It has been unexpectedly discovered that the addition of a natural or other pozzolan to non-spec coal ash significantly improves the properties of the non-spec coal ash to the extent it can be certified under ASTM C618 and AASHTO 295, as either a Class F or Class C coal ash. The natural pozzolan may be a volcanic ejecta, such as pumice or perlite. Other pozzolans may also be used for this beneficiation process. Many pozzolans are experimentally tested and may be used to beneficiate non-spec coal ash into certifiable Class F coal ash. Additionally, this disclosure provides a method of converting a Class C coal ash to a more valuable Class F coal ash. This discovery will extend diminishing Class F coal ash supplies and turn non-spec coal ash waste streams into valuable, certified coal ash pozzolan which will protect and enhance concrete, mortars and grouts.

The present invention relates to methods for the production of air-cured fiber cement products. More particularly, the present invention provides methods for the production of air-cured fiber cement products, at least comprising the steps of: (a) Providing cured fiber cement powder by comminuting cured fiber cement material; (b) Providing an aqueous fiber cement slurry comprising water, cementitious binder, natural or synthetic fibers and between about 5M % and about 40M % of said cured fiber cement powder; (c) Providing a green fiber cement sheet; and (d) Air-curing said green fiber cement sheet thereby providing an air-cured fiber cement product.

The present disclosure provides a concrete structure strengthened using a grid reinforcement material and non-shrink grout and a method of strengthening the same in which, when strengthening a concrete structure such as a concrete slab or a concrete wall body that is damaged or deteriorated, a grid reinforcement material is mounted on one side of the concrete structure, a formwork is formed on an outer side of the grid reinforcement material to have a required gap, and then the gap is filled with non-shrink grout so that the non-shrink grout is cured therein to strengthen the old concrete structure, thereby being able to automatically fill and repair cracks formed in the concrete structure just by injecting the non-shrink grout without separately performing crack repair on the old concrete structure. Also, the grid reinforcement material may be easily fixed or mounted using a grid fixing device and may be easily applied to strengthening of a concrete structure having a curved surface as well as a concrete structure having a flat surface such as a concrete slab or a concrete wall body. In addition, reinforcing bars may be additionally arranged in a gap between a surface of the concrete structure and the grid reinforcement material so that the grid reinforcement material increases a cover thickness, and thus the concrete structure is remarkably strengthened.

The present invention provides a concrete vacuum tube segment for a hyper-speed transportation system using ultra-high performance concrete (UHPC) and a manufacturing method thereof. A concrete vacuum tube segment for a hyper-speed transportation system can be easily manufactured using UHPC, in which shrinkage and structural cracking do not occur due to mixing a binder and a short fiber to secure airtightness on the basis of a maximum fill theory, and accordingly, shrinkage of the concrete vacuum tube segment can be reduced even in a partial-vacuum state in which the magnitude of drying shrinkage is very small and quick drying occurs; when mixing the UHPC, an antifoaming agent is mixed and a circular vacuum pump is used to remove generated entrapped air to minimize the entrapped air; and a capsule-type crack healing material, which is able to repair fine cracks, is compacted to secure airtightness of the concrete vacuum tube segment.

An activated pozzolan composition includes a fine interground particulate blend of an initially unactivated natural pozzolan and a supplementary cementitious material (SCM) different than the initially unactivated natural pozzolan. The initially unactivated natural pozzolan may include volcanic ash or other natural pozzolanic deposit having a moisture content of at least 3%, and the activated pozzolan composition can have a moisture content less than 0.5% The initially unactivated natural pozzolan may have a particle size less than 1 mm before intergrinding with the SCM. The SCM used to activate the initially unactivated natural pozzolan can be initially coarse or granular with a size greater than 1-3 μm and may include granulated blast furnace slag, steel slag, other metallurgical slag, pumice, limestone, fine aggregate, shale, tuff, trass, geologic material, waste glass, glass shards, basalt, sinters, ceramics, recycled bricks, recycled concrete, refractory materials, other waste industrial products, sand, or natural mineral.

An activated pozzolan composition includes a fine interground particulate blend of an initially unactivated natural pozzolan and a supplementary cementitious material (SCM) different than the initially unactivated natural pozzolan. The initially unactivated natural pozzolan may include volcanic ash or other natural pozzolanic deposit having a moisture content of at least 3%, and the activated pozzolan composition can have a moisture content less than 0.5% The initially unactivated natural pozzolan may have a particle size less than 1 mm before intergrinding with the SCM. The SCM used to activate the initially unactivated natural pozzolan can be initially coarse or granular with a size greater than 1-3 μm and may include granulated blast furnace slag, steel slag, other metallurgical slag, pumice, limestone, fine aggregate, shale, tuff, trass, geologic material, waste glass, glass shards, basalt, sinters, ceramics, recycled bricks, recycled concrete, refractory materials, other waste industrial products, sand, or natural mineral.

Disclosed herein is a composition comprising a cementitious material, a pozzolanic material, aplite, and an aqueous fluid. Also disclosed herein is a method of servicing a wellbore penetrating a subterranean formation, comprising: placing the composition into the wellbore; and allowing the composition to form a set cement. The composition can develop suitable mechanical properties and permeability after setting in a wellbore and be expansive.

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 concrete crack repair material based on nano materials includes raw materials as follows: seaweed, sulphoaluminate cement, natural sand, nano-silica fume, calcium formate, fly ash, anhydrous calcium sulphoaluminate, a polyester fiber, a water reducing agent, a corrosion inhibitor and water. By reasonably selecting the raw materials of the concrete crack repair material and making a reasonable ratio of the raw materials, the concrete crack repair material is obtained with excellent performance such as good compressive strength, bending strength and bond strength, and excellent impermeability and frost resistance. The concrete crack repair material can be used for the concrete crack repair in the marine environment, which has very important application values.

The present invention provides a coal-based solid waste transport and filling integrated machine mining system, comprising a filling hydraulic support (6) and a coal winning machine (7), said filling hydraulic support (6) comprises a hydraulic top plate and a base (601), said hydraulic top plate comprises a hinged front top beam (602) and a rear top beam (603), with a front probe beam (604) attached to front end of said front top beam (602) and a telescopic slide rod (1) connected to rear end of said rear top beam (603), a double transport and single filling non-stop equipment is fixed on the telescopic slide rod (1). The apparatus and method of the present invention weaken the impact of groundwater pollution on mine production and mine ecology, bring good economic and environmental benefits to the mine and promoting safe and green coal mining.