245 results about "Self-consolidating concrete" patented technology

The invention relates to the technical field of concrete preparation, in particular to high-performance self-compacting concrete and a preparation method thereof, solves the defects in the prior art, and comprises the following components: cement, fly ash, slag powder, graphene oxide, nano-silica aerogel, a water reducer and an air entraining agent. Through silanization modification and magnetic field induction, the problem of interface incompatibility of GO and SA is solved. Graded mass transfer paths are formed between nano layers of GO and mesopores and macropores of SA. And the CaCO3 seed crystal in the SA hole directionally guides the oriented growth of the C-S-H gel, so that the early strength development rate is increased.

The invention relates to a method for evaluating sulfate freezing and thawing resistance of recycled coarse aggregate self-compacting concrete. The method comprises the following steps: S1, preparing a recycled coarse aggregate self-compacting concrete test piece in which stones are completely or partially replaced by recycled coarse aggregate according to design requirements; s2, immersing the recycled coarse aggregate self-compacting concrete test piece in a freeze-thaw medium to carry out a freeze-thaw cycle test; s3, measuring a damage index of the recycled coarse aggregate self-compacting concrete test piece; s4, comparing the damage indexes of different recycled coarse aggregate self-compacting concrete test pieces to obtain the recycled coarse aggregate self-compacting concrete test piece with excellent comprehensive performance. According to the method, the influence of different replacement rates of the recycled coarse aggregate, different freeze-thaw environments and multiple freeze-thaw cycles on the performance of the recycled coarse aggregate self-compacting concrete can be accurately evaluated, so that theoretical basis and technical support are provided for improving the durability and engineering application of the recycled coarse aggregate self-compacting concrete in the sulfate freeze-thaw environment.

The invention provides a construction method of a CRTS III type slab ballastless track, and relates to the technical field of high-speed rail construction, and the construction method comprises the following steps: mounting base plate steel bars, side forms, end templates and limiting groove templates, placing foam plates at expansion joints, and reserving track slab pressing and anchoring holes; base plate concrete is poured, and base plate concrete formwork removal, surface finishing, maintenance and expansion joint construction are carried out after pouring; constructing a geotextile isolation layer and an elastic cushion layer; limiting groove steel bars and self-compacting concrete layer steel bar meshes are installed, and track plates are placed; before and after the track plate and the base plate are fastened by the pressing device, the track plate is finely adjusted by the fine adjustment device; and a self-compacting concrete formwork is installed, self-compacting concrete is poured, and post-pouring treatment and curing are conducted. The track plate and the base plate are fastened through the pressing device, so that the track plate, the base plate and the self-compacting concrete layer are tightly attached in the self-compacting concrete pouring period, and the situation that reworking or track laying is difficult due to the fact that the floating amount of the track plate is too large is avoided.

The invention belongs to the technical field of bridge construction, and particularly discloses an ultra-large-diameter concrete filled steel tube for an ultra-high cable bent tower, a concrete structure of the ultra-large-diameter concrete filled steel tube and a construction method. The super-large-diameter steel pipe concrete structure for the ultrahigh cable bent tower comprises a cable bent tower steel pipe structure and self-compacting concrete. The cable bent tower steel tube structure comprises a cable bent tower steel tube, an internal accessory structure and an external accessory structure; the internal accessory structure comprises shear nails, annular plates and stiffening ribs which are arranged on the inner wall of the cable bent tower steel pipe; the outer wrapping accessory structure comprises an outer wrapping steel shell wrapping the cable bent tower steel pipe. The strength grade of the self-compacting concrete is C60-C80, 100 kg-120 kg of the self-compacting concrete additive is doped in per cubic meter of concrete, and the self-compacting concrete additive comprises the following components in percentage by mass: 50%-60% of a calcium-magnesium composite expanding agent, 2.5%-4.5% of a hydration temperature rise inhibitor and 35.5%-47.5% of a rheology modifier. The super-large-diameter steel pipe concrete structure for the ultrahigh cable bent tower is compact in filling and free of cracking, and the concrete and the steel pipe cannot be disengaged in the whole life cycle of the early construction period and the long-term service period.

