Composite Pavement Research Articles

A New Design of Composite Pavement with Asphalt Interlayer between CRCP and Cement Treated Base Course

In Japan, composite pavements are adopted in expressways to ensure a long service life with minimum maintenance work. A typical design of the composite pavement utilizes a porous asphalt surface and a CRCP over a cement treated base course (CTB). An investigation on a 20 years old composite pavement revealed that the CTB was damaged due to water penetration and erosion. This finding promoted us to develop a new type of composite pavement, which introduces an asphalt interlayer (AIL) over the CTB to prevent the erosion. A structural design method for the new design of the new composite pavement was developed based on thermal and load stress calculations and fatigue analysis. Full scale test composite pavements were constructed and thermal and load strains measured on the pavements. A 3DFEM model was developed for stress calculation and validated by comparing the calculated and measured strains. The new design method provides 10 % reduction of fatigue damage by introducing AIL. It was also found that the fatigue damage increases six times if AIL is not used and CTB is eroded.

Composite Pavement Systems – A Sustainable Approach for Long-Lasting Concrete Pavements

This paper summarizes work performed under the Strategic Highway Research Program project R21 on developing MEPDG-compatible mechanistic-empirical design procedures, test methods, and construction guidelines and specifications, for two-lift PCC/PCC composite pavements and HMA/PCC composite pavements. Composite pavements consisting of high quality top layer(s) have been proven in Europe and in the United States to provide long lives with excellent surface characteristics and rapid renewal when needed. The lower PCC layer is a sustainable JPC or CRC pavement that utilizes recycled and lower cost locally available materials, thus reducing the need to haul aggregates over long distances. As part of this research, three full-scale instrumented test sections on the MnROAD mainline roadway (I-94, west of Minneapolis) were constructed in Spring 2010. The sections include one HMA/JPC and two two-lift PCC sections subject to real highway traffic. Accelerated Pavement Tests (APT) using the Heavy Vehicle Simulator (HVS) were used at the University of California Pavement Research Center (UCPRC) at Davis to evaluate various HMA/PCC test sections. These test sections were constructed in Fall 2009. The research also includes evaluation of in-service composite pavement across the U.S., Canada, and Europe. The results from these experiments were used to develop performance models and procedures for designing HMA/PCC and PCC/PCC composite pavements.

SHRP2 R21 Project Implementation: Two-Lift Concrete Paving on I-65, Nashville

Under Strategic Highway Research Program 2 (SHRP2) Project R21, detailed design and construction guidelines were developed for new composite pavement systems. These systems, consisting of either a hot-mix asphalt (HMA) or portland cement concrete (PCC) wearing course over a structural concrete layer (i.e., HMA/PCC or PCC/PCC), are promising technologies for providing sustainable roadways that can be constructed rapidly and rehabilitated (or renewed) with minimal disruption to the traveling public. New composite pavement systems have proven to provide long service life, excellent surface characteristics, exceptionally smooth ride quality, and high durability. As part of the SHRP2 Implementation Assistance Program, the Tennessee Department of Transportation (TDOT) integrated a two-lift (wet-on-wet) concrete composite pavement into a full-depth shoulder adjacent to a mainline reconstruction project on I-65 in Nashville. TDOT’s interest in the two-lift concrete pavement was driven by a recent specification change requiring a higher quality surface aggregate, and the I-65 project offered the opportunity to evaluate the viability and costcompetitiveness of the two-lift system. This paper describes the construction of the TDOT two-lift composite pavement, including critical aspects of the batching, transport, placement, and post-construction aspects of two-lift composite pavement construction.

Spragues Road Rehabilitation with an Unbonded Concrete Overlay Region of Waterloo, Ontario, Canada.

The work of this project includes the rehabilitation and widening of a 1.2 km (0.75 mile) section of Spragues Road (Regional Road No. 75) from Wrigley Road to the Region of Waterloo boundary in the Township of North Dumfries. The existing road is a rural two-lane composite pavement with partially paved and gravel shoulders. An initial geotechnical investigation determined that conventional road resurfacing strategies of the asphalt / concrete composite pavement were no longer cost-effective and additional assessments were completed to evaluate alternate rehabilitation strategies. Through this process, non-destructive testing was conducted to determine the structural adequacy of the concrete base and suitability for pavement preservation. Comprehensive field investigations determined the 80-year old concrete base was generally in good condition and should be preserved as part of the project. The final pavement design consists of re-profiling or cold planing the existing asphalt surface to meet proposed design gradients, installation of an asphalt intermediate separation layer and placement on an Unbonded Concrete Overlay, a unique rehabilitation treatment in the Province of Ontario.

