212 results about "Chloride ion penetration" patented technology

The invention discloses a loading device for testing the permeability of concrete chloride ions, which comprises a longitudinal loading system and a lateral loading system, wherein the longitudinal loading system comprises a longitudinal bearing steel plate, an 'L'-shaped positioning piece, a lateral high-strength transmission screw, a longitudinal steel base plate, a longitudinal dynamometer, a longitudinal ball seat, a longitudinal loading steel plate, a longitudinal hydraulic jack, a longitudinal fixing steel plate and the like; and the lateral loading system comprises a lateral bearing steel plate, an 'L'-shaped test piece block, a longitudinal high-strength transmission screw, a lateral steel base plate, a lateral dynamometer, a lateral ball seat, a lateral loading steel plate, a lateral hydraulic jack, a lateral fixing steel plate and the like. The invention also relates to a test method for testing the permeability of the concrete chloride ions by utilizing the loading device. The loading device and the test method solve the problems that the conventional device for testing the permeability of the concrete chloride ions cannot load tested pieces, cannot simulate the actual load condition of the conventional concrete and cannot measure the permeability of the concrete chloride ions under the condition of pressure load.

The invention discloses a high-ductility cement-based composite material for repairing a hydraulic concrete structure. The cement-based composite material is prepared from the following components in parts by mass: 20 to 60 parts of cement, 0 to 80 parts of fly ash, 0 to 80 parts of pulverized slag powder, 5 to 10 parts of light-weight calcium powder, 1 to 5 parts of nanometer SiO2, 25 to 40 parts of a fine aggregate, 20 to 40 parts of water, 0.1 to 1 part of a water reducing agent and 0.5 to 2.5 parts of polyvinyl alcohol fibers. According to the high-ductility cement-based composite material for repairing the hydraulic concrete structure, the air content of a mixture is 7 to 10 percent; at the 28-day age, the uniaxial tensile strain is greater than or equal to 5.0 percent, the cube compressive strength is greater than or equal to 60MPa, the frost resistance is greater than or equal to F500, the sulfate corrosion resistance is greater than or equal to KS300, the chloride ion penetration resistance DRCM is less than or equal to 2.0*10<-12>m<2> / s, and the tensile bonding strength with base structure concrete is greater than or equal to 5.0MPa. Under the condition of not mixing any air-entraining agent, preservative or thickening agent, the high-ductility cement-based composite material for repairing the hydraulic concrete structure provided by the invention has high durability, enhanced capability in synergistically acting with an existing structure and a remarkable repairing and reinforcing effect.

A water-based mixture of multi compounds was invented for the purposes of treating and providing an ultimate protection for large areas of concrete pavements against moisture and moisture-associated problems. The mixture preferably works from within the concrete as well as at the surface. A water-repelling function prevents water from penetrating the concrete matrix. A hygroscopic and hydrophilic behavior of its crystallization system within a concrete matrix minimizes moisture transmission through capillaries and connected voids. As a result, the mixture promises to provide a permanent treatment for moisture related problems, such as damage caused by repeated freeze and thaw cycles and chloride ion penetration as from deicing salts, as well as a permanent treatment for the so-called alkali-silica reactions.

The invention discloses a fast load testing device and method for a chloride ion migration coefficient of concrete. An elastic connecting piece in a state of compression is adopted for exerting a sustained load on a concrete sample and the concrete sample loaded with sustained stress is subjected to an electric accelerating chloride ion migration test to calculate the chloride ion migration coefficient of the concrete sample in the state. According to the invention, the fast load testing device and method for the chloride ion migration coefficient of the concrete aim at the problems that the conventional testing device for the chloride ion migration of the concrete can not exert a load on a tested sample and consequently can neither imitate the actual loaded state of in-service concrete nor determine the chloride ion migration coefficient of the concrete under sustained load; sustained and stable pressure is exerted on the concrete sample in longitudinal direction by the resilience of the elastic connecting piece; and the reduction of pressure stress caused by the creep of the concrete sample when a tensioning screw is used for exerting load can be avoided, so that the influence of the sustained load on the permeability of the chloride ions of the concrete can be researched.

