448 results about "Freezing thawing" patented technology

The invention discloses a system for testing rock damage and permeability under the coupling effect of temperature stress and circumferential seepage. The system comprises a frozen-heave force test device and a permeation test device, wherein the permeation test device comprises a pressure chamber for loading a rock test piece to be tested, a pressure loading device, a permeation pressure increasing and measuring device, a water bath heating device, an ultrasonic damage test device and a data acquisition device. The invention further discloses a method for testing rock damage and permeability under the coupling effect of temperature stress and circumferential seepage. The method comprises the following steps: carrying out repeated freezing-thawing tests on a rock by the frozen-heave force test device, measuring the frozen-heave force change of the rock test piece, putting the rock into the pressure chamber, applying a pressure to the rock test piece by the pressure loading device, and testing a rock permeation coefficient k and ultrasonic wave speed transmission time t under the action of flowing liquid with different temperatures and pressures so as to make a research on rock damage and permeability.

The invention relates to a water-heat-force coupling testing system for a large-scale high-pressure soil mass freeze thawing process. The system comprises a test bench, and a loading system, a temperature control system, a water charging system and a data acquisition system which are connected with the test bench. A test bench main body is a sampling barrel, can bear the maximum internal pressure of 15MPa and can contain a maximum sample of phi 500mm*1000mm. The loading system is arranged on the upper part of the test bench, the water charging system is arranged on the bottom of the test bench, and a sensor is buried in a soil mass and can acquire internal temperature, water and stress information of the soil mass. The temperature control system consists of a top plate, a barrel body, a bottom temperature control tube, a thermal insulation layer and a high and low temperature thermostatic bath and has a good temperature control effect. By virtue of the system, freeze thawing tests can be performed on large-scale samples according to a high-pressure solidification-loading freezing path, a dynamic water-heat-force coupling function in a freeze thawing process can be directly understood, and a deep soil mass freeze thawing process can be stimulated more truly, so that support is provided for water-heat-force coupling researches in the technical field of artificial deep stratum freezing.

The invention relates to a microwave liquid nitrogen synergic freeze thawing coal seam anti-reflection method. According to the method, a freeze thawing drill hole is drilled in a coal seam, and two gas extraction drill holes are constructed at two sides of the freeze thawing drill hole. A microwave antenna, a coaxial waveguide, a water injection tube and a liquid nitrogen tube are sent into the freeze thawing drill hole together; firstly, a water injection pump is started, and water is injected into the freeze thawing drill hole; then a liquid nitrogen pump is started, and liquid nitrogen is injected into the freeze thawing drill hole to freeze water in the hole into ice so as to fracture the coal seam; and finally, a microwave generator is started, and produced microwave reaches the microwave antenna via a rectangular waveguide, a waveguide converter and the coaxial waveguide and is radiated to the freeze thawing drill hole by the microwave antenna, so that ice in the hole is quickly melted and gasified, high-temperature high-pressure water steam continues to fracture the coal seam, and gas is continuously desorbed at high temperature and rushes to the gas extraction drill holes along fractures in coal. According to the invention, microwave radiation is combined with liquid nitrogen freeze thawing, thus greatly improving the porosity and the permeability of the coal seam, promoting gas desorption, and further greatly improving the gas extraction efficiency and having wide practicability.

The invention discloses a method for calculating dynamic water storage capacity runoff yield in soil freeze-thaw process, and belongs to a hydrological science category in geophysical science categories. The method comprises the following steps of: calculating frozen soil depths at different times in grids of a watershed according to soil temperature distribution; analyzing day-by-day spatial distribution conditions of the frozen soil depths so as to obtain field capacities, distributed along with time, of aeration zones in different grids of the watershed; finding out the maximum field capacities in different grids of the watershed, and calculating the maximum water-holding capacity of the watershed; and calculating a soil freeze-thaw runoff yield of the watershed according to the obtained maximum field capacities in different grids and the maximum water holding capacity of the watershed. According to the method disclosed by the invention, the day-by-day soil freeze/thaw, frozen soil depths and soil temperatures can be simulated according to observed air temperatures, and the day-by-day process of thaw/rainfall runoff can be calculated according to rainfall observation, so that the runoff simulation precision in soil thaw periods in spring is improved, scientific basis is provided for the spring flood prevention decisions, and the gap of frozen soil area runoff yield calculation in the existing home and aboard hydrological models is filled.

