1117 results about "Base course" patented technology

The invention provides a design method and system for an ultra-large-particle-size long-service-life asphalt pavement, and belongs to the technical field of long-service-life asphalt pavement design. The method comprises the steps of obtaining basic parameter information of a pavement design project; according to the basic parameter information, the thickness and variation parameters of the pavement structure layers meeting the thickness requirement are initially planned, and the material Poisson's ratio, the temperature distribution of each structure layer and the material modulus are determined; randomly generating pavement structure layer thickness, temperature distribution, material modulus and traffic load parameters by adopting a Monte Carlo method, and carrying out pavement mechanical response calculation; checking the reliability and fatigue damage of the flexible base asphalt pavement according to a fatigue limit theory and a cumulative damage theory respectively; according to the flexible base asphalt pavement rut prediction model, pavement rut checking calculation is performed, the reliability of a pavement structure under the environment-load coupling effect is improved, and the long service life of the pavement structure is achieved.

The invention discloses a cementing material for a solid waste-based road of a coal-fired power plant and a preparation method of the cementing material. The cementing material mainly comprises a cementing component, an alkali-activated component and a reinforcing component, the gelling component is a mixture of coal-fired power plant fly ash and furnace slag; the alkali-activated component is a mixture of alkali residues, red mud, blast furnace slag and coal-fired power plant desulfurized gypsum; the reinforcing component is rice hull ash or peanut hull ash. The mass ratio of the gelling component to the alkali-activated component is (4 / 1)-(10 / 1); and the addition amount of the reinforcing component is 1-3% of that of the main body material. The coal-fired power plant solid waste fly ash, the furnace slag and the desulfurized gypsum are used as main bodies, a small amount of other industrial solid waste is added, and the cementing material belongs to a full-solid-waste low-carbon cementing material and can be applied to a road base, a subbase or a base layer. The invention has the characteristics of low carbon emission, high solid waste consumption, simple production process and strong pavement performance, and in addition, the invention has a good stabilization effect on the problem that part of solid waste heavy metals and sulfate ions in a coal-fired power plant exceed the standard.

The invention discloses an asphalt pavement base crack identification method and device based on a ground penetrating radar, and belongs to the technical field of road engineering pavement maintenance. The method comprises the following steps: 1) carrying out crack image identification on a radar slice map through a YOLOv8n model; 2) based on an identification result, extracting A-scan signals of a crack area, and classifying time-frequency features by using a Light GBM model; and 3) clustering classification results through a'multi-segment clustering + PCA 'analysis method, and filtering false detection cracks. The device is used for executing the method. According to the method, the map and the time-frequency characteristics are fused, the problem that the false detection rate is high due to subjective labeling or objective interference of a single identification method is solved, experiments show that the false detection rate is reduced to 2.8% from 11.2%, and the accuracy and engineering applicability of crack identification are improved.

The invention belongs to the technical field of comprehensive utilization of industrial solid wastes, and particularly relates to a sawing mud-graphite tailing road base material as well as a preparation method and application thereof. The road base material is prepared by mixing saw mud, graphite tailings, a red mud-based cementing material, a reinforcing agent and water. The sawn mud-graphite tailing road base material is applied to a heavy traffic load road base with the strength requirement of 4.0-6.0 MPa. According to the sawing mud-graphite tailing road base material, all aggregates in a traditional road base material are jointly replaced by sawing mud-graphite tailings, and the red mud-based cementing material is adopted for curing, so that the utilization efficiency of solid waste recycling is greatly improved; and the problems of shortage of sand and gravel resources and high material cost of construction engineering in the road engineering construction process are relieved.

