97 results about "Resilient modulus" patented technology

The invention discloses a tire finite element modeling and multidirectional rigidity optimization method and system based on characteristic lines. The method comprises the following steps: extracting tire section characteristic lines from a three-dimensional digital model; introducing the tire section characteristic line into a finite element analysis environment, generating a three-dimensional tire geometric model by rotationally scanning the characteristic line, and performing grid division on the model; setting tire material attributes, performing zoning setting on the model according to a tire crown, a tire shoulder and a tire side wall, and setting tire thickness based on zoning; applying a constraint boundary condition at the center of the tire, and establishing a contact form of the tread and the ground; a progressive inflation pressure load is applied, the deformation state of the inflated tire is calculated, and longitudinal rigidity, radial rigidity and lateral rigidity calculation and analysis steps are set; the tire elasticity modulus and the cord fabric thickness are used as design variables, and an optimization algorithm is adopted to solve a multi-objective optimization function. The method has the advantages of being simple in modeling method and high in practical operability, the tire modeling threshold can be lowered, and the fund and time cost of refined modeling is reduced.

The invention relates to the technical field of road engineering, in particular to a detection method for evaluating cohesion characteristics of river-crossing shield tunnel waste slag improved soil for roadbed filling, which comprises the following steps: preparing a solidified soil sample; calculating coupling parameters; obtaining a static cohesion force and a dynamic cohesion force; obtaining a water stability coefficient; based on the collected roadbed filling characteristic parameters, the static cohesion, the dynamic cohesion and the water stability coefficient, constructing a dynamic resilience modulus correlation model; grading the cohesion characteristics of the solidified shield soil according to the coupling parameters and the dynamic rebound modulus; detecting actual values of the coupling parameters and the dynamic resilience modulus of the to-be-evaluated solidified soil, and determining the grade of the to-be-evaluated solidified soil; according to the cohesion characteristic detection method, the characteristics of shield tunnel soil particles, mineral composition and roadbed filling scenes are fitted, actual working conditions are simulated, and the solidification effect is quantified, so that a scientific basis is provided for engineering application of shield tunnel soil solidification improved roadbed, and the problems in the background technology are effectively solved.

The invention relates to the technical field of concrete durability evaluation, in particular to a compound green concrete salt freezing resistance durability evaluation system under a frozen soil environment, which comprises a data input unit, a decision information table storage unit, a rough set analysis processing unit and an evaluation output unit, the data input unit receives a sample data set containing freeze-thaw cycle times, dry-wet cycle times, freeze-thaw-dry-wet cycle times, long-term soaking time, composite salt concentration, gas content and fly ash mixing amount, and the decision information table storage unit stores a decision information table constructed based on a rough set theory. The influence factor combination and the relative dynamic elastic modulus percentage are associated, the rough set analysis processing unit establishes a mapping relation through attribute reduction and rule extraction and quantifies the weight of each factor, and the evaluation output unit outputs a relative dynamic elastic modulus predicted value, durability grade classification and key factor contribution sorting. And the salt freezing resistance durability of the concrete under the multi-factor coupling effect is accurately evaluated.

This invention relates to the field of concrete pouring technology, and discloses a method and system for regulating the cooling of hydration heat in large-volume concrete based on temperature difference control. The method includes the following steps: Step S101, constructing a thickness temperature profile; Step S102, calculating the zone temperature difference and the cooling rate in the middle section; Step S103, calculating the equivalent age field; Step S104, calculating the time-varying elastic modulus and relaxation time; Step S105, constructing a base constraint weighting function; Step S106, calculating the constrained viscoelastic thermal stress field; Step S107, calculating the potential energy centroid drift intensity; Step S108, outputting control commands. This invention achieves multi-factor coupled calculation and multi-objective collaborative optimization for regulating the cooling of hydration heat in large-volume concrete, ensuring that cooling regulation aligns with the core requirements of crack resistance in engineering projects, thereby reducing the possibility of hydration heat cracking in concrete.

