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Just owing to fatigue damage mechanics' obvious advantages that can reflect the essence of pavement cracking and facilitate the establishment of a connection between pavement performance and pavement structure, environment, and service life, the theory of fatigue damage mechanics has received increasing attention from road experts and scholars, and its application to asphalt pavement has been widely studied. However, current research still reveals problems that require urgent solutions, such as, the fundamentals of fatigue damage theory remain poorly understood, most research results have not yet been summarized, which hinder the development and wide use of fatigue damage theory. Therefore, this work conducts a systematic review of the fundamental content of fatigue damage mechanics and presents the research in the area of asphalt pavement, including the existing problems, some interesting topics that are worthy of further research are also suggested, which include the development of a triaxial damage constitutive model and a new damage evolution model capable of considering the influence of a mixture's viscoelastic characteristics, temperature, and loading rate on the damage evolution feature of the asphalt mixture. In addition, close-form solutions or viscoelastic calculation for asphalt pavement need to be derived, and other efficient large-scale or microscopic numerical methods for modeling pavement damage performance also need to be studied. The goal of the review is to promote the development and progress of fatigue damage mechanics in the area of asphalt pavement.

To construct a more durable long-life asphalt pavement with semi-rigid base, we combine different technical characteristics of long-life asphalt pavements reported at home and abroad. Different interlayer bonding conditions and moduli of the bottom sublayer are considered to analyze the mechanical-state differences among long-life asphalt pavements with semi-rigid base. The following two issues are discussed: fatigue failure in the surface layer and coordination between anti-rutting and anti-fatigue characteristics. Four-point bending fatigue tests are then used at various temperatures and loading modes to evaluate the anti-fatigue characteristics of high-modulus asphalt concretes. The index of accumulative dissipated energy is adopted to compare with materials in the upper sublayer. Analysis results indicate that the application of high-modulus asphalt concrete in long-life asphalt pavement with semi-rigid base can improve anti-rutting and anti-fatigue characteristics and has some rationality.

We analyze herein the characteristics of pavement temperature based on pavement- and atmosphere-temperature data collected from the environment-information data-acquisition system of the first full-scale test track, i.e., RIOHTrack, in China. The general rules of seasonal change and diurnal variation of RIOHTrack pavement temperature are examined for the first time. The fitting method of pavement-temperature diurnal-variation curve and pavement-temperature-variation curve with depth is studied. Considering the two dimensions of time and depth, the time- and depth-function models of pavement temperature are established, respectively. The fitting results of the measured data show that the established time-function model has high fitting accuracy for the diurnal temperature-variation curve of the pavement structure and can well fit the characteristics of asymmetric wave of the temperature curve. The depth-function model has high fitting accuracy to the change curve of pavement-structure temperature with depth and can well reflect the change law of pavement-structure temperature with depth. The analysis results and the established model can serve as a reference for the further study of pavement-temperature field and the evaluation of pavement performance.

Asphalt materials including binder, mortar, and mixture are extensively used in the field of pavement engineering considering their obvious viscoelastic properties. To study the phase-transition temperature (Tp) of asphalt materials, we apply dynamic mechanical analysis (DMA) to conduct several temperature-sweep mode tests and compare the Tp values among these materials with similar sizes. Meanwhile, 27 AC5 mixtures are tested to determine the impact of binder type, gradation and, binder content on Tp. Results indicate that the Tp of binder and mortar is negative, but that of mixture is positive. Good correlations among Tp of binder, mortar, and mixture with the same binder type are observed, showing that binder quality is the key factor affecting Tp. Gradation type also affects Tp, and the mixture with a finer gradation has a lower Tp. Among the AC5 asphalt mixtures, the Tp of AR mixture is lower than those of the others, thereby demonstrating better low-temperature performance.

Missing sensor data are unavoidable when sensors are used to monitor a system. These missing data largely affect the sensor applications. When missing data exist, the best method is estimation. Herein, we introduce the k-nearest neighbor on multiple-regression algorithm (KMRA), which builds on the KNN and multiple regression. In the process of estimation, KMRA considers both spatial correlations from its neighbor sensor and time correlations from its own time serials. After computing these two correlations, the algorithm combines them into a unified result of estimation. As KMRA involves spatial and time correlations, it has the efficiency and practicability as an algorithm. Examination results show that KMRA can precisely estimate the missing data.

