Continuously Reinforced Concrete Pavement Research Articles

Bambusa balcooa bamboo-reinforced concrete beams: experimental and FEM investigation for energy-efficient pavement construction.

This study explores the viability of using Bambusa bambos, sourced from Madhya Pradesh, India, as a reinforcement material in continuously reinforced concrete pavement (CRCP) construction, aiming to assess its potential as a sustainable alternative to traditional steel reinforcement. The research encompasses a comprehensive evaluation of physical and mechanical properties, including tensile, compressive, and bending strengths, and a detailed microstructural analysis using scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) of Bambusa bambos. The study involved finite element analyses that modeled bamboo-reinforced concrete (BRC) beams, exploring the impact of horizontal and vertical placements of bamboo strips on flexural behavior under bending loads. The analysis aided in observing compressive and tensile stresses generated in concrete and bamboo, with specific FEA results indicating that beams with vertically aligned bamboo strips in both the compression (compressive stress of 16.90MPa for beam B1) and tension zones (tensile stress of 7.22MPa for beam B1) withstand flexural stresses effectively. Additionally, the multi-criteria decision-making approach using the TOPSIS method to rank different beam designs. Key findings obtained from FEA indicate that the vertical alignment of bamboo strips in both the compression and tension zones of the beams is optimally effective in handling flexural stresses.

Comparative analysis of load transfer efficiency in plain and continuously reinforced concrete pavements

In this article, the continuously reinforced concrete pavement (CRCP) was presented, highlighting the recognized international success of the structure due to its high durability and low need for maintenance. The constructive details of four experimental sections of short extension show that the absence of shrinkage joints facilitates the execution process of this pavement and makes it less susceptible to errors typical of simple concrete pavement (SCP) designs. Tests with Falling Weight Deflectometer in the cracks allowed the calculation of load transfer between cracks (LTE). The results indicate a very high LTE for all cracks. Comparatively, LTE data from an experimental SCP located near the CRCP were analyzed. It was found that even without transfer bars and in winter, when the cracks are more open, the CRCP presents LTE values greater than 90%.

Dynamic behaviours of continuously reinforced concrete pavement on a layered transversely isotropic saturated subgrade under moving loads

AbstractThis paper aims to investigate the dynamic behaviour of continuously reinforced concrete pavement (CRCP) on a multi‐layered transversely isotropic saturated subgrade subjected to a moving load. The stress‐strain relationship of the CRCP is obtained based on classic lamination theory. Then, the differential governing equations of the pavement are established by D'Alembert's principle. Combining the Fourier series expansion and integral transform technique, the displacements of the CRCP in the wavenumber domain are derived. By introducing pavement‐subgrade interface conditions, the solution to the pavement‐subgrade system is acquired with the use of the extended precise integration method (PIM). The solution in the spatial domain is further obtained by the numerical inverse transform. The presented method and the corresponding program are verified. Finally, parametric studies are conducted to determine the effects of the reinforcement ratio and position, the load velocity and the subgrade stiffness.

Laboratory investigation on early-age shrinkage cracking behavior of partially continuous reinforced concrete pavement

As a form of durable pavement structure commonly used in the world, continuously reinforced concrete pavement (CRCP) has prominent problems caused by irregular crack distribution in the early stage. According to the characteristics of the discontinuous distribution of CRCP longitudinal steel bar stress and active crack control method, a rigid pavement structure called partially continuous reinforced concrete pavement (PCRCP) was proposed to simultaneously optimize the crack distribution pattern and reduce the longitudinal steel ratio in this paper. Since early-age shrinkage cracking behavior is a key factor affecting its durability. This paper purposes to assess the early-age shrinkage cracking behavior of PCRCP by comparing different reinforcement methods in laboratory experiments. Research results indicated that the early-age shrinkage behavior of PCRCP is basically the same as that of CRCP. The early-age shrinkage behavior of PCRCP is significantly improved than the advanced reinforced concrete pavement (ARCP). Restricted by the boundary and longitudinal steel bars system, the concrete beam produces a top-down nonlinear temperature and humidity gradient, resulting in various degrees of shrinkage deformation at different depths inside. The active crack control method can control the early-age concrete slab to form uniform crack pattern with straight lines or fewer bending cracks, which improves early-age cracking behavior significantly. This paper is to further deepen and develop the theory of CRCP early-age cracking behavior and provide basic theory support for the subsequent experimental section studies of PCRCP.