Disclosed are latex polymers and an aqueous coating compositions having excellent freeze-thaw stability, open time, stain resistance, low temperature film formation, foam resistance, block resistance, adhesion, water sensitivity and a low-VOC content. The latex polymers and aqueous coating compositions include at least one latex polymer derived from at least one monomer copolymerized or blended with an alkoxylated compound, for example an alkoxylated tristyrylphenol or an alkoxylated tributylphenol. Also provided is an aqueous coating composition including at least one latex polymer, at least one pigment, water and at least one freeze-thaw additive. Typically, the freeze-thaw additive in an amount greater than about 1.3% by weight of the polymer, typically in an amount greater than about 2% by weight of the polymer, in an amount greater than about 4% by weight of the polymer, in an amount greater than about 7.5% by weight of the polymer, in an amount greater than about 10% by weight of the polymer or in an amount greater than about 20% by weight of the polymer.

The invention relates to a concrete admixture, in particular to a composite cement preservative which can enhance the salty ion erosion resistance, freezing-thawing cyclic damage resistance and penetration resistance of concrete. The concrete preservative disclosed by the invention comprises the following components in percentage by weight: 30.0-50.0 percent of mineral admixture, 30.0-50.0 percent of expanding agent, 5.0-10.0 percent of corrosion inhibitor, 0.001-0.005 percent of air entraining agent and 1.0-10.0 percent of water reducing agent. By adopting the concrete preservative disclosed by the invention, the compactness of concrete can be enhanced, the concentration of sulfate ions capable of invading concrete can be lowered, the pore diameters of capillary pores can be reduced and the precipitating speed of calcium hydroxide from set cement can be restrained, so that the structural durability of concrete is enhanced. The concrete preservative is suitable for reinforced concrete structures in unfavorable geological regions, such as coal measure strata containing sulfate and magnesium and chloride ions, sulfide ore strata, seashore saline fields, coastal harbors and the like, as well as marine waters.

The invention relates to a device for simulating the migration and transformation of pollutants in a freeze-thawing process of soil. The device comprises four parts: a freeze-thawing box, a heating device, a refrigerating device and a controller, wherein the freeze-thawing box consists of a box body and a cold-air plate; two side surfaces of the box body are provided with glass windows, a space used for mounting the cold-air plate is reserved on the top part of the box body, and the cold-air plate is uniformly provided with air holes; two diagonals of the box body are equidistantly provided with temperature sensors; a plurality of earth column barrels are arranged in the box body, thermistor thermometers are vertically arranged on an upper layer, a middle layer and a lower layer in each earth column barrel, and each earth column barrel is connected with the controller; displacement sensors are arranged on the top plates above the earth column barrels, and the heating device is arranged at the bottom part of the freeze-thawing box; the refrigerating device is connected with a cold room; and the controller is arranged on the outer part of the freeze-thawing box, and connected with the freeze-thawing box, the heating device, the refrigerating device, the thermistor thermometers and the temperature sensors respectively.

A composition and method for reducing freeze-thaw heave risk over flash-filled voids are disclosed. A composition can include cementitious fly ash, water and cellular foam. The composition can optionally include a filler, e.g., Type F fly ash, or additional desired components. A method can include mixing the desired composition and applying the composition to a void. The method can optionally include determining the desired composition based on various factors.

A method of delivering an admixture providing freeze-thaw resistance to a cementitious composition is provided which includes the addition of a viscosity modifying admixture containing at least one of polymeric microspheres, at least partially degradable polymeric particles, or gas generating additives to cementitious compositions. The polymeric microspheres, at least partially degradable polymeric particles, and gas generating additives provide void spaces in the material matrix, and such void spaces act to increase freeze-thaw durability of the material.

