Composite Pavement Research Articles

Research progress of long-life asphalt pavement behavior based on the RIOHTrack full-scale accelerated loading test

Full-scale accelerated loading test is an efficient and effective method for simulating and studying long-term pavement performance because its loading and environment conditions are similar to those of real-world applications. In the past decades, this method has been recognized as an important support for the development of pavement design theory worldwide. In 2000, the long-life pavement was first presented by the researchers in Europe and the USA to obtain the most economical pavement during the whole life cycle. However, the completed design method of the long-life asphalt pavement has not been provided, especially for semi-rigid base asphalt pavement. In 2015, the Research Institute of Highway, Ministry of Transport constructed a 2.038-km-long full-scale field accelerated pavement testing track, which was named as RIOHTrack, to develop a long-life pavement suitable for China. The testing road has 25 asphalt pavement structure sections, and the average length of the testing section is 60 m. In all of the testing sections there were 19 structural testing sections, which are classified into six types, namely, the thin asphalt layer semi-rigid base pavement, the normal semi-rigid base pavement used in China, the composite pavement, the inverted pavements, the thick asphalt layer asphalt pavement, and the full-depth asphalt pavement respectively. In the first research phase, RIOHTrack planned to complete 50 million equivalent single axle loads ESALs (10 tons standard axle loading) by using trucks under the real environment. During the accelerated loading, two types of pavement performance detections were conducted. The first type is the real-time strain/stress responses and the environment information captured by the monitor sensors, and the other type is the periodic pavement performance detection measured by auto-detecting devices or artificial measures. In this paper, the bearing capacity, service performances, and inner mechanism responses under the couple of loading and environment were analyzed on the basis of the whole detecting data captured from December 2016 to January 2020. Four main conclusions were drawn. First, the influence of loading and environment on performance is considerably, and the influence degree of environment is even larger than that caused by the loading. Second, the pavement performance has structural dependence, the ranking of the six main types varies if evaluated using different performance indices, and the rutting depth prediction accuracy depends on the structural type. Third, the stress/strain monitoring results verify the nonlinear characteristic of asphalt pavement structure under the temperature and loading. To calculate the nonlinear effect in pavement behavior, a new mechanical analysis method was presented, which considers material and geometric nonlinearity theory. Lastly, to improve the prediction accuracy of the rutting depth, we utilized multivariate statistics to build the new prediction model based on the measured rutting depth data, and this model considers the changes in loading number and temperature change. The stage research results illustrate that the different type of pavement structure has its advantages and disadvantages, so the type of the long-life asphalt pavement should be multiple choice. China has the longest mileages of semi-rigid base asphalt pavements. Hence, long-life, semi-rigid base asphalt pavement building, and maintenance technology should be developed. More works should be carried out on mechanism analysis, prediction models, and failure criteria, and the accelerated loading test, such as RIOHTrack, will mainly provide support.

Statistics and Artificial Intelligence-Based Pavement Performance and Remaining Service Life Prediction Models for Flexible and Composite Pavement Systems

In their pavement management decision-making processes, U.S. state highway agencies are required to develop performance-based approaches by the Moving Ahead for Progress in the 21st Century (MAP-21) federal transportation legislation. One of the performance-based approaches to facilitate pavement management decision-making processes is the use of remaining service life (RSL) models. In this study, a detailed step-by-step methodology for the development of pavement performance and RSL prediction models for flexible and composite (asphalt concrete [AC] over jointed plain concrete pavement [JPCP]) pavement systems in Iowa is described. To develop such RSL models, pavement performance models based on statistics and artificial intelligence (AI) techniques were initially developed. While statistically defined pavement performance models were found to be accurate in predicting pavement performance at project level, AI-based pavement performance models were found to be successful in predicting pavement performance in network level analysis. Network level pavement performance models using both statistics and AI-based approaches were also developed to evaluate the relative success of these two models for network level pavement performance modeling. As part of this study, in the development of pavement RSL prediction models, automation tools for future pavement performance predictions were developed and used along with the threshold limits for various pavement performance indicators specified by the Federal Highway Administration. These RSL models will help engineers in decision-making processes at both network and project levels and for different types of pavement management business decisions.