Reinforcement design optimisation for continuously reinforced concrete pavement: one-mat vs. two-mat

ABSTRACT Over the years, thicknesses of continuously reinforced concrete pavement (CRCP) increased to accommodate rising truck traffic. With a fixed percentage of longitudinal reinforcement relative to the concrete cross-sectional area, thicker slabs necessitate more reinforcement and reduced bar spacing, potentially hindering consolidation. To address this issue, two-mat steel design was implemented in Texas for pavements with thickness of 330 mm (13 in.) or larger. Performance evaluations of thick CRCPs revealed that horizontal cracking developed at the depth of reinforcement where one-mat steel was placed, while no horizontal cracking was observed where two-mat steel was used. Pavement responses with one-mat and two-mat reinforcements with different depths were analysed by three-dimensional modelling with a finite element analysis (FEA) programme for the wide range of environmental loadings. Maximum concrete vertical tensile stresses around longitudinal reinforcement at transverse crack area are a good indicator of horizontal cracking potential; those stresses were evaluated, along with concrete stresses at top of the slab, which are responsible for top-down transverse cracking. The results show that the two-mat design causes higher concrete stresses at the top of the concrete slab and lower concrete stresses around the longitudinal reinforcement, leading to increased transverse cracks and a reduction in horizontal cracking potential.

Debonding failure of continuously reinforced bonded concrete overlay at early ages

ABSTRACT The structural behaviour and debonding mechanism of continuously reinforced bonded concrete overlay (CRBCO) on deteriorated concrete pavements subjected to environmental loadings are evaluated analytically and experimentally. It is shown that the temperature gradient in concrete significantly affects the debonding potential at the interface between CRBCO and existing continuously reinforced concrete pavements (CRCPs) and that the normal stress at the interface is the dominant cause of debonding failure. The results of factorial experiment show that the debonding potential can be reduced by decreasing the elastic modulus, coefficient of thermal expansion (CTE) and thickness of CRBCO, and by increasing the interfacial bond strength.

Evaluation and Improvement of the Current CRCP Pavement Design Method

Continuously reinforced concrete pavement (CRCP) is a representative type of concrete pavement constructed with continuous steel bars without intermediate transverse expansions. With reference to pavement conditions, CRCP is an exceptional type of concrete pavement according to the Highway Pavement Condition Index (HPCI) and International Roughness Index (IRI). The two main design methods for CRCP are AASHTO 86/93 and the Mechanistic-Empirical Pavement Design Guide (MEPDG). Because of limitations of the AASHTO 86/93 design method, the MEPDG method is more reliable. While incorporating the interactions among geometrics, pavement structure layers, material properties, subgrade, traffic, and environmental conditions, and the prediction values according to the MEPDG method, it matched the measured results of crack spacing and crack width. The MEPDG punchout, crack width and spacing, and load transfer efficiency (LTE) models were evaluated, and results were compared with the test sections in three European countries consisting of different construction details, which were investigated and recorded between 2019 and 2021. In this sense, a calculation tool was developed to consider the influence of different parameters in design process. In addition, sensitivity analyses were executed for the development of punchout, considering various input parameters. The track surveying and the evaluation of the results indicated that the design process can be improved with consideration of some criteria such as crack formation time or adjustment of the correlation between crack width and crack spacing. Due to the very important function of erosion and resulting pumping in the deterioration of CRCP, it is advisable to include the influence of the base layer and the influence of different shoulder type and heavy traffic volume or effect of deflection in the calculations.

Predicting transverse crack properties in continuously reinforced concrete pavement

Transverse crack properties (crack spacing and crack width) are important indicators of service life performance of continuously reinforced concrete pavements (CRCP). Crack properties are related to concrete material properties, reinforcement ratio, interface friction between both the concrete-base layer and concrete-steel, and the local climatic conditions. An improved analytical model with a bilinear concrete-base friction relationship is presented to predict crack spacing and crack width from concrete drying shrinkage and temperature contraction. The proposed 1D model was validated with test section data from a continuously reinforced concrete beam resting on asphalt base layer, which contained two reinforcement ratios, a standard paving concrete, and a lightweight aggregate concrete. A sensitivity study of model determined the bond stiffness coefficient between the concrete and reinforcement, bar spacing and diameter, elastic modulus of the reinforcement, and concrete drying shrinkage had the greatest impact on both crack spacing and crack width.