Waterborne coatings are described having an acceptable balance of properties both during the storage of coating, application and drying. The period in which irregularities in a freshly applied coating can be repaired without resulting in brush marks is referred to as the open time. Aqueous coatings generally employ dispersed high molecular weight polymers as binders. These binders often provide short open times when the coating is dried since the dispersed polymer particles tend to be immobilized quickly in the edge region of an applied coating. As a result, the viscosity of the coating increases rapidly, which leads to a limited window of workability. The instant invention provides additives that are not volatile but that will extend the time that the film is malleable after after it is applied without interfering with other attributes, such as the resistance of the coating to freezing while in the can prior to application.

The invention relates to an ultrahigh-performance cement-based composite material. Particle gradation of a polynary gelling material and particle gradation of aggregates are optimized, and a water reducer and other additives are used, so the compressive strength under 28d standard curing reaches 170MPa or above on the premise that concrete has good fluidity. The material has the following technical advantages: construction fluidity requirements are met under a low water-binder ratio; under standard curing conditions, the strength of the concrete in 7d age reaches 120MPa or above, and the strength of the concrete in 28d age reaches 170MPa or above; compared with RPC which only can be used to produce prefabricated parts, the composite material can be stirred and constructed in any occasions without hot curing or pressure forming; the impermeability, the carbonization resistance, the chloride ion penetration resistance and the freeze thaw cycle resistance of the composite material are better than those of common concrete; and the composite material can be used to produce member products with the cross section being 50% (or more) than the common concrete member products.

The invention discloses an organosilicon concrete protective agent and a preparation method. The organosilicon concrete protective agent comprises the main compositions in percent by volume: 50-60% of an alkyl alkoxy silane, 5-10% of terminal-substituted polydimethylsiloxane, 3-5% of an emulsifier, 0.05-1% of a catalyst, 5-10% of a solvent and 20-30% of water. The protective agent is prepared by uniformly mixing the alkyl alkoxy silane, terminal-substituted polydimethylsiloxane and the emulsifier in the organic solvent at room temperature, then adding the catalyst to perform a uniform reaction, then dropwise adding the completely-reacted oil phase system into deionized water, and performing high-speed shearing for obtaining a paste. The preparation method is simple, the coating operation is simple, the cost is low, when the concrete surface is coated with the organosilicon concrete protective agent, a layer of a hydrophobic film is formed along the aperture inner walls of concrete, so that freeze-thaw cycle, chloride ion erosion and the like can be prevented, and the organosilicon concrete protective agent is applicable to facilities such as highways, bridges, tunnels, seaport wharfs, airports and the like, and is applicable to industrialized production.

The invention discloses anti-seepage, anti-freeze-thaw self-compacting concrete and a preparation method thereof. The anti-seepage, anti-freeze-thaw self-compacting concrete comprises the following components in parts by weight: 350-370 parts of cement, 25-45 parts of fly ash, 25-35 parts of modified metakaolin, 30-50 parts of mineral powder, 770-800 parts of medium sand, 810-830 parts of crushedstone, 20-40 parts of silica fume, 170-180 parts of water, 1-3 parts of a water reducing agent, 20-34 parts of an expansion agent, 2-6 parts of an air entraining agent, and 10-20 parts of a fiber composition, wherein the fiber composition is prepared by mixing a modified polyester fiber, a basalt fiber and a polyacrylonitrile fiber in a mass ratio of 1:0.6-0.9:0.3-0.6. The anti-seepage, anti-freeze-thaw self-compacting concrete has the advantages of good workability and fluidity, and excellent anti-seepage performance and anti-freezing performance.

