90 results about "Porous asphalt" patented technology

The invention provides a method used for analyzing the porous asphalt mixture void structure by adopting a CT technique, comprising the steps of: preparing porous asphalt mixture specimens, scanning the porous asphalt mixture specimen by an X-ray CT machine, reinforcing and cutting CT images, extracting void characteristic, calculating the characteristic parameter of the void structure, analyzing void plane information, analyzing void space information and memorizing the analysis result. The method adopts the CT scanning technique, can exactly and quickly obtain the digital images of the porous asphalt mixture, reinforces and cuts the images, extracts the corresponding characteristic parameters of the void, carries out the quantitative description on the structural characteristic of the void by a fractal theory by virtue of the parameters, comprehensively reflects the void structure information, and avoids the effects of all characteristics of the porous asphalt mixture on the void evaluation. The parameters lays the foundation for further researching the effect rule of the void structure on the splitting tensile strength and the permeability of the porous asphalt mixture and for researching the void decay behavior of the porous asphalt mixture.

The invention provides a composition design method for making porous asphalt mixture material, which includes steps: the porosity rate of the porous asphalt mixture material is defined according to the requirement of eliminating dynamic hydraulic and improving drainage performance; initial asphalt content is defined by the calculation method; frame embedding and extruding structure and porosity rate are regarded as the fundamental basis in extracting the final gradation of raw material; asphalt leakage loss and porosity rate are regarded as the main control index in defining the optimum asphalt content; fiber is used for increasing asphalt content on the basis of guaranteeing the porosity rate, and rotary specimen compacting and forming process is adopted to ensure the porous asphalt mixture material to own both the functionality and durability design requirements. The composition design method for making porous asphalt mixture material can satisfy the porosity rate design requirement and road-using property requirement of the porous asphalt mixture material, can ensure the functionality, road-using property of the porous asphalt road surface, and the stable compaction property and good drainage function in the later stage of using, and can improve the durability of the road surface, thus having the advantages of popularization and application.

The invention relates to a preparation method of a tunnel asphalt surface layer material. A preparation method for damping porous noise-reducing tunnel asphalt pavement material is characterized in that it comprises the following steps: 1) preparation of high-viscosity and high-elasticity modified asphalt: base asphalt according to the mass ratio of each component: modifier SBS : Activated rubber powder: Viscosifying compatibilizer: Antioxidant: Stabilizer=100: 6.0~18.3: 20.2~45.7: 1.2~3.7: 0.2~1.4: 0.4~1.9, select; obtain high viscosity and high elasticity modification Asphalt; 2) Add flame retardant to high-viscosity and high-elasticity modified asphalt, heat and melt high-viscosity and high-elasticity modified asphalt to add flame retardant, stir for 3-9 minutes, and stand at 150-170°C for 15-30 minutes to obtain Flame-retardant high-viscosity high-elasticity modified asphalt; 3) according to the mass ratio, mineral material: flame-retardant high-viscosity high-elasticity modified asphalt: fiber stabilizer = 100: 3.6~5.2: 0.1~0.4, choose; noise tunnel asphalt surface material. The invention has the functions of noise reduction, flame retardancy and anti-skid.

The invention provides a semi-flexible composite pavement structure and a preparation method thereof. The semi-flexible composite pavement structure comprises components in percentage by weight as follows: 70%-80% of a macro-porous asphalt mixture matrix and 20%-30% of rubber powder cement mortar; the macro-porous asphalt mixture matrix is prepared firstly, then the rubber powder cement mortar is prepared, the rubber powder cement mortar is poured into a mixture gap of the macro-porous asphalt mixture matrix finally, and a product can be utilized after maintenance. According to the semi-flexible composite pavement structure, the defects of asphalt pavements and cement concrete pavements in China at present are overcome, rigidity of the cement concrete pavements and the flexibility of the asphalt pavements are integrated, the respective advantages of rigid and flexible pavement structures can be sufficiently played, the respective defects of the rigid and flexible pavement structures are overcome, and the semi-flexible composite pavement structure is a novel pavement structure with better pavement performance and higher cost performance.