The invention provides a loading device for testing concrete chloride ion permeability by coulometry. A steel bottom plate is provided with two screw holes; two parallel screws are inserted into the screw holes; an underdraught steel plate, an overdraught steel plate and a top plate which are parallel to the steel bottom plate are sleeved on the screws sequentially; a jack is arranged between the top plate and the overdraught steel plate; a dynamometer is arranged between the overdraught steel plate and the underdraught steel plate; the steel bottom plate is provided with a convex steel support upwards; the underdraught steel plate is provided with a convex steel pressing head downwards; a overdraught steel plate positioning bolt cap is sleeved on one screw on the upper part of the overdraught steel plate; and a top plate positioning bolt cap is sleeved on the other screw on the upper part of the top plate. The invention also provides a method for testing the concrete chloride ion permeability by the coulometry by utilizing the loading device. The loading device solves problems that the conventional concrete chloride ion permeability testing device cannot apply bending loads on tested pieces, cannot simulate the actual load-up condition of in-service concrete members, and cannot measure the concrete chloride ion penetrability under the condition of the bending loads.

The invention discloses polymer modified rubber mortar for a building leveling layer. The polymer modified rubber mortar is formed by doping three modified materials including rubber powder, a polymer and an organic fibre into modified cement mortar. The polymer modified rubber mortar is formed by mixing the following components in parts by weight: 30-40 parts of cement, 5-20 parts of water, 2-10 parts of the polymer, 50-90 parts of sand, 5-15 parts of the rubber powder, 0.05-0.15 part of the organic fibre, 0-5 parts of mineral admixtures, 0-1 part of an auxiliary, and 0-0.5 part of an additive. According to the freshly-mixed polymer modified rubber mortar, the thickness is controlled to be 7cm, during the curing period of 7 days, the compressive strength of the mortar is not less than 10 MPa, the rupture strength is not less than 3.5 MPa, during the curing period of 28 days, the compressive strength of the mortar is not less than 15 MPa, the rupture strength is not less than 5 MPa, the chloride ion permeation coefficient is not larger than 50*10<-14>m<2> / s, and the heat conductivity coefficient is not larger than 0.5W / m.k. The polymer modified rubber mortar disclosed by the invention can be used for effectively solving the problems of sugaring, peeling, crispiness, bulging, cracking and the like existing in the traditional cement mortar leveling layer, has the performance advantages of permeability resistance, crack prevention, thermal insulation, high tenacity and the like, can fully utilize waste rubber, can turn waste into wealth, and is suitable for various building leveling layers.

The invention discloses an organic composite reinforced concrete rust inhibitor and a preparation method thereof. According to the invention, the rust inhibitor is prepared from well-mixed materials of, by weight: 30-40% of alcohol amine carboxylate, 5-10% of sodium monofluorophosphate, 0.1-0.5% of an anionic surfactant, and balance of water. The rust inhibitor has a good diffusion performance inconcrete, and can simultaneously acts upon the cathodes and the anodes of steel bars. The trust inhibitor forms stable chelate rings with the steel bars, and has an excellent rust inhibiting performance. Also, the anions in the rust inhibitor can be combined with calcium ions in the concrete, such that precipitates are formed. With the precipitates, capillary pores in the concrete can be obstructed, and the chloride ion penetration resistance of the concrete can be improved.

The invention discloses a modified metakaolin-based permeation-resistant and crack-resistant agent for concrete. The modified metakaolin-based permeation-resistant and crack-resistant agent for concrete comprises: by mass, 10 to 75% of modified metakaolin, 5 to 40% of fine limestone powder, 4 to 40% of superfine coal ash, 1 to 20% of calcined hydrotalcite, 2 to 40% of fine quartz sand and 0.2 to 20% of solid silane powder. A preparation method of the modified metakaolin comprises the following steps of putting dry and washed kaolin into a bowl mill, carrying out grinding to obtain kaolin powder, carrying out calcination of the kaolin powder at a temperature of 500 to 1000 DEG C for 0.5 to 6.0 hours to obtain metakaolin, putting the metakaolin into a dispersion machine, adding an organic modifier of sulfamate or triethanolamine into the metakaolin, wherein a mass ratio of the metakaolin and the organic modifier is in a range of (5000: 1) to (100: 1), and carrying out dispersion to obtain the modified metakaolin having a contact angle of 50 to 100 degrees and a specific surface area of 8000 to 15000m<2> / kg. The modified metakaolin-based permeation-resistant and crack-resistant agentfor concrete can be utilized as a concrete additive, improves strength of concrete at different ages, does not produce obvious influences on concrete work performances, obviously improves anti-chloride ion penetration capability of concrete, reduces total shrinkage of concrete and improves crack resistance of concrete.

