Concrete Pavement Structure Research Articles

Full-scale field test of early-age behaviour of partially continuous reinforced concrete pavement

To address the damage characteristics and deficiencies of the existing continuously reinforced concrete pavement (CRCP), which are the high construction cost and irregular crack distribution patterns, a concrete pavement structure called partially continuous reinforced concrete pavement (PCRCP) is proposed. In this paper, the early-age (28 days, without traffic) behaviour of PCRCP subjected to environmental loading is investigated. To this end, full-scale field tests were carried out in Xiangjiagou Tunnel, Shanxi Province, China. Testing results showed that the PCRCP test section with the partial continuous reinforcement length of 100 cm and active crack spacing of 5 m can provide better early-age performance and lower initial construction cost in this study. The PCRCP test section with the active crack control method has a uniform crack distribution pattern with narrow width compared to the CRCP test section. The results of this study would provide data support and reference for the rational design of PCRCP.

Reducing Energy Demand in Concrete Pavements by the Use of Blended Cements

This research explores strategies to minimise energy consumption and enhance environmental sustainability in road construction. Focusing on concrete pavement structures, the study evaluates the impact of substituting Portland cement with environmentally friendly alternatives such as fly ash and blast furnace slag. A comprehensive model is employed to analyse the energy demands of different pavement types, considering various cement replacements over their lifetime, from the initial extraction of materials to the conclusion of construction. Results indicate an energy saving potential of 8.63% by substituting 10% of Portland cement with fly ash, while an impressive reduction of 58.63% in cement production energy is achieved by replacing Portland cement with 80% blast furnace slag. The study underscores the significant role of cement variations in mitigating energy consumption, emphasizes the potential of blast furnace slag as a sustainable alternative as well as highlights the significance of alternative cement types in reducing energy consumption in concrete pavement construction, aligning with environmental sustainability goals and offering insights for more eco-friendly infrastructure development.

Effects of Macro Fibers on Crack Opening Reduction in Fiber Reinforced Concrete Overlays.

Macro fibers have been extensively used in the construction of various concrete structures, including bridges, dams, tunnels, industrial floors, and pavements. However, their effectiveness in reducing crack opening widths in concrete pavements has not been fully explored. This study aims to delineate the role of fibers by identifying the optimal types and volumes for effectively controlling cracks in concrete pavement structures, particularly in thin overlays. The research investigates how different fiber types, such as synthetic and steel, and their respective volumes can mitigate crack propagation in concrete overlays. Additionally, it evaluates the performance of fiber-reinforced concrete overlays compared to conventional dowel bar systems in terms of crack width reduction and overall pavement durability. The findings aim to provide specific design criteria for incorporating macro fibers in concrete overlays to enhance structural integrity and longevity.

Pavement structures for extra heavy loads at multimodal traffic terminals

The subject matter of this study entails a brief overview of some of the methods for dimensioning pavement structures at container terminals, primarily located within ports and within freight rail stations, designed to withstand the loads imposed by very heavy vehicles (Heavy Duty Pavements). Within this study, an examination is provided on the methods for dimensioning cement concrete pavement structures for non-standard axle loads, as well as the results obtained through the application of these methods.

Visual Detection of Road Cracks for Autonomous Vehicles Based on Deep Learning.

Detecting road cracks is essential for inspecting and assessing the integrity of concrete pavement structures. Traditional image-based methods often require complex preprocessing to extract crack features, making them challenging when dealing with noisy concrete surfaces in diverse real-world scenarios, such as autonomous vehicle road detection. This study introduces an image-based crack detection approach that combines a Random Forest machine learning classifier with a deep convolutional neural network (CNN) to address these challenges. Three state-of-the-art models, namely MobileNet, InceptionV3, and Xception, were employed and trained using a dataset of 30,000 images to build an effective CNN. A systematic comparison of validation accuracy across various base learning rates identified a base learning rate of 0.001 as optimal, achieving a maximum validation accuracy of 99.97%. This optimal learning rate was then applied in the subsequent testing phase. The robustness and flexibility of the trained models were evaluated using 6,000 test photos, each with a resolution of 224 × 224 pixels, which were not part of the training or validation sets. The outstanding results, boasting a remarkable 99.95% accuracy, 99.95% precision, 99.94% recall, and a matching 99.94% F1 Score, unequivocally affirm the efficacy of the proposed technique in precisely identifying road fractures in photographs taken on real concrete surfaces.

