677 results about "Natural sand" patented technology

The invention relates to radiation shield concrete and a preparation method thereof. The radiation shield concrete is characterized by comprising a cementing material, coarse aggregates, fine aggregates, steel fibre, a high-efficiency slushing agent and water; the cementing material is composed of ordinary portland cement and inorganic mineral admixtures; the inorganic mineral admixtures are siliceous dust and coal ash; the fine aggregates are natural sand, boron glass powder and steel slag powder; the coarse aggregates are steel sections or a mixture of the steel sections and steel slag; the proportions of various types of components are as follows: 500 kg/m<3> of cementing material, 1400-2215 kg/m<3> of coarse aggregates, 750-950 kg/m<3> of fine aggregates, and 155-200 kg/m<3> of water; the high-efficiency slushing agent is 0.5-1.0% of the total weight of the cementing material by weight; and the steel fibre is 1.0-1.5% of the total volume of the concrete by volume. The radiation shield concrete has good mechanical property and lasting quality, good shielding effect on gamma rays, good effect on shielding neutron rays, can be used or comprehensively recycling wastes and has low cost.

The invention discloses a recycled aggregate medium-dry hard concrete prepared by using building waste, which comprises the following raw materials of coarse aggregate, fine aggregate, a gelatinizing agent, a water reducing agent and water, wherein the gelatinizing agent comprises cement and coal ash, and the coarse aggregate comprises 50-100 percent of recycled coarse aggregate prepared from thebuilding waste. A preparation method of the recycled aggregate medium-dry hard concrete comprises the following steps of: pretreating the building waste, removing impurities, remaining waste concrete, waste bricks and the like; crushing and screening to prepare the recycled coarse aggregate; mixing the recycled coarse aggregate, natural sand, cement and water according to the proportion, adding the coal ash and the water reducing agent, stirring uniformly to obtain a mixture; and squeezing and forming the mixture, curing for 2 days to obtain the recycled aggregate medium-dry hard concrete. The invention solves the problems of worsening ecological environment and the like caused by difficulty in treating the building waste; and the building wastes are used for manufacturing the recycled aggregate for replacing natural aggregate, the increasingly deficient natural aggregate and damage degree to the ecological environment are reduced, and the living environment of human beings is protected. The recycled aggregate medium-dry hard concrete prepared by using the method has high strength and high abrasive resistance, and can be used for building base installations such as city roads, housing constructions and the like.

The invention relates to low-viscosity easy-to-pump ultrahigh-strength concrete with average strength of 120MPa. The concrete comprises the following components at single-prescription dosage ratio of kg/m<3>: 400-440 parts of cement, 40-60 parts of silica fume, 60-80 parts of slag micro powder, 100-120 parts of microspheres, 700-750 parts of natural sand with fineness modulus of 2.8-3.2, 980-1,000 parts of stone, 19.5-22.75 parts of additive and 130-135 parts of mixing water, wherein the additive is a polycarboxylate-type high-performance water reducing agent Glenium 8008 and has high water reducing rate, strong viscosity reducing property and high slump retaining property; the expansion degree of the ultrahigh-strength concrete is kept at 700+/-50mm within 4 hours, the back taper time is controlled at 3-8 seconds, the viscosity is kept at 28-35Pa.s, and ultrahigh pumping of 300m and higher is easy to realize. The concrete provided by the invention can meet the performance requirements for ultrahigh concrete pumping of 500m and higher in terms of high slump retaining property, self-compaction property, strength property, low-viscosity property and the like.

The invention discloses a recycled aggregate ecological water permeable brick and a production method thereof. The raw material of the recycled aggregate ecological water permeable brick comprises a basic material, a surface material and water, the basic material comprises recycled aggregate, a gel material and additives, the gel material comprises cement, lime and coal ash, and the additives comprise a polycarboxylate superplasticizer and gelatine powder. The production method of the recycled aggregate ecological water permeable brick comprises the following steps: grading, extracting and preparing for discharging of the recycled aggregate, stirring the basic material, stirring the surface material, forming, curing and forming the finished product. The recycled aggregate ecological water permeable brick disclosed by the invention is produced by building wastes after resourceful treatment, which both promotes the resource utilization of the building wastes to improve the added value of products, and saves a large number of natural sand and stone resources; the produced recycled aggregate ecological water permeable brick has a high permeable rate, a high water-retention rate and high compressive strength, and the compressive strength reaches 30 MPa; and the permeation coefficient is 0.5 cm/s, which is 50 times as large as that of the existing national standard and much better than the properties of similar natural material products.