Field investigation of early-age behaviour of continuously reinforced concrete pavement with semi-rigid base

ABSTRACT This study investigates the early-age behaviour of continuously reinforced concrete pavement (CRCP) on the semi-rigid base, including structural behaviour during transverse crack propagation and curling behaviour both in the longitudinal and transverse direction. Field experiments are operated on a CRCP section in Wuhan, China. Vibrating wire strain gauges were installed at mid-slab and slab edge in the longitudinal and transverse direction for concrete strain and temperature measurement. Testing results showed the complexity of early-age behaviour of CRCP on semi-rigid base and curing with wet burlap sheets. An early-age transverse crack may originate from the bottom of the concrete slab due to the water absorption of the dry semi-rigid base. The development of a transverse crack took several cooling cycles. Curling behaviour in the longitudinal direction did not correspond to the temperature gradient after transverse crack occurrence. Typical curling motion in the transverse direction was found in the mid-slab rather than the slab edge. The findings of this study would lead to a better understanding of the early-age structure behaviour of CRCP on semi-rigid base and its impact on later road performance.

Application of Graphene-Based Nanomaterials as a Reinforcement to Concrete Pavements

Nanomaterials are considered to be one of the game-changing features in the modern world and nanotechnology is mostly reputed as the next-generation industrial revolution due to the extraordinary characteristics possessed by them at their very small scale. Graphene and graphene oxide are two main nanoscale materials that have seen a drastic increase in their use in cement-based composites due to exemptional enhancements in terms of strength and durability that can be imparted to compromise the inherent flaws of concrete and other cementitious composites. The main aim of this study was to investigate the effect of graphene and graphene oxide on improving the performance of cement-based composites and, particularly, of continuously reinforced concrete pavements (CRCP), which is one of the emerging trends in the transport sector due to various advantages they bring in over conventional flexible pavements and unreinforced concrete pavements. Fresh, hardened and durability properties of concrete with graphene-based nanomaterials were studied and the past experimental data were used to predict statistical interferences between different parameters attributed to concrete. According to the review, graphene-based nanomaterials seem to be promising to overcome the various CRCP distresses. Simultaneously, the possibilities and hinderances of using graphene and graphene oxide in cement-based composites as a reinforcement are discussed. Finally, the potential of using graphene in continuously reinforced concrete pavements is explored.

Peridynamic modeling of early-age cracking behaviour in continuously reinforced concrete pavement

ABSTRACT Continuously reinforced concrete pavement (CRCP) is frequently used for heavy traffic. In CRCP, early-age cracking can be caused by environmental loading freely and randomly, but only certain crack patterns can affect its long-term performance and induce distress such as punchouts. In this work, we introduce a peridynamic model that includes the time dependency of the environmental loading and material properties to investigate the early-age behaviour of CRCP and predict its cracking. The simulation results match those from field observations in terms of crack patterns, average transverse crack spacing, and crack width. We conduct parametric analyses and find the effects changing environmental conditions and design parameters have on crack patterns. An investigation of active crack control demonstrates that the model can be used to determine optimal pre-notch spacing, for specific environmental conditions, that leads to desirable crack patterns.

Construction of a Composite Pavement (Asphalt over Concrete) in Virginia

The U.S. Strategic Highway Research Program 2 (SHRP2) identified composite pavement as a “renewal solution” and the Virginia Department of Transportation (VDOT) received implementation funding to demonstrate its feasibility. In 2017, this funding was applied to support major rehabilitation of two westbound lanes of US 60 in Henrico County, Virginia, a project that essentially replaced 1.1 mi of deteriorated concrete pavement with a new composite system consisting of continuously reinforced concrete pavement (CRCP) overlaid with stone matrix asphalt (SMA). This paper documents the design and construction of this new composite pavement. It also includes results from through-the-thickness temperature monitoring and a summary of performance for the first 4 years after opening to traffic. Close oversight by researchers provided a review of challenges and associated lessons learned from the design and construction process. Current VDOT specifications and standards were sufficient for successful construction. The asphalt overlay appeared to reduce the temperature gradient within the CRCP and to moderate daily temperature swings. This insulating effect of asphalt is expected to lower curling and associated stresses in the concrete pavement, which may permit reduced concrete thickness requirements in designs and also enable longer service life. The cracks in CRCP were tight and were not expected to reflect through the SMA. Moreover, the SMA mixture was tested to be crack and rut resistant. Therefore, a crack- and rut-free long service life for this composite pavement is expected. A recent visual survey by researchers found no observable distresses after 4 years under traffic.

Evaluation of Design Procedure and Performance of Continuously Reinforced Concrete Pavement According to AASHTO Design Methods.

