18 results about "Saturated-surface-dry" patented technology

The utility model discloses an inactive micro-powder saturated surface dry sample forming and testing all-in-one machine which comprises a base, the base comprises a base and a hollow supporting boss arranged at one end of the base, and each side face of the supporting boss is provided with a hollow structure and / or a limiting groove communicated with an inner cavity; the sample forming mechanism is arranged on the base and comprises a water storage box for collecting water extruded in the process of pressing the to-be-tested sample and a forming mold which is detachably arranged in the water storage box and is used for filling the to-be-tested sample; the pressure applying mechanism is arranged on the base and is used for applying pressure to the forming mold so as to press and form the to-be-tested sample in the forming mold; and the displacement detection mechanism is arranged on the pressure applying mechanism and is used for detecting the displacement deformation of the sample pressed and formed in the forming mold. The utility model has the beneficial effects that the interference during sample preparation and lofting is avoided, and the accuracy and convenience of measurement are obviously improved.

The application discloses a kind of liquid-solid abrasion under concrete quality loss rate evaluation method and device, belong to civil engineering field.Concrete quality loss rate prediction model is defined, the saturated surface dry mass loss of concrete test piece before and after liquid-solid abrasion effect of different scouring rate, scouring angle, silt content is obtained by abrasion accelerated test, and the concrete quality loss rate is calculated;The calculated value of concrete quality loss rate is substituted into prediction model, and the to-be-solved parameter is fitted to obtain;The to-be-solved parameter fitted to obtain is substituted into prediction model, and the concrete quality loss rate under the liquid-solid abrasion effect of different scouring rate, scouring angle, scouring time, silt content is predicted using model.The abrasion accelerated test described above is realized using concrete quality loss rate test device.The abrasion of concrete member under the condition of different scouring rate, scouring angle, silt content in sea area can be realized by the present application to predict the quality loss rate.

The invention belongs to the technical field of building materials and concrete preparation, and particularly relates to application of surface wetting water absorption in recycled concrete preparation, in the application, a method for obtaining the surface wetting water absorption comprises the steps that the water absorption W of recycled aggregate in a saturated surface dry state and the water absorption Ww of the recycled aggregate in a water absorption saturated state are tested; the surface wetting water absorption rate is the difference value between W and Ww. According to the surface wetting absorption rate, the water amount required by the recycled aggregate to reach the surface wetting state can be obtained, and the water saturation of the recycled aggregate can be controlled through the water amount for surface wetting; the influence on the performance of the recycled concrete due to overlarge water consumption for wetting the recycled aggregate (for example, the water-binder ratio of the aggregate to a slurry interface is increased due to overlarge water consumption, and the compressive strength of the concrete is reduced) is avoided, so that the mechanical property of the recycled concrete is improved (the recycled concrete prepared by the method has higher compressive strength).

The invention provides a phase-change self-repairing lightweight aggregate concrete material and a preparation method thereof.The method comprises the steps that 1, phase-change self-repairing lightweight aggregates prepared from hexadecane, dodecanol, decanoic acid, lauric acid, tetradecanoic acid and a repairing agent are mixed according to the mass ratio of 1: 1: 1: 1: 1, and composite phase-change self-repairing lightweight aggregates are obtained; secondly, the shale pottery sand is pre-wetted to reach a saturated surface dry state; 3, uniformly dry-mixing silica fume, cement, fly ash, floating beads and nano-silica in a concrete mixer to obtain a primarily mixed dry material; 4, adding composite phase change self-repairing lightweight aggregate, 50% of water, 50% of an additive and 50% of carbon fibers into the primarily mixed dry material, and uniformly stirring to obtain a medium mixed material; and 5, adding shale pottery sand, 50% of water, 50% of an additive and 50% of carbon fibers into the medium mixture, and uniformly stirring to obtain the phase-change self-repairing lightweight aggregate concrete.

The application provides a method for measuring the saturated surface dry water absorption rate of concrete coarse aggregate, which mainly uses an oven, a metal mesh basket, a beaker, an electronic balance and other tools, constructs a quantitative relationship model of relevant parameters according to the mass change of the coarse aggregate before and after being soaked in different liquids, and calculates the saturated surface dry water absorption rate of the concrete coarse aggregate. The application is based on the pore structure characteristics and capillary adsorption characteristics of the coarse aggregate, uses the difference in the absorption capacity of the coarse aggregate for different liquids, and the difference in the density and the viscous coefficient of different liquids, and designs the method for measuring the saturated surface dry water absorption rate of the concrete coarse aggregate. The method has the characteristics of simple steps, low cost, reliable test, stable data, easy popularization and the like, overcomes the defects of the traditional method, such as large human operation error and serious subjective experience influence, and can be used for the research and development of automatic equipment and the design of software algorithm, and has good popularization and application value.