Joint Performance in Bonded Concrete Overlays of Asphalt

Bonded concrete overlays of asphalt pavements (BCOA), also known as whitetopping, consist of a thin concrete overlay on distressed asphalt or composite pavements. They typically have smaller panel sizes than traditional jointed plain concrete pavements (JPCP) in order to reduce stress levels. Faulting at the transverse joints is a distress in BCOA that is not currently addressed in current design procedures. The pumping mechanism that leads to this distress is the focus of this paper. Pumping in BCOA can develop at either the bottom of the overlay slab within the asphalt layer or at the bottom of the asphalt in the granular layer. It is essential to identify where the faulting initiates for each pavement structure, if accurate faulting models are to be developed for these pavement structures. An examination was conducted of 21 BCOAs located at the Minnesota Road Research Facility (MnROAD) to investigate how faulting initiates in BCOA and the rate at which it develops. To do this, the relationship between deflection load transfer efficiency (LTE) from falling weight deflectometer (FWD) testing and transverse joint faulting was examined. It was found that these parameters can be used in successfully defining when faulting initiates at the top of the asphalt and when it initiates at the top of the granular layer below the asphalt. Finally, the rate of the development of faulting in BCOAs resulting from pumping at the concrete/asphalt interface as well as pumping below the asphalt layer was compared to faulting predictions using current models. A good agreement between the observed and predicted faulting was not achieved.

Design of Concrete Pavement for the Ohio Turnpike’s Mainline Pavement Replacement: An Innovative Approach

This paper describes the design of a concrete pavement for a section of the Ohio Turnpike’s mainline pavement. This design is a part of the Ohio Turnpike and Infrastructure Commission’s ongoing project to replace its existing two lanes of 241.26 miles long mainline pavement in both directions (east and west). The original pavement was built as concrete pavement which was subsequently overlaid with asphalt. Resource International, Inc. used current methods of pavement design, including Mechanistic-Empirical Pavement Design Guide (MEPDG), to design a concrete pavement and a composite pavement for this project. The concrete pavement for this section of the Turnpike was designed as a wide width (14’) pavement for the outside lane. This made it possible to build an outside shoulder with Recycled Cement Concrete Aggregates from old pavement and still achieve the benefits of a tied shoulder (decreased slab thickness). The construction of this pavement section (as a composite pavement) was completed in 2011 (WB) and 2012 (EB). Performance data has been collected since its construction. This paper describes the design of the pavement and observations of its performance made so far. The details of testing methods used, analysis performed, and the results are also described in the paper.

Development of Innovative Techniques for the Instrumentation of Composite and Wet on Wet Pavement Sections at MnROAD

Composite and wet on wet concrete pavements are a promising solution for the economical, sustainable and durable construction and renewal of highways. Wet-onwet pavements consist of Portland cement concrete (PCC)-over-PCC, with a relatively thin PCC layer placed wet on a wet thicker layer made of a less expensive PCC mixture. A composite pavement here will be referred to as, a relatively thin hot mix asphalt (HMA) layer placed over a less expensive PCC mixture. In order to acquire knowledge on the performance of these pavements, three heavily instrumented pavement sections were constructed at the Minnesota Road Research Facility (MnROAD) in May 2010. The purpose of the instrumentation is to establish the magnitude of the environmental loads that develop within these pavements and the response of the pavement to both these environmental loads as we as traffic loads. Without this, the development of a rational mechanistic-empirical design process is not possible. The instrumentation of PCC pavements constructed in two lifts has never been performed before and presents a surmountable challenge. Discussed below are novel instrumentation techniques that were developed to overcome these challenges.

MnROAD SHRP2 R21 Composite Concrete Section Performance after Five-Years of Service

The Strategic Highway Research Program (SHRP2) R21 project “Composite Pavements,” completed in 2010 at MnROAD I-94, included both long-term full-scale pavement experiments and the development of new tools for pavement design and analysis. The R21 research focused on both asphalt-over-concrete and concrete-over-concrete (PCC-PCC) pavement systems. This paper focuses on the full-scale PCC-PCC results of the R21 project. Results show that these sections performed very well with no transverse or longitudinal cracking, minimal joint faulting, low IRI values and no obvious durability problems after five years of I-94 traffic. This evaluation also includes analysis of pavement data and a comparison of the PCC-PCC response relative to a conventional single-lift slab. Results indicate very similar performance for similar PCC total thickness and joint design. In addition, the paper also presents the predicted performance of these sections using the AASHTO M-E procedure to the field results at the MnROAD R21 PCC-PCC field sections. This discussion highlights challenges and opportunities in M-E design and performance modeling for PCC-PCC projects.