A half-mould shaping technology for metallic plate features that the solid particles are used to replace the rigid male mould. It includes such steps as providing high-hardness steel balls with diameter less than 4 mm or natural sand as force transfer medium, making a female mould, loading a metallic plate in it, adding said force transfer medium on the plate, and using a pressing head to press them for the plastic deformation of metallic plate.

The invention relates to a preparation method of machine-made sand capable of replacing natural sand. The machine-made sand is mixed by four or more than four kinds of sand in different specifications as semi-finished products under constraint of graduation, content of mountain flour, clay lump content and fineness modulus of sand for buildings. The method is helpful for recycling waste resources and has the advantages of low comprehensive cost, simpleness in operation, environment-friendly process, large-scale continuous production and the like. The technical quality of the product fully meets the standard of sand for buildings and can completely replace natural sand, so that the machine-made sand can be widely applied to the field of concrete for buildings such as bridges, roads, tubular piles and buildings.

The invention provides pre-coated sand, a preparation method of the pre-coated sand and a composite water permeable brick. The pre-coated sand comprises natural sand, pre-coating resin, pre-coating curing agent, coupling agent and lubricating agent. The pre-coating resin is weather-resistant alicyclic epoxy resin, and the pre-coating curing agent is modified alicyclic polyamine. The composite water permeable brick comprises a sand foundation surface layer and a concrete bottom layer; the sand foundation surface layer comprises pre-coated sand and surface material binding agent; and the concrete bottom layer comprises aggregate, cement, fly ash, water reducing agent and water, wherein the pre-coated sand is that of the present invention. The composite water permeable brick made of the pre-coated sand has the characteristics of high strength and good water permeability, the molding technology of the composite water permeable brick is simple, and the cost is low.

The invention provides a precast concrete pile and a manufacturing method thereof. The precast concrete pile is obtained by mounting concrete into a mold mounted with a reinforcement cage framework, closing the mold, tensioning the mold, centrifugally shaping the mold, curing the mold by steam at a normal pressure; releasing the mold and curing the concrete by steam at a high pressure; raw materials of the concrete comprise a cementing material, a fine aggregate, a coarse aggregate, an admixture and water, wherein the fine aggregate is a machine-made sand or a mixture of the machine-made sand and a natural sand; the percentage of the machine-made sand in the fine aggregate by weight is 5-100%; the machine-made sand is obtained by mechanically crushing stone raw materials, such as mine tailings, industrial tailings and the like, screening the crushed stone raw materials in a graded way and removing dust from the screened stone raw materials; fineness modulus of the machine-made sand is 2.3-3.8; grain gradation of the machine-made sand meets requirements on an area 1 or an area 2 of a standard sand; and stone powder content of the machine-made sand is 2-8 wt%. According to the invention, the concrete cost is reduced and resource utilization rate is increased; and the used machine-made sand has the advantages of low silt content and controllable stone powder content, so that the performance of the precast concrete pile is improved.

The invention relates to waterproof and crack-resistant mortar for buildings prepared from steel slag. The waterproof and crack-resistant mortar comprises the following components in weight percentage: 55-80% of steel slag with granularity of not more than 4.75 mm, 15-40% of silicates cements, 0.5-5% of acrylic acid gelatine powder, 0.05-5% of water-retaining agent, 0.1-1.0% of wood fiber, 0-0.5% of water reducing agent and 0-0.5% of organosilicon water repellent. Compared with the prior art, the waterproof and crack-resistant dry-mixed mortar for buildings is prepared from the steel slag which partially or totally replaces natural sand, thereby protecting natural ecology and environment, comprehensively utilizing the steel slag and improving additional values thereof and having the advantages of high waterproof efficiency, overall crack resistance, excellent impact resistance and flexibility, favorable construction and workability, energy saving, consumption reduction, stable performance and simple construction; and the mortar does not contain poisonous and harmful substances.