The invention discloses anti-freezing and salt-tolerant high-strength concrete and a preparation method and application thereof, and belongs to the technical field of green high-strength concrete preparation, the anti-freezing and salt-tolerant high-strength concrete comprises, by mass, 400-500 parts of a cementing material, 650-700 parts of fine aggregate, 1000-1100 parts of coarse aggregate, 0.01-0.015 part of an additive and 160-180 parts of water, the fine aggregate comprises machine-made sand and / or river sand, and the coarse aggregate comprises water and / or water. The mass of the machine-made sand accounts for 50% of the total mass of the fine aggregate. The compressive strength, elastic modulus, chloride ion penetration resistance and carbonization depth of the concrete are improved by adopting a double-doping (slag ash and fly ash) or triple-doping (fly ash, slag ash and silica fume) mode, and the concrete is excellent in freezing resistance, wear resistance and permeability resistance.

The invention discloses a method for quickly constructing a pre-stressed system of a post-tensioned pre-stressed cover beam in winter, and belongs to the technical field of cover beam construction. Comprising the steps that S1, a steel reinforcement framework, prestressed pipes, prestressed steel bars and the like are fixed according to a cover beam design drawing; s2, a plurality of wireless temperature sensors are arranged on the bent cap steel bars for temperature monitoring; s3, determining raw materials and dosage of capping beam concrete, and mixing the concrete; s4, the cover beam concrete is transported; s5, cover beam concrete is poured; s6, the whole process from pouring to hardening of the bent cap concrete is subjected to heat preservation and maintenance; s7, setting a temperature matching maintenance test piece, and determining a tensioning opportunity according to the compressive strength and the elastic modulus of the test piece; s8, selecting a grouting opportunity according to the temperature monitored by the wireless temperature sensor; and S9, quick-hardening phosphate mortar is selected, heating and heat preservation measures are applied, and anchor sealing concrete construction is conducted. According to the method, the winter construction speed of the post-tensioned prestressed cover beam can be increased, and the construction quality is guaranteed.

This invention discloses a method and equipment for evaluating the tensile toughness of recycled asphalt mixtures, relating to the field of analytical techniques for recycled asphalt mixtures. The method includes: acquiring variables related to the internal structure and external environment of the recycled asphalt mixture to be evaluated; the variables related to the internal structure include: internal structural state variables, the length of the aggregate-binder two-phase interface transition zone, and the elastic modulus; the variables related to the external environment include: tensile strain ratio, loading frequency, and dynamic modulus; and calculating the tensile toughness evaluation value of the cold recycled asphalt mixture based on a predetermined multi-parameter coupling relationship using the variables related to the internal structure and the external environment. This invention introduces environmental factors and internal structural parameters of the recycled asphalt mixture to establish a multi-parameter tensile toughness evaluation model, fully considering the material composition, microstructural distribution characteristics, load factors, and ambient temperature of the recycled asphalt mixture under stress in the structural layer, enabling accurate evaluation of the tensile toughness of the recycled asphalt mixture.

The invention belongs to the technical field of building materials, and relates to impermeable high-strength concrete and a preparation method thereof. The invention provides impervious high-strength concrete which is prepared from the following components in parts by mass: 150 to 200 parts of cement, 80 to 100 parts of organic and inorganic composite modified bentonite, 900 to 1300 parts of fine aggregate, 230 to 340 parts of coarse aggregate, 2 to 10 parts of additive and 250 to 350 parts of water, the organic and inorganic composite modified bentonite is obtained by modifying bentonite with polyepichlorohydrin dimethyl ammonium and then modifying the modified bentonite with hydroxyl polyaluminum chloride. The invention aims to solve the technical problem that the compressive strength and the elastic modulus of the concrete for the underground diaphragm wall are almost synchronously reduced along with the increase of the use amount of bentonite, so that the compressive strength and the elastic modulus are difficult to consider at the same time.

The invention relates to the technical field of engineering materials, and provides anti-cracking steel slag asphalt concrete and a preparation method thereof. The anti-cracking steel slag asphalt concrete is prepared from, by weight, 4-6 parts of asphalt, 5-10 parts of filler and 60-70 parts of aggregate, the filler is prepared from, by weight, 20-30 parts of steel slag powder, 20-25 parts of limestone powder, 0.3-0.5 part of polypropylene fiber and 0.3-0.5 part of dispersing agent, and the polypropylene fiber is composed of first polypropylene fiber and second polypropylene fiber. The elastic modulus and the fiber length of the first polypropylene fiber are different from those of the second polypropylene fiber. According to the technical scheme, the problem of insufficient cracking resistance of the steel slag asphalt concrete in related technologies is solved.

