Behavior Of Concrete Pavement Research Articles

In Situ Experimental Analysis and Performance Evaluation of Airport Precast Concrete Pavement System Subjected to Environmental and Moving Airplane Loads.

The behavior of airport precast concrete pavement (APCP) involving new design and construction concepts was experimentally analyzed under environmental and moving airplane loads, and the long-term performance of the APCP was evaluated using fatigue failure analysis. The strain characteristics and curling behavior of the APCP under environmental loads were comprehensively analyzed. The APCP slabs exhibited a pronounced curling phenomenon similar to conventional concrete pavement slabs. The dynamic response of the APCP subjected to impact loads was analyzed by performing heavy weight deflectometer tests. The test results confirmed that the vertical deformation of the APCP was small and within the typical range of vertical deformation of conventional concrete pavement. The dynamic strain response of the APCP under moving airplane loads was then analyzed and the strain variation during day and night times was compared. The strains during the day were found to be significantly larger than those at night under airplane loads because of the curling phenomenon of the APCP slabs. Finally, the long-term performance of the APCP was evaluated using fatigue failure analysis based on the obtained behavior. Even using the most conservative fatigue failure prediction model, the service life of the APCP was ascertained to be more than 30 years. Based on the overall results of this study, it is concluded that the APCP, which is designed to reduce slab thickness by placing reinforcing bars in the slabs via reinforced concrete structural design, exhibits typical behavior of concrete pavements and can be successfully applied to airport pavement rehabilitation.

Numerical simulation of concrete pavement response to temperature gradients

In this paper, we present a finite element simulation method for the behavior of concrete pavement slabs due to the temperature gradient between the top and bottom slab surfaces. The method takes the following characteristics into consideration: three-dimensional behaviors of the system; foundation layers between the pavement slab and the ground; contact interaction between the pavement slab and the foundation; dowel bars at the transverse joint of pavement slabs. To verify the simulation method, we use the experimental measurement results of a previously published study. Then, we apply the simulation method to investigate the behavior of concrete pavement in Phu Huu industrial zone, Thu Duc city.

Numerical simulation of concrete pavement response to temperature gradients

In this paper, we present a finite element simulation method for the behavior of concrete pavement slabs due to the temperature gradient between the top and bottom slab surfaces. The method takes the following characteristics into consideration: three-dimensional behaviors of the system; foundation layers between the pavement slab and the ground; contact interaction between the pavement slab and the foundation; dowel bars at the transverse joint of pavement slabs. To verify the simulation method, we use the experimental measurement results of a previously published study. Then, we apply the simulation method to investigate the behavior of concrete pavement in Phu Huu industrial zone, Thu Duc city.

Evaluation of mechanical properties and structural behaviour of concrete pavements produced with virgin and recycled aggregates: an experimental and numerical study

ABSTRACT Due to the large-scale use of materials in highways, the sustainability of materials has attracted considerable interest for years. In this respect, significant effort has been spent investigating the use of recycled aggregates in concrete pavements. This study has been carried out to fill the gap in the structural performance of recycled aggregate concrete pavements. First, properties of concrete mixtures, produced with virgin, recycled concrete and recycled brick aggregates were experimentally measured, and the results were compared. Then, finite element analyses were done by following a novel methodology that considers the well-known previous works. Results showed that replacement of coarse aggregates with recycled aggregates decreases the mechanical properties in various amounts. Due to the resulting performances, for the same slab thickness, decreased maximum stress, increased deflection and stress ratio values were found for recycled aggregate mixtures. Additionally, higher thicknesses and material requirements were found for recycled aggregate concrete for a similar life. Despite the decreased performance and increased material requirements, the use of recycled aggregates in pavements can still be a viable alternative for countries with limited natural resources and landfills. Therefore, based on the findings, several important discussions and suggestions were presented for future works.