Development of Systematic Mitigation Strategy Utilizing Computer-Based Guidelines for Reflective Cracking

AbstractComposite pavements currently are the most prevalent pavement type for highway rehabilitation projects in the US. However, composite pavements are susceptible to pavement distresses inheren...

Designation principle and method for functionally graded composite pavement

Designation principle and method for functionally graded composite pavement

Cracking models for HMA overlay treatment of composite pavements in Louisiana

ABSTRACT Cracking is one of the primary forms of distress suffered by hot-mix asphalt (HMA) overlay of composite pavements. Pavement cracking affects the ride quality and pavement service life by allowing water and debris to penetrate through the pavement structure. This paper presents the development of transverse cracking and longitudinal cracking performance models for overlay treatment of composite pavements in the state of Louisiana. Various factors that affect the cracking performance of overlay treatment were identified. Such factors include equivalent single axle load (ESAL), thickness of HMA and Portland cement concrete (PCC), functional classification of roadways, and newly developed temperature indexes. Regression analyses were performed to identify those factors and to develop cracking prediction models. In order to better predict the pavement service life, the existing condition of the pavement was also utilised through the models. The developed models provided an acceptable agreement between the measured and predicted crack values. It was found that the predictions were improved when the existing pavement condition was incorporated in the models. The resulting cracking models could be used by Louisiana Department of Transportation and Development (LADOTD) as a good pavement management tool for timely pavement maintenance and rehabilitation actions to maximise benefits, driver’s comfort, and safety.

Accelerated Pavement Testing for Rutting Evaluation of Hot-Mix Asphalt Overlay under High Tire Pressure

AbstractThis study focused on the rutting characteristics of two typical hot-mix asphalt (HMA) overlays in airfield composite pavement under high tire pressure: asphalt concrete (AC) and stone mast...

Effect of Different Rheological Models on the Distress Prediction of Composite Pavement.

In this paper, three different rheological models including a newly developed formulation based on the current Christensen Anderson and Marateanu (CAM) model, named sigmoidal CAM model (SCM), are used to estimate the evolution of roughness, rutting, and reflective cracking in a typical composite pavement structure currently widely adopted in South Korea. Three different asphalt mixtures were prepared and dynamic modulus tests were performed. Then, the mechanistic-empirical pavement design guide (MEPDG) was used for predicting the progression of the pavement distress and to estimate the effect of the three different models on such phenomena. It is found that the three different mathematical models provide lower and upper limits for roughness, rutting, and reflective cracking. While the CAM model may not be entirely reliable due to its inability in fitting the data in the high-temperature domain, SCM might result in moderately more conservative pavement design.

Studying Bump at Bridge Approach of Short Subgrade with Oblique Prestressed Concrete Overlaying Asphalt Layer

The differential settlement of short subgrade between two highway structures (bridges, tunnels, culverts, etc.) is significantly greater than that of the other subgrade for the insufficient compaction of short subgrade owing to limited construction site. This paper aims to establish the control criteria to prevent bump at bridge approach for differential settlement of short subgrade with oblique prestressed concrete overlying asphalt layer (AC + OPC) composite pavement. In this work, the short subgrade and AC + OPC composite pavement were defined. Meanwhile, the driving comfort was analysed and the control criteria for differential settlement of short subgrade with different lengths were obtained based on the driving comfort using the driving comfort test. Finally, the effects of different layer parameters on stress and deflection were investigated and the control criteria for differential settlement of short subgrade were established based on the void area beneath the slab using the finite element software ANSYS. Results show that the length of short subgrade between two highway structures is defined to be less than 200 m. The vehicle speed and longitudinal slope have significant effects on the vertical acceleration. The asphalt layer modulus, OPC layer thickness and modulus, base layer thickness and modulus, and foundation modulus have effects on the flexural stress and deflection, especially the OPC layer thickness. The relationship between the additional stress and void area beneath the slab is derived. In addition, the control criteria for differential settlement of short subgrade with different lengths are put forward based on the void area beneath the slab and driving comfort. The application of AC + OPC composite pavement can prevent bump at bridge approach of short subgrade effectively. The results of this paper can provide guidance for the application of AC + OPC composite pavement.