A novel approach for the mechanical response of cement concrete pavement structure considering the interlaminar interface shear slip effect

The traditional theoretical analysis method has many problems such as cumbersome calculation and low efficiency, and there is a relative lack of research on the simplified mechanical model in the field of road engineering. To further improve and enrich the existing theoretical analysis of pavement structures, and to realize the rapid analysis of the mechanical behavior of cement concrete pavement structure (CCPS), based on the state-space method, a new approach is proposed to analyze the mechanical response of the CCPS, taking the interlaminar interface shear slip effect into account. The CCPS is considered as a two-layered Euler beam. A state equation is established to investigate the static responses of the CCPS with explicit consideration of the interlaminar interface shear slip effect under the action of an arbitrary vertical load and is solved by matrix theory. Subsequently, the present solution is validated by the literature published and the numerical simulation. In addition, the effects of the interlayer shear stiffness, thickness of the base course, stiffness of Winkler foundation springs, and bending stiffness on the deformations of the CCPS, and the influence of external loads on the interlayer distributing shear forces are revealed. It is indicated that the interlaminar interface shear slip effect exhibits a significant influence on the deflection and bending deformation of the CCPS. Moreover, the proposed solution can not only be employed conveniently for the consideration of any interlaminar contact conditions and vertical load distributions but also be reduced to obtain the responses of a single-layer mechanical model.

Characterizing fatigue damage behaviors of concrete beam specimens in varying amplitude load

In this paper, the random and nonlinear mechanical characteristics of the composition distribution of concrete in each phase are investigated to solve the difficulty of fatigue damage test of concrete beam specimens under variable amplitude loading. A three-dimensional (3D) concrete composite random aggregate meso-model of concrete beam specimens is built with Digimat as a composite modeling tool. Subsequently, the bending-tensile strength and fatigue life of the model under four-point bending loading is analyzed and calculated using Abaqus finite element analysis model based on the concrete elastic-plastic damage criterion. The mechanical behaviors of concrete materials under static load failure, multistage fatigue loading, and random fatigue loading are studied. Finally, compared with the test results, the following conclusions are obtained. The random aggregate model and elastoplastic damage mechanics model of concrete composite constructed by concrete in Abaqus and Digimat can better describe the geometric and distribution characteristics of composite structure and aggregate in concrete beams and the mechanical behavior of fatigue and static load failure. The difference is 4.08 % with the experimental results, which verifies the validity and reliability of the numerical simulation model, and the fatigue life of concrete beams under random loading Sra and Srb is 1622 and 164 times, respectively. The research results have certain guiding significance and reference value for accurate calculation of bending and tensile strength of concrete beams under specified raw material and mix ratio and prediction of fatigue damage cracking in airport cement concrete pavement structure.

Mechanical behaviour of concrete pavement widening

When the old cement concrete pavement continues to be used for widening, compared with the new construction, there are some prominent challenges, such as non-uniform support of the new and old subgrades, additional settlement of the old subgrade caused by the widened new subgrade, and gap between the tie-bar added to the old pavement slab and the concrete. To reveal the difference in the mechanical behaviour of the widened and new cement concrete pavement structures under vehicle load, a finite element model of the cement concrete pavement widening is established with the use of KENSLABS computer programme. The influence weight of non-uniform support of old and new subgrades, additional settlement of new subgrade to old subgrade and gap between tie-bar added within old pavement slab and concrete on deflection in cement concrete pavement widening is clarified, and the control measures for the deflection are proposed.

Improvement strategies of cement concrete pavement structure on part-fill and part-cut subgrade

ABSTRACT The unavoidable transverse non-uniformity of settlement and moduli for part-fill and part-cut subgrade may have some critical impact on concrete pavement structures, hence, some structural optimisations of pavement based on the working conditions of subgrade are essential. In this study, on account of the practical working conditions of part-fill and part-cut subgrade, a finite element model of concrete pavement structure on part-fill and part-cut subgrade developed previously was conducted to analyse the effects of slab thickness, slab concrete modulus of rupture, tie bar diameter and tie bar spacing. Furthermore, improvement methods and strategies were analysed and proposed for the four parameters respectively with fatigue cracking design life under loading as the target and maximum stress at the bottom of slab as the criterion. The results verified the feasibility of incorporating non-uniformity of modulus and settlement into the design phase of concrete pavements on part-fill and part-cut subgrade. Additionally, concrete pavement parameter optimisation priority should be given to concrete modulus of rupture, slab thickness, followed by tie bar diameter and spacing. It can provide a useful reference for designing concrete pavement structures on part-fill and part-cut subgrade.