The invention discloses a rock-fill concrete pouring liquid level and compactness monitoring and evaluating method, and relates to the technical field of concrete construction. According to the invention, the compactness sensing probes are uniformly distributed in the warehouse, so that the whole warehouse surface can be comprehensively monitored. The probes are wrapped by high-strength and high-toughness materials, it is ensured that the probes cannot be damaged in the construction process, a three-dimensional Thiessen polygon method is adopted for segmenting the areas in the bin, each compactness sensing probe corresponds to one associated area, the segmentation method can adapt to irregular polygon boundaries, it is ensured that only one representative measuring point exists in each area, and the accuracy of the detection result is improved. Whether the probes are buried by the concrete or densely filled can be judged in real time through the numerical value change of the compactness sensing probes, and the liquid level position of the self-compacting concrete can be calculated according to the states of all the probes.

The present disclosure provides a production method and a mold for a ribbed prestressed composite slab of self-compacting concrete, including a long-line table bottom mold, side molds, end molds and a top mold. Side molds are respectively connected to the long ends of the long-line table bottom mold. The top mold is arranged at the upper end of the long-line table bottom mold, and both ends of the top mold are respectively connected to the corresponding side molds. End molds are respectively connected to the short ends of the long-line table bottom mold, and the shape of the upper edge of the end mold matches the shape of the side edge of the top mold. Both ends of the end mold are respectively connected to the corresponding side molds to form a cavity with an accommodating space. A number of holes through which prestressed steel wires can pass are provided on the end mold, and leak-proof plugs are detachably connected to the holes. The structure of the present disclosure is simple, which can make the construction of prestressed concrete composite slabs faster and more convenient, and at the same time can reduce the labor intensity of workers and improve production efficiency.

The invention provides a self-leveling UHPC wear-resistant floor and a construction process thereof. The self-leveling UHPC wear-resistant floor comprises a base layer, the upper end of the base layer is fixedly connected with a self-compacting concrete leveling layer, the upper end of the self-compacting concrete leveling layer is fixedly connected with a UHPC reinforcing layer, and the upper end of the UHPC reinforcing layer is fixedly connected with a UHPC surface layer; the top of the self-compacting concrete leveling layer is provided with partially exposed steel fibers and / or coarse aggregates; the UHPC reinforcing layer is composed of UHPC doped with reinforcing fibers and a reinforcing mesh, and the reinforcing mesh is arranged in the middle of the UHPC reinforcing layer and wrapped and fixed by the UHPC doped with the reinforcing fibers; the top of the UHPC reinforcing layer is provided with partially exposed steel fibers and / or coarse aggregates; the diameter of the steel fiber is 0.35-0.6 mm, and the length of the steel fiber is 30-60 mm; the coarse aggregate is solid waste. The self-leveling UHPC wear-resistant floor is high in strength, excellent in durability and wear resistance, environmentally friendly, free of pollution, low in cost and short in construction period, and has good engineering application value.

The invention discloses a rapid nondestructive detection method for high-speed rail plate-type ballastless track filling layer defects. According to the method, a mechanical impedance method and an impact echo method are organically combined for the first time aiming at internal defects such as void, open joint and cavity of a self-compacting concrete filling layer, and a two-stage detection mode of'rapid screening and positioning 'and'accurate quantitative diagnosis' is formed. In the first stage, mechanical impedance method rapid screening is conducted, specifically, 0.5-1.0 m grids are divided on the surface of a track plate, response signals are collected through polymer energy hammer excitation and a speed sensor, and a suspected defect area is positioned based on a statistical threshold value; in the second stage, accurate quantification is conducted through an impact echo method, grids are encrypted to 0.1-0.2 m in a suspected area, a response signal is excited and collected through an excitation and receiving integrated device trolley, and the defect type is judged according to a defect recognition function. Through the method, the detection efficiency can be improved by more than 5 times, the detection time of a single track plate is shortened to be within 10 minutes, and the method is suitable for short-time detection requirements of a skylight period of a high-speed rail.