The application discloses a kind of shotcrete and its preparation method, belong to building material technical field.It mainly includes the following weight parts of raw materials made: Portland cement 200~260 parts, fine sand 240~280 parts, 260~300 parts of gravel, fly ash 10~35 parts, composite steel fiber 5~10 parts, admixture 10~15 parts, no alkali accelerator 2~5 parts, water reducing agent 1~3 parts and water 80~110 parts.The shotcrete provided by the application adopts steel fiber and has excellent tensile strength and elastic modulus and other characteristics, and the composite steel fiber forms a three-dimensional network structure in the concrete to support the concrete;After adding fly ash and admixture to the concrete, it is beneficial to improve the compactness of the concrete, promote the development of early strength, and improve the compressive performance of the concrete.

The application discloses an interface adhesive as well as a preparation method and application thereof, and belongs to the technical field of concrete. A component A contains E-51 epoxy resin, elastic modulus enhancer a (a composite of single-sulfur calcium sulphoaluminate and high-sulfur calcium sulphoaluminate) and bonding enhancer b (nanoscale gel), etc.; a component B is a polyamide curing agent and a modified aromatic amine curing agent. The adhesive has an elastic modulus of about 40 GPa, is between UHPC and NC, can relieve interface stress concentration, can permeate and block microcracks at the same time, and can significantly improve bonding strength and durability. When the adhesive is prepared, the component A and the component B are stirred respectively, are mixed in proportion, and are vacuum degassed, and the adhesive is obtained. When the adhesive is constructed, the adhesive is coated on the surface of existing ordinary concrete first, and then an ultrahigh performance concrete reinforcing layer is poured.

Tire (1) for construction vehicle comprising two working layers (321, 322), comprising metallic reinforcements and at least two shrink-fit layers (331, 332), of axial widths less than those of the working layers (321, 322), and comprising metallic reinforcements, the innermost radial shrink-fit layer (332) being the shrink-fit layer of greatest axial width. At each axial end of the innermost radially enclosing layer (332), two contiguous rubber mixtures (51, 52, 61, 62), or decoupling mixtures, are arranged, one being radially inside the other, the decoupling mixture (51, 61) furthest radially from the end of the enclosing layer (332) has a dynamic modulus of elasticity measured at 23°C and 10% strain and at 10 Hz, at most equal to 0.7 times the dynamic modulus of elasticity of the decoupling mixture (52, 62) closest radially to the end of the innermost radially oriented shrinkage layer (332). Abstract figure: Figure 1.

The application discloses a kind of low modulus high ductility super-retarding concrete, the concrete includes by weight ratio: cement 254~360 parts, fly ash 68~108 parts, slag powder 68~70 parts, 5~16mm gravel 352~393 parts, 16~25mm gravel 660~729 parts, medium sand 669~705 parts, rubber powder 20 parts, polystyrene plastic 15 parts, water 150 parts, water reducing agent 5.9~7.5 parts, super-retarding agent 3.1~4.0 parts, water-based polyurethane 15 parts, nano composite hydrogel 15 parts, polyolefin elastomer 5 parts, polypropylene fiber 1.0 part, can have higher toughness, lower elastic modulus, and can reach design requirement strength and durability, simultaneously, when practical application, first, a layer of low modulus high ductility super-retarding concrete is poured, then continue to pour ordinary concrete, combined with other anti-cracking measures, can effectively reduce the constraint degree of bottom plate to upper portion, prevent temperature cracks.