The invention discloses a chloride ion immobilizing agent and an application method thereof, and belongs to the field of civil engineering materials. The chloride ion immobilizing agent is obtained by thoroughly mixing a layered double hydroxide (LDH) and a substance which can be hydrated to generate the LDH in certain parts by mass; chloride ion immobilization is realized by virtue of a chemical reaction between Ca-Al-LDH and a water reducing agent intercalation product (Ca-Al-SP-LDH) thereof, and a chlorine salt and meanwhile by use of the ion exchange characteristic of Ca-Al-Si-LDH and Mg-Al-LDH; as a result, the adverse effect of internal chloride ions on the properties of a cement-based material is reduced, the erosion action of the chloride ions to a reinforcement is relieved, and the chloride ions in the service environment are prevented from permeation and diffusion into the reinforced concrete. When the dosage of the chloride ion immobilizing agent accounts for 2%-5% of the weight parts of a cementing material, the immobilization rate of chloride ions inside the concrete is greater than 90%; internal doping or surface coating protection is capable of enabling the reinforced concrete impermeability to the chloride ions to be improved by I to II levels; the chloride ion immobilizing agent is suitable for sea sand concrete, marine concrete and mortar, magnesium oxychloride cement products, steel structures and reinforcements as well as concrete anticorrosive paints.

The invention relates to concrete material of high impedance and high anti-permeability and a preparation method thereof. The concrete material of high impedance and high anti-permeability is characterized in that the material is prepared by mixing and stirring raw materials of cement, lightweight aggregate, pebble, sand, polymer, mineral admixture, admixture and water; wherein, proportion of the cement, lightweight aggregate, pebble, polymer and mineral admixture is: 315-500kg / m<3> of the cement, 60-100kg / m<3> of the lightweight aggregate, 900-1,100kg / m<3> of the pebble, 2.0-5kg / m<3> of the polymer and 40-135kg / m<3> of the mineral admixture; addition amount of the admixture is 0.6-1 percent of weight of cementing material; volume rate of the sand is 38-40 percent; water cement ration is 0.3-0.5; the lightweight aggregate is shale pottery with a particle size of 0.05-2.5mm. The concrete material prepared by the method has high impedance and high chloride ion penetration resistant capacity.

The present invention provides the recipe of chlorine ion penetration resisting reinforcer for concrete in harbor engineering. The chlorine ion penetration resisting reinforcer consists of superfine silica powder 15-20 wt%, washed and calcined kaolin 20-25 wt%, high grade fly ash 20-25 wt%, ground blast furnace slag 20-25 wt%, nanometer fiber 5-10 wt%, superplasticizer 6 wt%, slump keeping agent 0.09 wt%, air entraining agent 0.09 wt%, and organic active excitant 0.12 wt%. The chlorine ion penetration resisting reinforcer has inorganic components as main functional materials dispersed homogeneously in concrete cementing material, and can improve the micro structure and hydration product composition inside concrete, raise compactness, adsorb and fix chlorine ion and lower the penetration of chlorine ion in hardened concrete, so as to improve the chlorine ion penetration resisting capacity of hardened concrete.

