An axial compression 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 axial compression column includes a steel tube (1), high-strength fresh concrete (2), normal-strength demolished concrete lumps (3), a spiral stirrup (4), and longitudinal erection bars (6). The spiral stirrup (4) is arranged at a middle part 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.

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.

The present invention relates to a method for treating waste material comprising organic components and low and/or medium level radioactive agents. The method comprises encapsulating the waste material into a matrix, gasifying the waste material at a temperature between 600 and 950° C. to form a gaseous fraction and a solid fraction comprising low and/or medium level radioactive agents and combustion residues of the organic components and encapsulating the solid fraction by a geopolymer matrix comprising metakaolin.

The present disclosure provides asphalt modified red mud for porous pavement material and an application thereof. The porous asphalt pavement material includes asphalt, red mud and aggregate; the mass ratio of asphalt to red mud is 1:(0.10-0.15), the mass ratio of the total mass of asphalt and red mud to aggregate is (0.08-0.12):1. With regard to the asphalt modified with red mud for porous pavement material provided in the present disclosure, asphalt is modified with red mud, and aggregate is added to synergize with red mud so as to improve the purification properties and mechanical properties of the porous asphalt pavement material efficiently. In the embodiments of the present disclosure, the purification rate of suspended matter by the asphalt modified with red mud for porous pavement material reaches 54.9-58.6%, and the purification rate of heavy metals (iron and lead) reaches 34.3-46.1%.

Methods and systems for calcining dewatered tailings and/or mine waste are disclosed herein. In some embodiments, the method comprises (i) processing dewatered tailings comprising clay minerals, (ii) calcining the processed tailings to produced calcined tailings, and (iii) altering a composition and/or one or more characteristics of the calcined tailings to produce a cementitious product. Altering the composition can include blending the calcined tailings with one or more additives, such as lime, dolomitic lime, lime kiln dust, argillaceous limestone, limestone, pulverized quicklime, ground calcium carbonate, quicklime, gypsum, natural pozzolans, artificial pozzolans, water, flow aids, or the like.

An asbestos waste neutralization device, that includes an acid tank and a vat containing a diluted acid solution, in which waste containing asbestos is dipped, the diluted acid solution neutralizing the waste containing asbestos during a neutralization reaction. The device further includes a filtration unit to separate, at the end of the neutralization reaction, solid inert waste from a liquid phase of the acid solution, and a regeneration unit for the liquid phase of the acid solution, which adjusts the hydrogen potential of the liquid phase of the acid solution by adding concentrated acid contained in the acid tank. In addition, the device includes an attenuation sensor for regenerated liquid phase of the acid solution from the regeneration unit, and a selective precipitation unit for the regenerated liquid phase of the acid solution, depending on the degree of attenuation the attenuation sensor senses.

An asbestos waste neutralization device, that includes an acid tank and a vat containing a diluted acid solution, in which waste containing asbestos is dipped, the diluted acid solution neutralizing the waste containing asbestos during a neutralization reaction. The device further includes a filtration unit to separate, at the end of the neutralization reaction, solid inert waste from a liquid phase of the acid solution, and a regeneration unit for the liquid phase of the acid solution, which adjusts the hydrogen potential of the liquid phase of the acid solution by adding concentrated acid contained in the acid tank. In addition, the device includes an attenuation sensor for regenerated liquid phase of the acid solution from the regeneration unit, and a selective precipitation unit for the regenerated liquid phase of the acid solution, depending on the degree of attenuation the attenuation sensor senses.

Multi-solid waste activated concretes with high-silicon iron ore tailings and preparation methods thereof are disclosed. In at least some embodiments, the concrete is prepared from raw materials including 360-380 kg/m.sup.3 of a cement, 30-40 kg/m.sup.3 of fly ash, 30-40 kg/m.sup.3 of a modified ultrafine sand of high-silicon iron ore tailings, 930-950 kg/m.sup.3 of a waste stone of tailings, 870-930 kg/m.sup.3 of a fine sand of tailings, 160-170 kg/m.sup.3 of water, and 4-8 kg/m.sup.3 of an additive.

Methods and systems for calcining dewatered tailings and/or mine waste are disclosed herein. In some embodiments, the method comprises (i) processing dewatered tailings comprising clay minerals, (ii) calcining the processed tailings to produced calcined tailings, and (iii) altering a composition and/or one or more characteristics of the calcined tailings to produce a cementitious product. Altering the composition can include blending the calcined tailings with one or more additives, such as lime, dolomitic lime, lime kiln dust, argillaceous limestone, limestone, pulverized quicklime, ground calcium carbonate, quicklime, gypsum, natural pozzolans, artificial pozzolans, water, flow aids, or the like.