Stress behavior of concrete pavement

Warping stresses and flexural stresses due to variation of thermal gradient and wheel load, respectively, cause cracking of rigid pavement. The distress in the pavement structure can be happened because of warping stresses induced by thermal gradient which causes curling effect due to temperature variation. The wheel load resulted flexural stresses which varies with the position and depends upon contact condition and repetition of load at a specific time interval. In the present study, a comparison of stresses of single layered rigid concrete pavement due to thermal load and wheel load have been done with varying slab thicknesses and modulus of subgrade reactions. The pavement has been modeled and analysed using SAP2000 finite element software. During modeling, the single layered rigid concrete pavements comprising of PQC has been considered without any joints at edges. The PQC slab has been considered with dense liquid foundation i.e. elastic. The self weight of pavement has been excluded in the analysis. It has been found that the interior thermal warping stresses are more sensitive with respect to slab thicknesses than modulus of subgrade reactions. It can also be stated that there is significant impact on stress behavior of the pavement due to combined effect of thermal gradient along with wheel load, especially for positive and negative thermal gradient considerations.

The role of temperature differential and subgrade quality on stress, curling, and deflection behavior of rigid pavement

Abstract To determine performance of rigid pavement, pavement engineers should not only conduct stress, curling, and deflection analysis, but also understand weather conditions and subgrade quality effects on rigid pavement performance well. This study aims to analyze and visualize the mechanical behaviors of rigid pavement in terms of stress, curling, and deflection using the KENPAVE Program under different curling temperature and subgrade quality. Besides, this study also evaluated temperature differential and k-value effects on the stress, curling, and deflection behavior of concrete pavement. The findings revealed that there is a linear correlation between stress and both k-value and curling temperature, with the latter having more significant impact in controlling stress than the former. However, even though curling is not affected by subgrade quality, it significantly depends on the temperature differential since a higher curling temperature produces higher curling behavior. Lastly, a higher temperature differential produces greater deflection, but a higher k-value produces smaller deflection. Nevertheless, deflection behavior has a more significant curve and the position of the highest deflection shifted towards the center of the slab as the curling temperature and subgrade quality increase.

Flexural fatigue behaviour of geogrid reinforced concrete pavements

This paper investigates the effect of geogrid reinforcement on the flexural fatigue behaviour of concrete pavements subjected to cyclic loads. Fifteen-notched concrete beam specimens with the dimensions of 150 × 150 × 550 mm were either unreinforced, reinforced with a single or a double geogrid layer. The geogrid was placed at a depth of 55 mm from the bottom of the specimen. The specimens were tested under cyclic four-point bending loads at a frequency of 7 Hz. Test results illustrate that significant improvement was achieved in the flexural strength and fracture energy of the concrete specimens reinforced with geogrid. Geogrid reinforced concrete specimens exhibited high resistance of crack mouth opening displacements. Reinforcing concrete specimens with a double geogrid layer significantly prolonged the cyclic life of the specimens. An equation for designing concrete pavements subjected to cyclic loads was developed.

Mechanical Behavior of Concrete Pavement considering Void beneath Slabs and Joints LTE

Dowel bars are arranged between two slabs of jointed plain concrete pavements to transfer load between them. The looseness of these dowel bars leads to the decrease of the load transfer efficiency (LTE). Meanwhile, repeated vehicle load can result in void near the joints. In this paper, the behaviors of concrete pavement under the effect of void size and joint stiffness were studied by using ABAQUS software. The FEA model was calibrated for different element parameters based on mesh convergence analysis and validated by comparison with previous studies. The voids beneath slabs were considered in this study, including the loaded slab and unloaded slab. The different effects of base course modulus on the stress of loaded slab are also analysed. It is concluded that the results show that the void size and joint stiffness affect the stress of the loaded plate. Smaller void size and larger joint stiffness will lead to the maximum stress located at the bottom of the loaded slab, and the void size has little effect on the stress of the loaded slab. Otherwise, the larger void size will cause larger stress. The effect of base modulus on stress is similar.