The invention discloses a method for evaluating attenuation degree of porous asphalt mixture void. The method is characterized by comprising the following steps: molding a plate test piece by rolling according to the grade of a porous asphalt mixture to be evaluated; coating a sealing material on three side faces and a bottom surface of the test piece to seal the surface voids, putting the test piece on a drainage coefficient tester, and taking a side face where the sealing material is not coated as a drainage channel; setting the testing slope of the drainage coefficient tester according to cross slope of the pavement, and testing to obtain an initial value of the drainage coefficient of the test piece; performing a wheel tracking test on the test piece, wherein the wheelmark track is required to be parallel to the drainage side face of the test piece during test; and after the wheel tracking test, testing the final drainage coefficient of the test piece by employing the drainage coefficient tester; comparing the final drainage coefficient with the initial value, and evaluating the attenuation degree of the porous asphalt mixture voids. The method can evaluate the attenuation degree of the porous asphalt pavement pore structure under the repetitive vehicle action and is used for selecting proper aggregate grading in the process of designing the porous asphalt mixture.

The invention relates to a semi-flexible composite pavement of which mixed cement slurry can automatically flow in holes of an asphalt mixture in a construction process. The composite pavement comprises an open-graded macro-porous asphalt mixture structure layer and pavement mortar which is filled in the holes of the macro-porous asphalt mixture, wherein the pavement mortar comprises 30 to 50 percent cement, 20 to 40 percent of sand, 2 to 4 percent of organic binder, 10 to 20 percent of active filler, 3 to 10 percent of shrinkage reducer, 0.2 to 0.5 percent of water reducer, 0.1 to 1 percent of early strength agent and water in an amount of 20 to 28 percent based on the total weight of all the components of the pavement mortar. The composite pavement of the invention has the advantages of high compression strength, short maintenance time, smoothness, compactness, seamlessness, skid resistance, wear resistance, crack resistance, durability and convenient construction. The invention also provides a construction method of the semi-flexible composite pavement. The method comprises the steps of base pavement treatment, open-graded asphalt mixture paving, on-spot pavement mortar stirring and grouting, maintenance and the like. In the construction method of the invention, the mortar is automatically filled in the holes of the asphalt mixture according to the gravity per self and high workability and fluidity, so influences which are caused by adopting vibration paving on asphalt frameworks are avoided.

A field permeameter for performing a falling head permeability test on porous road surfaces with three-dimensional flow through the road surface or test slab comprises a clear plastic cylinder (1), and a rubber lined base flange (5, 6) to seal the test cylinder against the road surface during operation. A trap or valve assembly (7, 8, 9) in the closed position permitting the setting up of the falling head test at any desired initial head water level in the test cylinder. The activation of the test being initiated by the sudden release of the trap (8) which causes the water retained in the cylinder to flow through the test road section. The falling head of water through the road being measured by a submersible pressure transducer (3) at the base of the cylinder. From the falling head data, and the conversion factors for converting three-dimensional to one-dimensional flow property, the permeability (k) and the flow exponent (m) of the porous road specimen can be determined.

The invention discloses a scouring freeze-thaw splitting test method for porous asphalt mixtures. The method comprises the following steps: firstly, performing grading and asphalt-aggregate ratio design on the porous asphalt mixtures, blending the porous asphalt mixtures indoors and forming test pieces; secondly, randomly equally dividing the test pieces into two groups, directly performing a splitting test on the first group of test pieces, scouring the surfaces of the second group of test pieces under the corresponding pressure intensity for the corresponding time according to the actual vehicle speed and pavement design traffic volume, performing a freeze-thaw test, and after the scouring freeze-thaw circulation is finished twice, performing the splitting test; finally, comparing the average splitting strength of the second group of test pieces with that of the first group of test pieces. According to the method, whether the design of the porous asphalt mixtures is reasonable or not can be judged and the water stability of different porous asphalt mixtures can be compared; also, an actual pavement sample can be analyzed, the performance of pavement materials in different service stages can be judged, the basis can be provided for developing pre-maintenance measures of pavement performance, and the long-term service performance of the pavement can be guaranteed.