Life Cycle Cost Assessment of Engineered Cementitious Composite (ECC) Precast Pavement in Singapore

Heavier trafficked road network in Singapore leads to some concerns about extended road closure during rigid pavement maintenance/rehabilitation process. A quicker pavement repair method using precast panels is potentially good alternative. This paper focuses on the life cycle cost analysis (LCCA) of a proposed precast concrete pavement (PCP) made of Engineered Cementitious Composite (ECC). A precast slab 5.0m x 3.6m x 0.22m is proposed as an alternative for maintenance and rehabilitation of Singapore rigid pavement. With the help of finite element method, this proposed slab is proved to withstand well construction load and has a lifetime of at least 40 years in Singapore heavy traffic condition. User delay cost due to lane closure, one of the key components of LCCA, is estimated with the help of the state of the art microscopic simulation tool for a selected case study area in Singapore. The LCC results show that initial cost contributes mainly on the total cost of ECC PCP whereas user cost is the most significant component in LCC of cast-in-place concrete pavement. ECC PCP can be a very economical solution in term of LCC for concrete pavement rehabilitation and maintenance depends on construction site locations and traffic volume.

The Development of Structural Design Method of Composite Pavement in Japan

The Development of Structural Design Method of Composite Pavement in Japan

Assessment of JPCP Slab and Joint Movement under Multiple Structural and Environmental Conditions

Jointed plain concrete (JPC) pavement slab curling and joint movement have been shown to play a major role in the cracking performance of conventional JPCP pavements and composite HMA/JPC pavements with a renewable surface. These movements have been assessed as part of the SHRP II R21 Composite Pavement project at the University of California Pavement Research Center ATIRC test track. Environmentally induced slab movement both internal and at slab joints was evaluated under several conditions; two slab thicknesses, doweled and undoweled slabs, and overlayed (two thicknesses) and non-overlayed JPC slabs. The aim of this paper is to summarize findings of slab movement research and how this movement is affected by different variables. With the increasing push toward mechanistic design for concrete pavements, the importance of this information becomes ever greater.

PCC Slab Temperature Gradients as a Function of Structure and Environment Experience from the SHRP II R21 Composite Pavement Test Track

The Strategic Highway Research Program (SHRP) II R21 Composite Pavement Research Project test track constructed at University of California Pavement Research Center (UCPRC) ATIRC facility has yielded significant Portland cement concrete (PCC) temperature data over the nearly past two years of testing. The nine different test sections consisted of combinations of plain and hot mix asphalt (HMA) overlaid jointed plain concrete (JPCP) pavement sections of varying thicknesses. Over 135 thermo couples were placed at five depths and three locations within each slab and have been continuously monitored since test track construction. This paper will identify the changes in PCC slab temperature gradients as a function of PCC slab thickness (178mm and 127mm), HMA overlay thickness (114mm, 64mm, and 0mm) and type (Polymer modified and rubber). Results provide important information about the thermal insulation effect of HMA layer to reduce temperature gradients in PCC layers and provide experimental data for continued evaluation of the effects of reduced temperature gradients on PCC layer cracking performance.

Rolling Resistance Evaluation of Pavements Using Embedded Transducers on a Semi-Trailer Suspension.

Road agency initiatives to reduce traffic-related greenhouse gas emissions are limited by the inability of current experimental methods to assess pavement impacts on vehicle energy consumption. This study addresses this by examining the rolling resistance of a semi-trailer suspension under highway conditions using a precise measurement system with embedded transducers. Data were collected over 174 km of highway, covering various pavement types under mild summer conditions. The analysis revealed notable differences in rolling resistance due to pavement characteristics, with more pronounced variations observed within pavement types than between them. For instance, geographically consecutive jointed rigid pavements showed a 34% variation in rolling resistance, likely correlated with harmonic excitations generated by slab presence, while flexible pavements exhibited up to a 21% variation under similar tire operating conditions. Composite pavements generally performed the worst, possibly due to interactions between bituminous materials and older cement-based foundations. The study also highlighted the critical role of tire operating conditions, showing a decrease of 0.09 kg/tonne in rolling resistance for every 1 °C increase in temperature. This research shows that precisely measuring the rolling resistance (±0.1 kg/tonne) in situ for heavy vehicles is feasible and underscores the need for additional data in diverse weather scenarios to better align laboratory results with on-road realities.