The invention discloses a method for measuring saturated surface dry water absorption of regenerated fine aggregate, and belongs to the technical field of building material testing. The method adopts a two-step method to separate free water on the surface of the regenerated fine aggregate, and comprises the following steps: firstly, rapidly removing free water among particles of the soaked saturated regenerated fine aggregate and on the surface of part of the particles through a centrifugal method; secondly, the evaporation rate of free water on the surface of the regenerated fine aggregate is controlled through a temperature control evaporation method; and then judging the saturated surface dry state of the regenerated fine aggregate by adopting a second inflection point appearing at a rapid descending section of the time and moisture content curve, thereby determining the saturated surface dry water absorption rate of the regenerated fine aggregate. According to the method, the saturated surface dry standard state and the corresponding saturated surface dry water absorption rate of the regenerated fine aggregate can be effectively determined, the conversion from qualitative evaluation to quantitative evaluation is realized, and the method is also suitable for testing the saturated surface dry water absorption rate of fine particles such as natural fine aggregate and machine-made sand.

The application provides a kind of iron tailings sand-containing machine-made sand concrete and a preparation method thereof, relates to the technical field of building materials and solid waste resource utilization, and includes obtaining iron tailings sand and machine-made sand, respectively detecting the fineness modulus, 0.075mm below particle content, water absorption and moisture content of the iron tailings sand, and the fineness modulus, stone powder content, water absorption and moisture content of the machine-made sand.The iron tailings sand-containing machine-made sand concrete and the preparation method thereof detect the performance state of the iron tailings sand and the machine-made sand, and combine saturated surface dry conversion, mixing water correction, pre-wetting correction, compound control and segmented mixing, etc.Processing flow, effectively regulate the preparation process of composite fine aggregate, thereby improving the mix proportion adaptability and preparation stability of the iron tailings sand-containing machine-made sand concrete, and reducing the workability fluctuation and performance instability caused by the difference in particle composition and water absorption characteristics of the two types of fine aggregate.

The invention discloses low-strength and low-density self-compacting lightweight aggregate concrete and a preparation method thereof. The low-strength and low-density self-compacting lightweight aggregate concrete is prepared from the following raw materials in parts by mass: 382.8 parts of ceramsite, 202.1 parts of water, 1.645 parts of a water reducing agent, 611.55 to 815.4 parts of river sand, 0 to 49.0 parts of expanded perlite, 155.1 to 470.0 parts of cement, 70.5 to 164.5 parts of fly ash, 70.5 to 164.5 parts of slag powder, 9.4 to 47.0 parts of silica fume and 0.455 to 2.275 parts of PP (Polypropylene) fiber. The preparation method comprises the following steps: weighing the substances in parts by mass, pre-wetting the ceramsite and the expanded perlite, and enabling the ceramsite and the expanded perlite to be in a saturated surface dry state; then uniformly mixing and stirring the weighed river sand, cement, fly ash, slag powder and silica fume with the ceramsite with the saturated surface dry and expanded perlite to obtain a mixture; fully mixing the weighed water and water reducing agent, adding the mixture for 3-4 times, and uniformly mixing and stirring to obtain mortar; finally, the weighed PP fibers are mixed into the mortar, the mixture is stirred to be uniform, and concrete slurry is obtained; pouring the slurry into a mold, covering the mold with a preservative film, and performing normal-temperature indoor maintenance to the age; the formula greatly reduces the use amount of cement and river sand, and has the advantages of good flowing property, light weight, high strength, energy conservation and environmental protection.

The invention relates to the technical field of water absorption determination, in particular to a water absorption determination method and device applied to recycled aggregate, and the method comprises the following steps: selecting a plurality of to-be-determined samples from the recycled aggregate, obtaining particle size distribution data of each to-be-determined sample, generating a particle size distribution curve, drying the soaked to-be-determined samples, and determining the water absorption of the recycled aggregate according to the particle size distribution curve. Collecting the mass of each sample to be detected at each moment in the drying process; calculating the distribution deviation degree of each sample to be detected; obtaining a potential moment; calculating a relative difference degree and a judgment coefficient of each potential moment, and obtaining a target moment; compensating the mass at the target moment to obtain the saturated surface dry mass of each sample to be detected; and correcting the saturated surface dry mass, calculating the water absorption rate of each sample to be measured, and measuring the water absorption rate of the recycled aggregate. According to the method, the influence of particle size distribution difference on water absorption determination is reduced, and the determination accuracy of the water absorption of the recycled aggregate is improved.

