The current invention concerns a method for preparing a coated particulate waste material, comprising the steps of: (a) providing a particulate waste material with an average particle size of between 0.1 and 5.0 mm, and (b) applying a coating material to said particulate waste material, whereby said coating material comprises at least one polymeric compound.

In a second aspect the present invention discloses a coated waste particle comprising a waste material core, and a coating surrounding said waste material core, whereby said waste material core has a particle size of between 0.1 and 5.0 mm and said coating comprises at least one polymeric compound.

A further aspect concerns a building material, comprising one or more coated waste particles.

The current invention concerns a method for preparing a coated particulate waste material, comprising the steps of: (a) providing a particulate waste material with an average particle size of between 0.1 and 5.0 mm, and (b) applying a coating material to said particulate waste material, whereby said coating material comprises at least one polymeric compound.

In a second aspect the present invention discloses a coated waste particle comprising a waste material core, and a coating surrounding said waste material core, whereby said waste material core has a particle size of between 0.1 and 5.0 mm and said coating comprises at least one polymeric compound.

A further aspect concerns a building material, comprising one or more coated waste particles.

Expansive cement compositions for use in subterranean wellbores that include a monophase amorphous hydraulic binder material (MAHBM). The MAHBM may include a plurality of particles having a silica core and an amorphous coating substantially surrounding the silica core. The coating may comprise, for example, a plurality of amorphous α-dicalcium silicate hydrate nanoparticles or microparticles. The MAHBM may be used as an expansion agent in a cement composition or used as an expansive cement by itself.

Expansive cement compositions for use in subterranean wellbores that include a monophase amorphous hydraulic binder material (MAHBM). The MAHBM may include a plurality of particles having a silica core and an amorphous coating substantially surrounding the silica core. The coating may comprise, for example, a plurality of amorphous α-dicalcium silicate hydrate nanoparticles or microparticles. The MAHBM may be used as an expansion agent in a cement composition or used as an expansive cement by itself.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source e.g. in an amount between 4-27 wt %) and a metal salt additive in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil, The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

The present invention provides calcium sulphate-based product having reduced shrinkage after exposure to high temperatures, the product comprising gypsum, a pozzolan source e.g. in an amount between 4-27 wt %) and a metal salt additive in an amount between 0.5 and 10 wt %). The pozzolan source may be selected from a kaolinitic clay material, fly ash, rice husk ash, diatomaceous earths, volcanic ashes and pumices, micro-silica, silica fume and silicone oil, The metal salt additive may be a metal salt which decomposes between a temperature of 300-500° C. to yield a metal oxide, e.g. magnesium nitrate.

A concrete composition that includes (i) a treated palm oil fuel ash, wherein the treated palm oil fuel ash is the only binder present, (ii) a fine aggregate, (iii) a coarse aggregate, and (iv) an alkali activator containing an aqueous solution of sodium hydroxide and sodium silicate. A cured concrete made from the concrete composition is also disclosed with advantageous compressive strength properties.

A concrete composition that includes (i) a treated palm oil fuel ash, wherein the treated palm oil fuel ash is the only binder present, (ii) a fine aggregate, (iii) a coarse aggregate, and (iv) an alkali activator containing an aqueous solution of sodium hydroxide and sodium silicate. A cured concrete made from the concrete composition is also disclosed with advantageous compressive strength properties.

The present invention provides a geopolymer cement, comprising: a geopolymer binder; and a setting control composition comprising: a viscosity control agent, a polymeric binder, and a retarding additive. The invention also relates to a geopolymer concrete comprising the geopolymer cement of the invention and aggregate material. The invention further relates to a method for controlling open time in a geopolymer composition, wherein a sufficient quantity of the setting control composition is added such that the open time is between 30 and 120 minutes. The present invention provides particular uses in construction of walls, flooring, and roofing, especially lightweight prefabricated panels intended to be used as structural, insulating or cladding elements.

The present invention provides a geopolymer cement, comprising: a geopolymer binder; and a setting control composition comprising: a viscosity control agent, a polymeric binder, and a retarding additive. The invention also relates to a geopolymer concrete comprising the geopolymer cement of the invention and aggregate material. The invention further relates to a method for controlling open time in a geopolymer composition, wherein a sufficient quantity of the setting control composition is added such that the open time is between 30 and 120 minutes. The present invention provides particular uses in construction of walls, flooring, and roofing, especially lightweight prefabricated panels intended to be used as structural, insulating or cladding elements.