The invention discloses a method for determining the anti-clogging performance of a porous asphalt mixture. The method comprises the following steps: adopting a compactness molding standard Marshall test piece; determining the water seepage coefficient of a porous asphalt mixture test piece by adopting the corresponding water seepage coefficient measuring device under the condition of not demoulding; scattering fine material at a certain amount and grading uniformly at the top of the test piece; filtering by uniformly spraying a certain amount of water; shaking the test piece while filtering; testing the residual water seepage coefficient after filtering; calculating the ratio of the residual water seepage coefficient of the test piece after the fine materials are scattered to the initial water seepage coefficient of the test piece before the fine materials are scattered; and defining the ratio as residual water seepage capability. The anti-clogging performance of the mixture is better when the ratio is larger, and otherwise, the anti-clogging performance is worse. By utilizing the method provided by the invention, the anti-clogging performance of the porous asphalt mixture is determined, thus the porous asphalt mixture composed of different materials can be optimally selected from the view of prolonging the use function of the pavement.

The invention relates to a pavement engineering material, and concretely relates to a semi-rigid asphalt pavement material and a preparation method thereof. The semi-rigid asphalt pavement material comprises, by volume, 75-85% of a macro-porous asphalt mixture and 15-25% of a grouting material; the macro-porous asphalt mixture is obtained through mixing mineral, a filler and rubber high-viscosity modified asphalt; and the grouting material is obtained through mixing fine particle modified emulsified asphalt, PC42.5 composite Portland cement, an active admixture, sands, water, a water reducer, an aluminum powder, an expanding agent, an air entraining agent, an antifoaming agent and limestone mineral powder. The semi-rigid asphalt pavement material has the advantages of good construction workability, strong high-temperature rut resistance and low-temperature cracking resistance, good durability, long fatigue life, good combination property of the macro-porous asphalt mixture with the grouting material, small temperature shrinkage and dry shrinkage cracks, energy saving, environmental protection, and realization of the high cost performance of recycling of solid wastes.

The invention discloses a method for determining the asphalt amount of a porous asphalt mixture. According to the method, the asphalt amount range limit of the porous asphalt mixture is determined through raveling and drain-down tests. In dependence on the result of the raveling test, the corresponding asphalt amount when the raveling loss is 15% is taken as the minimum asphalt amount OACmin, andthe corresponding asphalt amount when the drain-down loss is 0.3% is taken as the maximum asphalt amount OACmax. Based on the above situation and in dependence on the performance test result and structural characteristics of the mixture, the best asphalt amount of the porous asphalt mixture is calculated according to the formula OAC=OACmin+0.75(OACmax-OACmin). When OACmax exceeds 6.0%, 6.0% is used; and when OACmin is less than 4.0%, 4.0% is used. If there exist no intersection interval of OACmin and OACmax according to the raveling and drain-down tests, it shows that the material compositiondesign of the mixture is not reasonable and the material composition needs designing again. The method provided by the invention can be used to objectively and accurately determine the best asphalt amount of the porous asphalt mixture.

The invention relates to modified asphalt, preparation and applications thereof. The modified asphalt comprises asphalt and a filler, wherein the asphalt is high-viscosity asphalt, the filler comprises red mud, a weight ratio of the high-viscosity asphalt to the red mud is 1:x, and x is more than 0 and is less than or equal to 0.9. The preparation method comprises: adding a filler being subjectedto high-temperature drying into molten high-viscosity asphalt in three times so as to pave a porous asphalt pavement. Compared to the modified asphalt, the modified asphalt of the present invention has excellent high-temperature performance and excellent adhesion, such that the modified asphalt of the present invention can be well used for traditional compact asphalt pavements with characteristicsof heavy traffic, high temperature and serious traffic drainage and easily-loose porous asphalt pavements; and the modified asphalt of the present invention has high Brookfield viscosity, high rutting factor and high resilience rate compared to the ore powder-doped modified asphalt, and further has relatively good high-temperature performance and relatively good resilience.