The Guide for Design of Pavement Structures (AASHTO 86/93) and Mechanistic Empirical Pavement Design Guide (MEPDG) are two common methods to design continuously reinforced concrete pavement (CRCP) published by the American Association of State Highway and Transportation Officials (AASHTO) in the USA. The AASHTO 86/93 is based on empirical equations to assess the performance of highway pavements under moving loads with known magnitude and frequency derived from experiments on AASHTO road tests. The MEPDG is a pavement design method based on engineering mechanics and numerical models for analysis. It functions by incorporating additional attributes such as environment, material properties, and vehicle axle load to predict pavement performance and degradation at the selected reliability level over the intended performance period. In order to evaluate the CRCP design procedure and performance, crack width (CW) and crack spacing (CS) from five examined test tracks in Europe with different climate condition, base layer, geometry, and materials were collected in this paper and compared with predicted distresses as well as CW and CS from AASHTO 86/93 and MEPDG design methods. The results show that the interactions between geometrics, material properties, traffic, and environmental conditions in the MEPDG method are more pronounced than in the AASHTO 86/93 and the prediction of CS and CW based on MEPDG matched closely with the recorded data from sections.

Continuously Reinforced Concrete Pavement Cracking Patterns and Properties with Internal Curing and Active Cracking

Transverse cracking in continuously reinforced concrete pavement (CRCP) develops over time and may exhibit irregular patterns such as cluster cracks, Y-shaped cracks, and divided cracks. These undesirable cracking patterns can increase the probability of premature spalling and punchouts. Ideally, a uniform transverse cracking pattern with small crack widths leads to favorable long-term performance in CRCP. An experimental field project was constructed with internally cured concrete and active cracking to control crack initiation timing, patterns, and properties. Prewetted fine lightweight aggregate was used for internal curing, and edge notches of 2 in. depth and 2 ft length every 4 ft along the test section were sawcut for active crack control. The three experimental CRCP sections in Illinois were monitored for crack spacing, crack width, and formation of undesirable cracks over a 4-year period. Internally cured concrete significantly reduced the undesirable crack patterns relative to the control section. Internally cured concrete coupled with active crack concrete produced superior crack patterns and properties, that is, uniform crack spacing of 3.6 ft without cluster cracks, 0.2 mm surface crack width, and only a small number of undesirable cracks. Active crack control produced a higher number of transverse cracks near the terminal joint (last 150 ft) compared with the control section. Moisture and temperature management with active crack control during construction of the CRCP provided a desirable crack pattern and properties that should increase the overall service life of a pavement.

Maximum Likelihood Estimation of Parameters for Advanced Continuously Reinforced Concrete Pavement (CRCP) Punchout Calibration Model

Pavement performance prediction is the essential part of the pavement design, which is very important for highway agencies for the purpose of budget allocating. This study introduces a model of local calibration for punchout, which is the major structural distress of continuously reinforced concrete pavement (CRCP). It is assumed that the number of equivalent single axle loads’ (ESALs) leads to punchout follows a Weibull distribution. The parameters of Weibull distribution were estimated by maximum likelihood estimation (MLE). Additionally, an approach of estimating the initial value of the parameters was also presented before applying the Newton method for solving the likelihood equations. The regression result was found to fit the performance-monitoring data from LTPP very well. The proposed calibration model is capable of describing the punchout and can be employed to predict the failure rate and reliability of CRCP in the pavement design and the arrangement of rehabilitation activities.

Layer Composition of Continuously Reinforced Concrete Pavement Optimized Using a Regression Analysis Method

A procedure for determining the optimized composition of layer properties for a continuously reinforced concrete pavement (CRCP) system was constructed using field tests, finite element (FE) analysis, and regression analysis methods. The field support characteristics of a rigid pavement system were investigated using a falling weight deflectometer (FWD), dynamic cone penetrometer (DCP), and a static plate load test. The subgrade layer exhibited a more uniform condition than the aggregate base, and the modulus of the subgrade reaction of the aggregate base and subgrade combination (effective k-value) was improved by about 1.5 times by introducing a 2 inch (50.8 mm) asphalt stabilized base (ASB) layer. Thereafter, FE support models describing the actual field conditions were studied. The effects of the thickness of the stabilized base layer, the elastic modulus of the stabilized base material, and the effective k-value on the composite k-value of the support system were identified using a regression analysis method, and the results showed that the variables had a similar effect when determining the composite k-value. Afterward, a procedure for selecting the layer properties for producing a suitable composite k-value was constructed, and we identified that the maximum stress in the concrete slab was induced at different levels, even with identical composite k-values. Lastly, regression relationships were derived to estimate the maximum stress in the concrete slab by considering both the support layer properties and the concrete slab. Subsequently, an algorithm for selecting an optimized layer composition of the CRCP structure was construction considering the economical aspect.

