953 results about "Cement paste" patented technology

The invention provides an artificial intelligence concrete strength prediction method based on multi-scale morphological feature analysis, and the method combines multi-scale morphological feature analysis including surface texture and internal pore structure, and utilizes a deep learning algorithm to accurately predict concrete interface strength. The method comprises the following steps: simulating a pore filling rate and microcrack propagation resistance of an interface area by combining multi-scale concrete morphology information to obtain performance parameters of an interface transition area; calculating the deviation between the predicted strength and the actual strength to obtain a prediction precision index, and if the prediction precision index does not reach a preset threshold value, updating the strength prediction model parameters to obtain an updated strength prediction model; and calculating a strength prediction result according to the quantitative morphology feature vectors, the microcrack propagation path parameters and the cement paste hydration degree of various concrete material systems to obtain strength prediction precision. The method not only improves the accuracy of traditional strength evaluation, but also provides a scientific basis for optimizing the concrete proportion design.

Provided is a method and system for predicting a hydration reaction degree of cement based on a cycle generative adversarial network (CycleGAN). The method includes the following steps: S1, acquiring a micro-structure image of a cement paste test specimen; S2, establishing a micro-pore structure image dataset; S3, establishing a cement micro-hydration prediction model based on a CycleGAN; and S4, completing prediction based on a final cement micro-hydration prediction model. A deep learning algorithm is applied to micro-hydration prediction of cement. A complex theoretical formula is replaced with a data driven mode. Dependence on ideal hypotheses is reduced, and the accuracy of prediction on micro-hydration of cement is thus improved.

The invention relates to a deep coal underground gasification method which comprises the following steps: drilling a plurality of gasification wells in a land parcel, sequentially arranging the plurality of gasification wells into three rows from the edge of the land parcel, and fracturing a bottommost coal seam; the first row of gasification wells are injection wells, the second row of gasification wells are production wells, and the bottommost coal seam between the first row of gasification wells and the second row of gasification wells is gasified; when the gasification high-temperature area of the gasified coal seam is expanded to the front edge of the gas cooling area, the second gas gasification well is closed, the third gas gasification well serves as a production well, and the coal seam continues to be gasified; meanwhile, a fourth row of gasification wells are drilled; after the coal bed is gasified, the bottommost coal bed between the second row of gasification wells and the third row of gasification wells is gasified, and so on, the bottommost coal bed between all the rows of gasification wells is gasified; meanwhile, cement paste is injected into the first exhaust gasification well to fill the gasified goaf; and so on, filling the goaf between each row of gasification wells; sequentially gasifying and refilling each coal seam from bottom to top according to the method.

The invention relates to a pipe pile grouting expanded head pile forming process special for a prestressed concrete water jet cutter and a pipe, and belongs to the field of pipe pile construction. The large-head concrete block is integrally connected with the lower end of the tubular pile body and is in an irregular shape, the tubular pile body sequentially comprises a pile cap, a plurality of pipe joints and an inverted-cone-shaped pile head from top to bottom, the tubular pile body is provided with at least one high-pressure water or cement paste channel in the axial direction of the tubular pile body, and the pile head is provided with a material water hole communicated with the high-pressure water or cement paste channel. During construction, even if a special stratum is encountered, the hard stratum is impacted through the high-pressure water jet cutter, and static pressure or hammering is matched, so that the problem that an existing pipe pile is difficult to descend is solved. When the designed elevation is reached, guniting is carried out through high-pressure water or a cement paste channel in the pipe pile body, and a sphere-like expanded head is formed at the bottom of the pipe pile; the bearing capacity of a single pile can be improved, settlement of the pile body is limited, local displacement of the pile body is eliminated, and the anti-floating effect of the pile body is achieved.

