The present invention relates to cellulose ether compounds for increasing the open time and improving the wettability of cement-based mortars. The inventive cellulose ether compounds are formed from cellulose ether with one or more liquid antifoams incorporated therein. The inventive cellulose ether compounds are preferably used as modified cellulose ether in dry mortars for increasing the open time.

The present invention relates to cellulose ether compounds for increasing the open time and improving the wettability of cement-based mortars. The inventive cellulose ether compounds are formed from cellulose ether with one or more liquid antifoams incorporated therein. The inventive cellulose ether compounds are preferably used as modified cellulose ether in dry mortars for increasing the open time.

Fibers to be added to concrete to improve its properties are coated with an alkali-insoluble polymer, to provide adhesion of the fibers to the concrete. In a further improvement, nanoparticles are dispersed in an alkali-soluble polymer coating, and this is used to coat the fibers. When the fibers are mixed into the concrete mix, the nanoparticles are dispersed throughout the concrete, avoiding problems from agglomeration of the nanoparticles if simply added to the concrete mix.

Fibers to be added to concrete to improve its properties are coated with an alkali-insoluble polymer, to provide adhesion of the fibers to the concrete. In a further improvement, nanoparticles are dispersed in an alkali-soluble polymer coating, and this is used to coat the fibers. When the fibers are mixed into the concrete mix, the nanoparticles are dispersed throughout the concrete, avoiding problems from agglomeration of the nanoparticles if simply added to the concrete mix.

A concrete composition and method include a portion of fine aggregate bearing a coating of a polymer or an admixture, which may be a continuous coating layer or a layer of powdered, discrete particles embedded in a binder. The polymeric coating may be an admixture in powdered form, a super absorbent polymer (insoluble in water, but absorbing water), or another polymer such as the acrylamides, co-polymers thereof, polyacrylamides, or the like (soluble in water). The coating absorbs water, but particles are too small to form significant voids. Water is absorbed into the concrete mix in far greater proportions (e.g. w/c ratio over 0.5) improving workability, doubling workability time, and improving ultimate compressive stress (strength).

A concrete composition and method include a portion of fine aggregate bearing a coating of a polymer or an admixture, which may be a continuous coating layer or a layer of powdered, discrete particles embedded in a binder. The polymeric coating may be an admixture in powdered form, a super absorbent polymer (insoluble in water, but absorbing water), or another polymer such as the acrylamides, co-polymers thereof, polyacrylamides, or the like (soluble in water). The coating absorbs water, but particles are too small to form significant voids. Water is absorbed into the concrete mix in far greater proportions (e.g. w/c ratio over 0.5) improving workability, doubling workability time, and improving ultimate compressive stress (strength).

Hydrophobic aggregates for use in refractory castables and gunning mixtures and methods of their preparation. The aggregates here are formed by crushing insulating fire brick and coating the resulting particles with a hydrophobic component. The hydrophobic component may be a polydimethylsiloxane having a terminal silanol group. As a result of the coating process, the coated aggregate has very low levels of alkalis. The aggregates may be used to form refractory castables that do not undergo substantial alkaline hydrolysis due to the reduced levels of alkalis. The castables made from these aggregates display superior physical properties, including lower water content, lower permanent linear change, high strength, and superior thermal conductivity/insulation properties, while at the same time possessing lower density and requiring less water to be used during castable formation. These improved properties also are observed in gunning mixtures formed from these aggregates.

Hydrophobic aggregates for use in refractory castables and gunning mixtures and methods of their preparation. The aggregates here are formed by crushing insulating fire brick and coating the resulting particles with a hydrophobic component. The hydrophobic component may be a polydimethylsiloxane having a terminal silanol group. As a result of the coating process, the coated aggregate has very low levels of alkalis. The aggregates may be used to form refractory castables that do not undergo substantial alkaline hydrolysis due to the reduced levels of alkalis. The castables made from these aggregates display superior physical properties, including lower water content, lower permanent linear change, high strength, and superior thermal conductivity/insulation properties, while at the same time possessing lower density and requiring less water to be used during castable formation. These improved properties also are observed in gunning mixtures formed from these aggregates.

The present invention relates to a curable binder composition comprising: a) at least one organic binder comprising a polyisocyanate and a polyol, and b) at least 50% by weight of a filler in the form of quartz and/or slag, based on 100% by weight of binder composition.

Polyurethane composites and methods of preparing polyurethane composites are described herein. The polyurethane composite can comprise (a) a polyurethane formed by the reaction of (i) one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, and (ii) one or more polyols; (b) fly ash comprising 50% or greater by weight, fly ash particles having a particle size of from 0.2 micron to 100 microns; and (c) a coarse filler material comprising 80% or greater by weight, filler particles having a particle size of from greater than 250 microns to 10 mm. The coarse filler material can be present in the composite in an amount of from 1% to 40% by weight, based on the total weight of the composite. The weight ratio of the fly ash to the coarse filler material can be from 9:1 to 200:1.