Corrosion mitigating cement compositions and methods for their preparation are provided. The cement compositions are derived from self-cementing pozzolans and chemical accelerators, retarders, mechanical strength modifiers and corrosion inhibitors. The corrosion inhibitors include boron compounds such as boric acid. Concretes prepared using the cement compositions possess low conductivity and a conductivity which further decreases with aging.

A voltage source includes two electrically conductive terminals (101, 102) with an electrolyte (103) between them. Said electrolyte (103) is a mixture in which the main component is ash produced in a power plant or an incineration plant.

An acoustical geopolymer panel element includes a layer including a fibre component and a geopolymer binder made from a mixture including ground mineral wool, and an additional layer including mineral wool. The layer including a fibre component and a geopolymer binder has a density in the range of 20-400 kg/m.sup.3, a porosity in the range of 0.75-0.99 and a thickness in the range of 5-75 mm. The ground mineral wool may be ground glass or stone wool and the fibre component may be a wood fibre component, a polymer fibre component and/or a mineral wool component. Further, a geopolymer mixture is provided upon recycling mineral wool which is ground to powder and mixed with an alkali activator component. Additionally, a method for producing acoustical geopolymer panel elements includes grinding elements including mineral wool for provision of a powder component.

According to some embodiments, a curable mixture configured to set in the presence of water, wherein the mixture comprises magnesium oxide, a primary cementitious component and at least one accelerant. A proportion by weight of the primary cementitious component is 80% to 120% of a proportion of magnesium oxide by weight.

The invention relates to a method (100) for selecting the composition of a construction material including an excavated clay soil, said construction material composition to include deflocculating agent and activating agent quantities adapted to the excavated clay soil, said method including a step of receiving (130) a measured value of at least one physicochemical property of an excavated clay soil, and a step of selecting (170) a deflocculating agent quantity and an activating agent quantity adapted to the excavated clay soil. In addition, the invention also relates to a method (200) for calibrating a calculation algorithm for determining the composition of a site construction material, to a construction material formed from an excavated clay soil, and to a system (400) for preparing a construction material including an excavated clay soil.

A geopolymer cementing fluid with controllable thickening time includes the following components in parts by weight: 100 parts of a cementitious material, 10 parts-30 parts of an activator, 0.2 parts-5 parts of a retarder, 0.4 parts-4 parts of an anti-settling agent, and 30 parts-70 parts of water. The geopolymer cementing fluid of the present invention has the advantages of controllable thickening time, excellent compressive strength, good settlement stability, good rheological properties, green and eco-friendly, and the like. The geopolymer cementing fluid can be better suited for the operations of oil and gas well cementing and ensure cementing safety.

An additive for mineral binder composition, in particular accelerators for mineral binder compositions, in particular cementitious binder compositions. The accelerator includes 35 to 99.7 w % of at least one mineral filler F with a particle size D50<5 μm, preferably <4 μm, most preferred <3.5 μm, 0.3 to 65 w % of a sodium aluminate SA, and 0 to 45 w % of at least one other inorganic compound I selected from the group consisting of calcium aluminate cements and/or sulfates of alkali or alkaline earth metals. Further, corresponding mineral binder compositions as well as uses and processes, including the acceleration of setting and curing of mineral binder compositions at low temperatures.

A cementitious composition with accelerated curing at low temperatures particularly at temperatures <5 C., especially at temperatures <0 C. The cementitious composition consists of 2 components with a first component A including at least one ordinary Portland cement, at least one cement selected from calcium aluminate cement and/or calcium sulfoaluminate cement, a powder P, selected from the group consisting of carbonates or hydrogen carbonates of alkali and/or alkaline earth metals, optionally aggregates, optionally other additives and a second component B comprising at least one accelerator, an anti-freeze agent, water, and optionally other additives. The composition shows increased development of compressive strength, maintain good workability, and have particularly low shrinkage, also when cured at temperatures <5 C., especially <0 C., and as low as 10 C.

A granite stone powder phosphoric acid-based geopolymer and a preparation method thereof are provided. The granite stone powder phosphoric acid-based geopolymer is prepared from following raw materials in parts by weight: 35-70 parts of granite stone powder, 15-50 parts of metakaolin, 8-50 parts of fly ash, 8-30 parts of acid activation solution and 8-30 parts of solvent.

Class C fly ash-based cementitious materials, concretes, and related techniques are disclosed. In accordance with some embodiments, an activated class C fly ash-based cementitious material may be produced by intergrinding class C fly ash (e.g., classified to remove quartz and/or other contaminants and, thus, increase the reactive materials present), an activator, sodium citrate, borax, and a polycarboxylate material. The class C fly ash may have an amorphous glass content of about 60 wt % or more, a calcium oxide (CaO.sub.2) content of about 20 wt % or more, and a quartz content of about 10 wt % or less. The activator may be a chemical which reacts with class C fly ash to form strtlingite structures therein when introduced with water. In some cases, the cementitious material may be provided as an all-in-one powder blend. In some cases, techniques disclosed herein may be utilized in providing a fast-setting flowable fill material.