Deicing performance of cement pavement concrete mixed with chlorine salt antifreeze material

This study explores a cost-effective and efficient method for snow melting and deicing using a concrete pavement structure with pre-mixed chloride-salt antifreeze material. The mixed design method for road cement concrete with chloride-type antifreeze material is investigated by encapsulating NaCl and CaCl2 in organic resin capsules. The snow melting and deicing efficacy of cement concrete with chloride antifreeze material is evaluated through an automatic tracking measurement system. The results indicate that NaCl-type antifreeze material is more effective in reducing the freezing point of concrete surface solution than CaCl2-type antifreeze material. A composite antifreeze material (4% NaCl + 1% CaCl2) provides the strongest snow melting and deicing ability. An outward migration and diffusion model of chloride ion in cement concrete with antifreeze material is established to calculate the chloride ion diffusion coefficient, surface chloride ion content, and decay rate of concrete. The effective age of snow melting and deicing is analyzed using this model.

Structural optimization and performance evaluation of precast concrete pavement with composite base layer

This paper proposed a precast concrete pavement structure with the composite base layer comprised of the concrete beam and the filling low strength materials (B-PCP). The mechanical responses of the B-PCP induced by moving wheel loads coupled with temperature loads were analysed using the finite element method. Then the optimal geometry of the concrete beam was determined based on the sensitivity analysis, considering the tensile stress of both the slab and the beam of the base layer, the slab curling, and the faulting. Furthermore, the performance evaluation of the B-PCP was conducted by the numerical analysis and the scale experiment testing, respectively. The results showed that the optical concrete beam was 0.8 ∼ 1.0 m wide and 0.2 ∼ 0.3 m thick. The numerical results showed that the optimal B-PCP structure had a good fatigue resistance performance, and the corresponding slab curling decreased by almost 40% compared with that of the traditional precast concrete pavement. Meanwhile, the scale experiment testing verified that the optimal B-PCP structure exhibited an excellent ability to resist the deformation. The results also showed that the bearing capacity of the optimal B-PCP structure was larger than 350kN, indicating a good bearing capacity.

Concrete pavement with microwave heating enhancement functional layer for efficient de-icing: Design and case study

As traditional de-icing methods, such as applying road de-icing salt and mechanical methods, are inefficient and cause environmental pollution, a concrete pavement structure with a microwave heating enhancement functional layer (MHEFL) is proposed in this study. First, microwave heating (MH) test of magnetite with different particle sizes was performed and the mechanical strength of microwave-absorbing concrete (MAC) was tested to determine the limestone replacement particle size. Then, MH tests were performed to investigate the influence of ice covering on the heating ability of MAC and to study the temperature distribution at different depths. The results indicated that, when magnetite was used to replace limestone, magnetite particle sizes in the range of 16.0–19.0 mm improved the mechanical strength and MH rate. Water producted by ice degraded the heating performance of MAC; therefore, the critical de-icing period for eliminating this influence was determined to be 60–120 s. The optimal thickness of the functional layer was determined to be 3 cm. Finally, the pavement for microwave de-icing test was paved; field results indicated that the de-icing rate of the MHEFL pavement was increased by 60%, and the microwave leakage intensity of 2.710 W/cm2 satisfied the safety requirements. The results of this study indicated that the application of an MHEFL for road de-icing is effective and environment friendly as it dispenses with the need for using the de-icing salt.

An Inversion Algorithm for the Dynamic Modulus of Concrete Pavement Structures Based on a Convolutional Neural Network

Based on the spectral element method (SEM) and a convolutional neural network (CNN), an inversion algorithm for the dynamic modulus of concrete pavement structures is proposed in this paper. In order to evaluate the service performance of pavement structures more systematically and accurately via the existing testing techniques using a falling weight deflectometer (FWD), it is necessary to obtain accurate dynamic modulus parameters of the structures. In this work, an inversion algorithm for predicting the dynamic modulus is established by using a CNN which is trained with the dynamic response samples of a multi-layered concrete pavement structure obtained through SEM. The gradient descent method is used to adjust the weight parameters in the network layer by layer in reverse. As a result, the accuracy of the CNN can be improved via iterative training. With the proposed algorithm, more accurate results of the dynamic modulus of pavement structures are obtained. The accuracy and numerical stability of the proposed algorithm are verified by several numerical examples. The dynamic modulus and thickness of concrete pavement structure layers can be accurately predicted by the CNN trained with a certain number of training samples based on the displacement curve of the deflection basin from the falling weight deflectometer. The proposed method can provide a reliable testing tool for the FWD technique of pavement structures.