Design and maintenance of airport aprons: recommendations from thermomechanical analysis

In this study, general recommendations for apron design are made by analysing the thermomechanical behaviour of concrete pavements under the effects of aircraft traffic and the environment. This analysis provides designers with data for decision-making on dimensioning to minimise maintenance costs throughout the pavement lifecycle. Pavement thermal differentials and stresses were compared for five Brazilian regions, as represented by the capitals Brasilia, Manaus, Porto Alegre, Sao Paulo, and Teresina, considering the ambient temperature, solar radiation and typically-used coarse aggregate for each region. Parametric analyses for the pavement thermal differentials and stresses were also carried out. Thermal simulations were performed using a numerical model and ANSYS®/Multiphysic (Version 15.0) software, and structural simulations were performed using EverFE (Version 2.23) software. The resulting recommendations for the effective management of airport design provide clear guidance for the definition of metrics for managing apron pavement lifecycles.

Effect of geogrid reinforcement on the flexural behaviour of concrete pavements

This paper presents results of an investigation of the effect of geogrid reinforcement on the flexural behaviour of concrete pavements. Six concrete slab specimens having dimensions of 900 × 900 × 60 mm were prepared and tested. Three of the specimens were unreinforced and taken as references. The other three were reinforced with a triaxial geogrid layer located at 40 mm from the top of the specimen. To support the specimens during the testing, two layers of recycled rubber having a side dimension of 900 mm and a 60 mm total thickness were used. According to the location of the applied load, the specimens were divided into three groups. Each group included two specimens (unreinforced and reinforced specimen). The specimens of the first group were tested by applying a load at the corner of the specimen. For the second group, the specimens were tested by applying a load at the edge of the specimen. The load was applied at the interior of the specimens for the third group. The monotonic test load was applied at a rate of 0.25 mm/min. Study parameters investigated in this study included the ductility, fracture energy and formation of cracks of the specimens. Test results obtained indicate that the flexural performance and cracking resistance of the concrete slab specimens reinforced with the geogrid can be improved.

Influence of geogrid on the drying shrinkage performance of concrete pavements

The aim of this study is to investigate the effect of geogrid on the drying shrinkage behaviour of concrete pavements. For this purpose, two categories of concrete specimens were prepared and tested by drying them within the controlled environmental conditions, for 56days. The first category of specimens included casting and testing nine concrete prism specimens having dimensions of 75×75×280mm. These specimens were divided into three groups. The first group included three unreinforced concrete prism specimens and taken as references. The second group consisted of three concrete prism specimens reinforced with a single biaxial geogrid layer located at 20mm from the top of specimen. The last three specimens (third group) were reinforced with a biaxial geogrid layer placed at 37.5mm from the top of specimen. The second category of specimens, which was suggested in this study to simulate the behaviour of concrete pavements, consisted of preparing and testing six concrete slab specimens. They had dimensions of 30×280×280mm. The specimens of this category were divided into two groups. The first group included three unreinforced concrete slab specimens (References). The second group included three concrete slab specimens reinforced with a single biaxial geogrid layer placed at 15mm from the top of specimen. The changes in the length of the prisms and the changes in the area of the slabs were measured and evaluated. Test results obtained illustrate that, under the controlled drying conditions, the geogrid can slightly reduce the drying shrinkage strains of the concrete pavements.

Mixed mode fracture behavior of concrete pavement containing RAP - 3D finite element analysis

Reclaimed asphalt pavement (RAP) is commonly used to improve the sustainability of asphalt concrete pavement. The main objective of the present work is to study the effect of RAP content on the mixed mode fracture behavior of concrete pavement numerically. An extended finite-element model was adopted to simulate crack growth under mixed mode loading. Semi-circular bending (SCB) specimen was used with three different crack geometries, namely inclined crack at the middle with different inclination angles (SCB-1) and vertical crack subjected to asymmetric three point bending. The effect of specimen geometry on the mode I fracture toughness (KIC) has been studied. The relationships between both RAP content and specimen geometry and mixed mode fracture toughness have been correlated. It is found that, the present 3D finite element model is a good candidate to predict the fracture behavior of concrete pavement containing RAP. To examine the reliability of each type of specimen geometry for predicting KIC, the maximum undamaged defect size (dmax) concept has been applied. It is found that, KIC predicted from the classical SCB (SCB-1) is reliable compared the values predicted from the other specimen geometries. Where the ratio of dmax to the maximum aggregate size (dmax/MAZ) ranged between unity and 2 in the case of SCB-1, it ranged between 5 and 14 in the other cases. Furthermore, the relationship between the present numerical values of KIC predicted from SCB-1 specimen and the flexural strength measured experimentally by Hossiney et al. (2010) is strongly correlated.