The invention provides a door-shaped steel bar optimization method and system based on ballastless track interface damage analysis, and relates to the field of track traffic, the method comprises the following steps: determining track interlayer bonding parameters of a ballastless track based on interface comprehensive mechanical property test data of a concrete material composite test piece of the ballastless track, and establishing a finite element model of the ballastless track; a service temperature field of the ballastless track is calculated, and equivalent simulation of shrinkage of the self-compacting concrete layer is completed; on the basis of the multiple structure optimization variables, multiple door-shaped steel bar optimization schemes are determined, and the track interface damage area and distribution of the ballastless track under the combined action of shrinkage of the self-compacting concrete layer and the temperature load are calculated by utilizing a finite element analysis method based on a finite element model of the ballastless track corresponding to the door-shaped steel bar optimization schemes; the method has the advantages that the early-stage interface damage risk is reduced, and the durability and reliability of the track structure are improved.

The invention relates to the technical field of building materials, in particular to modified solid waste doped self-compacting low-carbon concrete and a preparation method thereof. The self-compacting low-carbon concrete is prepared from the following raw material components: cement, modified solid waste slurry, silica fume, modified solid waste aggregate, water and a polycarboxylic acid high-performance water reducing agent, the modified solid waste slurry is obtained by mixing solid waste mixed powder with water and modifying with a modifier in sequence; the modified solid waste aggregate is obtained by sequentially performing low-concentration hydrochloric acid solution soaking treatment, interface reinforcing agent rinsing modification treatment and drying treatment on solid waste mixed aggregate. By modifying and optimizing the solid waste, optimizing the mix proportion of the solid waste self-compacting concrete and preparing the special admixture for the solid waste self-compacting low-carbon concrete, the solid waste can stably play a role in the concrete, so that the mechanical property and durability of the concrete are improved, and the rheological property of the concrete can meet the requirements of the self-compacting concrete; according to the scheme, the low-carbonization effect can be achieved through waste utilization.

The invention relates to the technical field of geotechnical engineering anchoring, in particular to a method for testing the degradation characteristic of the bearing performance of a recyclable anchor rod under cyclic loading. The method comprises the following steps: preparing a unit body sample anchor-rock interface unit body sample, simulating weathered soft rock according to a specific ratio, pouring a self-compacting concrete anchoring body, and curing and forming; setting a combined parameter of a reference load ratio and a load cycle index, applying a triangular wave cyclic load to simulate a traffic condition, and executing a pull-out test to collect load-displacement data; constructing a two-parameter coupled shear strength degradation model based on test data, and proposing a shear stress-displacement curve model; an anchor rod load transfer control equation is established in combination with the Poisson effect, and shear stress distribution of the anchoring section is iteratively solved by adopting a discrete recursion method; the model is verified through a foundation pit engineering case, the ultimate bearing capacity degradation law of the anchor rod under long-term cyclic loading is predicted, and it is proved that the model can guide engineering safety design. According to the method, the coupling characterization of the cyclic load parameter and the interface degradation mechanism is realized.

The invention relates to the technical field of bridge engineering construction control and intelligent manufacturing, and discloses a steel pipe self-compacting concrete anti-disengaging method integrating whole-process prediction and compensation regulation. The whole method comprises the following steps: collecting and preprocessing a self-compacting concrete anti-falling data set, constructing a disturbance tensor, introducing a time response coupling kernel, calculating by combining the disturbance tensor to obtain a coupling potential energy expression, then obtaining a tensor potential energy fusion item according to the disturbance tensor and the coupling potential energy expression, and constructing an asymmetric disturbance potential field coupled dual-channel module. The tensor potential energy fusion item is combined to be spliced into a potential energy state tensor, a time trend response value and a variable coupling disturbance response value at the current moment are calculated through the potential energy state tensor, the obtained time trend response value and the variable coupling disturbance response value are fused and output, and a time sequence disturbance coding module is formed; and constructing a self-compacting concrete anti-void prediction model to output a predicted value so as to realize accurate prediction of steel pipe self-compacting concrete anti-void.