Prediction and environmental appraisal of traffic noise intensity by auto-regressive integrated moving average technique

Auto-regressive integrated moving average (ARIMA) assessment of traffic noise was conducted on different routes in Port Harcourt, Nigerian metropolis. This was achieved by measuring the traffic noise on the various routes of asphalt flexible and concrete rigid pavement structures with a meter for sound measurement with regards to the volume of traffic, vehicle movement rate, and location away from the midpoint of the highway. The average peak noise of traffic was obtained at selected distances of 5m, 10m, and 15m from the middle of the highway, for locations 1, 2, 3 and their mean average case 4 (Trunk A flexible pavement), for location 5 (Trunk C flexible pavement), and for location 6 (Trunk C rigid pavement). The results of the investigation show that the values of traffic noise at locations 1 to 3 and their mean average case 4 had the same range of high noise intensity as Trunk A flexible pavement and classified as heavy-traveled roads; while conversely, location 5 (Trunk C) had the same range of lower noise intensity, which was classified as light-traveled road. For Trunk C, the noise generated in a flexible pavement was less than that from a rigid pavement. Generally, the R2 values of the ARIMA models showed very good performance along selected travel routes. For case-specific distances, the ARIMA models performed very efficiently and had very high R2 values.

An analysis of the mechanical properties of precast steel fiber reinforced concrete pavement joints

As a result of the advantages of the steel fiber reinforced concrete pavement structure, which includes high strength, high stiffness, and high stability, a large number of steel fiber concrete pavements will be used for highway construction in China. As a result, numerous cracks develop, which significantly reduces the life of the road; therefore, the study of the jointing problem is vital. As concrete research on the influence of the load transfer capacity and service life of prefabricated steel fiber reinforced concrete joints on the structural design and use function of the whole and pavement panels, the paper proposes two joint forms, tongue-and-groove and overlap. Using experiments and software, the stress and reflection of prefabricated road panels of the two joint forms are analyzed for different axial loads. The analysis reveals that the maximum tensile stress, shear stress, and deflection of the precast panels of both joint forms increase linearly as the axle load of the vehicle increases, while the service life decreases relatively. The load transfer capacity is independent of the axle load magnitude, and the load transfer capacity difference between the two types of joints is minimal and excellent.

Cement concrete pavement responses considering part-fill and part-cut subgrade characteristics

ABSTRACT Part-fill and part-cut subgrade is widely distributed in mountainous highway engineering, and their resilient modulus and settlement exhibit significant transversal non-uniformity, which has an important effect on the performance of cement concrete pavement structure. A numerical model, focusing on a two-slab system on part-fill and part-cut subgrade, was developed by the finite element computer programme taking into account non-uniform settlement (a large range of partial contact) simultaneously with non-uniform modulus. Cement concrete pavement structure responses, including the load stress, vertical displacement and joint load transfer capacity were comprehensively investigated considering the two part-fill and part-cut subgrade characteristics. The results indicate that the non-uniform settlement has a higher impact on the concrete pavement structure than that of the non-uniform modulus in more cases. When the resilient modulus of the fill part is close to that of the cut part, the additional stress (relative stress increment) caused by the combination of the two factors is approximately the sum of the additional stress caused by the two factors individually.

Interlayer Shear Characteristics of Bridge Deck Pavement through Experimental and Numerical Analysis.

In order to study the interlayer shear behavior of bridge deck pavement, a numerical simulation was conducted to analyze the influence of varying interfacial conditions on shear stress at the bottom of pavement layers under the moving loading effect. Moreover, the shear strength of the different adhesive and waterproof adhesive materials was evaluated by conducting laboratory tests. The results showed that improving the bonding condition at the upper interlayer led to the reduction of the shear stress at the bottom of the pavement layers. With the increase of the friction coefficient of the upper interface to the full bonding state, the resulting shear stress at the bottom of the upper layer declined to the lowest value, which was about 35% of that of the full slip state. When the lower interlayer was in the full slip or partial bonding state, the resulting shear stress at the bottom of the lower layer decreased linearly with the increase of the friction coefficient of the upper interlayer. Moreover, once the contact state of the upper interlayer reached the full bonding state, the resulting shear stress at the bottom of the lower layer reached the minimum, which is about 88% of that of the full slip state. To improve the integrity and shear resistance of the bridge deck pavement structure, interlayer bonding should be strengthened. In this regard, the resin emulsified asphalt was determined as an appropriate adhesive material to be applied at the upper and lower interlayers. In addition, interlayer shear bond strength, regardless of the type of adhesive materials, was decreased with increasing temperature. Finally, statistical analysis results indicated that all factors of structure type, type of adhesive material, and temperature statistically have a significant effect on interlayer bond strength. The findings of this study could provide a theoretical basis and experimental support for improving the interlayer design and construction in the concrete bridge deck pavement structure.