The invention discloses a cement paste strength prediction method based on an integration algorithm. The method comprises the following steps: collecting original cement paste data; performing feature extraction on the original cement paste data to obtain to-be-predicted cement paste data; and sequentially inputting the to-be-predicted cement paste data into a trained convolutional neural network model, an XGBoost model and a random forest model to obtain the compressive strength of the cement paste test block with the standard size, so as to predict the cement paste strength according to the compressive strength of the cement paste test block with the standard size. According to the cement paste strength prediction method based on the integration algorithm, the strength of the cement paste is predicted by using three models, and respective advantages, the powerful capability of CNN in image and signal processing, the high efficiency of XGBoost in structured data processing and the robustness of a random forest in classification and regression problems can be utilized, so that the strength of the cement paste is predicted. Therefore, the prediction accuracy and robustness are improved.

The invention discloses a cement-based material mixing state intelligent regulation and control auxiliary agent and a preparation method and application thereof. The auxiliary agent is composed of reversible sulfonation modified degradable starch and acrylic resin containing hydroxyl. The method is characterized in that the sulfonated modified starch plays roles in dispersing and suspending cement particles and gravels and improving uniformity and flowability in the cement-based material mixing and injection molding stages, and the sulfonated starch is stimulated to be reversibly reduced into dialdehyde starch in a cement paste alkaline environment in the curing and curing stage; the molecules are mutually crosslinked to form a three-dimensional network structure, so that the effects of dispersing, suspending, adhering and fixing cement particles and gravels are achieved. Therefore, the prepared cement-based material mixing state intelligent regulation and control auxiliary agent has the intelligent effects of presenting different molecular structures and playing different roles in the stirring, injection molding and curing states, the preparation method is unique, the materials are easy to obtain, the application effect is remarkable, and the good application prospect is achieved.

The invention provides a data-driven intelligent stirring and quality prediction method, and is suitable for the field of stirring pile construction. According to the method, the data-driven neural network model is established, soil layer parameters, stirring parameters and construction quality are recognized, the state of a stirring machine is monitored in real time, the stirring process is dynamically adjusted, the comprehensive construction efficiency is improved, and the strength of a stirring pile can be predicted according to real-time data such as cement paste and the guniting amount by establishing the quality prediction model; and finally, intelligent construction is achieved, and the engineering quality and safety are improved.

The invention relates to the technical field of refractory materials, in particular to a waste magnesia-calcium brick-containing refractory material and a preparation method thereof, and the waste magnesia-calcium brick-containing refractory material comprises the following components: composite aggregate, calcium aluminate cement, urea resin-aluminum dihydrogen phosphate, active alpha-Al2O3 micro powder, silica micro powder and sodium tripolyphosphate. In the room-temperature spraying maintenance and low-temperature working stage, hydration of free CaO in the waste magnesia-calcium bricks and erosion of OH <-> are prevented through the hydrophobic effect of fluorinated polyphosphazene and modified zirconium oxide sol, and the compatibility and wettability of the composite aggregate and cement paste are improved through carboxylic acid groups of carboxyethyl silanetriol and polyethylene glycol monomethyl ether. According to the present invention, with the temperature rising, the aluminum dihydrogen phosphate forms the viscous liquid phase to wrap the aggregate so as to provide the temporary protection, the temperature continues to rise, the zirconium oxide and the nanometer Al2O3 react with the CaO and the MgO to generate the CaZrO3 and the MgAl2O3, the aluminum dihydrogen phosphate reacts with the nanometer Al2O3 in the system to generate the AlPO4, and the CaZrO3, the MgAl2O3 and the AlPO4 form the multi-phase fire-resistant structure so as to further improve the fire resistance of the fire-resistant material;

The invention discloses a method for predicting long-term creep of cement paste based on dielectric constants, which comprises the following steps of: finding out a relationship between a dielectric constant real part and a long-term creep modulus of the cement paste, firstly measuring the dielectric constant real part and the creep modulus, fitting to construct a corresponding function relational expression, verifying the constructed function expression, and finally predicting the long-term creep of the cement paste based on the dielectric constants. After the accuracy is verified, the method is applied to the long-term creep prediction of the cement paste. According to the method, the function relational expression related to the dielectric constant real part and the long-term creep modulus of the cement paste is established, the function relational expression can accurately predict the long-term creep of the cement paste, the corresponding creep modulus is obtained, and the precision of the prediction result can effectively meet the construction requirement; the whole prediction process is simple and easy to operate, the prediction precision of the long-term creep of the cement paste is greatly improved, the creep deformation of a stressed component of a building structure in a long-term stressed state can be controllably monitored, and then safe operation of an engineering structure is guaranteed.