This application relates to a method and system for designing the mix proportion of cement emulsified asphalt mortar for high-speed railways. The method includes the following steps: inputting design factors of the cement emulsified asphalt mortar to be designed into a design model; the design factors include raw material types, quantities, and environmental parameters; predicting and outputting performance indicators corresponding to the cement emulsified asphalt mortar to be designed through the design model; the performance indicators include fluidity, spreadability, working time, compressive strength, elastic modulus, and fatigue life; adjusting the design factors of the cement emulsified asphalt mortar to be designed according to the performance indicators and inputting them into the design model to obtain the performance indicators corresponding to the adjusted design factors; repeating the input and adjustment steps multiple times until the optimal design factors that meet the performance requirements are obtained and output. The system and equipment are used to execute the above method. This application has the advantages of high design efficiency, short cycle, low cost, and high accuracy.

The present application provides a corrugated steel web box girder lining concrete cracking risk analysis method and system, sets up displacement boundary conditions and temperature boundary conditions, establishes a corrugated steel web lining concrete model, carries out numerical calculation on the corrugated steel web lining concrete model, analyzes the numerical calculation results; based on the numerical calculation results, taking shrinkage effect, creep, concrete mold temperature and concrete surface heat preservation measures as the consideration factors, the influence of each consideration factor on the cracking risk of corrugated steel web lining concrete is analyzed; according to the influence of each consideration factor, the cracking risk of target corrugated steel web lining concrete in target environment is determined and adjusted. The present application analyzes the influence of hydration heat release efficiency, elastic modulus change and shrinkage and creep behavior of concrete on the crack resistance of lining concrete, which helps to determine the cracking risk.

This invention discloses a design method for pile-slab bridge deck pavement, belonging to the interdisciplinary field of engineering design and artificial intelligence. Specifically, it includes: data acquisition and preprocessing to establish a standardized design database; constructing a classification prediction model, completing model training and optimization; selecting core feature variables through intelligent feature importance analysis; calculating the pile-slab collaborative stress coefficient and predicting the equivalent elastic modulus of the pavement layer; calculating key parameters and iteratively optimizing the model; predicting and verifying the pavement layer thickness and material ratio parameters; calculating bond strength and predicting service life to ensure that design requirements are met; and completing final parameter optimization, outputting a final design scheme including core parameters, material ratios, and construction suggestions. This invention solves the problems of traditional design relying on experience, low accuracy, and difficulty in quantifying multi-parameter coupling, improving design efficiency and accuracy, extending the service life of the pavement layer, and is applicable to the pavement pavement design of various highway and municipal pile-slab bridges.

The invention discloses a hundred-year-durable high-strength C200 concrete and a preparation method thereof.The hundred-year-durable high-strength C200 concrete is prepared from, by weight, 550 parts of cement, 150 parts of mineral powder, 890 parts of quartz sand, 30 parts of efficient water reducing agent, 300 parts of silica fume, 50 parts of quartz powder, 300 parts of composite admixture, 300 parts of steel fiber and 160 parts of water.Compared with the prior art, the 28-day strength of the C200 concrete can reach 246 MPa, and the strength of the C200 concrete can reach 36MPa. The elastic modulus is 44 GPa; according to the present invention, the cement-based composite admixture has characteristics of chloride ion only 0.004%, 28-day carbonization of 0, impermeability grade of greater than P12, sulfate resistance grade of greater than KS150, anti-freezing grade of greater than F400, water-binder ratio of 0.216, and mineral admixture doping amount of more than 50%, can meet the 100-year durability requirement, effectively utilizes the industrial solid waste by compounding the admixture, reduces the cement consumption, reduces the carbon emission, and accords with the green and environmental protection development concept.

This invention provides a smart stress-relief sandwich layer for composite slabs and its preparation method. The sandwich layer comprises a smart responsive layer, a reinforcing layer, and a chemical anchoring layer arranged sequentially. The smart responsive layer is shape-memory polyurethane, and its elastic modulus can be dynamically adjusted over a wide temperature range by controlling the ratio of soft to hard segments. The reinforcing layer is a hybrid layer of carbon nanotube-modified basalt fibers and a polyurethane matrix, with the carbon nanotubes grown in situ on the surface of the basalt fibers via chemical vapor deposition. The chemical anchoring layer is composed of a silane coupling agent and a titanate coupling agent, forming a dual chemical anchoring interface. This invention achieves dynamic stress adaptation and stable cross-substrate bonding, making it suitable for key applications such as precast concrete composite slabs and steel-concrete composite structures, and possesses excellent engineering application value.