The present invention provides an artificial turf runway surface suitable for supporting take off, landing and taxiing of aircraft. The turf system cures many of problems and pitfalls associated with natural sand or grass systems, such as rutting, bare spots, erosion, unevenness, standing water as well as other problems associated with natural grass airstrips. The synthetic surface also removes nesting materials and food and thereby dissuades birds and other animals from landing and congregating thereon. The system includes a synthetic covering, such as an artificial turf covering, one or more sheeting or flow through membranes, a compacted rock base suitable for supporting the aircraft when landing, tacking off and taxiing.

The invention relates to a production method of a concrete mixture, in particular to a method of producing concrete mixture by using machine-made sand instead of natural sand. The machine-made sand and gravel after being measured are fed into a stirrer to be stirred uniformly, then 70-80 percent of water of the total water is added into the mixture, which is stirred again so as to lead the mixture to become wet; measured cementing materials are put into the stirrer, and the residual water of the total water and concrete additive are added into the stirrer to be stirred uniformly. The concrete mixture prepared by the invention overcomes the defects existed in the concrete mixture which is prepared by employing machine-made sand instead of natural sand with the existing traditional technology, thus improving the property of the concrete mixture which is produced by adopting machine-made sand.

The invention discloses a semi-flexible pavement material and a pavement construction method thereof. According to key points of the technical scheme, components of the semi-flexible pavement materialinclude an asphalt mixture serving as a large-pore matrix and cement slurry serving as a filler, wherein a weight percentage of the asphalt mixture is 70-80%; a weight percentage of the cement slurryis 20-30%; the asphalt mixture contains the following components in parts by weight: 1-2 parts of SBS modified asphalt, 4-5 parts of coarse aggregate, 0.5-0.8 part of fine aggregate, 0.2-0.3 part ofwater, 0.4-0.5 part of limestone dust and 0-0.005 part of a lithium salt composite early strength agent; the coarse aggregate is natural sand with a particle size of 13.2-16mm; the fine aggregate is natural sand with a particle size of 4.5-9mm; and the cement slurry contains the following components in parts by weight: 0.5-1.5 parts of Portland cement, 0.2-0.3 part of super-fine sand, 0.05-0.2 part of fly ash, 0.4-0.9 part of water, 0.05-0.09 part of a UEA expanding agent, 0.2-0.6 part of a water reducing agent, 0.01-0.05 part of polyvinyl alcohol and 0-0.5 part of BD emulsion. The aim of prolonging the service life of the semi-flexible pavement is achieved.

The invention discloses baking-free hollow thermal insulation blocks and a preparation method thereof. The baking-free hollow thermal insulation blocks are characterized by being prepared from the following raw materials in part by weight: 100 to 115 parts of waste ceramsite, 110 to 130 parts of cement, 90 to 100 parts of flyash, 23 to 27 parts of pearlstone, 190 to 210 parts of mountain flour, 170 to 190 parts of rive stone, 170 to 190 parts of river sand and 39 to 41 parts of water. Waste ceramic is adopted to be prepared into the waste ceramsite to replace partial natural sandstone, and the flyash replaces partial natural sand and cement, so that the damage to natural resources is reduced. The pearlstone is adopted to serve as fine aggregate of concrete to regulate the porosity of mortar and improve construction workability. The product has good mechanical properties and durability, also has good thermal insulation property, improves the thermal insulation capacity of buildings, and is suitable for various thermal insulation projects. The use and construction of the baking-free hollow thermal insulation blocks are same as that of a common block construction method. The technical scheme has the advantages that: the process is easy to operate, the raw materials are readily available and cheap, the production cost is lower, and the economic and social benefits are better.