The invention relates to the technical field of pavement materials, in particular to a solid waste-based cementing material stable coal-based solid waste road base material and a preparation method thereof. According to the material, secondary modified regenerated coarse and fine aggregate is used as a framework, coal gangue powder and granulated blast furnace slag micro powder are matched, and two-step engineering of dopamine / double-amino-terminated polyethylene glycol co-deposition grafting and high-modulus silicate pre-coating is adopted, so that the synergistic improvement of the surface wettability and the interface density of the aggregate is realized. The system is cooperated with low-modulus excitation liquid and polypropylene fibers, and the mixing uniformity of the material and the quality of an interface transition area are optimized through a thin-pulp stone-wrapping and densification segmentation process. The material gives consideration to high resilience modulus, rut resistance and durability, significantly reduces the problems of high water absorption, weak interface, early cracks and the like of the recycled aggregate, is adaptive to a traditional road construction window, and has good application prospects.

The application relates to the technical field of waterproof coiled materials, in particular to a preparation method of an anti-aging modified asphalt waterproof coiled material, which comprises a polyethylene film, a base layer and a modified asphalt base body, wherein the modified asphalt base body comprises the following raw materials in parts by weight: 45-60 parts of asphalt, 10-15 parts of SBS elastomer, 8-12 parts of a softening agent, 3-5 parts of a waterproof functional agent, 4-6 parts of an anti-aging agent, 5-9 parts of SBR, 5-10 parts of a composite filler and 0.03-0.05 parts of an initiator; the anti-aging modified asphalt waterproof coiled material prepared by the method has excellent waterproof performance, heat aging resistance and ultraviolet aging resistance, and the anti-aging modified asphalt waterproof coiled material also has a complex network structure, which endows the base body with excellent mechanical properties.

The invention relates to the technical field of waterproof coiled materials, in particular to a preparation method of an anti-aging modified asphalt waterproof coiled material, the anti-aging modified asphalt waterproof coiled material comprises a polyethylene film, a tire base layer and a modified asphalt matrix, comprising the following raw materials: 45-60 parts of asphalt, 10-15 parts of an SBS elastomer, 8-12 parts of a softening agent, 3-5 parts of a waterproof functional agent, 4-6 parts of an anti-aging agent, 5-9 parts of SBR, 5-10 parts of a composite filler and 0.03-0.05 part of an initiator. The aging-resistant modified asphalt waterproof coiled material prepared by the preparation method disclosed by the invention has excellent waterproof performance, thermal aging resistance and ultraviolet aging resistance, and the aging-resistant modified asphalt waterproof coiled material also has a complex net-shaped structure, so that a matrix is endowed with excellent mechanical properties.

The invention discloses a nondestructive testing method and system for the modulus of an asphalt road structure layer, and belongs to the technical field of nondestructive testing. According to the structure size of an actual to-be-tested road, a finite element model of the asphalt road structure layer is established, and a deflection point set corresponding to actual deflection detection and a dynamic drop weight load loading area are created; road structure parameter combinations are generated, mechanical responses of the asphalt road structure layer finite element model established by different road structure parameter combinations under the dynamic drop hammer load are calculated in a dynamic drop hammer load loading area, deflection values of a plurality of deflection points in a deflection point set are obtained, a deflection basin database is constructed to serve as a training sample, and the dynamic drop hammer load is calculated; the deflection values of the multiple deflection points serve as input, parameters of the surface layer modulus, the base layer modulus and the soil base modulus serve as output, and an inverse calculation model used for conducting nondestructive testing on the asphalt road structure layer modulus is obtained through training. According to the method, the structural layer modulus can be obtained by directly inputting deflection value data, so that the back calculation process is more accurate and efficient.

The invention discloses a polymer emulsion composite modified road base material and a preparation method thereof, and belongs to the technical field of traffic infrastructure engineering materials. The polymer emulsion composite modified road base material is prepared from the following raw materials: graded aggregate, super sulfate cement or geopolymer cement, water for mixing, vinyl acetate-ethylene (VAE) copolymer emulsion and a silane coupling agent. The preparation method comprises the following steps: mixing the VAE emulsion with water for mixing to obtain a polymer diluent; mixing graded aggregate with an inorganic cementing material, then adding the polymer diluent, and mixing to obtain a mixture; and then paving, compacting, forming and curing are carried out. By forming a VAE flexible network-C-S-H / ettringite hybrid network, the material has the remarkable advantages of higher mechanical strength and low cost, and can greatly improve and enhance the crack resistance and durability of the road base.