The invention discloses a microscopic crack dynamic in-situ characterization method, and relates to the technical field of crack in-situ detection. According to the method, a plurality of hardened cement paste bodies are soaked in a sulfate solution, the porosity development trend of the hardened cement paste bodies is obtained through a nuclear magnetic resonance test and a mercury injection test in the soaking process, a test sample and a test sample are prepared after soaking is finished, and the crack propagation length of the test sample is measured through a scanning electron microscope. According to the distance gradient between the sampling angle of the test sample and the exposed surface, space coordinates of crack cracking are converted into a time process along the center axis of the test sample, a delay microscope is established on the microscale, and the test sample is scanned by using X-ray computed tomography equipment in a matched mode; a crack propagation animation image is formed based on a crack form between adjacent X-ray tomography slices, and a crack development process is obtained by continuously capturing high-resolution images, so that omission of time information is avoided, and in-situ detection of microscopic cracks in a hardened cement paste sample is realized.

The invention relates to the technical field of well cementation engineering tools, and discloses an anti-falling float collar float shoe which comprises a float collar, a sleeve and a float shoe, the float collar, the sleeve and the float shoe are sequentially arranged from top to bottom, the float collar comprises a first pipe body, a first anti-falling connecting piece and a first one-way flow guide piece, the first one-way flow guide piece is arranged in the first pipe body, and the first anti-falling connecting piece is connected with the first one-way flow guide piece. The first pipe body is arranged at the upper end and the lower end of the first pipe body and used for preventing cement paste from flowing back into the casing pipe, and the first anti-disengaging connecting pieces are arranged at the upper end and the lower end of the first pipe body correspondingly. The design of the first one-way flow guiding piece and the second one-way flow guiding piece ensures that the cement paste can flow forwards into an annular space between the casing pipe and the well wall in the well cementation process; and cement paste is effectively prevented from flowing back to the interior of the casing pipe, so that the stability and the sealing performance of the casing pipe can be kept, and the casing pipe has the advantages of being high in practicability and firmness.

The invention relates to the technical field of drilling compositions, in particular to a composite plugging agent, a plugging composition and plugging cement paste for shale gas formation cracks. The composite plugging agent for shale gas stratum cracks is composed of a bridging material, a filling material and an end-capping material, the mass ratio of the bridging material to the filling material to the end-capping material is (1.2-1.4): 0.5: (0.1-0.3), the bridging material is organic fibers with the length of 3-5 mm, the filling material is composed of inert particles with the particle size of 35-280 [mu] m and micro-silicon with the particle size of 0.15-1 [mu] m, and the end-capping material is a mixture of silicon oxide and silicon oxide. The end-capping material is composed of organic fibers with the length of 8-9 mm and walnut shells with the particle size of 3-5 mm. Through compounding of different types of bridging materials, filling materials and end sealing materials and grading of fibers with different lengths and plugging particles with different particle sizes, the plugging agent can be matched with cement paste in complex cracks and large cracks (1-4 mm) of a stratum to form a stable and compact plugging layer, the compressive strength is high, effective retention is achieved, and the effect of plugging a complex leakage layer is achieved.

The invention relates to the field of building construction, in particular to a variable cross-section reinforcement cage cloth bag pile structure which comprises a reinforcement cage, a grouting pipe arranged in the reinforcement cage in a penetrating mode and a cloth bag arranged outside the reinforcement cage in a sleeving mode. The technical problem that an existing cloth bag pile structure is unstable in the construction process, a cloth bag shakes in the cement paste pouring process, and then the cloth bag pile structure is unstable is solved.