The invention relates to a determining method of an optimal asphalt dosage of a porous asphalt mixture. The determining method comprises the following steps: (1) determining a predicted asphalt film thickness according to the relationship between 175 DEG C power viscosity of an asphalt binder and an asphalt film thickness; (2) determining a predicted asphalt dosage according to a specific surface area computational formula of mineral aggregate and the predicted asphalt film thickness; (3) with the predicted asphalt dosage as a median and 0.3% or 0.5% as an interval change, forming five groups of asphalt dosages, performing a schellenberg asphalt leakage test and a cantabro dispersion test, and determining the optimal asphalt dosage range with the inflection points of the two curves as boundary; (4) forming five groups of test specimens through a vibration forming method to measure the connected voidage, and then, performing a uniaxial penetration test and an unconfined compressive strength test under a test temperature condition of 60 DEG C, and calculating a cohesive force C, wherein the asphalt dosage corresponding to the peak value of the cohesive force C is used as the optimal asphalt dosage; and (5) verifying the pavement performance. The invention provides a quick, convenient and reliable determining method of optimal asphalt dosage for designing the mixing proportion of porous asphalt mixture.

The invention provides a porous asphalt material as well as a preparation method and application thereof and relates to asphalt. The porous asphalt material comprises the raw materials of petroleum asphalt and a cross-linking agent according to the mass ratio of 1: (0.49-6.4). The preparation method comprises the following steps: adding the petroleum asphalt, the cross-linking agent and a cross-linking catalyst into a solvent sequentially, heating for cross-linking reaction, cleaning a product obtained through reaction through methanol, then extracting the product obtained through reaction through methanol and dichloromethane and drying so as to obtain the porous asphalt material. The degree of cross-linking of the prepared porous asphalt material reaches 94% or above, the porous asphalt material passes a nitrogen adsorption test at 77 K, and results of a CO2 adsorption test under 1 bar at 273 k and 298 k, an H2 adsorption test under 1 bar at 77 k and a methylene blue dye adsorption test at 298 k for 1 h by the porous asphalt material show that the porous asphalt material can be applied to the adsorption application fields of gas adsorption and storage, dye adsorption and treatment and the like.

The invention discloses a method for evaluating anti-clogging performance of a porous asphalt mixture. According to the method, a horizontal or vertical cross-section image of a test piece is acquired by the adoption of CT scan equipment. Image software is applied to process the acquired CT image, including threshold processing, gap fitting, gap area and quantity statistics and the like. Cross-section image information, mainly including cross-section average gap quantity, cross-section gap gross area and average single gap area, can be calculated. Quantitative evaluation can be carried out on the anti-clogging performance of the porous asphalt mixture test piece according to a parameter value of the average single gap area. The larger the average single gap area value, the better the anti-clogging performance of the mixture; and the smaller the average single gap area value, the poorer the anti-clogging performance of the mixture. The method provided by the invention can be used to evaluate the anti-clogging performance of the porous asphalt mixture, thus comparing and selecting porous asphalt mixtures of different materials from the angle of prolonging service function of pavement.

The invention discloses a porous asphalt mixture gap blocking experiment method. The method comprises the following steps: firstly, designing grading and an oil-stone ratio according to a practical pavement, mixing to obtain a porous asphalt mixture indoor, forming a test piece, and sealing the lower surface of the test piece by wax; subsequently, uniformly paving blocking dust on the upper surface of the test piece, and applying a wheel load corresponding to a practical vehicle speed on the pavement to the upper surface of a pressure intensity washing test piece of the pavement by a washing experiment machine; and dividing the mass of blocking dust carried away by water and the mass of blocking dust left on the upper surface of the pressure intensity washing test piece from the total mass of paved blocking dust so as to obtain the mass of blocking dust inside the test piece. By the method, not only is the situation of blocking a porous asphalt pavement by dust grains with different sizes scientifically evaluated and is a good basis provided for pavement washing and maintenance, but also the influence of different conditions such as the porosity, the vehicle speed and the particle sizes of blocking dust grains to the blocking of the porous asphalt pavement can be analyzed, reasonable reference is provided for optimization on pavement maintenance, and the washing and maintenance effect is improved.