The invention belongs to the field of constructional engineering materials, and relates to uncovering self-compacting concrete as well as a preparation method and application thereof. The uncovering self-compacting concrete comprises a liquid material and a dry material; the liquid material contains a water reducing agent, a slump retaining agent, a thickening time control agent, a defoaming agent, a polymer emulsion, a beautifying agent, a viscosity reducer, water, and optional air entraining agent, stabilizer and preservative; the dry material contains glass powder, glass sand, cement, broken stone, gypsum, an expanding agent, gas-phase nano silicon dioxide toughened high-strength micro powder, modified sulfonated phenolic resin and a viscosity modifier. According to the uncovering self-compacting concrete disclosed by the invention, the problem of high bleeding rate caused when a polycarboxylic acid water reducer and a slump retaining agent are applied to production of the uncovering self-compacting concrete can be perfectly solved through synergistic cooperation of all the components, and meanwhile, the advantages of high transparency and strong scratch resistance caused by replacement of an admixture with a regenerated glass material are reserved; the strength of the uncovering self-compacting concrete is effectively reduced, the bleeding rate is reduced, and the setting time is prolonged.

The invention provides a self-compacting concrete pumping resistance calculation method, which belongs to the field of pumping and comprises the following steps: S1, establishing an initial pumping parameter model according to pipeline geometric parameters of a pumping pipeline, initial physical characteristics of self-compacting concrete and pumping process parameters; s2, pumping working condition data are collected in real time and subjected to digital filtering processing, and the filtered concrete flow velocity is obtained; s3, calculating the dynamic plastic viscosity of the self-compacting concrete under the current working condition by utilizing a dynamic rheological evolution model according to the pumping time, the pumping environment temperature and the relative humidity; and S4, according to the initial pumping parameter model, the dynamic plastic viscosity and the filtered concrete flow velocity, pressure losses of different sections of the pumping pipeline are calculated, and the total pumping resistance is obtained based on the pressure losses of all the sections. According to the method, the calculation accuracy of the total pumping resistance of the pumping pipeline is improved through the concrete dynamic rheological characteristics, the environment temperature and humidity effect, the pipeline geometric parameters and the pumping process parameters.

The invention discloses an intelligent material distribution method for a ballastless track. The intelligent material distribution method comprises the following steps of feeding and storage, butt joint of a hopper and a pouring opening, discharging control and discharging stop control. According to the intelligent material distribution method for the ballastless track, operation is convenient, working condition data in the pouring process are monitored in real time, the pouring effect of the base plate and the track plate can be visually obtained through an information platform interface, it can be ensured that self-compacting concrete slurry completes extrusion and push type discharging in the flowing process through hopper simulation design and use, and the construction efficiency is improved. The pouring quality is improved, and the problem that the ballastless track pouring forming material distribution effect is poor is solved; in addition, interlocking control is carried out on feeding storage, butt joint of the hopper and the pouring opening, discharging control and discharging stop control, and the intelligent high-quality pouring construction production requirement can be met.

The invention provides a concrete construction method of a steel-concrete combined cover beam, aiming at a steel box cover beam under the conditions of light weight and complex internal structure, firstly, the performance of concrete is specifically limited, and secondly, in the pouring mode, a plurality of pouring holes are formed in the top surface of a steel box at intervals in the length direction of the steel box, so that the steel-concrete combined cover beam is formed in the top surface of the steel box. A non-pressure hopper is adopted to feed self-compacting concrete into the pouring hole to fill the inner space of the steel box. On the premise that the mechanical property and the volume stability of the concrete are guaranteed, the passing performance of the concrete in a narrow space is improved by adjusting the mixing ratio, and the self-compacting performance of the concrete is improved, so that the concrete can be smoothly and completely filled during construction; and the risk of deformation and damage of the steel box caused by overlarge local pressure due to complex structure of stiffening ribs and steel strands in the steel box and poor trafficability of concrete when a pumping construction mode is used is eliminated, and an unexpected construction effect is achieved.

The invention discloses recycled aggregate self-compacting concrete with excellent impervious and waterproof effects, and relates to the technical field of recycled aggregate concrete.The recycled aggregate self-compacting concrete is prepared from, by mass, 160-180 parts of aggregate particles, 280-300 parts of cement, 3-4 parts of water reducing agent, 1-3 parts of thickening agent, 2-11 parts of air entraining agent, 80-120 parts of mineral admixture, 100-200 parts of water and 7-9 parts of expanding agent. The recycled aggregate self-compacting concrete prepared by the invention is improved in strength, durability and impermeability and waterproofness, and the quality stability of the recycled aggregate is ensured, so that the quality and performance of the finally prepared recycled aggregate self-compacting concrete have consistency, and the recycled aggregate self-compacting concrete can be prepared according to a certain proportioning sequence and proportion. The water-cement ratio is reduced, and the compactness, durability and impermeability and waterproof performance of the concrete are improved at the same time.

