The present invention relates to a fiber-reinforced cement based or cementitious material, and process for making, where the reinforcing fiber is a chemically treated cellulose or non-cellulose fiber. The fiber reinforced cementitious material includes (i) cement, (ii) optionally, sand, aggregate, or sand and aggregate, and (iii) chemically treated fibers having a polyvalent cation content of from about 0.1 weight percent to about 5.0 weight percent based on the dry weight of the treated fibers. The present invention further provides for a fiber reinforced cementitious material having a weak acid content of from about 0.5 weight percent to about 10 weight percent based on the dry weight of the treated fibers.

Cementitious material reinforced with chemically treated cellulose fiber

Described are setting and hardening accelerators for hydraulic binders and said binder comprising compositions that are free of alkali metals and chlorides. The setting and hardening accelerators comprise, as main component, water-soluble fluoride comprising aluminum salts and water-soluble sulfate comprising aluminum salts, as well as optionally complexing agents and/or amines. In comparison with alkaline accelerators, said mixtures result in an essential shortening of the setting time and a fast development of compressive strengths.

Alkali-free setting and hardening accelerator

An alkali-free accelerator for sprayed concrete is prepared by dissolving aluminium sulphate and amorphous aluminium hydroxide in water which optionally contains one amine, and optionally adding at least one stabiliser, selected from hydroxycarboxylic acids and phosphoric acids and non-alkaline salts thereof, and at least one defoaming agent.

Preparation of concrete accelerator

The invention relates to a ternesite calcium sulfoaluminate clinker and to a ternsite clinker having 20 - 100 wt.-% C5S2$ and less than 15 wt.-% C4A3$, and to the use of ternesite as an additive in calcium-sulfoaluminate (ferrite)(belite) clinker (CSA(F)(B)), calcium-sulfoaluminate (ferrite)(belite) cement, and to binding agents containing 10 - 90 wt.-% CSA(F)(B) and 90 - 10 wt.-% ternesite.

Calcium sulfoaluminate cement with ternesite

A liquid quick-setting admixture which comprises element components including a sulfur component, an aluminum component and an alkali metal component, and a complex forming agent; a shotcreting material; and a method for shotcreting using them. The liquid quick-setting admixture preferably contains 100 parts in terms of SO3 of the sulfur element component, 25 to 110 parts in terms of Al2O3 of the aluminum element component, 2.5 to 50 parts in terms of R2O (wherein R represents an alkali metal atom) of the alkali metal element component, and 2.5 to 75 parts of the complex forming agent. The liquid quick-setting admixture allows a shotcreting work being excellent in quick setting characteristics, and is improved in storage stability.

Liquid quick-setting admixture, shotcreting material and method for shotcreting using them

The invention concerns novel liquid solidifying and hardening accelerators obtained by a process in which the following components: component a: basic aluminium salts and/or aluminium hydroxide; component b: aluminium sulphate and/or sulphuric acid; component c: organic carboxylic acids or mixtures of at least two of the organic carboxylic acids; component d: aluminium salts of organic carboxylic acids; component e: organic and/or inorganic sulphates and/or hydrogen sulphates and/or carbonates and/or hydrogen carbonates and/or alkaline earth oxides and/or alkaline earth hydroxides, are reacted in water at temperatures of up to 150 °C such that a solution is obtained, wherein: 1. all the components or a selection of the components react with one another such that the molar ratios of aluminium to sulphate in the end product are between 0.83 and 13.3 and the molar ratios of the aluminium to organic carboxylic acid are between 0.67 and 33.3; or 2. all the components apart from component e or a selection of the components apart from component e react with one another such that the molar ratios of aluminium to sulphate in the end product are between 0.83 and 13.3 and the molar ratios of aluminium to organic carboxylic acid in the end product are between 0.67 and 33.3; or 3. component e is subsequently dissolved in the reaction product according to point 2. The compounds can be used in combination with other compounds.

Lunkenheimer Rudolf

Papers

Solidifying and hardening accelerator for hydraulic binders

Strøknings- og hærdningsaccelerator for hydrauliske bindemidler