The invention discloses a water-non-dispersible cement paste system for well cementation. The water-non-dispersible cement paste system comprises the following components in parts by weight: 100 parts of oil well cement, 2-3 parts of an expanding agent, 1-5 parts of an anti-dispersing agent, 0.5-2 parts of a drag reducer, 0-0.1 part of a defoaming agent and 40-45 parts of water, the anti-dispersing agent is formed by copolymerizing the following components in percentage by mass: 15 to 60 weight percent of acrylic acid, 0 to 15 weight percent of N, N-dimethyl acrylamide, 30 to 85 weight percent of acrylamide, 0 to 10 weight percent of N-vinyl pyrrolidone and 0 to 1.5 weight percent of ethylene diamine tetraacetic acid disodium salt; the drag reducer is obtained by graft polymerization of a polyacrylic acid monomer and fatty acid vinyl ester in a molar ratio of (8-36): 1; the polyacrylic acid monomer is formed by copolymerizing 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid, sodium p-styrenesulfonate and acrylamide according to a molar ratio of (0.08 to 0.6): 1: (0.05 to 0.3): (0.1 to 1); the water non-dispersible cement paste system for well cementation has good dispersion resistance and flowing property, and the water invasion resistance of the cement paste is effectively improved.

The invention discloses a preparation method of a cellulose ether grafted concrete slurry purifying agent. The preparation method is characterized by comprising the following steps: (1) mixing and stirring urea, deionized water and hydroxypropyl methyl cellulose ether into transparent mucus; (2) adding a silane coupling agent, N, N-methylene bisacrylamide and a polyether monomer, and continuously stirring uniformly; (3) preparing three dropwise adding solutions and a polymerization inhibitor solution; (4) simultaneously dropwise adding the three dropwise adding liquids into the material obtained in the step (2) at a constant speed; and (5) keeping the temperature after dropwise adding, adding the polymerization inhibitor solution obtained in the step (3), and supplementing a proper amount of water to obtain the cellulose ether grafted concrete slurry purifying agent. The urea solution is used for preventing the agglomeration phenomenon of the cellulose ether in the synthesis process, and meanwhile, the coupling agent is used for connecting cellulose ether molecules to molecular side chains; the macromolecules connected with the cellulose ether structure can provide steric hindrance, so that the fullness degree of cement paste is improved, and the paste extraction effect is achieved.

The invention discloses a preparation method of a cement-based structured electrolyte with high ion conductivity and the electrolyte, and the preparation method comprises the following steps: mixing a polymer solution, cement and fine sand to obtain a polymer-cement paste; and performing low-temperature closed maintenance on the polymer-cement paste, and standing at room temperature to obtain the cement-based structured electrolyte. The controlled phase separation technology is adopted, elastic phase separation of a polymer network is carried out earlier than cement hydration, cement becomes a framework of the polymer network in a self-adaptive mode in the hydration process, the interface of the polymer network and the cement is good, and a continuous high-conduction ion channel can be formed; and the preparation process is simple to operate and high in repeatability.

Chemical test methods for evaluating the alkali-silica reactivity (ASR) of an aggregate or an aggregate within a particular concrete job mix design by exposing the aggregate to a simplified system with the same or simulated long-term pore solution conditions is provided. ASR is a chemical reaction occurring between alkaline hydroxides within cement paste and certain types of amorphous silica found in mineral aggregates. Causing an accumulation of internal pressure within concrete structures due to the formation of a hygroscopic gel through the absorption of water, ASR leads to expansion and cracking of concrete. The present test method determines the reactivity index (RI) of a given aggregate, or an aggregate as it is to be used in a proposed concrete job mix design by determining the average concentrations of calcium, aluminum, and silicon across multiple tested samples, wherein the RI is the ratio of the concentrations of silicon to that of aluminum and calcium combined.

The invention relates to the technical field of shield construction, in particular to an under-pressure tool changing construction method for a high-water-pressure long-distance shield to penetrate through a soft and hard composite stratum. Comprising the steps of double plugging (secondary grouting is conducted behind the wall of a segment at the shield tail through double-liquid slurry, and polyurethane is injected into a shield body shell at the middle shield position), tunnel advanced grouting reinforcement, tunnel face mud film retaining wall construction, tool replacement under pressure and pressure reduction and cabin exiting. The construction method has the beneficial effects that secondary grouting is conducted on the wall back of the shield tail segment through cement paste and water glass, polyurethane is injected into a shield body shell in a matched mode to form a closed water stop ring, a double-blocking system is formed, underground water is prevented from moving forwards, a gap between a shield body and surrounding rock is filled, stability of a soil body above a shield is guaranteed, and the construction quality is improved. Secondly, advanced grouting reinforcement and bentonite mud film retaining wall manufacturing are conducted, it is guaranteed that the air pressure in the soil cabin and the water and soil pressure outside the cabin are balanced, and the safety of under-pressure tool changing construction is improved.