The present invention provides a self-compacting concrete formwork, which relates to the technical field of concrete formwork. The device includes a formwork frame, a track plate, a cross bar and a pressurizing mechanism. A slurry discharge port is provided on the side wall of the formwork frame, a track plate is provided above the formwork frame, a slurry inlet is provided on the track plate, a cross bar is provided above the track plate, and both ends of the cross bar are respectively connected to a pressurizing mechanism. The pressurizing mechanism includes a fixing member, a motor, a cam, a connecting rod, a spring and a bracket. The fixing member is provided on the outside of the formwork frame, the fixing member is connected to the motor, the output end of the motor is connected to the cam, the cam is located on the cross bar, a connecting rod is installed on the cross bar, the upper and lower parts of the connecting rod are respectively provided with springs, one end of the connecting rod is connected to the fixing member, the other end of the connecting rod is connected to the bracket, and the bracket is connected to the fixing member. The present invention improves the concrete filling efficiency, enables the concrete to completely fill the formwork, and ensures the discharge of internal air, thereby effectively improving the concrete molding quality.

The present invention discloses a BIM application and formwork construction technology method for a suspended inverted frustum-shaped concrete structure, which relates to the technical field of cast-in-place concrete pile construction. It includes BIM modeling, determining erection technical parameters, visual disclosure, formwork support system erection, formwork support system acceptance, steel bar fabrication and installation, concealed acceptance, and pouring and monitoring process steps. It simplifies the processing of complex suspended structure formwork, and the installation is in place at one time, improving the construction efficiency and ensuring the project quality; the gravity of the suspended structure is concentrated on 6 suspension columns and the ring beam, and the layout of the force-bearing vertical poles of the formwork support adopts the coordination of concentration and integrity to ensure the stability of the formwork; the suspension columns penetrate the entire space model, and the node steel bars are dense and complex. Partial binding and forming outside the formwork and then hoisting into the formwork are adopted to solve the problem of difficult binding of the inclined suspension column steel bars; self-compacting concrete is used to effectively solve the problems of difficult pouring and vibration of concrete in the narrow space with dense steel bars and thin inclined plates.

The present invention provides a multi-scale toughening and shrinkage-compensating C80 high-crack-resistant self-compacting concrete and a preparation method thereof. The present invention uses low-shrinkage and crack-resistant composite cement to compensate for the shrinkage of C80 concrete, avoiding the disadvantage that general expansive agents are difficult to function due to the low water-cement ratio design of ordinary C80 concrete, and solving the problem that C80 concrete is prone to shrinkage and cracking. The present invention uses multi-scale hybrid fibers to strengthen toughness and crack resistance, and uses high-strength fine steel fibers, multi-anchor steel fibers, and temperature-shrinkage-induced organic fibers to improve the toughness of C80 concrete and its crack resistance in the heating / cooling stages on a macro scale; and uses CaCO3 and CaSO4 composite whiskers and nano-silica-modified water-based polyurethane to form a uniform three-dimensional toughening network inside the cementitious slurry, thereby improving the tensile strength and toughness of C80 concrete on a micron scale. This allows C80 concrete to have the characteristics of low shrinkage, high toughness, and high crack resistance.

The invention discloses self-compacting concrete and a preparation method thereof, and belongs to the technical field of concrete.The self-compacting concrete is prepared from, by mass, 310-320 parts of cement, 75-85 parts of fly ash, 100-110 parts of mineral powder, 830-850 parts of machine-made sand, 770-790 parts of milling material coarse aggregate, 35-40 parts of steel fiber, 8-12 parts of rubber fiber, 25-30 parts of viscosity modifier, 175-180 parts of water and 7.5-8 parts of polycarboxylic acid type water reducer. According to the self-compacting concrete and the preparation method thereof, the coarse aggregate is prepared by virtue of the rubber fibers, the steel fibers, the viscosity modifier, the machine-made sand and the milling material, so that the problems that the existing self-compacting concrete is insufficient in impact resistance, the rubber component easily floats upwards, and greenization and high performance are difficult to consider at the same time are solved.