Evaluation of Behavior of Jointed Concrete Pavement Considering Temperature Condition in a Tunnel by Finite Element Method

PURPOSES: The behavior of a concrete pavement in a tunnel was investigated, based on temperature data obtained from the field and FEM analysis. METHODS: The concrete pavement in a tunnel was evaluated via two methods. First, temperature data was collected in air and inside the concrete pavement both outside and inside the tunnel. Second, FEM analysis was used to evaluate the stress condition associated with the slab thickness, joint spacing, dowel, and rock foundation, based on temperature data from the field. RESULTS : Temperature monitoring revealed that the temperature change in the tunnel was lower and more stable than that outside the tunnel. Furthermore, the temperature difference between the top and bottom of the slab was lower inside the tunnel than outside. FEM analysis showed that, in many cases, the stress in the concrete pavement in the tunnel was lower than that outside the tunnel. CONCLUSIONS : Temperature monitoring and the behavior of the concrete pavement in the tunnel revealed that, from an environmental point of view, the condition in the tunnel is advantageous to that outside the tunnel. The behavior in the tunnel was significantly less extreme, and therefore the concrete pavement in the tunnel could be designed more economically, than that outside the tunnel.

Optimal design for concrete pavement situated above box culvert: experimental and numerical study

This study examined the pavement distress data obtained from the field as well as the effects of the soil cover depth, joint position and reinforced slab length on the behaviour of concrete pavement using the finite element method. An ultimate strength model with a similarity of 1/2 was designed and constructed. Finite element analysis incorporating an implicit direct numerical integration scheme was conducted to obtain an optimal design for the pavement structure above a box culvert. An accelerated pavement test was conducted for validation, in which a realistic traffic load was imposed on the pavement model constructed in the laboratory. The strain histories were measured at each section and compared with those of numerical analysis. The optimal joint position and reinforced slab length that can minimise the damage to the pavement structure above a box culvert were also determined.

Three-Dimensional Finite Element Analysis of Doweled Joints in Concrete Pavements

Concrete pavements are usually selected by pavement engineers for roads subjected to heavy traffic loading and feature high maintenance and construction costs. As such, the structural behaviour of concrete pavements with doweled joints is evaluated herein using Finite Element Method. The pavement system is modelled using three-dimensional brick elements and five loading cases are applied to replicate realistic vehicular loadings approaching and leaving the joint. The structural behaviour of the pavement at the doweled joint is investigated for: (1) pavement with and without voids, and (2) different dowel bar spacing. The amount of load transfer was obtained from the shear force in the beam elements that simulate dowels. Results show that the voids underneath the joint causes an increase in the vertical displacement of the concrete slab and vertical stress at concrete/dowel bar interface which may result in crushing of the concrete and dowel loosening. Wider dowel spacings result in increased shear forces and the size of the region containing engaged dowels does not change significantly with dowel spacing, only effecting the distribution of shear forces. The study shows that the dowel bars perform effectively as a load transfer device in the concrete pavement system even under severe conditions.

박스형 암거와 보강슬래브에 의한 줄눈 콘크리트 포장의 거동

PURPOSES : Hollows are easily made, and bearing capacity can be lowered near underground structures because sublayers of pavement settle for a long time due to difficult compaction at the position. If loadings are applied in this condition, distresses may occur in pavement and, as the result, its lifespan can decrease due to the stress larger than that expected in design phase. Although reinforced slab is installed on side of box culvert to minimize the distresses, length of the reinforced slab is fixed as 6m in Korea without any theoretical consideration. The purpose of this paper is investigating the behavior of concrete pavement according to the cover depth of the box culvert ad the length of the reinforced slab. METHODS : The distresses of concrete pavement slabs were investigated and cover depth was surveyed at position where the box culverts were located in expressways. The concrete pavements including the box culverts were modeled by finite element method and their behaviors according to the soil cover depth were analyzed. Wheel loading was applied after considering self weight of the pavement and temperature gradient of the concrete pavement slab at Yeojoo, Gyeonggi where a test road was located. After installing pavement joint at various positions, behavior of the pavement was analyzed by changing the soil cover depth and length of the reinforced slab. RESULTS : As the result, the tensile stress developed in the pavement slab according to the joint position, cover depth, and reinforced slab length was figured out. CONCLUSIONS : More reasonable and economic design of the concrete pavement including the box culvert is expected by the research results.

