The present invention relates to the use of carbon dioxide gas to cure concrete media by applying a pressure differential created through a partial replacement of the original ambient volume of air present in a curing enclosure with pure CO2 gas.

Oil ash comprising carbon in an amount in the range of 60% to 89% is an effective set retarder in a cement composition. The oil ash prolonged the initial and final setting time of cement paste and retained the slump flow in concrete for a longer time than concrete without the retarder. Also, the addition of oil ash to cement marginally improved the compressive strength of concrete. The advantage of oil ash is that it can be used as a solid retarder of cement hydration to substitute for the conventional commercial retarding admixtures with a limited shelf-life.

A disclosed structural and light concrete includes a binding matrix and light aggregates. The binding matrix has a volume fraction from approximately 20% to approximately 50% of a concrete total volume and include: (1) a Portland Type I, II, III, IV or V cement or a mixture thereof, in a dose of at least 100 kg/m3 of concrete; (2) supplementary cementitious materials in a proportion of up to 4 times by volume of Portland cement; (3) a water component having a volume fraction relative to cement and supplementary cementitious materials in a range from approximately 0.2 to approximately 0.7; and (4) a maximum volume fraction of calcium hydroxide (CH) of approximately 10%. The light aggregates correspond to a volume fraction a range from approximately 30% to approximately 80% of the total concrete volume. Properties include increased compression resistance, decreased density, lower thermal conductivity and higher quotient of density resistance.

The present invention is directed to methods of preparing biocement. The methods disclosed herein employ microbial or enzymatic means first to generate acid which dissolves CaCO.sub.3, and then to degrade urea, producing CO.sub.3.sup. ions which increase the pH and lead to the reprecipitation of CaCO.sub.3. The precipitation of CaCO.sub.3 acts as a cementation process which can bind together particulate materials to yield mortars, concretes and suchlike. The invention further provides construction materials formed by the methods of the invention, and bacterial strains which can be used in the methods of the invention to generate organic acids.

Use of a foam mortar as a bonding agent for floorings, includes the foam mortar containing protective colloid-stabilized polymers of ethylenically unsaturated monomers.

In one aspect, composite polymeric composition and related materials are described herein employing waste products from the agricultural and energy industries. Such composite polymeric compositions and materials can repurpose agricultural and petroleum waste products for various applications including, but not limited to, building and/or infrastructure materials. In some embodiments, a composite polymeric composition described herein comprises polysaccharides, lignin or combinations thereof covalently cross-linked via linkages comprising sulfur.

The present invention provides cementitious tile adhesives comprising ordinary Portland cement, sand or another inorganic filler, and from 0.12 to 0.6 wt. % of total solids of one or more polyether group containing crosslinked cellulose ethers. The present invention also provides methods of making the polyether group containing crosslinked cellulose ethers comprising crosslinking a cellulose ether at 90 C. or less, in an inert atmosphere, e.g. nitrogen, in the presence of a polyether group containing crosslinking agent and in the presence of alkali; the process may comprise part of a stepwise addition process of making of a cellulose ether itself in which the crosslinking of the cellulose ethers precedes at least one addition of alkyl halide or alkylene oxide to form, respectively, alkyl or hydroxyalkyl groups on the cellulose.

Crumb Rubber augmented masonry blocks including cement, aggregate, water, and crumb rubber. Crumb rubber is extracted from scrape tires after being processed and then mixed in specified percentages with aggregate, cement and water. In the present disclosure sand, which is used in the formation of conventional blocks, is replaced with crumb rubber to produce a sand-free masonry block containing crumb rubber. The developed crumb rubber masonry blocks satisfied the ASTM non-load bearing requirements in addition to satisfying the water absorption test.

The invention relates to a solid particulate calcium nitrate composition having particles with an average particle size of between 0.1 and 1 mm and comprising an anti-caking agent, wherein the anti-caking agent consists of a solid particulate silicate with an average particle size of between 0.05 and 750 m. The invention furthermore relates to a pre-blend binder composition comprising such a solid particulate calcium nitrate composition. Also a dry mortar mix or tile adhesive composition and a dry concrete mix comprising an aggregate and such a pre-blend binder composition. Also a method for producing a solid particulate calcium nitrate composition, the use of a solid particulate silicate as anti-caking agent for a solid particulate calcium nitrate composition and the use of a solid particulate calcium nitrate composition as a setting accelerator for cementitious pre-blend binder composition are disclosed.

The present invention provides dry mix compositions for cement-based tile adhesives having both improved open time and slip resistance comprising one or more gel-like crosslinked cellulose ethers containing polyether groups, preferably, a mixed cellulose ether having polyoxypropylene dioxyethylene ether crosslinks. The gel-like water-soluble crosslinked cellulose ethers containing polyether groups of the present invention are formed from low to medium viscosity cellulose ethers and contain polyether groups having from 2 to 15, or, preferably, 13 or fewer oxyalkylene groups, or, preferably, 7 or more oxyalkylene groups. The present invention also provides methods of using the dry mixes in cement-based tile adhesives.