The invention relates to a package of performance additives for bitumen or bituminous compositions including an acidic adjuvant and a H.sub.2S scavenger chosen from organic or inorganic copper salts. The invention also relates to the use of said H.sub.2S scavenger in order to reduce the H.sub.2S emissions of bitumen or of a bituminous composition treated with the acidic adjuvant. The invention additionally relates to a process for the preparation of a bituminous composition. The preparation process according to the invention makes it possible to obtain bitumen/crosslinked polymer compositions having better mechanical and dynamic properties in comparison with the bitumen/crosslinked polymer compositions of the prior art, while substantially reducing the releases of hydrogen sulfide (H.sub.2S).

Disclosed are various methods for reducing levels of elemental sulfur within gypsum products such as wall board. Gypsum sometimes includes increased levels of elemental sulfur. Such sulfur can be corrosive and otherwise harmful at elevated levels. The disclosure contemplates reacting the elemental sulfur with copper to copper sulfide. This reaction has the benefit of reducing the levels of elemental sulfur present within the final gypsum product. The copper can be added at any of a variety of locations in the manufacturing process. This is a very efficient method for reducing elemental sulfur in the production of gypsum products.

Disclosed are various methods for reducing levels of elemental sulfur within gypsum products such as wall board. Gypsum sometimes includes increased levels of elemental sulfur. Such sulfur can be corrosive and otherwise harmful at elevated levels. The disclosure contemplates reacting the elemental sulfur with copper to copper sulfide. This reaction has the benefit of reducing the levels of elemental sulfur present within the final gypsum product. The copper can be added at any of a variety of locations in the manufacturing process. This is a very efficient method for reducing elemental sulfur in the production of gypsum products.

Disclosed are various methods for reducing levels of elemental sulfur within gypsum products such as wall board. Gypsum sometimes includes increased levels of elemental sulfur. Such sulfur can be corrosive and otherwise harmful at elevated levels. The disclosure contemplates reacting the elemental sulfur with copper to copper sulfide. This reaction has the benefit of reducing the levels of elemental sulfur present within the final gypsum product. The copper can be added at any of a variety of locations in the manufacturing process. This is a very efficient method for reducing elemental sulfur in the production of gypsum products.

Disclosed are various methods for reducing levels of elemental sulfur within gypsum products such as wall board. Gypsum sometimes includes increased levels of elemental sulfur. Such sulfur can be corrosive and otherwise harmful at elevated levels. The disclosure contemplates reacting the elemental sulfur with copper to copper sulfide. This reaction has the benefit of reducing the levels of elemental sulfur present within the final gypsum product. The copper can be added at any of a variety of locations in the manufacturing process. This is a very efficient method for reducing elemental sulfur in the production of gypsum products.

The present invention describes a hardening accelerating admixture for hydraulic binders, the accelerator being based on transition metal silicate hydrates having the general formula: aMe.sub.xO.sub.y bMO cAl.sub.2O.sub.3 SiO.sub.2 dH.sub.2O 1) whereMe represents a transition metal whose molar coefficient a is in a range between 0.001 and 2, preferably between 0.01 and 1; M represents an alkaline earth metal whose molar coefficient b is in a range between 0 and 2, preferably between 0.3 and 1.6; The molar coefficient c for Al.sub.2O.sub.3 is in a range between 0 and 2, preferably between 0.1 and 1; H.sub.2O represents the hydration water of the silicate hydrate whose molar coefficient d can vary within a wide range between 0.5 and 20; x and y can both be equal to 1 or different, depending on the valence of the transition metal, given that the valence of the oxygen atom in the metal oxide is equal to 2.

The present invention describes a hardening accelerating admixture for hydraulic binders, the accelerator being based on transition metal silicate hydrates having the general formula: aMe.sub.xO.sub.y bMO cAl.sub.2O.sub.3 SiO.sub.2 dH.sub.2O 1) whereMe represents a transition metal whose molar coefficient a is in a range between 0.001 and 2, preferably between 0.01 and 1; M represents an alkaline earth metal whose molar coefficient b is in a range between 0 and 2, preferably between 0.3 and 1.6; The molar coefficient c for Al.sub.2O.sub.3 is in a range between 0 and 2, preferably between 0.1 and 1; H.sub.2O represents the hydration water of the silicate hydrate whose molar coefficient d can vary within a wide range between 0.5 and 20; x and y can both be equal to 1 or different, depending on the valence of the transition metal, given that the valence of the oxygen atom in the metal oxide is equal to 2.

Cementitious compositions and methods for the preparation of corresponding cementitious compositions, appropriate oxidatively degraded polysaccharides and methods for producing the same, as well as the use of oxidatively degraded polysaccharides as water reducing agents in cementitious compositions, wherein the compositions include an oxidatively degraded polysaccharide as a water reducing agent to provide similar water reducing properties to cementitious composition formulated with lignosulfonates. The oxidatively degraded polysaccharides have the advantage over lignosulfonates of a lower price and a more consistent quality and are expected to be compatible with polycarboxylate ether cement additives.