The invention discloses a processing method for building waste foamed concrete composite heat preservation building blocks. The invention provides a processing method for the building waste foamed concrete composite heat preservation building blocks. By virtue of the processing method, the performance of a recycled material can be optimized to the maximum extent, so that the compression strength, the shear strength and the heat preservation performance of a finished product can be guaranteed. Each building block comprises a base body and a heat preservation core body. A building block preparation process comprises base body forming, core body preparation, maintaining and drying working procedures; each base body comprises cement, an active mixed material, a modifier and a recycled aggregate. A processing method for the recycled aggregate comprises the steps of (1) classifying and initially sorting building waste; (2) roughly crushing building waste to prepare granular recycled coarse aggregates of which the dimension is smaller than 10mm; (3) performing mechanical enhancement on the recycled coarse aggregates, adding natural sand into the recycled coarse aggregates according to a weight ratio of 1:(0.2 to 1), and taking fine sand, which has the particle size of 0.25-0.5 mm, in the mechanically enhanced aggregates for later use. According to the method, the building blocks are high in bonding strength and uniform, the water absorption property of a single unit is reduced, the production cost is lowered, and the production technology is simple and feasible.

The invention relates to a face plate rock-fill dam structure of reasonably utilizing sand gravel material and a construction method thereof. The invention aims at providing a face plate rock-fill damstructure of reasonably utilizing sand gravel material and a construction method thereof; a sand gravel material near a dam site is put in a drying area of the middle part of a dam body so as to avoid additionally open up a rock-fill material field and protect the biological environment. The face plate rock-fill dam structure of reasonably utilizing sand gravel material is provided with a dam main body; the upstream side of the dam main body is sequentially laid with a transition layer, a cushion layer and a face plate from inside to outside; a special cushion layer is arranged below the cushion layer; a dam base of the upstream side of the main body is provided with a rock ballast backfill area and a silt backfill area, the downstream side of the main body is provided with a dry stone pitching, and a downstream dam base is provided with an oversize stone pressing stone area; and the main body comprises a main rock-fill area and a secondary rock-fill area, a sand gravel area positioned above a seepage line is arranged in a hollow cavity surrounded by both the main rock-fill area and the secondary rock-fill area, and the bottom part of the sand gravel area and the low altitude position of a downstream surface are provided with inverted filter protection layers. The invention is used in face plate dam engineering of the natural sand gravel material near the dam site.

The invention relates to recycled green concrete with low cement content. The recycled green concrete is the concrete prepared through reclaimed sand and recycled stone instead of natural sand and stone, and recycled micro powder, slag and limestone powder instead of most of the cement, wherein the reclaimed sand and recycled stone are obtained by treating construction wastes taking waste concrete as major by cleaning, crushing, grading and mixing in a certain proportion.

The invention provides an earth and stone material grading optimization determining method which comprises the following steps of: changing granularity fractal dimension of earth and stone materials for the earth and stone materials with particle distribution meeting fractal distribution characteristics; preparing a grading earth and stone material sample with different particle size distribution functions; establishing a function relationship of extreme value dry density, modulus of compression, shearing strength and grading granularity fractal dimension through a field or indoor test; and regulating the granularity fractal dimension to obtain earth and stone material grading with a better filling relationship, easier compactness, higher modulus and strength. The earth and stone material grading optimization determining method can be used for a particle grading optimization design of rockfill materials and natural sand gravel materials.

The invention belongs to concrete materials and in particular relates to reactive powder concrete which can be maintained at room temperature. The non-steamed reactive powder concrete of the invention is prepared by mixing cement, superfine steel slag powder, natural sand, steel fiber, water reducing agent and water in a mass ratio of 1: 0.10-0.25: 1.25-1.45: 0-0.25: 0.01-0.04: 0.15-0.28. In the invention, natural sand replaces quartz sand, the 200-grade reactive powder concrete is prepared by maintenance at room temperature, so raw material cost and concrete maintenance cost can be obviously reduced; a great amount of industrial residues are used, so the non-steamed reactive powder concrete has the advantages of low cost, sources conservation, waste recycling, environment protection and the like. The maintenance process of the non-steamed reactive powder concrete needs no high temperature or high pressure, so the production and construction processes are simplified. The non-steamed reactive powder concrete is applicable to production of thin-wall products or elongated members and can be used for producing reinforced concrete members such as plates, blocks and the other structure forms, so the market application prospect is promising.

