A precast concrete molded body is provided, which is a cured product of a concrete composition. The concrete composition comprises: a microcapsule; cement; and at least one type of aggregate. The microcapsule is provided with a core-shell structure having i) a core made of a water repellent organosilicon material selected from the group consisting of organosilanes, organosilane partial condensation products, and branched siloxane resins, and ii) a shell made of a silicon-based network polymer containing silica units. The concrete composition contains 0.01 to less than 0.5 parts by weight of microcapsules per 100 parts by weight of cement. Thereby, a precast concrete molded body can be provided, having high strength, as well as at least one of the following properties: air content stability, substance penetration prevention, and freeze-thaw resistance.

The embodiments described herein generally relate to methods and chemical compositions for coating substrates with a composition. In one embodiment, an adhesive composition is provided comprising a reaction product of a polyacid selected from the group consisting of an aromatic polyacid, an aliphatic polyacid, an aliphatic polyacid with an aromatic group, and combinations thereof, or a diglycidyl ether; and a polyamine; and one or more compounds selected from the group consisting of a branched aliphatic acid, a cyclic aliphatic acid with a cyclic aliphatic group, a linear aliphatic, and combinations thereof. The adhesive composition may be used to cover a substrate.

A carbonation-resistant cementitious blend containing cement, an expandable agent present, a dispersion agent, a fluid loss additive, a defoamer, and an olive waste. Concrete samples made therefrom and methods of producing such concrete samples are also specified. The addition of olive waste provides enhanced durability (carbonation resistance) and maintains mechanical strength (e.g. compressive strength, tensile strength) after exposure to CO.sub.2 and/or brine. The resulting concretes are suitable cementing material for oil and gas wells as well as wellbores for geologic carbon sequestration.

A permeable, pourable concrete that has water permeability of on average about 1 inch per hour and compressive strength of an average of about 3000 psi, the permeable concrete comprising a mixture comprising blast-furnace slag, sand, gravel and Portland-type or equivalent cement, the concrete mixed with a predetermined ratio of water, poured into a predetermined form as desired, and set to harden until sufficiently strong.

The invention relates to compositions of cement and concrete having properties of resistance, modulus and expansion which are significantly improved, using an additive for cement based on thermoplastic styrene-butadiene-styrene (SBS) copolymer in cationic latex, when compared with non-modified cement and concrete references.

Methods of forming a carbon fiber reinforced carbon foam are provided. Such a method may comprise heating a porous body composed of a solid material comprising covalently bound carbon atoms and heteroatoms and having a surface defining pores distributed throughout the solid material, in the presence of an added source of gaseous hydrocarbons. The heating generates free radicals in the porous body from the heteroatoms and induces reactions between the free radicals and the gaseous hydrocarbons to form covalently bound carbon nanofibers extending from the surface of the solid material and a network of entangled carbon microfibers within the pores the porous body, thereby forming a carbon fiber reinforced carbon foam. Carbon fiber reinforced carbon foams and ballistic barriers incorporating the foams are also provided.

A foam concrete with elemental sulfur has constituents that include a cement, a fine filler, an elemental sulfur in powder form, a coarse aggregate, a water, and a foam solution. The foam solution includes a foaming agent and a foaming water. The foam concrete has a compressive strength of at least 26 MPa, a thermal conductivity of less than 0.30 W/mK and a maximum dry weight of 1620 kg/m.sup.3.

The main weaknesses of masonry buildings, especially those made of clay, against earthquakes are: high weight, which increases the earthquake force that is proportional to the weight; low resistance that causes an early crushing of walls and ceilings; lack of ductility, which causes the masonry buildings to collapse immediately after cracking. These weaknesses have been the main causes of collapse of masonry buildings in past earthquakes in various parts of the world. Also, many of the restoration works, done on the historical monuments that were made by the mentioned materials, showed their inadequacy in some recent earthquakes This invention improves clay, as an eco-friendly, low-cost material with high workability, to present a better seismic behavior, by decreasing its specific weight to less than tones/m.sup.3 and increasing its tensile resistance up to five times of the ordinary clay, and giving better insulation capabilities against heat, sound and moisture to it.

Disclosed are a rock similar material satisfying a water-induced strength degradation characteristic and a preparation method and use thereof. The rock similar material satisfying the water-induced strength degradation characteristic includes an aggregate, a cementing material, and an additive, where the aggregate includes quartz sand, barite powder, and bentonite, and the cementing material includes cement and gypsum.

This invention relates to a solidifying agent for solidifying radioactive waste, and more particularly to a solidifying-agent composition for solidifying radioactive waste, including alumina cement and a gypsum powder. The solidifying-agent composition including alumina cement and a gypsum powder is capable of effectively minimizing an increase in the volume of a solidified radioactive waste product to a level satisfying physical and chemical safety regulations upon the solidification of radioactive waste.