The invention discloses a testing method of freeze-thaw resistance performance of an unsaturated porous asphalt mixture and a testing method of frost heaving strain. The method comprises the followingfour parts: control of porous asphalt mixture saturability, testing of frost heaving stress, testing of frost heaving residual strain, and calculating of freeze-thaw dissipated energy. Relative freeze-thaw dissipated energy is calculated through the area of a triangle formed by an original point in a two-dimensional rectangular coordinate system formed by stress and strain, a point of a ratio offrost heaving stress peak to tensile strength, and a point of a ratio of residual frost heaving stress to tensile fracture strain within a freeze-thaw cycle. The method can quantificationally evaluatethe freeze-thaw resistance performance of the porous asphalt mixture at any saturability by using relative freeze-thaw dissipated energy, and provides an analysis means for optimization of the porousasphalt mixture in cold regions.

The invention relates to a method for recovering a clearance of a porous asphalt pavement, which comprises the following steps of: carrying out dust-absorption treatment to pollutants in the asphalt pavement clearance, preparing a cleaning solution, flushing a porous asphalt pavement with high-pressure cleaning solution, and the like. A great deal of researches and experiments show that the method can effectively recover the clearance of the porous asphalt pavement, improve the water permeability and various pavement performances of the porous asphalt pavement and prolong the service time of the porous asphalt pavement. The invention can be used for cleaning clearance blockage of the porous asphalt pavement.

The invention discloses a water-retaining and cooling pavement material and an application thereof. The water-retaining and cooling pavement material is prepared from expanded perlite powder, cement, sepiolite powder, quartz sand powder, water-absorbent resin and a water reducing agent in an appropriate mass ratio. The water-retaining and cooling pavement material is applied to surfacing, and porous asphalt mixture or a porous cement concrete material with the void ratio of 20-30% is combined, so that finishing strength and performance of the pavement material are improved, and the aim of lowering temperatures of a pavement and a pavement surface is achieved.

The invention discloses a testing device and method for measuring frost heaving stress and release characteristics thereof of a rutting plate of porous asphalt mixture, and the device comprises a rutting plate fixing device, a resistance earth pressure box, and a static strain tester. The use of the device includes the following steps of forming a test piece of the rutting plate of the porous asphalt mixture, controlling its pore water saturation, simulating the freeze-thaw process of the rutting plate of the porous asphalt mixture, outputting strain through the static strain tester, and calculating stress through a formula. By comparing the stress changes in different directions, the directional differences of frost heaving stress and release characteristics are analyzed. By observing thestress change of the rutting plate during melting, the stress release characteristics during melting are analyzed. By comparing the frost heaving stress and release characteristics of the rutting plate with or without ruts, the influence of ruts on the freeze-thaw durability is judged.

The invention discloses an anti-stripping test device for surface aggregates of porous asphalt pavements or porous concrete pavements. The test device comprises a supporting machine frame, a test piece assembling area, a wheel simulation mechanism, a loading mechanism, a wheel steering control mechanism, a reciprocal motion control mechanism, a temperature control machine, an observation window and a visual control platform. The device can well simulate the surface aggregate anti-stripping conditions of the porous pavements under conditions of different pavement temperatures, loads and vehicle running states and can obtain the main factors influencing the anti-stripping capacity of the surface aggregates of the porous pavements by combining raw material test analysis, thereby providing a basis for the selection of raw materials and design of mixture composition in a pavement design process.

The invention belongs to the technical field of road pavement materials and particularly relates to a cold-mix colored porous asphalt cement preparation method. A formula comprises, by weight, 90-95% of one-component high-strength polyurethane and 5-10% of EVA (ethylene-vinyl acetate copolymer), wherein the one-component high-strength polyurethane comprises, by weight, 17.8-23.2% of polyether polyol 210, 18.5-24.9% of isocyanate, 52.2-58.6% of dichloromethane and 0.04-0.07% of polymerization catalyst. The preparation method includes 1), preparing the one-component high-strength polyurethane; 2), mixing the one-component high-strength polyurethane with the EVA according to weight percentages of 90-95% and 5-10% so as to obtain cold-mix colored porous asphalt cement. All indexes of the cold-mix colored porous asphalt cement prepared according to the formula and the preparation method reach or exceed national standards, and porous asphalt produced from the cement has more excellent durability, high rutting resistance and the like.