The utility model relates to the technical field of template mounting and dismounting, and discloses a device for quickly mounting and dismounting a template in a limited space, which comprises a main body mechanism, and is characterized in that the main body mechanism comprises a ditch body, a pavement base layer, a leveling layer, a steel pipe, universal wheels, a steel plate, a cast-in-place reinforced concrete cover plate, I-shaped steel, a pull rod hole, a through hole, a pull rod body and a matched nut, the pavement base layer is fixedly arranged at the outer end of the ditch body, the leveling layer is fixedly arranged at the upper end of the pavement base layer, the steel pipe is located in the ditch body, the universal wheels are fixedly installed at the lower end of the steel pipe, the universal wheels are located at the upper end of the pavement base layer, and the universal wheels are movably connected with the pavement base layer. According to the quick mounting and dismounting device for the formwork in the limited space, by mounting the main body mechanism, a traditional cast-in-place cover plate support construction technology is changed, original ground welding assembly is adopted, the whole formwork is hoisted to the corresponding position to be fixed, and the quick mounting and dismounting device has the advantages that time consumption is low, the support body can be recycled, cost is saved, and the safety risk is low.

The invention provides an optimization design method of a fiber rubber gravel seal layer for inhibiting pavement reflection cracks. The optimization design method comprises the following steps: determining optimal fibers; determining an optimal aggregate; preparing a plurality of groups of third test pieces by taking the optimal fiber dosage, the optimal aggregate spreading amount and the optimal rubber asphalt dosage as variables through an orthogonal test; and combining the third test piece with the base layer with the crack and the overlay layer, preparing a fourth test piece, carrying out a reflection crack simulation test, and determining the combination of the material with the optimal crack resistance according to the test result. The method takes the reflection crack resistance of the fiber rubber asphalt macadam seal as a main evaluation index, and has the advantages of scientificity, reasonability and accuracy compared with the prior art. The fiber rubber gravel sealing layer obtained through the design method has excellent reflection crack resistance, the crack resistance of the composite pavement can be remarkably improved, the pavement maintenance and repair cost can be reduced, the pavement service cycle can be prolonged, and the fiber rubber gravel sealing layer has wide popularization and application prospects.

The invention discloses a municipal road rapid repairing structure and a construction method thereof.The municipal road rapid repairing structure comprises a plurality of base layer repairing blocks, the base layer repairing blocks are installed in grooves formed in damaged parts of a roadbed, every two adjacent base layer repairing blocks are connected in an inserted mode, and buffer repairing blocks are arranged on the upper surfaces of the base layer repairing blocks; the buffer repairing blocks are connected in an inserted mode, the upper surfaces of the buffer repairing blocks are covered with surface layers, the base layer repairing blocks are connected in an adhesive mode through fast curing adhesives, and the base layer repairing blocks and the roadbed are connected in an adhesive mode through fast curing adhesives. And the base layer repairing block and the buffer repairing blocks as well as the adjacent buffer repairing blocks are also bonded and connected through the rapid curing adhesive. The prefabricated base layer repairing block and the buffer repairing block are adopted, so that the cast-in-place and maintenance time is shortened, road repairing can be completed in a short time, and the influence on traffic is reduced. And the repairing blocks are further reinforced through rapid bonding glue, so that the strength of the whole repairing structure is improved.

The invention provides an efficient grouting widening construction method for a new and old water-stabilized base layer, and belongs to the technical field of grouting construction.The efficient grouting widening construction method comprises the steps that foundation treatment is conducted on a widening area, and an old road side line is kept straight; excavating steps and setting elevation control; preparing a water-stable mixture and a cement grouting body according to a designed ratio; a synchronous grouting machine is fixed to one side of a splicing seam of the paver; blending cement paste and carrying out double-layer stirring; a cement paste permeation and diffusion control system is adopted for precise grouting, and the cement paste outlet amount is dynamically adjusted; an Euler loop rolling path planning system is used for guiding rolling operation, and a splicing area is rolled twice through a small road roller; after completion, immediately covering and preserving for seven days; and the optimal material composition is designed through a water-stable mixture proportioning optimization system. According to the method, efficient connection and integrity improvement of the splicing position of the new and old cement-stabilized base layers are achieved through a systematic process and an accurate control means.

