A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement: SF:NP in the cementitious blend composition lies in the range of (24-63): (5-44): (32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

A cementitious blend composition and a concrete mix composition preferable for making concrete resistant to high temperatures and alkaline conditions, particularly for making durable concrete for constructing an alumina digester tank in an aluminum smelter. The cementitious blend composition includes at least one hydraulic cement, silica fume (SF), and natural pozzolan (NP), wherein a weight percent ratio of at least one hydraulic cement: SF:NP in the cementitious blend composition lies in the range of (24-63): (5-44): (32-40) with the sum of the weight percentages of the at least one hydraulic cement, the SF, and the NP not exceeding 100%. The concrete mix composition comprises water and the cementitious blend composition, wherein a weight ratio of the water the cementitious blend composition is 0.2-0.5, and wherein the concrete mix composition has a content of the cementitious blend composition of 400-550 kg/m.sup.3.

Methods of wellbore cementing are provided. A method of analyzing a solid particulate including: measuring a water requirement of the solid particulate; and determining an approximation of specific surface area of the solid particulate from the water requirement.

Methods of wellbore cementing are provided. A method of analyzing a solid particulate including: measuring a water requirement of the solid particulate; and determining an approximation of specific surface area of the solid particulate from the water requirement.

Methods and compositions are provided that relate to cementing operations. Methods and compositions that include pumice in geopolymer cement compositions comprising slag.

Methods and compositions are provided that relate to cementing operations. Methods and compositions that include pumice in geopolymer cement compositions comprising slag.

A concrete comprises in relative parts by weight: 100 of Portland cement; 0.25 to 9 of a defoamer; 0.001 to 6 of a surfactant; 0 to 230 of coarse gravel and/or fine gravel and/or shear enhancers; 0 to 85 of sand; 0 to 60 of a particulate pozzolanic or non-pozzolanic material or a mixture thereof having a mean particle size less than 15 micrometers; 0 to 80 of a particulate pozzolanic or non-pozzolanic material or a mixture thereof having a mean particle size between 15 to 88 micrometers; 0.3 to 18 of a water-reducing superplasticizer; 0 to 14 of polyethylene fibers; and 5 to 40 of water. An air mixing process using a tightly sealed mixing tool is used to thoroughly mix the constituents of the concrete before adding the water for curing. By adjusting relative parts in the composition, concretes of high and ultrahigh performance can be achieved efficiently.

A concrete comprises in relative parts by weight: 100 of Portland cement; 0.25 to 9 of a defoamer; 0.001 to 6 of a surfactant; 0 to 230 of coarse gravel and/or fine gravel and/or shear enhancers; 0 to 85 of sand; 0 to 60 of a particulate pozzolanic or non-pozzolanic material or a mixture thereof having a mean particle size less than 15 micrometers; 0 to 80 of a particulate pozzolanic or non-pozzolanic material or a mixture thereof having a mean particle size between 15 to 88 micrometers; 0.3 to 18 of a water-reducing superplasticizer; 0 to 14 of polyethylene fibers; and 5 to 40 of water. An air mixing process using a tightly sealed mixing tool is used to thoroughly mix the constituents of the concrete before adding the water for curing. By adjusting relative parts in the composition, concretes of high and ultrahigh performance can be achieved efficiently.

A free-flowing powder composition includes at least one substrate having pores and an external surface between said pores, said surface functionalized with at least one accelerator for a hydraulic setting composition, said accelerator being liquid, hygroscopic, or deliquescent, and wherein after 15 minutes of immersion of free-flowing powder composition in water at 20° C. at least 80% in weight of said accelerator is solubilized, said free-flowing powder composition being immersed in an amount of water sufficient so that the saturation concentration of said accelerator cannot be reached. There is also a method for preparing said free-flowing powder composition. The use of said free-flowing powder composition as an additive for mortar or concrete composition provides an accelerating effect, an anti-ageing effect and an anti-dusting effect. A dry mortar or concrete composition includes a hydraulic binder, said free-flowing powder composition and a granulate, wet mortar or concrete composition and hardened body obtained therefrom.

A free-flowing powder composition includes at least one substrate having pores and an external surface between said pores, said surface functionalized with at least one accelerator for a hydraulic setting composition, said accelerator being liquid, hygroscopic, or deliquescent, and wherein after 15 minutes of immersion of free-flowing powder composition in water at 20° C. at least 80% in weight of said accelerator is solubilized, said free-flowing powder composition being immersed in an amount of water sufficient so that the saturation concentration of said accelerator cannot be reached. There is also a method for preparing said free-flowing powder composition. The use of said free-flowing powder composition as an additive for mortar or concrete composition provides an accelerating effect, an anti-ageing effect and an anti-dusting effect. A dry mortar or concrete composition includes a hydraulic binder, said free-flowing powder composition and a granulate, wet mortar or concrete composition and hardened body obtained therefrom.