The invention provides a porous asphalt pavement flying disease detection method based on noise signal identification. The porous asphalt pavement flying disease detection method comprises the following steps: (1) tire / pavement noise signal acquisition: completing acquisition of tire / pavement noise of a porous asphalt pavement to be detected by adopting a close-range method; (2) feature signal extraction: setting an analyzed unit distance length, performing noise reduction processing and spectrum conversion on a noise signal extracted on site, and performing feature extraction on the processednoise signal; and (3) calculating a flying disease detection result: inputting the signal characteristics obtained in the step (2) through a flying damage degree discrimination model to obtain a flying damage percentage and a flying damage degree in a unit distance. According to the porous asphalt pavement flying damage detection method based on noise signal recognition, accurate, rapid and intelligent testing of the porous asphalt pavement flying damage degree is achieved, and a decision basis is provided for selection of the maintenance opportunity and the maintenance technical scheme of the special pavement structure.

The invention discloses a novel pitch-based spherical porous doping method for modifying hard carbon negative electrode material, and includes such steps as pulverizing high-temperature coal-based pitch, adding crosslinking agent under N2 protection, stirring and heating molten pitch, crosslinking reaction between pitch and crosslinking agent to prepare crosslinked pitch, adding oxidant, adding O2, stirring and isothermal reaction to obtain crosslinked oxidized pitch; (2) spray granulation; (3) carbonization of pitch microspheres; (4) coating and graphitization of pitch-based hard carbon. By using low temperature spray granulation method to prepare regular spherical porous asphalt-based microspheres, spherical hard carbon prepared by carbonization and coating has compaction density of morethan 1.1 g / cm3, the compaction density is high, reversible specific capacity is greater than 400 mAh / g, first coulombic efficiency greater than 80%, the capacity retention ratio after 500 cycles is greater than 85%, the 30C / 1C capacity retention ratio is greater than 98%, electrochemical performance is better, the effects of safety and environmental protection, and economy and efficiency are achieved, the process is simple, and industrial large-scale production is easy to realize.

The invention discloses a testing device of coagulated frost depth and deformation non-uniformity of a surface of a porous asphalt mixture and a method thereof. The testing device comprises a cylindercontainer made of organic glass, an atomizer, a temperature-humidity controller, a strain tester and a CT scanner. The method comprises the following steps: firstly scanning a porous asphalt mixtureMarshall specimen by using the CT scanner and reconstructing to obtain a specimen three-dimensional model, then pasting a plurality of resistance strain gages on the side of the specimen along a circumferential direction, putting the specimen in the cylinder container and putting the cylinder container into a refrigerator, then introducing water vapor atomized by the atomizer, enabling the humidity in the cylinder container to be stabilized at 96%-98% by using the temperature-humidity controller, collecting readings of the resistance strain gages by using the strain tester, calculating non-uniformity coefficient and evaluating the deformation non-uniformity of the porous asphalt mixture, finally scanning the specimen again and reconstructing a model, and measuring the coagulated frost depth by using Boolean calculation. The testing method and the device thereof are capable of quantitatively evaluating the coagulated frost depth and the deformation non-uniformity of the surface of the porous asphalt mixture.

The invention discloses a method and device for blocking pores of a porous asphalt mixture, a frost heaving method of a blocked mixture and a frost heaving-resistant performance evaluation method. A bottom cover and a base are screwed on left and right sides of a cylindrical container containing a porous asphalt mixture test specimen. Through injection of a suspension of clay and clean water intoa top cover and base multiple times and drying multiple times, pores of a porous asphalt mixture are gradually blocked through clay particles. The mixture for pore blocking is wrapped with sponge, fully absorbs water and is frozen so that frost heaving of the mixture after pore blocking is realized. Through a Cantabro scattering test, a change rate of the scattering loss of the porous asphalt mixture before and after frost heaving evaluates frost heaving resistance after pore blocking.