Evaluating the Early-Age Crack Induction in Advanced Reinforced Concrete Pavement Using Partial Surface Saw-Cuts

The technological innovation of continuously reinforced concrete pavement (CRCP) that contains a significantly reduced amount of reinforcement and the same fundamental behavior as CRCP is called advanced reinforced concrete pavement (ARCP). This new concept of a rigid pavement structure is developed to eliminate unnecessary continuous longitudinal steel bars of CRCP by using partial length steel bars at predetermined crack locations. In Belgium, partial surface saw-cuts are used as the most effective crack induction method to eliminate the randomness in early-age crack patterns by inducing cracks at the predetermined locations of CRCP. The reinforcement layout of ARCP is designed based on the distribution of steel stress in continuous longitudinal steel bar in CRCP and the effectiveness of partial surface saw-cuts as a crack induction method. The 3D finite element (FE) model is developed to evaluate the behavior of ARCP with partial surface saw-cuts. The early-age crack characteristics in terms of crack initiation and crack propagation obtained from the FE simulation are validated with the field observations of cracking characteristics of the CRCP sections in Belgium. The finding indicates that there is fundamentally no difference in the steel stress distribution in the partial length steel bar of ARCP and continuous steel bar of CRCP. Moreover, ARCP exhibits the same cracking characteristics as CRCP even with a significantly reduced amount of continuous reinforcement.

Tensile Performance of SHCC Road-Bridge Link Slabs in Fully Jointless Bridges

Deformation of the main girder is absorbed by a continuously reinforced concrete pavement (CRCP) with microcracks in fully jointless bridges. The conventional fully jointless bridge has been challenged by durability and reliability issues because the CRCP is vulnerable to crack and hard to control the crack width when it suffers temperature variation. In this paper, a new type of fully jointless bridge with the road-bridge link slabs using strain-hardening cementitious composite (SHCC) material is investigated. First, an experiment was carried out to study the material properties of SHCC material for a preliminary assessment of road-bridge link slab performance using this material. Results found that SHCC is adequate for link slabs for its high tensile ductility and fine cracks development. Second, an SHCC slab model tensile test was carried out to study the absorptive capacity and the crack distribution of the SHCC slab. Results verified the high absorptive deformation capacity of the SHCC slabs. When the longitudinal deformation reaches 10 mm, the surface cracks in the SHCC slab are fine and dense, the crack width is kept in 80 μm, and the internal force is small. Third, by comparing the tensile test results with a conventional CRCP slab with same length, it is found that an SHCC slab has higher absorption capacity, better crack distribution, and smaller internal force than a CRCP slab. Finally, through ABAQUS finite element modelling, the stress performance of SHCC road-bridge link slabs is simulated using a trilinear constitutive model. The calculated results are consistent with the experimental results.

Rebar corrosion of a continuously reinforced concrete pavement being used for more than 30 years on the Jungbu Expressway, Korea

We evaluated rebar corrosions in a continuously reinforced concrete pavement (CRCP) in use for more than 30 years through field surveys. Ultrasonic shear-wave tomography analysis and concrete coring indicated that horizontal cracks occurred within approximately 300 mm from the transverse cracks in both sound and deteriorated parts. Longitudinal rebar corrosion was only observed within approximately 150 mm from the transverse cracks. X-ray computed tomography image analysis revealed that the loss of cross-sectional area in the rebar due to corrosion, which was the largest within 70 mm from the transverse cracks, was generally 15–22%, whereas the loss at a distance of greater than 70 mm from the transverse cracks was largely decreased to approximately ≤ 4%. The chloride content in concrete at the rebar depth did not exceed the critical value, except in areas adjacent to transverse cracks. Our results suggest that the effect of rebar corrosion on long-term CRCP deterioration is insignificant.

Research on the technique of reinforced concrete pavement with large spacing joints

ABSTRACT Currently, punchout distress in continuously reinforced concrete pavement (CRCP) frequently occurs even if the reinforcement design strictly adheres to specifications. In this study, a new concept called reinforced concrete pavement with large spacing joints (RCPS) is proposed, and a new isolation layer is applied to the RCPS on the basis of laboratory results. Finally, a test road is constructed to verify the rationality of the structure of RCPS. The results show that reducing the friction and bonding strength between the isolation layer and pavement is the key to implement RCPS. The design method of RCPS not only retains the good bearing capacity of CRCP but also overcomes the problem in which the dry shrinkage and temperature stresses of CRCP cannot be released, which leads to punchouts.