To research the compatibility and adhesion of rubber asphalt, the correlation of the asphalt components and rubber content with conventional properties of rubber asphalt was analyzed. The effects of asphalt component, rubber content, thin-film oven testing, and ultraviolet (UV)-aging testing on the adhesion properties of rubber asphalt were analyzed by measuring the surface free energy and its component based on the theory of surface free energy. Results show that the three major indicators of rubber asphalt are obviously affected by the properties of matrix asphalt, i.e., rubber asphalt has low penetration, high softening point, and movement viscosity processed by the matrix asphalt with high resin and asphaltene content. With increased rubber content, the penetration of rubber asphalt decreases and its softening point increases, but its ductility value is closer. Viscosity decreases when rubber asphalt is stored at high temperature, and viscosity decreases by 60% when stored for 8 h at 180℃. The surface energy of rubber asphalt increases with increased rubber content. After thin-film oven testing of 5, 10, and 15 h, the surface energy of rubber asphalt increases, but the change rate of surface energy decreases. The effect of UV aging on the surface properties of rubber bitumen is not obvious. The surface energies of rubber asphalt processed by different components of matrix asphalt after 10 and 20 d of UV aging differ.

Aggregate segregation is an important factor affecting the early distress and durability of asphalt pavement. To analyze the segregation tendency of aggregates on the mesoscopic scale, firs...

The related research and application status of potential energy technologies for road at home and abroad were comprehensively investigated and systematically analyzed in this study to provide theoretical guidance and technical support for the development and utilization of road potential energy sources. The applicability of different types of power generation technologies, such as photovoltaic power generation, piezoelectric power generation pavement, and road speed reducer power generation equipment, was analyzed, and the development direction for future research of road energy was proposed in this paper.

The vibration reduction effect of compacted stone mastic asphalt (SMA) mixture with rubber particles or rubber powder has been widely explored, but the vibration reduction effect of common ...

Asphalt binder is very sensitive to temperature and exhibits bonding or lubrication effects at different temperatures. The bonding/lubrication properties of asphalt affect the mixing, compa...

To effectively evaluate the contact characteristics of a particle system, an aggregate contact-slip tester was developed in this investigation on the microscopic level. Contact indexes, inc...

The aim of this research is using a waste wood–based bio-oil as the modifier of petroleum asphalt and analyzing its modification mechanism. The four components, infrared spectrum, and molec...

Under the comprehensive action of environmental temperature and vehicle loads, asphalt pavement is prone to certain issues, such as high-temperature wheel ruts. Thermally activated shape-me...

Macroperformance, i.e., skid resistance, high-temperature, and compaction performance, are related to the functional performance, safety, and durability of asphalt pavement. Currently, the ...

Given the application characteristics and shortcomings of basalt fiber in road engineering, improvements to its reinforcing effect in asphalt mixture, such as reinforcing, toughening, and b...

With the basic principle of polymer chemistry and physics as basis, the preparation technology of colored asphalt was proposed and main technological parameters and parameter level were selected. The influential technological parameters in different levels acting on the performance of cementing material were analyzed through range analysis. On this basis, the critical factors affecting the performance of cementing material and optimal technological parameters for cementing material preparation were found.

To investigate the law that governs changes in excess pore water pressure during the sinking of a pipe pile with a group of holes, excess pore water pressure is monitored during the process of sinking a pile between a pipe pile without holes and three types of pipe pile with holes based on model test. The influences of the time-space dissipation of excess pore water pressure are analyzed by considering the factors of sinking pile sequence and disposal hole mode. The variation rules for excess pore water pressure dissipation with time, depth, radial distance, and sinking pile sequence are also established during the process of sinking the pile. On the basis of comparison and analysis, the pipe pile with holes, which are penetrated in a radial manner, achieves the lowest excess pore water pressure peak and the fastest dissipation rate, which are the most favorable conditions for reducing the squeezing effect of the pile, and the best pile driving effect is achieved. Moreover, the results can provide a reference for the application of pipe piles with holes in engineering practice.

Joints are weak links in the structure of cement pavements, and heavy traffic sections must be set up to maintain the transmission capacity of the board and to ensure the long-term use of pavements. However, with the advancement of force transferring rod construction technology, concrete with ratio and construction control of the influence of the force transmission rod actual spatial location and design of the location will inevitably produce some deviations. Given that such deviation will rapidly reduce the transfer capability of the board, the deviation of the transmission rod must be controlled in the construction process. However, basic data on the transmission rod are lacking. To this end, this paper conducts an experiment in the Beihei Expressway in Heilongjiang Province using MITSCAN2, and the test results are compared with the actual test data of two highways in the US and Canada. Some technical measures for improving the deviation of the transmission rod in the construction process are then proposed based on the detection and analysis results.