Evaluating the effects of cement asphalt emulsion paste as a grouting material on the fatigue and thermal contraction properties of semi-flexible asphalt composite pavement

Semi-flexible asphalt (SFA) composite pavement is widely used in pavement engineering for its high load-bearing capacity, enhanced durability, impermeability, and resistance to fuel and oil spillage. However, its cracking resistance remains a concern, influenced by repeated vehicle loads and thermal contraction stresses. This study investigates the impact of cement asphalt emulsion paste as a grouting material on SFA’s fatigue and thermal contraction. SFA specimens were grouted with cement paste (CP) containing 20%, 40%, and 60% asphalt emulsion. These specimens were subjected to indirect tensile strength, resilient modulus, and fatigue tests, along with evaluation of thermal contraction behavior using coefficient of thermal contraction. Results indicated that adding asphalt emulsion to CP enhances the flexibility and ductility of SFA but reduces its indirect tensile strength and stiffness modulus. A mathematical model was introduced to predict the resilient modulus based on indirect tensile strength tests. The fatigue analysis demonstrated significant difference in fatigue resistance between SFA and AC16 materials. Incorporating asphalt emulsion also improved SFA’s thermal contraction behavior.

Consistency Testing of Light Weight Deflectometer (LWD) Tool Pusjatan on Composite Road (Case Study of Road Section Soreang New Ring Road, Bandung Regency)

In an era of rapid technological and infrastructural development, the quality of roads is critical to ensuring efficient and safe mobility. Composite roads, which consist of a mixture of different types of construction materials, have become an attractive option in road development in various regions. However, to ensure the success of composite roads, structural consistency and performance must be considered. A Light Weight Deflectometer (LWD) is a device used to measure the instability of road layers by applying surface pressure and measuring the resulting deflection. Although the use of LWD is common in the road construction industry, specific research on LWD consistency testing of composite roads is limited. This study investigates and analyzes the consistency of LWD on composite roads to improve the understanding of its performance. The results of the study on composite pavements conducted at three points with 30 trials showed a coefficient of variance of less than 5%. This result indicates very strong data consistency. Based on these consistency values, the LWD is acceptable, but it needs to be correlated with other tools to determine its validity. If the consistency and correlation meet the requirements or are less than 5%, LWD has a good chance of being used in composite pavements.

Laboratorial investigation on optical, thermal and pavement performance of biomimetic dark reflective coatings with composite structure for pavement cooling

The surface temperature of asphalt pavement in summer can reach up to 70 °C, which leads to poor outdoor thermal comfort and exacerbates the urban heat island effect. Reflective coatings can effectively reduce pavement temperature, but their intrinsic light color with high reflectance causes safety issues such as glaring. In this study, based on the biomimetic idea of chameleon skin structure, composite pavement coatings for cooling and anti-glare were developed. Their optical properties, thermal behavior, adhesion and skid-resistance performances were investigated. The results showed that near-infrared reflectance of black and grey double-layer reflective coatings could reach 0.66 and 0.70, respectively (58 % higher than single-layer coatings). The optimal mass fraction of perylene black in the upper black/grey coating was 2.94 % and 0.74 %, respectively. The double-layer dark coatings could decrease the temperature by 14 °C at the depth of 3 cm below road surface, which achieved cooling effect close to that of white single-layer reflective coatings. The adhesion between coating and stone was generally higher than the cohesion of asphalt, therefore, opening traffic for a period of time or carrying out micro-milling before coating could improve the abrasion resistance. Due to increase in the thickness of the double-layer coating, the microscopic texture of road surface was reduced, thereby reducing skid-resistance. However, it still met the standard requirements. This study intends to provide a reference for developing pavement coatings that balance cooling and visual safety to mitigate the heat island effect, and improve the sustainability of transportation infrastructure.

