Disclosed herein are low density fiber cement articles, such as fiber cement building panels and sheets, comprised of multiple overlaying fiber cement substrate layers having small and uniform entrained air pockets and low density fillers distributed throughout. The combination of entrained air pockets and low density fillers provide a low density fiber cement matrix with physical and mechanical properties similar to comparable low density fiber cement matrix without entrained air pockets.

The invention relates to a self-setting porous cement foam (2) comprising a protein foam as the structuring agent, the cement foam (2) having pores when set, and the cement foam has a water absorption coefficient of between 0.5 and 7 kg/(m.sup.2.Math.h0.5).

The invention relates to a self-setting porous cement foam (2) comprising a protein foam as the structuring agent, the cement foam (2) having pores when set, and the cement foam has a water absorption coefficient of between 0.5 and 7 kg/(m.sup.2.Math.h0.5).

A system and associated methods for processing unhardened concrete are disclosed. It at least one embodiment, the system for processing unhardened concrete includes a means to estimate a quantity of returned concrete; a foam adder to add foam to the quantity of returned concrete; a mixer to mix the added foam and returned concrete together to create treated concrete; a discharger to discharge the treated concrete; a discharge area configured in which to allow the treated concrete to set and harden; a converter to convert the hardened treated concrete into a particulate or aggregate form; and a user to determine the specific utilization of the particulate or aggregate form loose material.

A system and associated methods for processing unhardened concrete are disclosed. It at least one embodiment, the system for processing unhardened concrete includes a means to estimate a quantity of returned concrete; a foam adder to add foam to the quantity of returned concrete; a mixer to mix the added foam and returned concrete together to create treated concrete; a discharger to discharge the treated concrete; a discharge area configured in which to allow the treated concrete to set and harden; a converter to convert the hardened treated concrete into a particulate or aggregate form; and a user to determine the specific utilization of the particulate or aggregate form loose material.

The present invention relates to a gypsum composition comprising recycled gypsum and a foam former comprising at least one alpha-sulfo fatty acid disalt, to a process for production thereof and to an article comprising the gypsum composition of the invention. The present invention further relates to the use of a foam former comprising at least one alpha-sulfo fatty acid disalt for reducing the wet density of an aqueous gypsum composition having a recycled gypsum content of at least 0.5% by weight.

The present invention relates to a gypsum composition comprising recycled gypsum and a foam former comprising at least one alpha-sulfo fatty acid disalt, to a process for production thereof and to an article comprising the gypsum composition of the invention. The present invention further relates to the use of a foam former comprising at least one alpha-sulfo fatty acid disalt for reducing the wet density of an aqueous gypsum composition having a recycled gypsum content of at least 0.5% by weight.

A process for fireproofing materials, using the following steps: a) placing a material in contact with a viscoelastic suspension obtained by mixing a pozzolanic material with an alkaline activation solution having at least one soluble metal hydroxide; b) geopolymerizing the viscoelastic suspension; c) obtaining a fireproof material with a geopolymer.

A process for fireproofing materials, using the following steps: a) placing a material in contact with a viscoelastic suspension obtained by mixing a pozzolanic material with an alkaline activation solution having at least one soluble metal hydroxide; b) geopolymerizing the viscoelastic suspension; c) obtaining a fireproof material with a geopolymer.

A surfactant composition is disclosed comprising a first alkyl sulfate surfactant, optionally a second alkyl sulfate surfactant, and optionally an alkyl ether sulfate. The first and second alkyl sulfate surfactants have Formula (1):

##STR00001##

and the alkyl ether sulfate has Formula (2):

##STR00002##

in which R.sup.1 and R.sup.2 are independently selected linear or branched alkyl or a combination thereof having from 6 to 14 carbon atoms, y has an average value from 0.1 to 5, and M.sup.1 and M.sup.2 are cations independently selected from sodium, calcium, ammonium, or a combination of two or all of these. Use of the composition as a foaming agent for gypsum slurries, and of the gypsum slurries for formation of gypsum boards, are disclosed.