Short and Long-Term Field Performances and Optimal Timing of Chip Seal in Hot and Humid Climates

Chip seal is a preventive maintenance technique typically applied on relatively low traffic roads to reduce pavement deterioration rate and to defer the need for costly rehabilitation activities. This study aims to address the common challenges with chip seal application in hot and humid climates such as Louisiana to ensure the maximum benefits are achieved. Specifically, this study evaluated the short and long-term field performances and optimal timing of chip seal by analyzing the cracking, roughness, and overall pavement conditions of 47 flexible and composite pavement sections in Louisiana. Furthermore, potential moisture damage in asphalt concrete after chip seal application was assessed. Results indicated that chip seal extended pavement service life by 4–17 years based on the pre-treatment pavement conditions and pavement type (flexible or composite). Based on the cost benefit analysis, it is recommended to use alternating cycles of asphalt overlay and chip seal on low volume roads (less than 5,300 vehicles per day) with chip seal applied when the pavement condition index (PCI) of the pavement drops to a value between 70 and 74. In this case, significant monetary savings could be achieved when compared with adding chip seals at different time periods (outside the recommended range of PCI between 70 and 74). Results also showed that the application of chip seal does not seem to contribute to moisture damage. Instead, shallow groundwater conditions present in the State seem to contribute to moisture damage in asphalt pavements owing to moisture entrapment underneath the asphalt layer.

Physical and chemical properties of non-exhaust particles generated from wear between pavements and tyres

A road simulator was used to generate wear particles from the interaction between two tyre brands and a composite pavement. Particle size distributions were monitored using a scanning mobility particle sizer and an aerosol particle sizer. Continuous measurements of particle mass concentrations were also made. Collection of inhalable particles (PM10) was conducted using a high-volume sampler equipped with quartz filters, which were then analysed for organic and elemental carbon, organic constituents and elemental composition. Tyre fragments chopped into tiny chips were also subjected to detailed organic and elemental speciation. The number concentration was dominated by particles <0.5 μm, whereas most of the mass was found in particles >0.5 μm. The emission factor from wear between pavements and tyres was of the order of 2 mg km−1 veh−1. Organic carbon represented about 10% of the PM10 mass, encompassing multiple aliphatic compounds (n-alkanes, alkenes, hopanes, and steranes), PAHs, thiazols, n-alkanols, polyols, some fragrant compounds, sugars, triterpenoids, sterols, phenolic constituents, phthalate plasticisers and several types of acids, among others. The relationship between airborne particulate organic constituents and organic matter in tyre debris is discussed. The detection of compounds that have been extensively used as biomass burning tracers (e.g. retene, dehydroabietic acid and levoglucosan) in both the shredded tiny tyre chips and the wear particles from the interaction between tyres and pavement puts into question their uniqueness as markers of wood combustion. Trace and major elements accounted for about 5% of the mass of the tyre fragments but represented 15–18% of the PM10 from wear, denoting the contribution of mineral elements from the pavement. Sulphur and zinc were abundant constituents in all samples.

Shear strength evaluation of composite pavement with geotextile as reinforcement at the interface

This research was conducted to investigate the shear strength at the interface between polymer concrete and asphalt concrete with geotextile as reinforcement at the interface of these two types of concrete. The samples were tested for the parameters of different surface conditions [rough and smooth], curing types [room and thermal curing], temperature effect and the impact of geotextile as reinforcement. To investigate the correlation between these parameters, four different testing conditions were implemented. The results showed a significant improvement of shear strength for rough surface sample as compared to smooth surface sample. Moreover, samples cured in oven had lower shear strength as compared to samples cured in room condition. Besides that, high temperature has an adverse impact on the shear strength at the interface between polymer concrete and asphalt concrete due to the weakening of asphalt concrete at high temperature. As for samples reinforced with geotextile, the shear strength resistance was better as compared to unreinforced samples. Through visual observation, the types of failure under all testing conditions were mixed failure mode.