The invention belongs to the technical field of building materials, and particularly relates to a marine cement doped with modified metakaolin. The marine cement doped with modified metakaolin is prepared by evenly mixing the following raw materials at a certain weight ratio: portland cement, slag powder, pulverized fuel ash, silica fume, white carbon black and modified metakaolin. The marine cement doped with modified metakaolin has the advantages of being simple in preparation technology, good in anti-cracking performance and the like; the chloride ion penetration resistance property of the concrete can be improved obviously, the anti-erosion capability of concrete in a large-volume water conservancy project under a marine environment can be solved, and the durability, strength and other working performances of a concrete structure in the water conservancy project under a marine environment can be enhanced.

This invention introduces a concrete chloride ion permeability fast - corrosion testing method is: put the concrete specimen has a network-reinforced in the middle in the NaCl and 0.3 M NaOH, distilled water preparation and 3.0% in the chemical percentage of pure quality NaCl, and 0.3 M NaOH aqueous solution mixed, in the environmental temperature was 23 or so, with NaCl solution should be soaked every one week replacement once, in the testing process after inspection and test soaking solution of NaCl concentration of 60 +- 0.1 volts the plus DC, in the test cycle, not more than 24 hours in regular record current value, and growth of over 10% / 24 hours, the application of NT BUILD 208, AAHSTO T260 accurate determination of concrete powder samples of the acid chloride Cl-content, chlorine ion concentration measurement accuracy should reach 0.001%.

The invention relates to a concrete protection paint which comprises the following raw materials in parts by weight: 60-96 parts of vinyl-containing monomer, 2-20 parts of carbonyl / formyl-containing vinyl monomer and 1-10 parts of diazanyl-containing monomer. The preparation method comprises the following steps: under stirring conditions, mixing and dropwisely adding vinyl monomer, carbonyl / formyl-containing vinyl monomer and a silane coupling agent into an emulsifier water solution to obtain a monomer emulsion; synchronously and dropwisely adding an initiator water solution and the monomer emulsion into a base solution at 50-90 DEG C to carry out emulsion polymerization, and adding diazanyl-containing monomer to obtain a polymer emulsion; and evenly mixing the polymer emulsion with a film-forming assistant, a plasticizer, a leveling agent, a defoaming agent and water to obtain the concrete protective paint. The invention solves the problem of lower water resistance when the traditional ambient crosslinking material is used for concrete protection, and can effectively lower the concrete carbonization and chloride ion permeability; and the film can not easily crack in a freeze-thawing environment.

The invention discloses alkali-activated slag mortar. The alkali-activated slag mortar consists of the following components in part by weight: 100 parts of mineral powder, 100 to 300 parts of water slag, 4 to 15 parts of alkali activator and 30 to 60 parts of water. The alkali-activated slag mortar can improve carbonization resistance, freeze-thaw cycle resistance, chloride ion penetration resistance and interface compactness of the mortar, provides a new route of water slag utilization and increases the utilization ratio of wastes.

The invention discloses a construction method of a multi-scale prediction model of a chloride ion diffusion coefficient of prestressed concrete. The method is characterized by: regarding the concreteas a cement-based composite material composed of different-scale materials, establishing prediction models of chloride ion diffusion coefficients of the different-scale cement-based materials in sequence with gradual transition from small-scale hardened cement slurry to large-scale concrete, then considering influences which are of prestress inside the prestressed concrete and on chloride ion diffusion thereof, and finally, establishing the multi-scale prediction model of the chloride ion diffusion coefficient of the prestressed concrete. According to the method, influences of prestress levelson chloride ion diffusion are studied by starting from multi-scale structure formations of the cement-based materials, and the established multi-scale prediction model of the chloride ion diffusion coefficient of the prestressed concrete has very important significance for chloride ion penetration resistance study and durability design of the prestressed concrete.

The invention provides a method for repairing and reinforcing pile foundations in ocean splash zones. The method is characterized by comprising the following steps: firstly carrying out interface treatment on the splash zones and the zones needing repair near the splash zones aiming at different pile body types, fixing end hoops for bearing upper construction loads on the lower edges of the repaired zone, installing external molds and then continuously pouring a self-compaction ultra high toughness cementitious composite (UHTCC). The method has the following beneficial effect: erosion of dry-wet alternation and chloride ion permeation in the splash zones, temperature difference and sea wave impact effect can be effectively resisted, thus ensuring the durability of pile bodies under the environmental condition of severe corrosion.