To harmonize the conflict between the durability and drainability of porous asphalt mixtures, the coarse aggregate void filling (CAVF) method is introduced to the design of a porous asphalt mixture. Bulk volume relative density is used as a measure to evaluate the compaction effect, and the temperature at which the compacting specimen reaches the maximum bulk volume relative density is selected as the optimum compacting temperature. At this temperature, a porous asphalt mixture specimen is modeled, and its properties, such as water stability, high-temperature stability, permeability, and skid resistance, are tested. Test results show that adopting the temperature at which the compacting specimen reaches the maximum bulk volume relative density as the optimum compacting temperature is reasonable. Moreover, the water stability, high-temperature stability, permeability, and skid resistance of the designed porous asphalt mixture exceed the specification requirements. The designed mixture shows good stability even at a high temperature of 70℃. This finding proves that the CAVF method presents advantages when used to design asphalt mixtures with a skeleton interdocking structure.

To study the critical height of secondary salinization of silty soil subgrade, this paper examines the salt migration law in the secondary salinization of the non-saline soil subgrade in the Yellow River impact plain area via laboratory and numerical analyses using COMSOL Multiphysics. The results show that (1) if the top of subgrade has not yet formed poly salt, then the internal roadbed will also not form poly salt. and it shows the trend of gradually decreasing from the bottom to the salt distribution in the subgrade; (2) the relationship among the weak internal saline soil formation of critical height, the groundwater mineralization degree, and the underground water level at the top of the subgrade can be used to establish an approximate correlation and regression formula for the Yellow River impact plain area for estimating the weak internal saline soil formation of critical height; and (3) the influence of the groundwater mineralization degree on the secondary salinization of silty soil subgrade in the Yellow River impact plain area is significantly higher than those of the buried depth of groundwater and the filling height of subgrade.

The technical characteristics combined with the pre-crack at home and abroad present the early strength of grassroots without the material repair technology.However, the grassroots space mesh microcracks must be implemented in the early period of heavy traffic, and widely related transverse cracks reflective of asphalt pavement cracking probability, which decreases asphalt pavement status, are also improved; a finite element method was analyzed to simulate the ideal type of crack between the two kinds of mechanical asphalt pavement crack under the form of responses, and the surface layer of microcracking technology life asphalt pavement is calculated. This study found that the microfracturing technique reduced the life of the asphalt surface to some extent. However, to solve the problems of the conventional repair techniques for readily reflective cracks and to achieve a rapid restoration of the technical requirements, a microcracking technology rapid repair in the grassroots has indicated a certain feasibility.Considering that crack forms are drawn, the fatigue life of the asphalt surface, the definition and control of the size of the cracks in the construction, and other related issues require further studies under actual crack forms.

An asphalt pavement performance evaluation model based on deflection is established by combining the subjective deflection weight obtained from the improved analytic hierarchy process and the objective deflection weight obtained from the entropy method through the variable weight principle. The established model is used to comprehensively evaluate asphalt pavement performance. This model is implemented in two ways, namely, introduction of high-speed deflectometer and observation of long-term pavement performance; hence, the application of the new pavement performance evaluation model is guaranteed. Results show that the evaluation result of the new model can reflect each index weight proportion of asphalt pavement performance on the basis of the existing specification and real-time parameter evolution rule of asphalt pavement. The new model can reflect the actual pavement quality objectively and accurately.

A finite element model was established by Abaqus to investigate the mechanical characteristics of continuously reinforced concrete pavement (CRCP) with basalt fiber reinforced polymer (BFRP...

A box girder bridge was simulated by ANSYS software, where the interlaminar relation of the bridge deck pavement was assumed to be frictionally sliding rather than continuous. Stresses of t...

This study proposes a finite element model to simulate traffic loads on continuously reinforced concrete pavement (CRCP) by using basalt fiber reinforced polymer (BFRP) bars, considering th...

The asphalt mortar specimens of AC-13 asphalt mixture with removed coarse aggregates are prepared using a static pressing method to study the changes in the dynamic modulus of asphalt morta...

After defining the fatigue damage variable and constructing the residual flexural strength damage model, nonlinear mathematical equations of residual flexural strength and parameters, such ...

This paper investigated the mechanism of resistor network for road deicing with finite element analysis. It also derived the differential equations and boundary conditions of a mathematical...