A front tyre (1) for a motorcycle wheel is described, comprising an equatorial plane (X-X) and a tread band (8) having an overall axial extension (L) and comprising a radially outer portion (11) and a radially inner portion (12) made of a first vulcanized elastomeric material, said radially outer portion comprising: a1) a central annular portion (L1) arranged astride the equatorial plane (X-X) of the tyre (1) and made of a first vulcanized elastomeric material; and a2) a pair of lateral annular portions (L2, L3) arranged on opposite sides of the central annular portion (L1) with respect to the equatorial plane (X-X) of the tyre (1) and made of a second vulcanized elastomeric material. In the tyre (1), the ratio R1 between the dynamic elastic modulus E' of the second vulcanized elastomeric material measured at 10 Hz frequency and 23°C and the dynamic elastic modulus E' of the first vulcanized elastomeric material measured at 10 Hz frequency and 23°C is comprised between 0.6 and 1.2. In the tyre (1), the ratio R2 between the loss factor of the second vulcanized elastomeric material measured at 10 Hz frequency and 70°C and the tandelt of the first vulcanized elastomeric material measured at 10 Hz frequency and 23°C is comprised between 0.6 and 1.2.

This invention discloses a high-temperature resistant, high-strength, low-elasticity, high-density cementing material, relating to the field of cementing materials technology in oil and gas development. It comprises the following components by weight: 100 parts oil well cement; 35-40 parts strength stabilizing material; 50-300 parts density regulator; 0.3-0.5 parts high-strength toughening material; 0.8-1.5 parts flexible sealant; 0.2-0.4 parts suspension stabilizer; 0.5-0.8 parts dispersant; 2-3 parts fluid loss reducing agent; and 0.8-2.0 parts retarder. The oil well cement is of grade G and grade D. The mixed oil well cement has a cement mass ratio of 8:2. The high-strength toughening material is a mixture of modified carbon fiber, modified polyether ether ketone fiber, modified polyether sulfone fiber, β-type silicon carbide whiskers and potassium hexatitanate whiskers in a mass ratio of 40-60:15-25:15-25:5-8:2-4. The flexible sealant is a mixture of high-temperature resistant modified polycarbonate and sulfonated asphalt in a mass ratio of 8:2. This mixture can achieve self-toughening of the cement stone, so that the prepared cement slurry not only has good construction performance, but also has the characteristics of high strength and low elastic modulus under high temperature conditions.

Provided in the present disclosure are a core flooring layer of a light-foamed SPC floor and a light-foamed SPC floor. Based on the total weight of the core flooring, the core flooring of the present disclosure contains 65.0˜75.0 wt % of calcium carbonate, 18.0˜25.0 wt % of polyvinyl chloride resin, 2.2˜3.0 wt % of a foaming regulator, 2.5˜3.3 wt % of a stabilizer, 0.10˜0.20 wt % of a plasticizer, 0.10˜0.15 wt % of an external lubricant, 0.1˜0.40 wt % of an ADC foaming agent, and 0.5˜1.0 wt % of an NC foaming agent. The present disclosure can greatly reduce the density of a SPC floor while improving the static bending strength, flexural elastic modulus and peeling strength, and reducing heating warpage.

The invention discloses a modulus increasing agent for a cold-mixed asphalt mixture and a preparation method of the modulus increasing agent, and relates to the technical field of road engineering materials, the modulus increasing agent which is stable at high temperature, excellent in dynamic mechanical property and resistant to cracking at low temperature is prepared by optimizing components and a process; according to a modulus increasing agent premixing process, the asphalt is easier to disperse under a cold mixing condition, the dynamic modulus of a cold-mixed asphalt mixture is improved, meanwhile, relatively good low-temperature performance is kept, the compatibility of fibers and asphalt is improved through silane treatment, and after lignin fibers are oxidized and grafted, fumed silica is added to improve the dispersity and avoid fiber agglomeration; the SBS modifier and the tackifying resin cooperate to form an elastic network, so that the elasticity modulus of the asphalt is improved; the silane coupling agent reinforces interface bonding of the fiber and asphalt, and the plasticizer is added to counteract low-temperature brittleness of the resin, so that the asphalt modulus is improved, and water erosion is reduced. The modulus increasing agent for the cold-mixed asphalt mixture is particularly suitable for the technical field of road engineering materials, and has good popularization and application values.