The invention discloses a permeable grout grouting effect prediction method and system based on PSO-RBF, and relates to the field of grouting repair engineering.The method comprises the following steps that the porosity and the water content of different pavement base layers are collected, grouting influence factor data are obtained, the grouting influence factor data comprise the single-hole grouting amount, the grouting hole depth and the grouting hole distance, and the grouting influence factor data are obtained; the porosity, the moisture content and the grouting influence factor data are divided into a training set and a test set, a grouting coring sample compressive strength prediction model is generated through a particle swarm optimization RBF neural network model, a predicted value of the grouting compressive strength is obtained through prediction, and a grout diffusion depth predicted value is obtained through the same steps. And calculating a comprehensive grouting performance evaluation coefficient according to the two groups of predicted values and measured values, comparing the comprehensive grouting performance evaluation coefficient with a preset error threshold value, and judging that a predicted result meets a precision requirement if the comprehensive grouting performance evaluation coefficient does not exceed the error threshold value. Through the particle swarm optimization-based RBF neural network, permeation type slurry grouting restoration can be realized, and accurate grouting effect prediction can be realized.

The invention discloses a steel bridge deck combined pavement structure with high strength and corrosion resistance and a construction method thereof. The steel bridge deck combined pavement structure sequentially comprises a steel panel base layer, a middle pavement layer, a bonding layer and a wearing layer, wherein the middle pavement layer is formed by basalt chopped fiber UHPC and basalt fiber composite material grid ribs; the middle pavement layer is obtained by casting basalt chopped fiber UHPC on site, and meanwhile, the basalt fiber composite material grid ribs are arranged in the UHPC. On the premise that the overall thickness of the steel bridge deck combined pavement structure is effectively reduced, the overall corrosion resistance and strength of the steel bridge deck combined pavement structure can be greatly improved.

The present invention discloses a crack-resistant and durable long-life asphalt pavement structure and its construction method, which relates to the technical field of asphalt pavement construction. It includes an asphalt surface layer, a reinforcement mesh, positioning piles, and fixing rings. A geotextile stress absorption layer is provided under the asphalt surface layer, and a prime coat is provided under the geotextile stress absorption layer. The prime coat is SBS modified emulsified asphalt. By using polypropylene geotextiles to reinforce the pavement structure and form a composite structure with road materials, it has strong interfacial effects and reinforcement functions, forms a good whole with the surface layer and the base layer, effectively prevents or delays the cracking of asphalt pavements, improves the service life of the asphalt surface layer. After the polypropylene geotextiles are combined with the prime coat oil, it has excellent waterproof effects, prevents surface water from seeping into the pavement structure and eroding the roadbed, and extends the service life of the pavement.

The invention discloses a geogrid and EICP synergistically reinforced soil embankment structure and a construction method, and relates to the technical field of soil embankment structures. Comprising a pavement base layer, an embankment bearing layer and a natural soil foundation layer, and the natural soil foundation layer is used as a soil embankment structure support and is arranged at the bottommost layer; the pavement base layer is used for bearing an upper driving load and uniformly transferring the upper driving load to the embankment bearing layer below; and the embankment bearing layer is used for bearing the upper load transmitted by the pavement base layer. The engineering performance is improved through the multi-layer synergistic effect, the core reinforcing layer is of an innovative space grid structure and is composed of a prefabricated geogrid, a grid support arranged in the inclined direction and a rigid stress plate frame, a three-dimensional force transmission network is formed, the limitation of a traditional reinforcing method is broken through, and the engineering performance is improved. In addition, the grating support is arranged at a specific angle, the structural rigidity is guaranteed, and the stress concentration phenomenon is avoided.