Effects of Construction Conditions on Built-In Temperature Gradient of Concrete Pavement: A Numerical Study

The built-in temperature gradient of concrete pavement formed during hardening period caused by various construction conditions will permanently exist in the pavement, which will have significant influence on the service behavior of concrete pavement. However, it’s still not involved in the current Specifications of Cement Concrete Pavement Design for Highway in China. In this paper, a user subroutine based on the ABAQUS code was developed to simulate the effects of weather condition, paving time, curing method, raw material temperature on built-in temperature gradient. The analyses indicate that these factors always produce obvious positive gradient in the slab and the influences of the first three aspects are obvious and the paving temperature of mixture has limited effect on the increasing of the final set temperature gradient. Furthermore, built-in temperature gradient is proposed as an index to evaluate the influences of various construction factors and optimize construction measures.

Temperature Gradient and Curling Stresses in Concrete Pavement with and without Open-Graded Friction Course

Curling stresses of concrete pavement can be very damaging, and reducing the temperature swings would be very beneficial. This study includes a field instrumentation effort with pavement temperature sensors to quantify the thermal behavior of concrete pavement with and without an open-graded asphalt rubber friction course. The study shows a nonlinear temperature profile across slab thickness, with a large change in temperature between day and night at the top of the concrete slab, and little change at the bottom of the slab. Adding an open-graded friction course over the concrete pavement reduces the temperature fluctuation between day and night as a result of the aeration effect, which is increased by traffic. A three-dimensional (3D) finite-element analysis with a nonlinear temperature gradient shows that adding the friction course reduces the curling stresses in the summer. Furthermore, since traffic increases the aeration effect, sections without traffic show lower effect of friction course on reducin...

Influence of vehicular positions and thermal effects on structural behaviour of concrete pavement

Structural response of concrete pavements is influenced by the position of the axle loads and if critical load positions are not considered in concrete pavement analysis, the design may be inadequate and lead to early failure of the pavement. Whilst there has been a great deal of research conducted on concrete pavement performance and deterioration under vehicular loads and environmental forces, there is a lack of adequate information on effects of vehicular load positions on pavement responses. Critical positions of different axle groups in uncurled and curled jointed concrete pavement with different configurations were determined in the current study. Results indicate that structural performance of concrete pavements is significantly affected by boundary conditions between concrete slab and base. Corner loading was found to be critical in bonded concrete pavement. Corner loading is also critical when a separation occurs between unbonded concrete slab and base. Furthermore, the benefits offered by unbonded boundary condition cease at a certain differential temperature. Hence, a particular care needs to be considered in project constructed in extremes of heat or cold. In presence of high differential temperature together with axle loading, joint faulting in unreinforced concrete pavements is affected by concrete slab thickness.

Concrete pavement slab under blast loads

The main objective of this paper is the analysis of the behaviour of concrete pavements subjected to blast loads produced by the detonation of high explosive charges above them. This subject is of particular interest in terrorist attacks in cities, since important conclusions about the location and magnitude of the explosive charge can be drawn from simple observation of the pavement damage. Experimental results for a concrete slab lying on the ground and subjected to blast loads are presented. The slab was lying on the ground and was tested with different amounts of explosive suspended in air over it. Numerical results are compared with those obtained with a simplified plastic limit analysis and those obtained with two types of numerical simulations performed with two different codes. Some conclusions about the effect of the blast load on the concrete slab and about different tools available for the analysis of this type of problem are stated in the paper.