Mechanical Response and Anti-Reflective Crack Design in New Asphalt Overlays on Existing Asphalt Overlaying Composite Portland Cement Pavement

A detection and evaluation system containing a two-level index of structural integrity and bearing capacity was constructed based on ground-penetrating radar (GPR) and a falling weight deflector (FWD). This system was constructed to solve problems with the detection, evaluation, and structural and material design of asphalt rehabilitation for the prevention and control of asphalt reflection cracks in asphalt overlaying composite Portland cement pavement. Based on the detected data from the GPR and FWD, the reasonable and recommended thickness range of the stress-absorbing layer was determined by the finite element method, and the optimization design of an anti-reflective crack structure is proposed. Furthermore, a material design and engineering application of the stress-absorbing layer was carried out. The results show that an additional 10 cm layer of repaved asphalt can reduce temperature stress by 64.1%, reduce fatigue stress by 29.3% at the cement slab bottom, and extend the service life by 23.1 years. The reasonable thickness of the stress-absorbing layer ranges from 1.6 cm to 2.0 cm, and the recommended structural combination design is a 4 cm SMA-13 upper layer, a 4 cm AC-16 lower layer, and a 2 cm stress-absorbing layer overlaying existing asphalt overlay. The impact toughness of the designed stress-absorbing layer is 1.05 times and 1.44 times that of the other stress-absorbing layer and the AC-16 asphalt mixture, respectively, which have been successfully used for more than 5 years. The recommended design rehabilitation has good engineering application. The uniformity of the stress-absorbing layer can reach 63%, and an anti-reflective crack effect is expected. The results of this study provide design methodology and experience for composite pavement repaving.

Mechanical and instability analysis of asphalt overlay during construction on cement concrete pavement with a large longitudinal slope

ABSTRACT There are insufficient stability problems in overlay construction on tourist highways in mountainous and island areas, especially the pavement with a large longitudinal slope. To elaborate on the instability characteristics of overlay, the construction stage of overlay is divided into loose state, paving stage and initial compaction stage. The moulding methods of specimens during the paving and initial compaction stages were determined. The evolution law of contact-slip characteristics and shear strength of overlay was analysed. The mechanical models of the construction stability of the composite pavements were constructed, instability characterisation methods were proposed and instability characteristics of asphalt overlay during construction were discussed. The results show that the paving state of overlay can be simulated by changing the rolling frequency and the compaction number. There is a risk of slip instability of loose overlay and the longitudinal gradient should be less than 12% to reduce this risk. The critical instability equivalent area ratio and critical slip area proposed can quantitatively describe the shape of the instability body and the instability critical condition. The longitudinal gradient significantly affects the interlaminar instability, but the internal instability mainly depends on the shear strength of asphalt overlay.

Study on Mechanical Properties of Tunnel Flame Retardant Asphalt Pavement Considering the Ablative Effect

With the widespread utilization of composite pavements in highway tunnel projects, the flammability issue of asphalt layers has garnered increasing attention. Previous research has demonstrated that the addition of flame retardants effectively reduces the occurrence of pavement fires. However, there are few studies combining asphalt flame retardant technology with tunnel composite pavement structures. Therefore, this paper, considering the context of actual engineering projects, uses ABAQUS software to analyze and calculate the mechanical response of the tunnel composite pavement, considering the thickness of various asphalt layers under the ablation depth. Key design indexes such as shear stress and lower tensile strain of the asphalt layer, the bottom tensile stress of the cement concrete subgrade, and interlayer shear stress between the asphalt layer and cement concrete subgrade of composite pavements are analyzed using the nonlinear finite element analysis method. The findings enable the determination of the optimal thickness of the composite pavement asphalt layer combination after ablation, thus contributing to enhancing the safety of tunnel pavements.

Study on preparation and properties of antifreeze compound road dust suppressant

Open-pit mine pavement dust dries and breaks easily. As such, a composite pavement dust suppressant with good wettability, moisturizing, coagulation, and antifreezing properties in winter was investigated. Monomer screening and orthogonal experiments were conducted, using evaporation rate, permeability rate, viscosity, and freezing point as evaluation indexes. Consequently, a dust suppressant solution is a mixture of glycerol (GLY), sodium dodecylbenzene sulfonate (SDBS), polyacrylamide (PAM), compound propylene glycol (PG), and potassium acetate (PA). The characteristics of the dust suppressant and its interaction mechanism with road dust were measured and analyzed. The results showed that the optimal ratio of the antifreeze-type composite dust suppressant is 3%GLY, 0.30%SDBS, 0.07% PAM, and 50%PG + 10%PA; the contact angle is 27.62°, which can effectively wet coal dust. Moreover, it easily forms hydrogen bonds with water molecules to release free -OH, which increases the oxygen-containing functional groups in the dust. The maximum viscosity is 25.4 mPa·s, and the hydrophobic groups adsorbed on the surface of the dust can condense and agglomerate the dust to form large particles, and effectively inhibit the occurrence of dust. It freezes at − 34.2 ℃, resists a temperature of − 30 ℃ without freezing, and improves dust suppression efficiency and antifreezing effect in cold areas.