The invention discloses an expressway pit pond early warning method and system based on time sequence feature fusion, and relates to the technical field of intelligent traffic monitoring and road maintenance. The method comprises the following steps: S1, collecting multispectral image information of a road surface, synchronously obtaining external information, and respectively generating multispectral and external data sets; s2, correcting and fusing the multispectral data, extracting multidimensional features, and constructing a time sequence optimization feature vector in combination with external data; s3, inverting states of a bonding layer, a base layer and a surface layer in the pavement according to a mapping relation between spectral characteristics and structure parameters, and generating an implicit structure health index; s4, taking the time sequence optimization feature vector, the implicit structure health index and the external data set as input, and utilizing an LSTM model to predict a pit-pond formation probability and a development trend; and S5, calculating a dynamic risk level according to a prediction result. Through fusion analysis of multispectral time sequence characteristics and structural health states, full-period early warning from early damage to forming damage of a pit and a pond is realized, and support is provided for accurate maintenance.

The invention belongs to the technical field of intelligent construction, and relates to application of fabricated pavement plate changing construction and the Internet of Things technology, in particular to an intelligent control and optimized construction method for fabricated pavement plate changing based on the Internet of Things, which comprises the following steps: S1, intelligent monitoring and disease recognition; s2, generating an intelligent construction scheme; s3, automatic cutting and old plate removal; s4, base layer treatment and prefabricated slab installation; s5, grouting and leveling; s6, intelligent joint filling and protective layer construction; s7, whole-process real-time monitoring and dynamic adjustment are carried out; and S8, remote health monitoring. According to the invention, the sensors are embedded in the road surface and the precast slab, and the Internet of Things platform is combined, so that the real-time monitoring of the road surface state and the accurate recognition of the disease are realized. Remote control and collaborative operation of construction equipment are achieved through the Internet of Things technology, the construction efficiency and the resource utilization rate are improved, and full-life-cycle management of prefabricated slabs is achieved.

The invention relates to a road surface base material for a harbor industry solid waste-based cargo storage yard and a preparation method of the road surface base material, and belongs to the technical field of road engineering. The storage yard pavement base material is mainly composed of dredged mud and sand, broken stones, activated iron smelting waste residues, water, a solid waste-based cementing material and cement. The invention also provides a preparation method of the storage yard pavement base material. According to the method, solid waste resources in the port-near industrial park can be effectively utilized, and environmental pollution caused by solid waste stacking is reduced. And the low-value solid waste can be effectively utilized for green building material production, so that the green building material production cost is reduced. The carbon emission can be effectively reduced, and the development of green and low-carbon economy of the harbor industry is assisted.

Methods for producing an asphalt-based slurry seal composition are provided. An asphalt-based slurry seal base composition comprising asphalt emulsion, water, polymer emulsion, and solar reflective additive is obtained, where the seal base composition is free of an aggregate. Aggregate comprising a particle size mesh of no higher than mesh number 20 is obtained. The base composition is mixed with the aggregate obtaining slurry seal composition. The slurry seal composition is applied to an asphalt surface. Asphalt-based slurry seal compositions comprising asphalt emulsion, water, extender, sand, polymer emulsion, clay, fiber, solar reflective additive, and aggregate comprising a particle size mesh of no higher than mesh number 20 are also provided.

The invention discloses a steel slag base pavement structure and a construction method thereof. The pavement structure comprises a soil base compaction layer, a gravel functional layer, a cement stabilized steel slag layer, prime coat oil, a stress absorption layer, tack coat oil, waterproof geotechnical cloth, an asphalt concrete lower surface layer and an asphalt concrete upper surface layer which are sequentially laid from bottom to top. The cement-stabilized steel slag layer is formed by mixing cement and steel slag according to the weight ratio of (4-5%): (95-96%), the crushing value of the steel slag is smaller than or equal to 35%, the soaking expansion rate is smaller than or equal to 2%, the iron content is smaller than or equal to 2%, the free calcium oxide content is smaller than 3%, and the maximum particle size is smaller than or equal to 37.5 mm. The invention relates to the technical field of road engineering, in particular to a steel slag base pavement structure and a construction method thereof.