The invention discloses high-durability aluminoferrite cement-based self-compacting concrete and a preparation method thereof, and belongs to the technical field of maritime work concrete.The high-durability aluminoferrite cement-based self-compacting concrete is prepared from 60-70 parts of freeze-thaw-resistant clinker, 20-30 parts of chlorine-resistant steel slag micro powder, 8-13 parts of high-strength corrosion-resistant desulfurized gypsum, 0.8-1.3 parts of an additive, 88-124 parts of coarse aggregate, 76-116 parts of fine aggregate and 22-38 parts of water. According to the freeze-thaw-resistant clinker, the freezing resistance of concrete is enhanced by reducing the porosity and the pore diameter. The desulfurized gypsum subjected to crystal form regulation and control enhances the sulfate corrosion resistance of the concrete. The PAA / QCS-CA hydrogel enables the early strength of the concrete to be rapidly increased, accelerates the construction progress, and ensures that the airport pavement can be rapidly put into use. The high-strength corrosion-resistant desulfurized gypsum can promote early hydration of the cement and improve the early strength.

This invention relates to the field of deep foundation pit support construction technology, specifically a nested support construction process for deep foundation pit elevator shafts and sump pits. It solves the problem that traditional caisson waterproofing technology is prone to failure due to pit wall collapse in highly permeable gravel strata, making it difficult to create stable construction conditions. The process includes a steel caisson support structure, within which a steel caisson waterproofing structure is nested. This steel caisson waterproofing structure is used in conjunction with the steel caisson support structure for nested construction. This invention, through the nested cooperation of the steel caisson support structure and the steel caisson waterproofing structure, and the injection of a self-compacting concrete filling layer, achieves an integrated support and waterproofing effect during construction. It creates a stable, dry, and enclosed working space in easily collapsible, highly permeable strata, solving the problem of failure of traditional single waterproofing technology and creating safe and reliable conditions for subsequent structural construction.

The present invention discloses a low-shrinkage self-compacting micro-expansion concrete and a preparation method thereof. The concrete comprises 270-330 parts of cement, 80-120 parts of fly ash, 30-70 parts of slag powder, 10-50 parts of a composite expansion agent, 700-900 parts of sand, 900-1100 parts of stone, 7-11 parts of a water reducing agent, 0.1-2 parts of an internal curing agent, 0.5-1 part of fiber, and 140-160 parts of water; the internal curing agent comprises 5-25 parts of maltodextrin, 1-10 parts of filler, 5-15 parts of macromolecular organic matter, 5-30 parts of ionic monomer, 5-30 parts of non-ionic monomer, 0.01-1 part of cross-linking agent, 0.001-0.1 part of initiator, 1-10 parts of neutralizing reagent, and 60-90 parts of water. The concrete has excellent workability, pumpability, high strength, and low shrinkage, and can also achieve self-curing, solving the problem that the effect of the expansion agent is not obvious due to the difficult curing of ordinary self-compacting concrete.

The invention relates to the technical field of water conservancy and hydropower engineering, in particular to a self-compacting rock-fill concrete dam body construction method which comprises the following steps: rock-fill body construction: screening out rock-fill materials with the particle size of not less than 300mm, and conveying the rock-fill materials to a foundation surface in a bin to form rock-fill bodies with gaps; self-compacting concrete body construction is conducted, specifically, self-compacting concrete is pumped to the upper portion of the rockfill body, the self-compacting concrete flows to fill gaps between the rockfill materials, and the self-compacting concrete is solidified and hardened into a self-compacting concrete body 3; the particle size of coarse aggregate in the self-compacting concrete is not larger than 20 mm, and the content of needle-sheet-shaped particles is not larger than 8%. According to the method, the particle size of the rockfill material is limited, and the particle size of coarse aggregate and the content of needle-sheet-shaped particles in the self-compacting concrete are limited; the self-compacting concrete can be fully filled into gaps between dam bodies of rockfill materials, so that the compactness of the dam bodies is improved, the risk of dam body engineering structure damage is reduced, and the construction quality of the dam bodies is improved.