The invention relates to recycled high-performance concrete and a preparation method thereof. The recycled high-performance concrete is prepared from recycled coarse aggregates, made from crushed construction waste, as a raw main raw material, and added with natural sand, cement, coal ash, aluminum dross, an admixture, graphene and water in a stirring manner. According to the preparation method, a micropore of a cement-based composite material is filled with a nanometer material, namely graphene, so that the effects of reinforcing, toughening, and reducing the shrinkage are achieved. The aluminum dross produced in the electrolytic aluminum production process is adopted as the admixture; and aluminite powder in the aluminum dross expands in water, so as to play a shrinkage-compensating role. The concrete is small in shrinkage besides good working performance, durability and relatively high strength, and can be widely applied to road engineering, structure engineering and the like.

The present invention discloses a self-compacting concrete prepared from iron ore tailings, and a preparation method thereof. The self-compacting concrete is prepared through adding 38.00-46.00% of a coarse aggregate, 23.00-37.00% of a fine aggregate, cement, 15-24% of a cementing material and 0.30-0.48% of an additive to water. The coarse aggregate is prepared through mixing crushed stones with particle sizes of 5-20 mm. The fine aggregate is the mixed sands prepared from iron ore tailings and machine-made sands or natural sands, wherein the mixed sands meet the technical requirements of thesands in the region II, preferably that a mass ratio of the iron ore tailings to the machine-made sands or the natural sands is 3:7-7:3. The cementing material is a mixture, wherein the mixture comprises cement, fly ash and ground slag powder. A mass ratio of the water to the cementing material is 0.30-0.50. The additive is a mixture, wherein the mixture comprises a water reducing agent and a tackifier, the water reducing agent is a polycarboxylic superplasticizer, the tackifier comprises a cellulose polymer or an amide polymer. With the present invention, the damage to the ecology environment due to the natural sand mining is reduced; the damage to the environment due to the iron ore tailings is reduced; the waste can be utilized; a purpose of reutilization of the resource is achieved; with adopting the iron ore tailings, the concrete cost can be substantially reduced, and significant social benefits and economic benefits are provided.

The invention provides a strength controllable coal ash-based polymer concrete. The polymer concrete comprises a mixed solid phase and a mixed liquid phase, wherein the weight ratio of the mixed solid phase and the mixed liquid phase is 11:1, the mixed solid phase comprises the following components in parts by weight: 45-55 parts of coarse aggregate gravel, 13-33 parts of fine aggregate natural sand, 19-27 parts of coal ash, 0-8 parts of silica fume, and 0.05-0.12 part of sodium tripolyphosphate, and the mixed liquid phase comprises the following components in parts by weight: 67-75 parts of liquid sodium silicate for industrial use, and 25-33 parts of 10-18mol/L of sodium hydroxide solution. A preparation method for the coal ash-based polymer concrete is simple, has no toxicity and no contamination, and has low cost, and the raw material spreads all over the world and is expected to be used in fields such as corrosion resistant concrete construction, utilization of industrial wastes, rapid patching materials, high-strength high performance materials and the like. Furthermore, according to the coal ash-based polymer concrete, large amount of industrial waste coal ash can be efficiently used, so that the coal ash-based polymer concrete has great significance to conservation of energy and resources and environment protection. The invention also provides the preparation method of the coal ash-based polymer concrete.

The invention discloses high-performance steam-curing-free durable concrete containing metakaolin and a construction method of segments. The steam-curing-free durable concrete containing metakaolin is characterized by comprising the following components in parts by weight: 100 parts of silicate cement, 10-50 parts of pulverized fuel ash, 5-20 parts of metakaolin, 180-280 parts of natural sand, 300-370 parts of broken stone, 0.6-1.0 part of polycarboxylate water reducer, and 37-45 parts of mixing water. Concrete segments with the designed size and shape, which are prepared by the construction method disclosed by the invention, have the characteristics of good operation performance, achievement of rapid turnaround of a mold without steam curing, low energy consumption, high early-stage, middle-stage and later-stage mechanical properties, excellent durability and good volume stability.