A method for forming cement-based cementitious material includes: pouring a cement paste into a mold; applying an electrical current to the cement paste to perform an electro-osmotic reaction; and transferring the reacted cement paste into a water tank for curing, thereby obtaining a functionally graded cement-based cementitious material. A pair of electrodes is placed in the mold and connected to an external power source. The compressive strength of the functionally graded cement-based cementitious material in the middle is lower than that at either of both ends.

The present disclosure discloses a modified calcium silicate board, and belongs to the technical field of floors and decorative boards. A modification method comprises steps of: dipping a calcium silicate board in a silicon dioxide solution with a solid content of 95% or more, completely absorbing the silicon dioxide solution until the calcium silicate board is saturated, and drying the dipped calcium silicate board; and carrying out sizing hardening on any surface of the modified calcium silicate board to obtain the calcium silicate board, so as to enable the triamine impregnated paper to be directly laminated with the calcium silicate board in a hot-pressing manner, and enable the surface bonding strength to reach 1 MPa; wood veneers, fireproof plates and other materials are subjected to coldbonding, the peeling strength of the product meets the requirements, and the practicability of the calcium silicate board is effectively improved.

Provided is a MgAl.sub.2O.sub.4 sintered body, which includes a relative density of the MgAl.sub.2O.sub.4 sintered body being 90% or higher, and an L* value in a L*a*b* color system being 90 or more. A method of producing a MgAl.sub.2O.sub.4 sintered body is characterized by that a MgAl.sub.2O.sub.4 powder is hot pressed at 1150 to 1300° C., and is thereafter subjected to atmospheric sintering at 1350° C. or higher. Embodiments of the present invention address the issue of providing a high density and white MgAl.sub.2O.sub.4 sintered body and a sputtering target using the sintered body, and a method of producing a MgAl.sub.2O.sub.4 sintered body.

The invention relates synthetic silicate granules comprising a mixture of SiO.sub.2, Al.sub.2O.sub.3 and Na.sub.2O, which can be obtained by sintering; to their use in manufacturing an agglomerate stone material and to the agglomerate stone material resulting thereof.

The present invention is directed to a method of making such gypsum panel. For instance, the method comprises: providing a first facing material; providing a gypsum slurry including calcium sulfate hemihydrate, water, and a silicon containing compound onto the first facing material; providing a second facing material onto the gypsum slurry to form a continuous gypsum sheet; allowing the calcium sulfate hemihydrate to hydrate to form calcium sulfate dihydrate; cutting the continuous gypsum sheet to form a gypsum panel; supplying the gypsum panel to a heating or drying device; and providing a gaseous mixture from the heating or drying device to a regenerative thermal oxidizer.

Efflorescence resistance of concrete blocks is enhanced through the use of glass powder in the concrete composition. The glass powder permits a reduction in the cement content; the glass powder also creates a pozzolanic reaction to change the free calcium ions in calcium hydroxide to calcium silicate to fix the calcium ions inside concrete. The composition includes cementitious binding material of ordinary Portland cement, fly ash, calcium sulfoaluminate cement, ground-granulated blast-furnace slag in an amount from 20 to 25 wt. %. Coarse aggregate is provided from 10 to 15 wt. percent. Fine aggregate is from 32 to 39 wt. %. The composition further includes glass powder having a diameter of less than approximately 75 microns in an amount from 17 to 23 wt. %. Water is present in an amount from 6 to 9 wt. %. The dry density of formed paving blocks is 1800-2200 kg/m.sup.3.

The present invention relates to a process for producing silica-based thermal insulation moulded body comprising at least 50% by weight of synthetic amorphous silica and not more than 50% by weight of natural silica with a specified particle size, thermal insulation moulded body obtainable by this process and the use thereof for thermal and/or acoustic insulation.

A cement slurry in a downhole well has a composition that includes a cement in an amount of 60% to 80% by weight of the cement slurry, water in an amount of 20% to 40% by weight of the cement slurry, and a retarder in an amount of 0.1% to 2% by weight of the cement slurry. The cement includes 70% to 90% of at least one silicate by weight of the cement. The retarder includes sodium lignosulfonate with an alkali content of no more than 5.0 g Na.sub.2O equivalent/liter of admixture.

The invention provides a high temperature resistant Portland cement slurry and a production method thereof. The high temperature resistant Portland cement slurry comprises the following components by weight: 100 parts of an oil well Portland cement, 60-85 parts of a high temperature reinforcing material, 68-80 parts of fresh water, 1-200 parts of a density adjuster, 0.1-1.5 parts of a suspension stabilizer, 0.8-1.5 parts of a dispersant, 3-4 parts of a fluid loss agent, 0-3 parts of a retarder and 0.2-0.8 part of a defoamer. The high temperature resistant Portland cement slurry has a good sedimentation stability at normal temperature, and develops strength rapidly at a low temperature. The compressive strength is up to 40 MPa or more at a high temperature of 350° C., and the long-term high-temperature compressive strength develops stably without degradation. Therefore, it can meet the requirements for field application in heavy oil thermal recovery wells, reaching the level of Grade G Portland cement for cementing oil and gas wells.

The present invention relates to an autoclaved aerated concrete having a content of tobermorite of at least 12.5 wt % and a content of amorphous CSH phases of at least 30 wt %, based on the total weight amount of autoclaved aerated concrete, the process for producing said autoclaved aerated concrete using a silica source, which comprises a soluble silica species and a low curing temperature and the use of a silica source, which comprises a soluble silica species for the production of an autoclaved aerated concrete.