An ocean engineering concrete cover strengthened material and a manufacture method thereof, which is prepared by gel component (comprising cement, mineral admixture and modifier), framework component (superfine sand) and property adjusting component (comprising small crack component and micro crack self-healing component) according to certain ratios by the blend-milling technique. In the construction site of the ocean engineering concrete cover, pre-produced ocean engineering concrete cover strengthened material is adopted to prepare the ocean engineering concrete cover, thus simplifying concrete construction procedures and being convenient for quality control. The ocean engineering concrete cover strengthened material of the invention is applied to the ocean engineering concrete cover, which can effectively improve the durability of the ocean engineering concrete and especially can improve the capability of resisting chloride ion penetration.

The invention provides a tensile load applying device for a concrete chloride ion permeability coulometric-process test, and a test method. In the tensile load applying device, four threaded holes are formed at the four corners of a steel bottom plate, four parallel screws are fastened into the threaded holes, and compression springs, and a tensile steel plate, a pressing steel plate and a top plate, which are parallel with the steel bottom plate, are sleeved on the screws; four threaded holes are formed in the middle of the four edges of the steel bottom plate, four through holes are formed in the middle of the four edges of the tensile steel plate, and tensile screws are inserted into the through holes; and the tensile screws above the tensile plate are sleeved with through hole ball seats and fixed nuts, and the lower ends of the tensile screws are connected with a tensile force measurement device. The invention also provides a concrete chloride ion permeability coulometric-process test method using the applying device. The applying device provided by the invention solves the problem that the conventional concrete chloride ion permeability test device is incapable of applying tensile load onto a tested piece, simulating the actual load state of in-service concrete member and measuring the concrete chloride ion permeability under a tensile load condition.

The invention discloses oxidized-graphene modified silicon ash and a preparation method thereof, oxidized-graphene concrete resisting chloride ion penetration and a method thereof. Each cubic meter of oxidized-graphene concrete contains the following components in mass by weight: 150-350kg / m3 of cement, 40-100kg / m3 of coal powder ash, 800-1300kg / m3 of coarse aggregate, 500-700kg / m3 of fine aggregate, 20-50kg / m3 of oxidized-graphene modified silicon ash, 0.5-8.0kg / m3 of water reducing agent and 105-175kg / m3 of water. The oxidized-graphene modified silicon ash and the preparation method disclosed by the invention have the advantages that firstly the oxidized-graphene modified silicon ash is prepared by an electrostatic self-absorption method, the oxidized graphene can be uniformly coated on the surface of the silicon ash by the method, and then the oxidized-graphene modified silicon ash is uniformly dispersed in the concrete by designing the proportioning ratio of the concrete; researches show that the mechanical property and the chloride ion penetration resistance of the oxidized-graphene concrete prepared by the invention are obviously improved, so that the oxidized-graphene concrete has important significance for developing cement concrete materials with high property and high functionalization.

The invention relates to a method for rapidly determining the chloride ion permeation resistance of concrete. The method comprises the following steps: slicing concrete, putting the obtained sliced concrete into a vacuum water-saturated device, pumping to a certain vacuum degree, injecting deionized water to the obtained vacuum chamber, and maintaining the vacuum degree for a certain period of time to make apertures in the concrete full of water; and carrying out alternating current impedance test of a test piece to obtain a characteristic conductivity, and calculating via a conversion formula to obtain an equivalent dielectric flux in order to evaluate the chloride ion permeation resistance of concrete. The method has the advantages of determination of the dielectric flux of concrete within a very short period of time, simplicity, reliable data, no less, and realization of multi-time test of the same test piece.

