, MA, United States of America

Paul C Scheiner