The invention discloses a viscosity reduction type concrete admixture and a preparation method thereof, and belongs to the technical field of concrete admixtures. The admixture comprises a viscosity reduction type polycarboxylic acid water reducing agent, a hydrophobic surfactant, an air entraining agent, a defoaming agent, a retarder and water, wherein the viscosity reduction type polycarboxylic acid water reducing agent is prepared from a polyether monomer, unsaturated acid, a viscosity reduction functional monomer, an oxidizing agent, a reducing agent, a chain transfer agent, a neutralizing agent, a catalyst and deionized water. The viscosity reduction type polycarboxylic acid water reducer added in the admixture effectively reduces the HLB (hydrophile-lipophile balance) value of the surface of cement paste through the polymerization of phosphate groups in the viscosity reduction functional monomer, improves the flowability of concrete, and realizes the viscosity reduction effect. The mixing amount level of the admixture is 1.0-1.8%, and the admixture has the characteristics of low mixing amount, environment-friendly preparation process and excellent viscosity reduction effect, and has no negative influence on indexes such as concrete strength and the like.

The utility model discloses a blanking structure for a cement paste mixer. The blanking structure comprises a cover cap, an L-shaped conveying pipe and an L-shaped water outlet pipe, according to the discharging structure for the cement paste stirrer, the top of a stirring pot of a cement paste stirrer body is buckled with a cover cap matched with the stirring pot, mounting tables are symmetrically and fixedly connected to stand columns on the rear side of the cement paste stirrer body, a cement storage bin and a water liquid storage bin are arranged on the mounting tables correspondingly, and an L-shaped water outlet pipe is fixedly connected to the bottom of the water liquid storage bin; the bottom of the cement storage bin is fixedly connected with an L-shaped conveying pipe, the cement storage bin and the water storage bin are blocked through the bin cover, the cement storage bin and the water storage bin are connected with the cover through cooperation of an L-shaped water outlet pipe and the L-shaped conveying pipe and a connecting pipe, so that closed feeding is conducted, and the cover covers the top of a stirring pot of the cement paste stirring machine body. Therefore, the problem of powder overflow in the stirring and feeding process is effectively avoided, and the situation that dust pollutes air in the feeding and stirring process is avoided.

The invention relates to the technical field of building materials, in particular to phase-change recycled aggregate, a preparation method thereof and an anti-freezing water-stable material. The phase-change recycled aggregate comprises a base material and a packaging layer coating the surface of the base material, the base material comprises a porous decoration waste aggregate structure and an organic phase-change material, and the organic phase-change material is located in gaps of the porous decoration waste aggregate structure; the porous decoration waste aggregate structure comprises aerated concrete aggregate; the encapsulation layer includes a first cementitious material. According to the invention, the phase-change material is used for infiltrating and filling holes in the surface of the aerated concrete aggregate, and then the cement paste is used for wrapping and packaging, so that the reinforcement of the recycled aggregate is completed, the water absorption of the recycled aggregate is reduced, the phase-change material is packaged in the aggregate, and the separation loss of the recycled aggregate is reduced; the high-temperature heat absorption and low-temperature heat release performances of the organic phase-change material are utilized to relieve the stress damage of temperature impact to the internal structure, so that the heat preservation period during winter construction can be prolonged, and the effective hydration time of the cement can be prolonged.