The application discloses a pre-mixed high-density compensation shrinkage wet spraying concrete yield shear stress regulation method and relates to the technical field of wet spraying concrete of hydraulic underground caverns, which comprises the following steps: S1, determining a yield shear stress target value τ0,targ in advance; and S2, according to the design strength and the slump, initially selecting the high-density compensation shrinkage wet spraying concrete water-binder ratio W / B, the cement mass mc, the silica fume mass msi, the expansive agent mass mexp, the water consumption mw, the water reducing agent mass mwr, the saturated surface dry state aggregate total mass ma and the mass fraction mPa,i of each particle size aggregate mixing ratio parameters. The application solves the wet spraying concrete mixing ratio production regulation and control problem oriented by the yield shear stress in the wet spraying construction process, realizes the wet spraying concrete production mixing ratio optimization adjustment based on the target yield shear stress, significantly reduces the rebound rate and the pipe blocking probability, and has obvious economic and social benefits.

The present invention belongs to the technical field of building materials, and discloses a modified recycled aggregate, a preparation method thereof, and an application thereof. The preparation method of the modified recycled aggregate of the present invention comprises the following steps: soaking the recycled aggregate in an alkaline solution containing calcium, then adding ethyl orthosilicate and tetrabutyl titanate, then adding a plant-active silicon oxide compound and conducting a hydrothermal reaction, filtering, and uniformly dispersing the mineralized bacteria on the surface of the filtrate to obtain the aggregate. The modified recycled aggregate prepared by the present invention has a significantly lower saturated surface dry water absorption rate than that before modification, and compared with the concrete prepared from the unmodified aggregate, the slump, 28d compressive strength and impermeability of the recycled aggregate concrete prepared from the modified recycled aggregate of the present invention are significantly improved. In summary, the modified recycled aggregate prepared by the present invention realizes resource utilization and performance optimization, which is of great significance for environmental protection, low-carbon development and sustainable development of concrete.

The invention provides a nitrogen fixation and carbon fixation synergistic waste concrete regeneration method and recycled concrete, and belongs to the technical field of recycled concrete.The method comprises the following steps that S1, waste concrete is sequentially subjected to coarse crushing, acetic acid solution activation and medium crushing and conveyed to a fluidized bed reactor to be roasted and reconstructed, and activated aggregate is prepared; s2, introducing the industrial flue gas containing nitrogen oxides into the fluidized bed reactor filled with the activated aggregate through a gas input device, and carrying out mineralization reaction at 40-60 DEG C; s3, injecting carbon dioxide into the fluidized bed reactor, and carrying out nitrogen fixation and carbon fixation collaboration to obtain coated aggregate; s4, carrying out water washing and surface modification on the coated aggregate obtained in S3 by using water washing equipment to obtain saturated surface dry aggregate; and S5, preparing the recycled concrete by using the saturated surface dry aggregate. The problem that in the prior art, waste concrete and industrial flue gas do not cooperate, and certain resource waste is caused is solved.

The invention relates to the technical field of constructional engineering construction, and discloses a metro depot track prefabricated column grouting construction method which comprises the following steps that firstly, a prefabricated column is positioned above a structural bottom plate, and a grouting gap at the bottom is sealed through a plugging assembly comprising a rigid hoop and a flexible liner; then, a grouting device is connected to the lower grouting hole, and grouting materials are pumped from bottom to top to fill an inner cavity; when thick slurry overflows from the upper slurry outlet hole, pumping is stopped, a gravity slurry supplementing device is connected to the highest interface of the top surface, and other orifices are closed; injecting slurry into the funnel container to enable the liquid level to be higher than the top surface of the prefabricated column, supplementing the slurry into the funnel container by utilizing hydrostatic pressure until the liquid level is stable and does not descend any more, and sealing the hole. According to the method, the saturated surface dry treatment of the base surface and the rheological property control of the slurry are combined, through the two-stage operation of mechanical grouting and high-position gravity slurry supplementing, internal air bags and shrinkage disengaging are effectively eliminated, and the compactness and integrity of the prefabricated column connecting joint are guaranteed.