The invention relates to an air conditioner aluminum pipe and a preparation method thereof, and belongs to the technical field of aluminum alloy material preparation. Through gradient matching of silicon carbide powder with different particle sizes, silicon carbide with smaller particle sizes is deposited at the bottom of silicon carbide with larger particle sizes, a gradient distribution type filler layer with a compact inner core layer and higher outer shell layer strength is formed, and when an alloy component vibrates, stress is generally concentrated on the surface layer, so that the vibration resistance of the alloy component is improved. The high-strength filler on the surface layer can improve the hardness and crack resistance of the surface layer, and the high-density filler on the core part ensures the toughness of the matrix and balances the crack resistance and impact resistance, so that the interface stress generated by the difference of elastic modulus between the filler and the matrix is avoided, and the risk that the filler matrix interface becomes a fatigue crack source is reduced. And meanwhile, silicon carbide has high hardness, high strength and good heat conductivity. A high-hardness wear-resistant layer can be formed on the surface layer of the alloy material through gradient distribution, wear and crack initiation in the vibration process are resisted, and the anti-vibration fatigue performance is improved.

The application belongs to the technical field of fiber preparation, and particularly relates to a modified basalt fiber YB-2400 and a preparation method thereof, which comprises the following steps: basalt raw material crushing and screening, blending with silicate glass, modification after removing iron oxides through high-temperature reduction and magnetic separation, high-temperature melting in a melting pool, homogenization in a homogenization pool, high-speed wire drawing, and surface infiltration treatment; the basalt particles, silicate fiber powder and modifiers are arranged in the raw material, and iron removal treatment, homogenization treatment, high-speed wire drawing, surface infiltration and other treatment steps are arranged, so that the iron oxides are effectively removed; in combination with blending modification and surface treatment, the mechanical strength, elastic modulus, toughness and corrosion resistance of the basalt fiber are significantly improved; the preparation process is simple and can be continuously produced, and the cost is controllable; the modified continuous basalt fiber prepared by the application has excellent performance, can be widely applied to high-end building materials, automobile parts, corrosion-resistant pipes, special composite materials and other fields, and has good industrialization popularization prospect.

The present application relates to oil and gas well engineering cementing material field, disclose a kind of in oil and gas well reconstruction wellbore cementing operation method, wherein, the method comprises: with aqueous epoxy resin, first part cement and second part cement preparation cement slurry, then cement slurry is injected into cement sheath;Wherein, the weight ratio of aqueous epoxy resin, first part cement and second part cement is 1:30-60:75-125;The epoxy equivalent of the aqueous epoxy resin is 900-1300g / eq, D50 is 0.3-0.4 μm, D90 is 0.4-0.5 μm;The ratio of D50 of first part cement and second part cement is 1.5-10:1, and the ratio of D90 is 1.5-4.5:1.The obtained cement slurry has higher compressive strength and lower elastic modulus, while the fluidity is better, and the cement slurry density meets the needs of different pressure system shale gas reconstruction wellbore.

The invention relates to the technical field of asphalt concrete mix proportion design methods, in particular to a modified hydraulic asphalt concrete mix proportion optimization method based on OED-MNLR-GA-PSO. The method comprises the following specific steps: 1, determining a mix proportion parameter of the modified hydraulic asphalt concrete, and carrying out test design through an orthogonal test; 2, establishing a modified hydraulic asphalt concrete data set by taking the bending strain, the compression resilience modulus and the water stability coefficient as research targets, and obtaining a nonlinear mapping relation function of the bending strain, the compression resilience modulus, the water stability coefficient and the mix proportion by utilizing a multiple regression model; 3, constructing a relational expression between the mix proportion parameters of the modified hydraulic asphalt concrete and the economic cost; and 4, establishing a constraint between the mix proportion and the performance, and realizing multi-objective optimization of the hydraulic asphalt concrete mix proportion based on GA-PSO. According to the design of the method, the mix proportion precision is higher, and the adaptive capacity is improved.