The invention discloses a foam light soil upright roadbed pouring method, and belongs to the technical field of upright roadbed construction, a raw material proportioning processing module and a pouring processing module are included, a foaming agent diluent is prepared into foaming liquid through a physical method, then compressed air is injected into the foaming liquid to prepare foam, and the foam light soil upright roadbed is formed. The foam, the cement, the active admixture, the water, the additive, the sandy soil and the industrial waste residue material are mixed and stirred according to a preset proportion to prepare a to-be-poured mixed solution, the to-be-poured mixed solution is conveyed to a pouring area through a pipeline, and layer-by-layer pouring is carried out. The method is designed for the situation that the high-fill soft soil upright roadbed is prone to collapse, cement paste and foaming foam are prepared and poured into the upright roadbed according to the preset proportion, layer-by-layer pouring is adopted, EPS foam plates are used for partitioned pouring, the pouring quality is guaranteed, meanwhile, the pouring efficiency can be remarkably improved, and the construction period is shortened; and the longitudinal and transverse gradients are adjusted by using a base material, so that the slope surface of the whole upright roadbed meets the design requirements.

The utility model provides a roadbed structure of a soft soil foundation, which relates to the technical field of roadbed structures and comprises a soft foundation layer, a soil filling layer, a pavement layer and a reinforcing mechanism. According to the roadbed structure of the soft soil foundation, the geotechnical grid is flatly laid and placed on the soft foundation layer, the pouring pipes are inserted into the threaded pipe openings in the two ends of the geotechnical grid, the conical heads move downwards to be inserted into the soft foundation layer below, the threaded connectors and the threaded pipe openings are fixed together through the threaded sleeves, the reinforcing mechanisms are fixed, and the pouring pipes are filled with cement paste; cement paste flows out from the grouting holes in the bottom and the peripheral side of the grouting pipe through the pipe cavity and diffuses towards the periphery, in the grouting process, pressure can be generated when the cement paste is injected into the soft base soil layer, loose soil particles in the soft base soil body are squeezed towards the peripheral side through the pressure to be densified, and after the cement paste is solidified in the soil layer, a solid cementing material is formed. Loose soil particles are bonded together, so that the shear strength and the bearing capacity of a soil body are improved, and sedimentation and deformation are reduced.

The invention relates to the technical field of asphalt pavement structure design, in particular to a heavy-load durable asphalt pavement gradient structure in a multi-field coupling environment and a design method, and the structure comprises a high-modulus base layer, a tough middle layer and an anti-slip surface layer which are sequentially stacked from bottom to top; the dynamic modulus of the high-modulus base layer is larger than or equal to 14,000 MPa, the thickness of the high-modulus base layer is 18-25 cm, the fracture energy of the tough middle layer is larger than or equal to 1.5 kJ / m, the thickness of the tough middle layer is 8-12 cm, the structural depth of the anti-skid surface layer is larger than or equal to 0.8 mm, the thickness of the anti-skid surface layer is 4-6 cm, and the modulus gradient ratio of the base layer to the middle layer to the surface layer is (2.8-3.5): (1.4-1.8): 1. According to the method, a simulation model for coupling a temperature field, a humidity field and a heavy load stress field and a freeze-thaw damage factor quantification formula are established, so that dynamic analysis of a multi-factor collaborative degradation effect such as freeze-thaw cycle, high-temperature rutting and interlayer shear is realized, and the performance prediction precision under the environment and load coupling action is greatly improved.

The present application relates to a kind of anti-cracking building solid waste road flexible base mixture and its preparation method, base mixture includes building solid waste mixed aggregate, pitch, mineral powder;Building solid waste mixed aggregate is composed of broken concrete aggregate, broken brick, broken ceramic, broken glass, the mass ratio of broken concrete aggregate, broken ceramic, broken glass in the coarse aggregate of building solid waste mixed aggregate is (68-74):(23-29):(0.1-0.6);Pitch is heavy intersection 70 # matrix asphalt or 90 # matrix asphalt any one or combination thereof;Mineral powder is limestone mineral powder with 90%-100% purity, particle diameter is 0.8um-12um.The present application can reduce the crack of road base caused by temperature shrinkage and dry shrinkage on one hand, effectively prevent the phenomenon that base layer cracking leads to surface layer reflection crack;On the other hand, building solid waste is applied to road base, not only reduces material cost, saves natural mineral resources, but also can protect ecology, solve environmental pollution and other problems, with obvious environmental benefits, economic benefits and social benefits.