The invention relates to an ultra-low temperature freeze-thaw cycle test method of a cement-based material. In the method, liquid nitrogen is taken as a freezing raw material, and with utilization of the ultra-low temperature effect of the freezing raw material in gasification, the matrix of the cement-based material is damaged from the gel pore level so as to speed up freeze-thaw damage progress and quickly evaluate the freezing resistance and durability of the cement-based material. The invention achieves the convenience and quickness of the freeze-thaw cycle test of the cement-based material, and solves the problem of inconveniences of construction work and quality control due to slow process of the freeze-thaw cycle test. Moreover, the invention has the advantages of convenient, fast, good economic benefit and the like.

An optical fiber concrete freezing-thawing expansion strain monitoring sensor comprises a single mode anti-bending optical fiber winding coil, a temperature compensation optical fiber grating, a concrete cylinder which is 5cm-8cm in diameter, a cement mortar protective layer, a steel pipe and an optical cable. The concrete cylinder is manufactured by concrete which has a same ratio as measured concrete materials, and the optical fiber winding coil is used for directly measuring circumferential deformation of the concrete cylinder caused by freezing-thawing. Circumferential deformation of the concrete cylinder in a whole measuring point can be monitored from a service period to the whole process that the protective layer is cracked and stripped after the interaction process of a plurality of freezing-thawing circulating periods is undergone, so that concrete freezing-thawing expansion strain is accurately monitored. An optical fiber sensor technology is adopted, so that durability of the sensor is greatly improved. The sensor manufactured through a packaging method is suitable for freezing-thawing expansion strain monitoring of bridges, dams and other concrete structures, and the optical fiber concrete freezing-thawing expansion strain monitoring sensor has the advantages of being simple in process, convenient to arrange, high in accuracy, long in service life and the like.

Composition and process of surface modification of soil particles by coating to improve fertility, better moisture and nutrients retention, flooding resistance, and longer freeze-thaw-freeze cycle life.

The invention discloses a high-temperature melt unloading device capable of achieving continuous glass solidification treatment of high-level liquid waste for a cooling crucible. The high-temperature melt unloading device comprises a crucible bottom and a freeze-thawing valve unloading device body. The freeze-thawing valve unloading device body comprises an unloading pipe and a medium-frequency induction coil. The unloading pipe is connected to the lower portion of the crucible bottom and designed to be in a sleeve mode. The unloading pipe is wound with the medium-frequency induction coil. According to the high-temperature melt unloading device, operation is easy, the process is controllable, and continuous, safe and stable operation of the device is ensured when solidification treatment is carried out on radioactive waste through the cooling crucible.

Methods for stabilizing chemical compounds, particularly pharmaceutical agents, using nanoparticulate compositions are described. The nanoparticulate compositions comprise a chemical compound, such as a pharmaceutical agent, and at least one surface stabilizer. The component chemical compound exhibits chemical stability, even following prolonged storage, repeated freezing-thawing cycles, exposure to elevated temperatures, or exposure to non-physiological pH conditions.

The invention relates to a snow melting system and a method for recycling accumulated snow, particularly to a hot-air circulating two-layered snow melting system and the method for recycling accumulated snow, which solve the problems that the existing method for treating the accumulated snow wastes resource and pollutes the environment. The hot-air circulating two-layered snow melting system includes a two-layered subsurface-flow constructed wetland landscape pond and a snow melting well, wherein the snow melting well includes a thermal insulation cover, a well wall, a thermal insulation operation door, a heating grate A, a heating layer, a bottom heating pipe, a water drain pipe, a first step, a first rotating shaft, a heating vertical pipe, a groove and a filter grating. The method includes the following steps: collecting the accumulated snow, throwing the accumulated snow into the snow melting well through the thermal insulation operation door, and carrying the melted snow to the two-layered subsurface-flow pond through the deposited and overflowed clear water. The hot-air circulating two-layered snow melting system avoids the environmental pollution caused by snow melting agent, as well as the resource waste caused during accumulated snow transferring and toppling, is environment-friendly, facilitates the timely accumulated snow treatment, avoids the pollution caused by long-time exposure, and solves the road freezing problem caused by repeated freeze-thaw. The method is used for recycling the accumulated snow.