Tire (1) for construction vehicle comprising two working layers (321, 322), comprising metallic reinforcements and at least two shrink-fit layers (331, 332), of axial widths less than those of the working layers (321, 322), and comprising metallic reinforcements, the innermost radial shrink-fit layer (332) being the shrink-fit layer of greatest axial width. At each axial end of the innermost radially enclosing layer (332), two contiguous rubber mixtures (51, 52, 61, 62), or decoupling mixtures, are arranged, one being radially inside the other, the decoupling mixture (51, 61) furthest radially from the end of the enclosing layer (332) has a dynamic modulus of elasticity measured at 23°C and 10% strain and at 10 Hz, at most equal to 0.7 times the dynamic modulus of elasticity of the decoupling mixture (52, 62) closest radially to the end of the innermost radially oriented shrinkage layer (332). Abstract figure: Figure 1.

The application discloses a kind of compound cement-based concrete of doping pyrite and wood ash, including the following weight parts of raw materials: cement 438 parts;Fly ash 27.35-82.05 parts;Rubble 1182 parts;Sand 430.1-480.7 parts;Pyrite fine sand 25.3-75.9 parts;Wood ash 27.35-82.05 parts;Water reducing agent 8.0-8.2 parts;Water 161 parts.The application is by simultaneously doping 15% pyrite in sand instead of sand, doping 15% wood ash in cement and fly ash instead of fly ash, the mechanical property of concrete is improved most, early strength, cubic compressive strength, tensile strength, elastic modulus can be greatly improved, it can be inferred that wood ash-pyrite improves the overall mechanical property of concrete, wood ash-pyrite can effectively improve the toughness, impact resistance and crack resistance of concrete.The mechanical property of the concrete of the application is obviously superior to the superposition of the concrete of doping wood ash alone and the concrete of pyrite fine sand, and reflects the effect of 1+1>2.

pneumatic tire, which includes a tread section, wherein the tread section is made up of a rubber composition comprising a rubber component and silicon dioxide, where the content of an isoprene-based rubber in the rubber component is greater than 40% by mass, where the silicon dioxide content based on 100 parts by mass of the rubber component in the rubber composition is greater than 30 parts by mass, and where 30 °C-ΔE* (0.25 % - 1.0 %) represents a difference between a complex modulus of elasticity at a dynamic strain of 0.25 % and a complex modulus of elasticity at a dynamic strain of 1.0 %, measured under a condition of a temperature of 30 °C, a frequency of 10 Hz and an initial strain of 5 %, of the rubber composition, and T in mm represents a thickness of the tread section, 30 °C − Δ E * ( 0.25 % − 1.0 % ) 6.0 MPa or more is ¨ gt , and 30 °C − Δ E * ( 0.25 % − 1.0 % ) / T 0.45 or more is ¨ gt .

The invention provides a pneumatic tire capable of improving driving stability while maintaining good durability and rolling resistance. The pneumatic tire is provided with a tread portion (1), a pair of side wall portions (2), and a pair of bead portions (3), a carcass layer (4) is spanned between the pair of bead portions (3, 3), a plurality of layers of belt layers (7) in which belt layer cords intersect each other between the layers are disposed on the outer peripheral side of the carcass layer (4) of the tread portion (1), and a cover layer (8) including cover layer cords (8C) oriented in the tire circumferential direction is disposed on the outer peripheral side of the belt layers (7). Wherein the cover layer cord (8C) is a polyester fiber cord having an elongation in the range of 2.0-4.0% under a load of 2.0 cN / dtex, and the loss elastic modulus E ''of the polyester fiber cord when measured at a frequency of 20 Hz, an initial load of 300 g, a strain of + / -0.1%, and a temperature increase rate of 2 DEG C / min has a peak temperature of 115 DEG C or more and a peak value of 12000 MPa or less. The cord angle theta of the belt layer (7) with respect to the tire circumferential direction is in the range of 27 DEG to 40 DEG.