Study on Construction Technology of Latex Cement Mortar Pouring Composite Pavement

Pouring composite pavement is one ideal type of pavement structure, but research on the pouring composite pavement is still in its infancy, especially in the construction technology. The normal pavement construction machinery is not compatible with this kind of pavement structure, while the construction efficiency is relatively low, which is not conducive to large-scale construction and affects its popularization and application. Based on the latex cement mortar pouring composite pavement developed by the authors, the pouring composite pavement construction methods of macroporous open-graded asphalt pavement and latex cement mortar are mainly introduced in this paper. According to the characteristics of macroporous open-graded asphalt mixture, the mixing temperature, dry/wet mixing time, paving speed, rolling combination mode and temperature of the mixture were studied, and the key construction process was put forward; For the construction of latex cement mortar, the construction technology of cement mortar production, pouring method and pouring time are mainly studied, and the construction process of cement mortar pouring is put forward.

Development of a new design method for composite pavement structure

HMA/PCC composite pavement is a new type of durable pavement structure which is a rigid-flexible combination. The composite pavement structure with excellent design has better durability. However, due to less domestic use, there is no effective structural combination design method in china. In this paper, a new structural design method of HMA/PCC composite pavement is put forward, in which the maximum thickness of asphalt concrete is designed according to the allowable permanent deformation, and the lower limit of the thickness of asphalt concrete is designed with the allowable shear stress of bond layer as the index. The composite slab model was used to design the thickness of concrete layer.

Study on structural optimization of latex cement mortar pouring composite pavement based on finite element method

Pouring composite pavement is one new type of pavement structure, which has excellent resistance to permanent deformation. However, due to the difference in the properties of cement-based materials and asphalt-based materials, the interfacial adhesion is not sufficient, which makes the pouring composite pavement have cracking defects. The adhesion of mortar modified by latex agent can improve the crack resistance of composite pavement. In this paper, the mechanical behavior of pavement is simulated by finite element method, and the deflection, bending, tensile stress / strain, shear stress / strain and so on of latex cement mortar pouring composite pavement with different thickness structures are calculated and analyzed. The mechanical control index of pouring composite pavement is obtained, and the thickness of semi-flexible pavement structure which meets the mechanical requirements of pavement is optimized at the same time.

Mechanical characterisation of interface shear strain of multi-layer composite pavement

ABSTRACT As interface bonding is a weak part of multi-layer composite, it is necessary to take a research on interface bonding mode of asphalt pavement overlay on cement concrete structure, which include: common bonding, super bonding and stress absorbing layer (SAL) sandwich. The strain gage method was used to collect strain values to evaluate the strain distribution at each of the following four locations: the middle of the asphalt pavement layer, the interface between the asphalt pavement concrete at the mid-span, L/4 span and fulcrum. There is a difference on the quantitative analysis of the strain distribution of bonding modes at each location. It can be concluded that strong bonding controls the force and deformation concentrated at the interface. It is also favourable to reduce the shear force and prevents extension at the interface. The results can explain well the mechanical characteristics at the interface in different bonding modes and provide technical support for the selection of overlay mixture and bonding mode.

Sensitivity analysis of stormpav composite pavement

This study investigates the design and performance of modified composite pavement called StormPav. In this study, the sensitivity analysis is carried out by using available freeware to prove whether the StormPav composite pavement is able to provide long-life pavement and better levels of performance, both structural and functionally, than the traditional pavements. For this case, the sensitivity analysis is included data for fatigue behavior, rutting in the HMA (Hot Mix Asphalt) layer, and temperature gradient reduction of PCC slab with an HMA overlay. The StormPav composite pavement is actually an innovation IBS green pavement with structural, environmental and economic advantages. Inspired from Legos concept, the StormPav is made out of modular panels or “roadblocks” that are like enormous lego pieces that assemble and interlocking together forming a uniform settlement and at the same time acting as the monolithic character. The idea of StormPav is actually to minimize the usage of material in the composite pavement but provide the same strength and benefits as composite pavement.

