Fast-setting Portland cement compositions for filling voids, such as mine shafts and excavated utility trenches, are described. The Portland cement compositions set quickly and are useful when traditional slow setting compositions are less desirable. The acceleration of the set time results from the addition of dry calcium chloride to the Portland cement composition. The compositions consist of Portland cement, dry calcium chloride, water and sometimes preformed cellular foam. Some compositions can include also include fly ash. The compositions may have a compressive strength of between 0 psi and 30 psi after 4 hours, a compressive strength of between 30 psi and 120 psi after 24 hours, a compressive strength of between 200 psi and 500 psi after 28 days, a penetration resistance of between 0.1 tsf and 5 tsf after 10 hours, a penetration resistance of between 0.8 tsf and 10 tsf after 24 hours, and a removability modulus of between 0.2 and 1.0 after 28 days. Also disclosed are methods of filling a void with fast-setting Portland cement.

Methods of using the set-delayed cement slurries and compositions resulting from the combination of the set-delayed cement slurries are also described. A method may comprise providing a first set-delayed cement slurry comprising a pozzolanic cement and/or a Portland cement, water, and a first cement set retarder; providing a second set-delayed cement slurry comprising calcium-aluminate and a second cement set retarder; mixing the first slurry and the second slurry to form a cement composition; and allowing the cement composition to set.

A foam concrete has constituents that include a cement, a sand, a coarse aggregate, an oil ash, a water, and a foam solution. The foam concrete has a compressive strength of at least 20 MPa, a thermal conductivity of less than 0.41 W/mK and a maximum weight of 1650 kg/m.sup.3.

A method of generating a wellbore treatment fluid comprising: obtaining a target Young's modulus; calculating a compressive strength requirement from a correlation comprising compressive strength and Young's modulus using the target Young's modulus as an input; classifying a plurality of solid particulates using correlations; calculating a reactive index and/or a water requirement for at least one of the solid particulates; and selecting two or more solid particulates from the plurality of solid particulates to create a wellbore treatment fluid, wherein two or more solid particulates are selected such that when the wellbore treatment fluid is prepared and set, the set wellbore treatment fluid has a 24 hour compressive strength greater than or equal to the compressive strength requirement.

The invention relates to a method for producing a solid construction material which is preferably substantially free of hydraulic binder, comprising the steps of: a. extracting a mineral fraction comprising argillaceous particles of a soil; b. optionally adjusting the particle size of the mineral fraction extracted, in particular in relation to its clay, sand, gravel or loam content, if necessary; c. preparing a first aqueous grout from at least one part of the mineral fraction extracted and optionally adjusted in terms of particle size; d. adding a dispersant that can disperse the argillaceous particles in the first grout in order to obtain a second aqueous grout, e. adding a coagulant that can promote the agglomeration of the argillaceous particles in the second grout in order to obtain an aqueous construction material grout; f introducing the construction material grout into a formwork; and g. allowing the evaporation of the water contained in the material grout in order to obtain a solid construction material.

A geopolymer foam composition, an article comprising a geopolymer foam composition, methods for making a geopolymer foam composition, and uses of a geopolymer foam composition.

The invention comprises a concrete form. The form comprises a first concrete forming panel having a first primary surface adapted for forming and contacting plastic concrete and a second primary surface opposite the first primary surface; a layer of insulating material contacting and substantially covering the second primary surface of the first concrete forming panel; and an insulating blanket adjacent the first concrete forming panel. A method of using the concrete form is also disclosed.

Disclosed are a cement composition additive with improved compressive strength and workability, including a polycarboxylic acid copolymer and/or a salt thereof, zinc oxide particles, and a predetermined amount of gluconic acid and/or a salt thereof, and a cement composition containing the same.

A seismic steel tubular column with internal local restraint and filled with high strengthen compound concrete containing normal-strength demolished concrete lumps, and a construction process. The seismic column includes a steel tube (1), high-strength fresh concrete (2), normal-strength demolished concrete lumps (3), horizontal stirrups (4), and longitudinal erection bars (5). The horizontal stirrups (4) are arranged at upper and lower ends inside the steel tube (1). The high-strength fresh concrete (2) is poured and the normal-strength demolished concrete lumps (3) are put alternately inside the steel tube (1). A compressive strength of the high-strength fresh concrete (2) is 30˜90 MPa greater than that of the normal-strength demolished concrete lumps (3).

Water-based paint is used as a sacrificial agent to reduce the detrimental effect of carbon-containing fly ash on the entrainment of air in concrete. The invention provides a composition for reducing the effect of carbon contained in fly ash on air entrainment in cementitious mixtures comprising water, cement, fly ash and entrained air. The composition comprises water-based paint and one or more of pulverized or un-pulverized pozzolan, pulverized or un-pulverized cementitious solids, a superplasticizer, a defoamer, an air-entraining admixture, a water-reducing admixture, a retarding admixture, an accelerating admixture, a hydration control admixture and a rheology modifying admixture. The invention also provides a method of reducing the effect of carbon on air entrainment in carbon-containing fly ash, comprising mixing the fly ash with water-based paint.