Lightweight construction panels, such as gypsum plaster-board, are commonly used to provide internal partitions in buildings It is known to cover, either partially or fully, the panel with an aqueous material such as gypsum plaster or jointing compound. It has been found that known panels expand when they absorb water. This gives rise to several undesirable results such as the gypsum plaster or jointing compound cracking as the panel expands as moisture is absorbed. The present invention provides a panel comprising a gypsum matrix including fibres in an amount of at least 0.8 wt % relative to the gypsum, a polymeric additive in an amount of at least 0.8 wt % relative to the gypsum, and at least one phosphate additive. A panel having such a composition has been found to have desirable characteristics.

A process of sequestering CO.sub.2 is generally described. The process involves the use of geopolymeric precursors to which the CO.sub.2 is added. The process for a solid, cementitious material comprising geopolymer(s) and CO.sub.2.

A method for preparing a silane coupling agent/silica/plant fiber composite includes the following steps: S1: pretreating plant fiber; S2: preparing hydrolysate of a silane coupling agent; S3: preparing a silane coupling agent/plant fiber composite; S4: preparing a silica nanoparticle dispersion; and S5: preparing a silane coupling agent/silica nanoparticle/plant fiber composite. Through the covalent interaction among a silanol group (Si—OH) formed by hydrolysis of the silane coupling agent, Si—OH of the silica, and a hydroxyl group (—OH) on the surface of the plant fiber, the present invention enables silica nanoparticles to be grafted on the surface of the plant fiber. Using a hydrophobic film formed by the silane coupling agent, harmful ions are prevented from invading, and the volume stability of the fiber is improved. Using the pozzolanic activity of the silica nanoparticles, the alkalinity and calcium hydroxide content around the fiber are reduced.

A fire-resistant gypsum panel comprises: a gypsum core layer comprising set gypsum and a high temperature sag-resistant material including mineral wool in an amount between 0.2% and 3.0% by weight of gypsum.

The present invention discloses inorganic pelletized perlitic lightweight granules and a preparation process and use thereof. The present invention develops through encapsulation technology a novel type of lightweight particles, namely, inorganic pelletized perlitic lightweight granules comprising expanded perlite as a core material and a cementitious material as a shell material, forming a core-shell structure in which a perlite core is encapsulated in a cementitious shell. The cementitious material including cement and fly ash is coated onto the surface of expanded perlite particles through an encapsulation process by a pelletizer under controlled water spraying. The resulting inorganic pelletized perlitic lightweight granules are lower in cost and easier to produce, and have better fire resistance, higher crushing strength, and better compatibility with concrete. The inorganic pelletized perlitic lightweight granules can overcome the problems of conventional lightweight concrete, such as high water absorption and inconsistent performance.

A refractory composition including refractory aggregate, one or more matrix components, and silicate-coated set accelerator particles. The silicate-coated set accelerator particles can include one more of silicate-coated calcium hydroxide, magnesium hydroxide, calcium chloride, calcium carbonate, magnesium carbonate and calcium sulfate. Suitable silicate coatings include sodium silicate, potassium silicate, lithium silicate and mixtures thereof. A method of recovering an aged refractory composition, a settable composition and a method of manufacturing silicate-coated calcium hydroxide particles are also provided.

The present invention refers to a mineral matter powder preparation by wet process without acrylic additive or other grinding aid additives and to the use of said mineral matter after an optional hydrophobic treatment. Said mineral material having superior dispersing properties.

A highly thixotropic 3D printing concrete and a manufacturing method therefor are provided. The weight percentage of each component calculated per cube of concrete is: 35-40% of cement, 0.1-0.4% of polycarboxylate superplasticizer, 0.1-0.4% of polypropylene fiber, 1.0-3.0% of special thixotropic agent for 3D printing concrete, and 12.5-14.5% of water, and the remainder is sand.

The present invention relates to the use of an additive which is an aqueous system of specific polyether silicones in clinker and cement preparation. The additive improves the grinding efficiency and also results in an improvement in the cured properties of cementitious compositions employing cement so produced.

Hundreds of thousands of concrete bridges and hundreds of billions of tons of concrete require characterization with time for corrosion. Accordingly, protocols for rapid testing and improved field characterization systems that automatically triangulate electrical resistivity and half-cell corrosion potential measurements would be beneficial allowing discrete/periodic mapping of a structure to be performed as well as addressing testing for asphalt covered concrete. Further, it is the low frequency impedance of rebar in concrete that correlates to corrosion state but these are normally time consuming vulnerable to noise. Hence, it would be beneficial to provide a means of making low frequency electrical resistivity measurements rapidly. Further, prior art techniques for electrical rebar measurements require electrical connection be made to the rebar which increases measurement complexity/disruption/repair/cost even when no corrosion is identified. Beneficially a method of determining the state of a rebar without electrical contact is taught.