The invention discloses a modified cement slurry for rapidly repairing concrete, comprising following components in weight ratio: 30-70% of cement, 15-55% of aggregates, 12-15% of fly ash, 2.5-7.5% of latex powder, 0.25-5.5% of early strength admixture, and 0.25-1% of antifoaming agent. The modified cement slurry also comprises an expanding agent by weight of 0-2.5% of total weight and a thickening agent by weight of 0-2.5% of total weight. The modified cement slurry for rapidly repairing concrete can quicken the initial set of the cement slurry, promote water reducing rate of mortar, reduce unit weight of the newly-stirred mortar, and obviously promote flexural compression ratio, binding intensity and chloride ion penetration resistance of slurry, and the durability of concrete after rapidly repairing.

The invention relates to a device for testing the permeability of concrete chloride ions and application thereof. A tensile loading device for testing the permeability of the concrete chloride ions by an electric quantity method is characterized in that: a screw rod between a steel bottom plate and a tensile steel plate is provided with a compression spring; a screw rod on the upper part of the tensile steel plate is sleeved with a tensile steel plate positioning bolt cap; a screw rod on the lower part of a compression steel plate is sleeved with a compression steel plate positioning bolt cap; screw rods on the upper part and lower part of a top plate are sleeved with a lower top plate fixing bolt cap and an upper top plate fixing bolt cap respectively; the middle points of four sides of the steel bottom plate are provided with threaded holes; the tensile steel plate is provided with a through hole which corresponds to the threaded holes; a tensile screw rod is arranged in the through hole; the tensile screw rod is sleeved with a ball seat which is provided with upper and lower through holes and a fixing bolt cap on the upper part of the tensile steel plate; and the lower end of the tensile screw rod is connected with a tensile dynamometer. The problem that the conventional device for testing the permeability of the concrete chloride ions cannot apply continuous tensile load to a tested piece is solved.

The invention discloses a method for carrying out reinforced concrete anticorrosion by using nanometer silica. The method comprises the following steps: 1, processing the surface of concrete to make the surface be flattened, and brushing the surface with an aqueous blanket; 2, uniformly mixing two components of nanometer silica according to a ratio of 1:1, disposing for 2h, and uniformly coating the surface of the concrete with the obtained mixture to make a nanomaterial form a film; and 3, disposing for 6h or above, and coating the nanomaterial to improve the thickness of the nanomaterial formed film. The surface of common concrete, heavily stressed concrete and special additive concrete is protected by using the nanometer silica; a transparent or colored compact protection film with the thickness of 20-30[mu]m is formed on the surface of the concrete at normal temperature in order to meet long-term carbonizing resistance, anticorrosion, chloride ion penetration prevention, biological erosion prevention, and shedding and spalling prevention requirements of the concrete; and the above obtained protection coating layer has the characteristics of high wear resistance, high corrosion resistance and easy cleaning.

The invention discloses a highly durable permanent column template. The column template comprises a column template body and is characterized in that the column template body is a thin-walled cylinder; grooves are formed in the surface on the inner side of the thin-walled cylinder; and reinforcement bars are embedded in the two ends of the thin-walled cylinder. The shape of the cross section of the column template body is the same with that of a column to be poured and is circular, rectangular or polygonal; the cross section size and the height of the column template body are the same with those of the column to be poured; and the thickness of the column template body is that of the protective layer of the column to be poured. The grooves are circularly formed in the surface on the inner side of the thin-walled cylinder of the column template body. The reinforcement bars are embedded in the thin-walled cylinder for 15 cm to 20 cm and extend out of the two ends of the thin-walled cylinder for 15 cm to 20 cm. The column template body is prefabricated with ECC (Engineered Cementitious Composites). The highly durable permanent column template has the advantages of high tensile ductility and excellent creak control capability, is superior to common concrete in chloride ion penetration resistance and water penetration resistance, can improve the durability of concrete structures, facilitates the construction, and shortens the construction time.

The invention provides a test method of a cement-based material chloride ion penetration depth. The method uses a mould disclosed in a patent of which the patent number is 'ZL201120473976.2' and used for an electrochemical impedance spectroscopy online test in a cement hydration process to carry out full-course maintenance and a chloride ion penetration test for cement materials. Electrode plates of 40mm*40mm arranged at two ends of the mould are detached during chloride penetration to enable the cement materials to be eroded by the chloride ions; when the test is to be carried out, the electrode plates are mounted at the two ends of the mould to carry out the electrochemical impedance spectrum test; finally the chloride ion penetration depth of the cement materials are reflected and calculated through regular variation of electrochemical parameters. The test method disclosed by the invention has the advantages that the mould and cement test pieces are not easy to damage, repeatable detection is achieved, the error is small and the operation is convenient.