The invention discloses a method for determining an initial modulus of a semi-rigid base of an in-service asphalt pavement, and relates to the technical field of road engineering, a preset monitoring point of the in-service asphalt pavement is detected through a drop weight deflectometer, and a base modulus value is obtained through back calculation based on a deflection detection result; based on the transverse distribution coefficient of the carriageway, respectively calculating the accumulated axle load action times of the preset monitoring points; establishing a basic layer modulus damage model with basic layer initial modulus parameters by utilizing the structure behavior equation; and detecting basic layer modulus values under different accumulated axle load action times by using a drop weight deflectometer, performing regression fitting to obtain model parameters, obtaining a complete basic layer modulus damage model, and obtaining a basic layer initial modulus. According to the method, the initial modulus of the base layer is determined through the drop weight deflectometer.

The invention discloses a ground penetrating radar-based pavement asphalt base grouting effect evaluation method, which relates to the technical field of road engineering, can be used for representing the repairing effect of grouting on a pavement asphalt base, and comprises the following steps: coring to test parameters such as base electromagnetic parameters and volume parameters of each phase; testing the relative dielectric constant of the used grouting material; testing the two-way travel time of electromagnetic waves in the base layer before grouting; calculating a comprehensive correction coefficient; testing the two-way travel time of electromagnetic waves in the base layer after grouting; and calculating the probability distribution interval of the filling density of the base layer after grouting. Compared with an existing manual coring observation method, the method has the advantage that the detection efficiency and coverage are remarkably improved.

The invention discloses an asphalt mixture for an anti-crack ultrathin overlay and a preparation method thereof, the asphalt mixture comprises 45-60 parts of 5-10 mm graphite coated coarse aggregate, 10-15 parts of 3-5 mm graphite coated coarse aggregate, 20-30 parts of 0-3 mm graphite coated fine aggregate, 2.0-4.0 parts of mineral powder and 4.8-5.8 parts of high-performance modified asphalt, wherein the modified asphalt is prepared from 90 parts of matrix asphalt, 7-8 parts of a six-arm star-shaped SBS modifier, 1-2 parts of oxidized polyethylene, 2-4 parts of rubber oil, 0.1-0.13 part of a sulfur stabilizer and 1-2 parts of conductive carbon black, an aggregate graphite coating layer and grading design are optimized, a dynamic compensation proportioning method is matched, a high-speed shearing and low-speed stirring coupling process is adopted in the preparation process, and the modified asphalt is prepared. Stable performance of the modified asphalt is ensured; the method is suitable for construction of an ultrathin overlay with the thickness of 1.5-2.0 cm, is high in durability, can prevent upward development of base layer cracks through the property of self-repairing at the temperature of 60 DEG C or above, and has enough crack resistance.

The invention relates to a device and method for measuring bonding-sliding friction parameters between an asphalt pavement base layer and a cushion layer, and relates to the technical field of road engineering asphalt pavements, and the device comprises a test piece restraining mechanism which is of a double-layer collaborative frame structure and comprises an upper test piece bearing part and a lower test piece fixing part, the upper-layer test piece bearing part is used for accommodating a base-layer sliding test piece, the lower-layer test piece fixing part is used for accommodating a cushion-layer sliding test piece, the upper-layer test piece bearing part and the lower-layer test piece fixing part are aligned up and down, plate surfaces are overlapped, and a real interface contact state of a base layer and a cushion layer is constructed. According to the invention, the double-layer square test piece, the horizontal thrust device and the electronic measuring equipment are organically integrated with the counterweight load, so that the accurate measurement of the bonding-sliding friction parameters between the base layer and the roadbed cushion layer is realized. The integrity and the test precision of the interface are ensured, the stress state of the pavement base is truly represented, and high-precision characterization of bonding-sliding friction parameters is realized.