Abstract: The present invention relates to a method of providing thermal insulation and fire-resistance to buildings, by filling voids or spaces in and around structural members with a low density thermally insulating and fire-resistant cementitious composition containing a high proportion of a relatively smooth-surfaced, vesicular, expanded perlite. The method includes placing a flexible, woven, fire-resistant bag in the space to be filled, so as to act as a containment vessel, pumping a cementitious composition into the bag to fill a space by conforming to the shape of the space, while the bag simultaneously contains the cementitious composition in the desired position, and allowing the composition to cure into a lightweight, fire-resistant, and thermally insulating concrete. The method is particularly useful in and directed to remedial, post-construction applications in occupied buildings.

Abstract: An admixture for a dense and durable concrete mix consisting essentially of diatomaceous earth and silica fume in the ratio of from 1 to 1 up to 1 to 8. Optionally, fly ash and lignosulfonate dispersant may be added to the admixture.

Abstract: A pumpable backfill grout which hardens into a controlled low strength material and an additive for making up such a backfill grout. The grout consists essentially of portland cement, a smooth surfaced vesicular expanded perlite, fly ash, fine aggregate, water, an air entraining agent, a quick dispersing thixiotropic suspending agent and a bentonite thickening agent.

Abstract: Aluminum leafing flakes for expanding grout are adhered to microparticles to distribute the flakes in dry and wet grouts. The flakes have a protective coating sensitive to the alkalinity of dry and wet grouts alkaline. The coated flake carrying microparticles may be blended and stored with dry grouts or used directly with wet grouts as part of a fluidifier for the grout.

Abstract: A method of packaging dry grout involving a novel aluminum product for use in packaged dry grout. Aluminum flakes conventionally used as an expanding agent in a grout fluidifier are coated with a film which has limited sensitivity to the moisture and the alkali (cement) in dry grout and are then blended with the materials (comprising cement ) to be packaged as a dry grout for mixing with water to form a wet grout. The coating used is highly sensitive to the water and/or alkaline nature of the wet grout and readily deteriorates when the dry grout is mixed with water. A coating and binder, e.g., sodium silicate, may be used to coat the aluminum flakes and to adhere the aluminum to micro-particles, such as glassy microspheres, prior to a dry grout blending operation.