The invention discloses a concrete coating protecting system. The concrete coating protecting system comprises a concrete permeating type primer and a high-build weather-resistant finishing coat, wherein the permeating type primer comprises a component A1 and a component B1 with the mass ratio of 3-1 to 1-1; the high-build weather-resistant finishing coat comprises a component A2 and a component B2 with the mass ratio of 1-3 to 3-1. The invention also provides a construction method. According to the concrete coating protecting system, the permeating type primer is capable of improving the intensity of a foundation and preventing the foundation form cracking; the high-build weather-resistant finishing coat is high in solid content, low in viscosity, environmentally friendly, fast to cure, short in period, high in tensile strength and elongation percentage, and outstanding in pursuit performance. Therefore, the concrete coating protecting system is outstanding in alkali resistance, ageing resistance, resist to chloride ion penetration, and capable of prolonging the service life of a concrete structure.

The invention provides marine ultra-high performance concrete and a preparation method thereof. The marine ultra-high performance concrete comprises the following raw materials in parts by weight: 450to 650 parts of cement, 50 to 200 parts of silica fume, 5 to 50 parts of nano silicon dioxide, 100 to 200 parts of mineral powder, 100 to 200 parts of fly ash, 1000 to 1300 parts of sand, 35 to 200 parts of steel fibers, 0.5 to 3.0 parts of polypropylene fibers, 1 to 10 parts of a hydration heat inhibitor, 20 to 45 parts of an additive and 180 to 220 parts of water. Compared with the prior art, the marine ultra-high performance concrete has good flowing property, good fluidity retaining capacity, and relatively low slump loss. In addition, the marine ultra-high performance concrete has low early hydration heat and good anti-cracking performance, and also has excellent mechanical properties and relatively high compressive strength. Moreover, the marine ultra-high performance concrete is high in compactness, has excellent chloride ion penetration resistance, has good durability in a marine environment, and thus has a wide market prospect.

The invention discloses a concrete surface protection nano paint which comprises the following components in parts by weight: 24-26 parts of nano silicon dioxide, 29-31 parts of n-butanol, 5.5-6.5 parts of butyl acetate, 7.5-8.5 parts of ethyl orthosilicate, 14-16 parts of trimethoxy silicane, 11-13 parts of isobutyl triethoxy silane and 3-5 parts of C12 alcohol ester. The invention also discloses a technique for preparing the concrete surface protection nano paint. The concrete surface protection nano paint can be applied to surface protection of various types of ordinary concrete, high-stress concrete and special additive concrete. The concrete surface protection nano paint can form a transparent or colored compact protective film with the thickness of 20-30 micrometers on the concrete surface, thereby satisfying the requirements of long-term carbonization resistance, corrosion resistance, chlorine ion permeation resistance, bioerosion resistance, shedding and peeling resistance and the like for the concrete. The protective coating has the characteristics of high wear resistance, high corrosion resistance and high cleanness.

The invention belongs to the technical field of concrete mix proportion optimization design, and particularly discloses a durable concrete mix proportion optimization method based on RF-NSGA-II. The method comprises the following steps: constructing a concrete durability index system, collecting sample data of each variable in the concrete durability index system, and establishing an original sample set according to the sample data; training a random forest regression calculation model by adopting the original sample set; evaluating the trained random forest regression calculation model to respectively generate random forest prediction models of concrete relative dynamic elastic modulus and chloride ion permeability coefficient; and taking the random forest prediction models as target functions, taking a value range of concrete materials and a mix proportion relationship among the materials as constraint conditions, and performing durable concrete mix proportion multi-target global optimization by adopting an NSGA-II model. The method is high in prediction precision, high in generalization capability and anti-noise capability, high in optimization precision, high in robustness andcapable of rapidly obtaining a globally optimal solution.