Vibration experiment of CTCP-CRCP composite pavement under heavy traffic

The accelerations of sandwich-type composite pavements consisting of cross-tensioned concrete pavement (CTCP), asphalt sand (AS) stress-absorbing layer, and continuously reinforced concrete pavement (CRCP) layers from the top to the bottom were measured under different traffic loads. First, the acceleration spectra of double plates of composite pavements were measured under axle loads of 100, 200, and 300 kN using an embedded accelerometer. The universal mean of the acceleration ratio of CTCP to CRCP was defined as the stress-absorbing ratio of the AS layer as obtained through statistical analysis of the test data. A frequency spectrum was obtained for the pavement under each vehicle load by using Fourier transformation. Test results show that the maximum acceleration of CTCP and CRCP in composite pavements was 0.022, 0.039, and 0.059 ms−2 and 0.01, 0.015, and 0.025 ms−2 under vehicle loads of 100, 200, and 300 kN, respectively. The corresponding mean stress-absorbing ratio of the AS layers was 3.38, 3.15, and 3.46. The results suggest that the proposed composite pavement is suitable for roads with heavy traffic because its stress-absorbing layer can effectively reduce the pounding caused by heavy loads on the pavement.

Analysis of the operating conditions of mobile composite airfield pavements

Safety maintenance is a key and essential condition for flight operations performance by aircraft. It refers to all functional elements of an airport, i.e. runways, taxiways and aprons, as part of the movement area at civil, as well as military airports. Airfield pavements, likewise the aircraft and technical personnel of ground control directly affecting the safety of flight operations, are the integral part of each functional element of an airport. Airports in the event of force majeure, critical events and foremost, in the event of war threat are the facilities that would be the first objects to focus on. As a result, airfield pavements constructions would be destroyed and require quick reconstruction that guarantee its restoration of operational readiness and safety conditions for operating aircraft. Existing technology and methods of airfield pavement reconstruction could not meet the stringent time requirements of military operations, that is why mobile, composite airfield mats have been developed. In the paper, operational and maintenance advantages of the elastic, mobile airfield mat ELP-1 KRATER manufactured by Shipyard Żuławy are shown. There is presented the computational model of composite pavement which co-operates with subbase and also shown are the results of field tests, performed by the Air Force Institute of Technology. Moreover, there are presented the results of load-bearing capacity of the composite airfield mat ELP-1 KRATER received during field tests.

Influences of Surface Characteristics and Modified Asphalt Binders on Interface Shear Strength

Weak bonding between layers of pavement leads to damages on the composite pavement. Bonding plays an important role in the durability and maintenance of composite pavement layers. The present study evaluates the factors effective in bond strength of the interface between concrete and asphalt pavements. The factors considered for this purpose include steel slag percentage in the concrete pavement, different types of modified bitumen, and rates of tack-coat. To measure the bond properties, direct shear and shear fatigue tests were carried out. In addition, texture depth and abrasion resistance were used in accordance with EN 1338 standard to measure the roughness properties of concrete pavement. The test results showed that 50% replacement of steel slag with aggregate resulted in an increase in physical properties and texture depth of concrete pavement. Moreover, the results of the shear strength test of composite pavement revealed that the optimal rate of using tack-coat varies between 0.6 and 0.9 l/m2 and depends on the type of tack-coat. Finally, a higher shear strength was obtained for crumb rubber bitumen containing hydrated lime compared to crumb rubber modified bitumen and control bitumen.

Reflective cracking reduction by a comparison between modifying asphalt overlay and sand asphalt interlayer: an experimental evaluation

ABSTRACT Reflective cracking is a frequent type of distress in asphalt concrete (AC) pavements that decreases pavement service life in a newly constructed AC overlay. In this study, natural zeolite and hydrated lime were added to crumb rubber modified (CRM) asphalt binder in order to assess their effects on reducing propagation of reflective cracks in composite pavements. CRM asphalt binder containing these additives was used in both AC overlay and sand asphalt interlayer to investigate crack propagation in the composite specimen under dynamic cyclic loading. The results show that asphalt interlayer modification is more effective than AC overlay modification (using CRM binders containing additives) in controlling reflective cracks. In other words, sand asphalt interlayer modification is more capable of absorbing the energy of crack propagation and, consequently, delaying the crack propagation. The results also indicated that simultaneous modification of both the interlayer and overlay significantly decreases reflective cracking potential. With respect to the significant role of additive type in crack propagation delaying, the results show that CRM binders containing natural zeolite are more efficient in crack mitigation compared to CRM binders containing hydrated lime.