The invention is an evaluation method for the efficiency of degrading automobile exhaust on semi-flexible pavement, which belongs to the technical field of functional pavement, and solves the problem of long test period, high cost, unintuitive, difficult real-time and direct presentation of photocatalyst degradation for the evaluation of semi-flexible pavement degrading automobile exhaust. The question of effect. The present invention firstly prepares the asphalt mixture rutting slab test piece with a porosity of 25% to 35% and the cement mortar containing TiO2, pours the porous asphalt mixture rutting slab, and removes excess cement mortar on the surface; puts the test piece in the test room , start the gasoline engine, and press the test button of the automobile exhaust analyzer at the same time to monitor the concentration change of the automobile exhaust gas; when the concentration of each component of the exhaust gas reaches the predetermined initial concentration range, record the initial concentration of each component of the exhaust gas, turn on different light sources respectively, and record the components of the exhaust gas The concentration value was observed continuously for 2 hours, and the test results were analyzed to quickly and intuitively evaluate the degradation effect of semi-flexible pavement on automobile exhaust, providing a reliable evaluation method for the development of high-efficiency photocatalytic pavement.

The invention relates to a method for purifying vehicle tail gas by using a porous asphalt pavement loaded composite modified photocatalyst. The invention belongs to the technical field of functionalpavements, and solves the problems of more water damage, difficulty in catalyst surface enrichment of tail gas, incapability of fully utilizing visible light, low photocatalytic efficiency, poor degradation effect and the like caused by poor dispersity of modified TiO2 nanoparticles loaded on the porous asphalt pavement at present. The preparation method comprises the following steps: firstly activating a carbon molecular sieve, then preparing copper-carbon nanotube co-doped modified TiO2 sol, fully mixing the carbon molecular sieve with the sol, and repeatedly loading the sol for three timesto prepare a carbon molecular sieve / copper-carbon nanotube co-doped TiO2 composite photocatalyst; adding the composite photocatalyst into the porous asphalt mixture for replacement of a part of the fine aggregate according to different proportions; and finally, testing the degradation effect of different doping amounts of the composite photocatalyst on different components in the vehicle tail gasand the influence on the pavement performance of the asphalt mixture, and determining the optimal doping amount of the composite photocatalyst. The method has the advantage of improving the vehicle tail gas degradation effect of the porous asphalt pavement.

The invention discloses a designing method for the basalt fiber porous asphalt mixture matching proportion. The designing method comprises the following steps that firstly, raw materials are selected;secondly, gradation design is conducted; thirdly, the optimum asphalt aggregate proportion is determined; and fourthly, the matching proportion designing index is verified to obtain the object matching proportion of a porous asphalt mixture. According to the designing method provided by the invention, operation is easy, the cost is saved, the tedious operation that a raveling test is implementedto determine the asphalt aggregate proportion of the porous asphalt mixture is avoided, the using quantity of asphalt is determined reasonably, various properties of the asphalt mixture are ensured, the blindness and work amount of the matching proportion designing stage are lowered, and the engineering efficiency is improved remarkably.

The invention relates to a discrete element method-based double-layer porous asphalt pavement drainage characteristic analysis method, and belongs to the technical field of double-layer porous asphaltpavement drainage characteristics. By means of the discrete element simulation technology, the problems that irregular geometrical shapes and surface textures of aggregate are difficult to explain bya continuous medium pavement model, and adhesive force, viscoelastic plasticity, pore microstructure and drainage performance between an upper surface layer and a lower surface layer in a porous asphalt pavement influence each other are solved. According to the method, a double-layer porous asphalt pavement model is established mainly through discrete element software, coupling calculation is conducted on the double-layer porous asphalt pavement model and fluid dynamics software, and the double-layer porous asphalt pavement drainage characteristic rule is obtained through analysis. Accordingto the method, the irregular geometrical shape of the aggregate, the asphalt adhesive force and the granularity and the viscoelastic plasticity of the mixture can be well expressed, the asphalt mortarand gap three-phase structure formed by the drainage asphalt mixture serving as coarse aggregate, fine aggregate and an asphalt cementing material is effectively simulated, and the improvement of a model and drainage characteristic research accuracy is facilitated.