The strength characteristics of solidified desert aeolian sandy soil are investigated to expand its scope of application in road engineering. Its suitability as sub-base of pavement structure is analyzed in terms of its strength. The unconfined compressive strengths of the solidified desert aeolian sandy soil specimens with different contents of curing agent are measured using a pavement material strength meter. The microstructures of aeolian sand and the solidified aeolian sandy soil to which the curing agent PX is added are analyzed by scanning electron microscopy(SEM). The strength characteristics and strength formation mechanism of the solidified Aeolian sandy soil are revealed by the analyses. The results point to the following conclusions: (1) the solidified aeolian sandy soil with 10% PX and cured for 7 d achieves an unconfined compressive strength that meets the strength requirement of the pavement sub-base. (2) the strength of the solidified soil is associated with the content of PX, and the optimal dosage is10%. (3) the SEM image shows that intergranular filling consisting of gel and cumularspharolith is formed after adding the curing agent PX. This formation changed the adhesive strength between the soil particles, accounting for the chief cause of the increase in overall strength.

The in-situ falling weight deflectometer (FWD) tests were conducted to develop a temperature correction method for asphalt pavement dynamic deflection. Results indicate that different value...

The dynamic responses of different slope types are analyzed using the shaking table model test to study the influences of slope position and ground motion parameters on the dynamic response...

To investigate the stress state and crack propagation of asphalt surface course bottom, the weight function of a rectangular plate with a single edge crack is derived based on weight functi...

For multi-feature fusion in automatic recognition of pavement distress images, we proposed a multi-feature fusion method based on manifold learning. In this method, the intrinsic features o...

Mileage piles is an effective flag to pavement information positioning. However, the problems in positioning inaccuracies and error accumulation remain. By analyzing the primary errors in t...

Numerical simulations and laboratory tests on soil samples with compaction degrees of 94%, 96%, and 98% are carried out to study the laws of capillary water rising and control techniques. T...

Using a flexible asphalt pavement structure with a graded crushed stone base is an effective means to solve reflection cracking, which frequently occurs in the semi-rigid asphalt pavements ...

The influence of an early-strength agent on the frost resistance of a cement-stabilized macadam material used in road engineering was explored by mixing 5% cement into the cement mixture in...

This paper proposes an equation to decompose the dynamic stability (DS) and its controlling criterion of an asphalt surface course into DS of the asphalt mixture layer. Wheel tracking tests...

The multilevel mixing method for aggregate gradation design was optimized based on the division of the functions of coarse and fine aggregates. The mixing procedures were simplified. The mi...

Rollable prefabricated asphalt pavement technology consists of prefabricating and crimping the asphalt pavement in the factory. It can be laid on the pavement as carpets so that the constru...

Finite element models of integrated (IPSS) and separate (SPSS) pile-anchor supporting structures are built by using ABAQUS software, and differences in the mechanical performance of these s...

To understand the influence of formation methods on the performance of graded gravel, graded gravel specimens composed through two common methods, i.e., compaction and vibratory formation, were analyzed. First, the K change method was adopted to design the graded gravel; subsequently, the graded gravel specimens were generated through the aforementioned methods. The maximum dry density, optimum moisture content, and CBR values of the specimens were measured separately, and the parameters were analyzed comprehensively. The analysis of the ideal data indicated that (1) compaction formation severely disturbed the previous gradation of graded gravel, particularly the gradations from 13.2 mm to 1.18 mm; (2) vibratory formation slightly disrupted but basically maintained the previous gradation; (3) the CBR values of the graded gravel specimens formed through vibratory formation were almost twice as high as those generated through compaction formation; and (4) a densely graded gravel specimen does not in...

A slope model that shows the geogrid structural construction at the Nanning outer ring expressway is established using FLAC3D after the property of typical expansive soil in Nanning was tes...

In order to characterize the ability of tension and compression deformation of asphalt mixture more truly and to improve the test efficiency and scientificity of the tension and compression...

In this study, a hard-grade paving asphalt with a penetration, of 10/20 (0.1 mm) and a limestone aggregate were used to produce a hard-grade asphalt mixture AC - 20 (HaGAM). Basic performan...

To study the change law of the dynamic characteristics of soft soil, particularly the inadequate bearing capacity of highway and railway roadbeds induced by traffic loads, the soft soil in ...

This study investigated the purifying effect of tourmaline-modified asphalt on automobile exhaust. Six types of tourmaline-modified asphalt concrete were prepared, aiming to achieving excel...

Compared with flat slope sections of asphalt pavement, the loading time of low-speed vehicle load to uphill sections with long and large longitudinal slope is much longer, under the compreh...

To cope with the phenomenon of moisture imbalances in subgrades due to excavation, the resistivity of different excavation subgrades (deep excavation section, shallow excavation section, an...

Based on this reality that surrounding rocks of deep undergrounds engineering repeatedly bear geological force and excavation disturbance, the integrity and mechanical properties were weake...