The utility model provides a repairing system for corrosion of a photovoltaic concrete pile head, and relates to the field of photovoltaic concrete piles, the repairing system comprises a self-compacting concrete layer, a concrete anti-corrosion coating and a plurality of blocking ring pieces prefabricated and formed by UHPC materials; the segmented ring sheets and the assembled cylindrical structure integrate the advantages and characteristics of UHPC materials, and have high strength, high toughness, high impermeability, freeze-thaw resistance, chemical erosion resistance and impact resistance; a plurality of block ring pieces prefabricated and formed by UHPC materials are spliced on the outer side of a concrete pile head to be repaired on site to form a cylindrical structure, preferably, the block ring pieces are made into semicircular ring pieces, and two pieces can be spliced into the cylindrical structure, so that the construction difficulty is effectively reduced, the splicing is rapid, and the operation is simple; self-compacting concrete slurry is poured into a filling cavity gap between the cylindrical structure and the to-be-repaired concrete pile head, the slurry is a finished product prefabricated material, and the quality of cast-in-place self-compacting concrete is ensured through field construction; in addition, the concrete anticorrosive coating is coated outside the cylindrical structure made of the UHPC material, so that the durability of the structure is further enhanced.

This invention discloses a self-compacting concrete pouring device and method for slab track, belonging to the field of slab track construction technology. It includes a concrete hopper with a cylinder connected to its lower end. The cylinder is equipped with an opening and closing mechanism, which comprises an elastic rubber cylinder and a metal elastic strip sleeved on its outer side. A motor drives the metal elastic strip to move around the cylinder, achieving precise adjustment of the opening degree of the elastic rubber cylinder's inner cavity, thereby controlling the concrete discharge flow rate. A scraping mechanism is also provided inside the concrete hopper. During the reciprocating opening and closing process, the scraping mechanism is driven by a transmission mechanism to rotate stepwise along the inner wall of the hopper, automatically scraping away residual concrete. This invention achieves precise electric control of the concrete flow rate and simultaneously completes automatic cleaning of the inner wall during the discharge process, effectively improving pouring quality and construction efficiency while reducing manual labor intensity.

The present invention proposes a method for calculating the pumping resistance of self-compacting concrete, which belongs to the field of pumping. The method comprises: S1: establishing an initial pumping parameter model based on the geometric parameters of the pumping pipeline, the initial physical properties of the self-compacting concrete, and the pumping process parameters; S2: real-time acquisition of pumping condition data and digital filtering to obtain the filtered concrete flow rate; S3: calculating the dynamic plastic viscosity of the self-compacting concrete under the current working conditions using a dynamic rheological evolution model based on the pumping time, pumping ambient temperature, and relative humidity; S4: calculating the pressure loss in different sections of the pumping pipeline based on the initial pumping parameter model, the dynamic plastic viscosity, and the filtered concrete flow rate, and obtaining the total pumping resistance based on the pressure loss in each section. The present invention improves the accuracy of calculating the total pumping resistance of the pumping pipeline by taking into account the dynamic rheological properties of concrete, the effects of ambient temperature and humidity, the geometric parameters of the pipeline, and the pumping process parameters.

The invention discloses a long-tunnel large-diameter PCCP (prestressed concrete cylinder pipe) transportation, installation and construction method, relates to the technical field of water conservancy and civil engineering construction, is suitable for installation and construction of a PCCP in a tunnel and a narrow space, and comprises the following steps: step 1, finishing hoisting, transportation, adjustment and centering installation of the PCCP in the tunnel by adopting a beam-carrying type pipeline transportation and installation vehicle; secondly, after the PCCP is installed, self-leveling concrete or self-compacting concrete is backfilled through the pumping or relay pumping technology, and a gap between the outer wall of the PCCP and the inner wall of the tunnel is backfilled; the piggyback type pipeline transportation and installation vehicle is selected, has the functions of walking, bearing, hoisting and precise positioning, and can flexibly work in tunnels and narrow and small spaces. Compared with traditional construction equipment, the vehicle can rapidly complete hoisting, transportation, adjustment and centering installation of the pipeline, and the connection time of all construction links is shortened.