The application discloses a kind of low additional water full recycled concrete based on recycled fine aggregate wet packing gradation optimization and preparation method thereof, belong to building material technical field.The application is classified into three intervals by natural gradation recycled fine aggregate, after pre-wetting to saturated surface dry state, the wet loose bulk density under each mass proportion combination is determined, and the highest density is selected as the optimal artificial gradation;60% of the saturated surface dry water absorption of all recycled aggregates is determined as additional water;cement, recycled fine aggregate, recycled coarse aggregate, initial water and water reducing agent are used to prepare by using the layered feeding process of "cement pre-mixing→ neat paste preparation→ coarse aggregate→ fine aggregate".The obtained concrete has a slump of 160-190mm, a 28-day compressive strength of 25-40MPa, good fluidity, can meet the construction requirements of conventional concrete structure, and does not need chemical modification, low cost, suitable for building solid waste large-scale utilization.

The application provides a nitrogen-fixing and carbon-fixing synergic waste concrete recycling method and recycled concrete, and belongs to the technical field of recycled concrete, and comprises the following steps: S1, waste concrete is sequentially subjected to coarse crushing, acetic acid solution activation, medium crushing, and is transported to a fluidized bed reactor for calcination reconstruction to obtain activated aggregate; S2, industrial flue gas containing nitrogen oxide compounds is introduced into the fluidized bed reactor containing the activated aggregate through a gas input device to cause a mineralization reaction at 40-60 DEG C; S3, carbon dioxide is injected into the fluidized bed reactor to realize nitrogen fixation and carbon fixation synergy, and coated aggregate is obtained; S4, the coated aggregate obtained in S3 is washed and surface modified by using a water washing device to obtain saturated surface dry aggregate; and S5, the saturated surface dry aggregate is used to prepare recycled concrete. The application solves the problem that waste concrete and industrial flue gas are not synergized in the prior art, thereby causing certain resource waste.

The utility model belongs to the field of engineering design, and particularly discloses a fine aggregate saturated surface dry state quantitative spraying and stirring device for assisting fine aggregate density and water absorption tests, which comprises a base, a stand column fixed on the base, a cross rod movably connected with the top end of the stand column, and one end of the cross rod capable of rotating around the top end of the stand column. Through the arrangement of the quantitative sprayer and the stirrer, not only can the amount of water added each time be accurately controlled, but also atomization spraying adding is implemented, and the materials are uniformly dispersed in the aggregate under the assistance of mechanical stirring, so that the aggregate can reach a saturated surface dry state more quickly, and subsequent tests are facilitated.

The invention relates to the technical field of concrete, in particular to concrete capable of circularly absorbing and releasing water and a preparation method thereof.The concrete comprises high-water-absorption aggregate and a functional additive, floating beads are adopted as an open pore water storage unit, shale sand provides structural strength support, ceramsite serves as an open pore water storage medium, and the functional additive is added into the open pore water storage unit; the cement, the coal ash and the polycarboxylic acid water reducing agent are supplemented to synergistically optimize the performance of the slurry. The preparation process comprises the following steps: saturatively soaking the aggregate to a saturated surface dry state; pre-mixing the shale sand and the ceramsite with the cement and the coal ash which are added in batches; then introducing floating beads for temporary stirring, injecting clear water by stages, synchronously adding a water reducing agent, and fully stirring to form a homogeneous mixture; and finally, pouring and vibrating, and completing standard curing in a constant-temperature and high-humidity environment. According to the method, the concrete has high mechanical strength and a long-acting water absorption and release circulation function, and the technical bottleneck that the water storage capacity and the structural performance of a traditional material are incompatible is broken through.

The invention relates to a new and old road cement stable base splicing construction method, belongs to the technical field of road construction, and mainly solves the problem that a new and old road splicing position is insufficient in bonding strength and easy to crack. According to the technical scheme, the method is characterized by comprising the steps of cleaning an old road step interface, controlling the saturated surface dry state with the water content within the range of 8%-12%, brushing cement paste with the water-cement ratio of 0.25-0.35 on the old road step interface, conducting manual material supplementing during paving, dynamically regulating and controlling the pouring speed of the cement paste with the water-cement ratio of 1.8-2.2 before initial pressing so as to form a stable slurry film, conducting rolling and seam splicing through rubber wheels, and conducting paving. And after final pressing, secondary grouting and covering maintenance are conducted. The method provided by the invention can effectively enhance the splicing strength of the new and old road cement-stabilized base layers, prevents cracking, and is used for road extension and maintenance engineering.