A hydrophobic admixture, for cementitious materials such as cement paste, mortar, and concrete, includes solid polymer particles with a coating of hydrophobic agent and surfactant. The solid polymer particles adhere to exterior surfaces of hydrated cement particles in the cement matrix. The solid polymer particles deliver the hydrophobic agent into the cement matrix which is hydrophilic. The hydrophobic agents are distributed uniformly throughout the cement matrix. The solid polymer particles can be crumb rubber particles derived from waste rubber tires, recycled plastics and similar solid materials. The hydrophobic liquid agent is derived from waste lubricant oil, spent motor oil, base oil, esters of fatty acids, vegetable oil and the like. Fine particles such as activated carbon, silica fume and spent catalyst can be employed to fill the large pores or cracks that develop in the cementitious matrix. The cured cementitious materials exhibit high contact angles and high compressive strengths.

A filler material includes a combination of a cement and a solid waste. The solid waste is in a proportion of about 6% up to about 94% of the filler material. The filler material can be used to strengthen the stability of landfills.

A filler material includes a combination of a cement and a solid waste. The solid waste is in a proportion of about 6% up to about 94% of the filler material. The filler material can be used to strengthen the stability of landfills.

A low strength backfill material having a 28 days compressive strength less than approximately 2.0 MPa is provided. The backfill is suitable for use in areas with dense underground utilities due to its high excavatability and good thermal conductivity. The backfill includes a cementitious binder of approximately 1 weight percent to approximately 10 weight percent and fine aggregates in an amount of approximately 40 to approximately 75 weight percent. Filler is provided at 20 microns to approximately 100 microns for high flowability. A density-controlling agent of 0.0001-5 weight percent is used such that the density of a cured backfill material is approximately 1600 kg/m.sup.3 to 2000 kg/m.sup.3. Thermally conductive particles having a size range of approximately 0.01 microns to 500 microns in an amount of approximately 0.1 to 10 weight percent are evenly dispersed throughout the backfill.

A low strength backfill material having a 28 days compressive strength less than approximately 2.0 MPa is provided. The backfill is suitable for use in areas with dense underground utilities due to its high excavatability and good thermal conductivity. The backfill includes a cementitious binder of approximately 1 weight percent to approximately 10 weight percent and fine aggregates in an amount of approximately 40 to approximately 75 weight percent. Filler is provided at 20 microns to approximately 100 microns for high flowability. A density-controlling agent of 0.0001-5 weight percent is used such that the density of a cured backfill material is approximately 1600 kg/m.sup.3 to 2000 kg/m.sup.3. Thermally conductive particles having a size range of approximately 0.01 microns to 500 microns in an amount of approximately 0.1 to 10 weight percent are evenly dispersed throughout the backfill.

Described herein are processes for the activation of glass pozzolan as well as the activated product. Methods of using the activated product are also described.

The present application discloses various cementitious compositions that incorporate waste materials therein. In some embodiments, the waste materials incorporated in the compositions are mixed construction and demolition fines, including but not limited to small pieces of glass, wood, metal, drywall, cardboard, masonry, and other architectural material and waste materials. Various methods for using said compositions are also disclosed.

A preparation method of a plant-mixed warm regenerated asphalt mixture, comprises the following steps: preparing a RAP material, a new aggregate, a mineral powder, a new asphalt and a regenerant with a total mass percentage of 100%; heating and stirring the RAP material, adding the regenerant, and continuing to heat and stir; placing the product in a development bin for development, wherein a development temperature is 40 C. to 150 C., and a development time is 0.5 h to 6 h; mixing, heating and stirring a product with the new aggregate; and after mixing and heating the product with the new asphalt, adding the mineral powder, and stirring to mold. Addition of the regenerated asphalt mixture in the development process improves the regeneration effect of the old asphalt, and pavement performances of the formed regenerated asphalt mixture can fully reach that of a hot-mixed asphalt mixture produced entirely with new materials.

A preparation method of a plant-mixed warm regenerated asphalt mixture, comprises the following steps: preparing a RAP material, a new aggregate, a mineral powder, a new asphalt and a regenerant with a total mass percentage of 100%; heating and stirring the RAP material, adding the regenerant, and continuing to heat and stir; placing the product in a development bin for development, wherein a development temperature is 40 C. to 150 C., and a development time is 0.5 h to 6 h; mixing, heating and stirring a product with the new aggregate; and after mixing and heating the product with the new asphalt, adding the mineral powder, and stirring to mold. Addition of the regenerated asphalt mixture in the development process improves the regeneration effect of the old asphalt, and pavement performances of the formed regenerated asphalt mixture can fully reach that of a hot-mixed asphalt mixture produced entirely with new materials.

The present invention relates to a modified red sludge or a modified bauxite residue and processes for producing same, and to a storage medium comprising a modified red sludge, a heat store comprising a storage medium and numerous uses of a It modified red sludge as storage medium, more particularly in a heat store system. The modified red sludge here contains the following components: haematite (Fe.sub.2O.sub.3), corundum (Al.sub.2O.sub.3), rutile (TiO.sub.2) and/or anatase (TiO.sub.2), quartz (SiO.sub.2), optionally perovskite (CaTiO.sub.3) and optionally pseudobrookite ((Fe.sup.3+, Fe2+).sub.2(Ti, Fe.sup.3+)O.sub.5) and/or nepheline ((Na,K)[AlSiO.sub.4]). A novel material is thus provided, and production thereof is described for use as storage medium in a sensitive energy storage system in the low-, medium- or high-temperature sector.