The invention discloses a preparation method of solid waste for filling a karst cave, and relates to the technical field of buildings. Comprising the following steps: pretreating solid waste to obtain first pretreated solid waste; sieving the first pretreated solid waste to obtain a second pretreated solid waste; mixing the second pretreated solid waste with a slurry additive to obtain karst cave filling slurry; wherein the solid waste comprises at least one of mud, excavation soil and sludge. The solid wastes such as the slurry, the excavation soil and the sludge have the characteristics of fine particles, easiness in stirring, good dispersity and no pipeline blockage, so that the pollution of materials such as low-grade concrete, neat cement paste and composite paste slurry to water and soil environments can be avoided, and the raw material cost required by pouring and backfilling construction can be saved; and the outward transportation cost of solid wastes such as surface soil and slurry and the cost for treating environmental pollution are saved.

The utility model discloses a JDG guide pipe connecting mechanism which comprises a heat-shrinkable sleeve and a locking mechanism, guide pipe connectors are arranged on the two sides of the heat-shrinkable sleeve, guide grooves are formed in the inner sides of the guide pipe connectors, self-locking plug pins and spring mechanisms are arranged on the guide grooves, the self-locking plug pins are connected with the spring mechanisms, the locking mechanism is a buckle, and the heat-shrinkable sleeve is connected with the heat-shrinkable sleeve. According to the quick locking device for the JDG guide pipe, through the combination of the heat-shrinkable sleeve, the self-locking structure and the quick locking device, cement paste is prevented from permeating into the guide pipe, and the construction efficiency and the sealing performance are improved.

The invention provides a post-grouting FRP steel pipe pile construction method and device and a miniature composite pile. The method comprises the steps that firstly, bottom positioning parameters of a composite pile comprising multiple sections of pile body rod units are obtained, and according to the bottom positioning parameters, segmented grouting equipment comprising an air bag, an air injection hose and a grouting hose is hoisted to the bottom of the pile; the air bag is inflated through the air injection hose to form a closed grouting space; cement paste is injected into the space through a grouting hose, and the cement paste is injected into an external soil body around the pile body rod unit through a one-way circulation hole in the pile body rod unit; when the interior of the pile body of the composite pile is filled with cement paste and external grouting is completed, grouting is stopped, and air in the air bag is released; and the equipment is lifted to the previous section of pile body rod unit, and the steps are repeated till full-length grouting of the pile body is completed. Through precise positioning, segmented grouting and intelligent control, it is ensured that the pile body and soil around the pile are filled with cement paste, the bearing capacity and corrosion resistance of a pile foundation are enhanced, and efficient and durable foundation reinforcement is achieved.

The invention provides a construction method for punching transformation of a sandwich perlite composite wall. The construction method comprises the following steps that S1, construction preparation is conducted; s2, measuring and marking the sideline of the opened hole on the wall body with the opened hole; s3, a back-jacking supporting unit supported between a floor and a top plate is arranged in front of the wall with the opened hole; s4, water drilling and hole taking are conducted on the wall with the opened hole along the periphery of the side line, a grouting nozzle is embedded in the hole, and pressure grouting is conducted; s5, lintel construction is conducted on the wall with the opened hole along the side line; s6, the original masonry in the sideline range is statically dismantled through a water drill; s7, constructional columns are arranged on the two sides of the opened hole; and S8, the back-jacking supporting unit is dismantled. Pearlite in the wall body is fixed by adopting a pre-pressure cement paste injection technology, so that the problems that the construction is influenced and the thermal insulation performance of the wall body is reduced because the pearlite flows out in the punching process are solved; and drilling and dismantling of the wall body are achieved through water drill static dismantling, large disturbance to the wall body is avoided, and construction safety is guaranteed.

The invention discloses a soil nailing and soilbag combined side slope protection system and a construction method thereof, relates to the technical field of side slope protection engineering, and aims to solve the technical problems that when a traditional soil nailing wall protection system is arranged, the surface of a side slope needs to be covered with a large amount of cement paste, and pollution is likely to be caused to the environment. The bag body is made of high-strength polyester fiber materials, the appearance of the bag body is a cuboid, and when the bag body is filled with soil, the total length of the bottom face is 1.5 m, the width is 0.4 m or 0.2 m, and the height is 0.2 m; the filler is slope in-situ soil, and the in-situ soil obtained through excavation is tamped and compacted; the soilbag unit is composed of a plurality of soilbags, each layer is composed of four standard soilbags 1 filled with aggregate and two standard soilbags 2 filled with aggregate, and each soilbag unit is provided with two layers of soilbags which are overlapped. According to the method, the slope can be supported without adding any concrete, and the method has the advantage of being good in environment-friendly performance.