Experimental investigation on the interfacial shear bond performance of non-water reacting polymer and concrete

Non-water reacting polymer is widely used in the construction and trenchless rehabilitation of underground spaces and concrete pavement structures. The damage mechanism of interface between polymer and concrete is crucial, but is yet still unclear. In this study, Shear tests of the polymer-concrete composite specimens with different surface roughnesses and polymer densities were conducted, and the fitting model of the bond strength with the polymer density and surface roughness were derived. The failure characteristics of the composite specimens were studied by acoustic emission technology and the microstructure features of polymer in the edge, middle, and interface positions were analyzed by scanning electron microscope. The interface bond strength increased significantly with the increased of polymer density when the polymer density was larger than 0.15 g/cm3. For polymer-concrete composite specimens with different polymer densities and surface roughnesses, the failure modes of the specimens are quite different and the failure modes can be divided into polymer matrix failure, interface failure and concrete matrix failure. AE activity exists throughout the failure process of polymer-concrete specimen and is most significant in the final failure stage. The accumulative AE ringing counts and energy sharply increase indicated that the specimen is about to fail. The polymer cell structure at the interface and edge positions can be divided into three areas: high-density cell structure, belt-shaped continuous area and low-density cell structure area, and the interface polymer cell structures were affected by the polymer density and the interface roughness. The work provides a better understanding of the influencing factors, failure modes and damage mechanism of the bond performance between non-water reacting polymer and concrete.

Influence of Crack Spacing/Layer Thickness Value on Reflection Crack Propagation Mechanism Under Low Temperatures

The damage of asphalt concrete pavement (AC pavement) structure caused by reflection crack is an urgent problem in many areas of China, especially in cold regions of China, so it is necessary to study how to reduce the reflective cracking and prevent the AC pavement structures cracking. The acoustic emission (AE) information is fetched in this paper to study the AE characteristics of pavement structures and the crack propagation law inside the system. On the above basis, cracks with crack spacing/layer thickness values of 1.25, 2.5, 3.75, and 5 were prefabricated in the foundation course by the numerical simulation method. The models with different foundation course crack spacing were calculated by Realistic Failure Process Analysis finite element software. The influence of varying crack spacing on the propagation mechanism of reflective cracks in the foundation course structure was studied. The results show that the AC pavement structure has prominent AE characteristics. The faster the cooling rate is, the more serious the damage to the AC pavement surface is. In addition, with the increase of crack spacing/layer thickness value, the stress level between cracks increases continuously. Most of the stress will make the cracks expand toward the foundation course structure, and only a tiny part of stress is used to form reflective cracks. In practical engineering, it is suggested to increase the crack resistance of foundation course materials and preset some small spacing cracks in the large spacing cracks in the foundation course.

Analysis of the Coupling Effect of Thermal and Traffic Loads on Cement Concrete Pavement with Voids Repaired with Polymer Grout

Under the repeated action of traffic and thermal loads, a cement concrete pavement slab may partially lose contact with its base course, and voids may develop underneath the slab. Such distress will greatly impact the pavement performance. To fill the voids and restore the base support to the slab, the technology of polymer grouting has been increasingly adopted in recent years due to its advantages of quick application and high efficiency. There is, however, a lack of research on the mechanistic responses and performance of such a repaired rigid pavement under coupled influences of thermal and traffic loads. Existing literature has mainly focused on normal cement concrete pavement structures (i.e., without polymer grouted voids). This study intends to fill the research gap by investigating the time-domain characteristics of thermal stress response of a cement concrete pavement with underlying voids filled with polymer grout, along with design traffic loads. The finite element method was adopted with a 3-dimensional nonlinear temperature field within the pavement. A program module was developed in the Abaqus FEA software environment for temperature effect analysis. It was found that under the coupling action of thermal and traffic loads, thermal stress had a greater influence on the critical slab stress at the slab corner than those at other slab locations. Through the comparative analysis before and after polymer grouting repair, the critical tensile stress at the slab corner under the vehicle and thermal loads can be effectively reduced. The polymer performance is stable after three years.