Carbon capture method for an industrial plant off-gas involves removing mercury and / or other heavy metals from the off-gas by contacting the off-gas with an at least partially hydrated cement paste as sorbent in a scrubber before a concentration step of the off-gas to concentrate CO2. The at least partially hydrated cement paste is simultaneously carbonated and loaded with the mercury and / or other heavy metals during contacting with the off-gas and is used as supplementary cementitious material in composite cement. The at least partially hydrated cement paste is used as sorbent in a scrubber before a concentration step of the off-gas to concentrate CO2.

The invention provides a polyoxyalkylene ether macromonomer, a preparation method and application of the polyoxyalkylene ether macromonomer in preparation of a polycarboxylate superplasticizer, the polyoxyalkylene ether macromonomer is obtained by performing ring-opening polymerization reaction on an initiator and an alkylene oxide monomer under the action of a deprotonation reagent, and the initiator is allyl mercaptan or methyl and phenyl substituted allyl mercaptan. The polycarboxylate superplasticizer is obtained by free radical copolymerization reaction of an acid monomer and the polyoxyalkylene ether macromonomer under the action of an initiator and a reducing agent. Allyl sulfide is easy to generate uniform cracking of carbon-sulfur bonds in the polymerization process, polyoxyalkylene ether sulfydryl free radicals are generated, chain transfer is achieved, in the chain transfer process of the polyoxyalkylene ether macromonomer, a transferred chain still retains terminal double bonds and can participate in polymerization again, and the polyoxyalkylene ether macromonomer has a good polymerization effect. Therefore, polycarboxylic acid synthesized by using the polyoxyalkylene ether macromonomer has a certain branched topological structure, and cement paste dispersed by the polyoxyalkylene ether macromonomer has better workability.

The invention discloses a rapid tool lifting system for road and bridge construction. The rapid tool lifting system comprises a rail and a sliding table installed on the rail in a sliding mode. The driving mechanism is fixedly mounted on the sliding table; the lifting mechanism is mounted at the upper end of the driving mechanism; the connecting seat is fixed at the lifting end of the lifting mechanism; the lifting mechanism is fixedly mounted at the front end of the connecting seat; and the winding mechanism is detachably mounted at the upper end of the connecting seat. The rainproof cloth which can be controlled by the rolling mechanism is arranged on the outer side of the lifting mechanism, so that the flexible protective cover which can be opened and closed is formed, when the tool is lifted and moved, the rainproof cloth can be put down, a wrapping space is formed, the tool is effectively prevented from colliding and scraping with a surrounding bridge structure (such as a pier, a guardrail and a box girder), and the service life of the tool is prolonged. And meanwhile, most of pollutants such as dust and cement paste can be isolated, cleaning of tools and a lifting mechanism is protected, and the service life of equipment is prolonged.

The invention discloses a seabed shallow casing section thermal insulation structure for polar region supercritical carbon dioxide drilling, which comprises a casing, a thermal insulation coating, a protective coating, an annular cement slurry layer, an electric heating pipe, a sensor module, a wireless conductive module, a ground system and a seabed wireless transmission module, and is characterized in that the electric heating pipe is fixed on the outer wall of the casing through a hoop; the outer wall of the casing pipe is sequentially coated with a heat preservation coating, a protective coating and an annular cement paste layer from inside to outside, the wireless conductive module is integrated at the end of the casing pipe, and the ground system comprises a ground data acquisition system and a ground control center. The sea surface platform is provided with a ground data acquisition system and a ground control center which are connected with the seabed wireless transmission module through an umbilical cable, and temperature and pressure data acquired by the sensor module are uploaded to the ground control center. According to the invention, the problems of rapid heat loss, annular air channeling, casing mechanical property degradation, poor drilling fluid fluidity and the like of the seabed shallow casing section in the polar region extreme low-temperature environment are solved.