Behavior Of Pavements Research Articles

Pavement Performance Testing of the Newly Constructed Port Reitz and Moi International Airport, Mombasa Access Road

The 6.4 km long Port Reitz/Moi International Access Road project constructed under the design and build procurement method with an inherent risk of poor quality. A post-construction pavement performance evaluation is thus critical to evaluate the extent to which poor quality occurred. The International Roughness Index was measured using the Hawkeye-2000 Digital Laser Profiler with Pavement Logging Video Camera mounted on a calibrated vehicle and data was analysed using the Hawkeye Processing Toolkit Version 5.0.45, while the road roughness Rating was based on the Australian Road Research Board. The video record was analysed in blocks of equal lengths of 100 m for observation and assessment of the surface defects. The level of defects observed graded together with the IRI measurements gave the Present serviceability Index. Pavement Serviceability Index (PSI) was computed in compliance with ASTM 6433. The falling weight deflectometer equipment meeting the requirement of ASTM D4694 - 09 and ASTM D4695 used to measure pavement deflections under known load simulated the behaviour of the as-built pavement under loading, thus giving the pavement strength and the expected pavement life span. The deflection measurements were conducted on all lanes at intervals of approximately 100 m. The raw deflections (rd) data were converted to normalised deflection (nd) to simulate a standard pressure of 707 KPa from a dual-wheel assembly of 10-ton (100-kN). Back calculation of deflection data done using Rosy Design Software determined the layer strength and residual life. The analysis indicates that the road has residual life ranging from 20-6 years compared to 20-year design life consistent with the assumptions by Ogunsanmi (2019) that Design and Build contracts have an inherent risk of poor quality. In addition to incorporation and monitoring of quality through the design, construction and maintenance stages of the project, identification, evaluation, management, and monitoring of the inherent project risks are recommended for Design and Built Contracts in road projects.

Behavior of Flexible Pavements by the Addition of Plastic Waste

Plastic trash production and disposal pose a serious threat to the environment, causing pollution and global warming. The characteristics and strength of plastic trash used in bituminous roads and pavements are improved. Also, it will be beneficial for India as a way to handle plastic waste disposal and numerous road/pavement flaws including ruts, potholes, corrugation, etc. Polythene, polystyrene, and polypropylene are the types of plastic trash that are used. The waste plastic is crushed, covered with gravel, and combined with hot bitumen to create a mixture that is used to build roads and pavement. The pavement will be strengthened and become more durable as a result. Its ground-breaking technology will also work in India's hot, humid climate. Both environmentally sustainable and cost-effective.

Mixed mode I+II fracture parameters and cracking trajectory of heterogeneous multilayer pavement structure containing reflective crack

AbstractUsing aggregate generation and packing algorithm technique coupled with finite element method, a part of reconstructed asphalt pavement structure with five layers and containing a bottom‐up crack was simulated. For more realistic modeling and more accurate analyzing the cracking behavior of pavement, a region surrounding the initial crack (and bottom‐up crack) region and its neighborhood was modeled as a heterogeneous two‐phase (aggregate/mastic) mixture. The results of numerical analyses showed that a significant difference exists between the crack tip fracture parameters (i.e., KI, KII, Keff, T‐stress, and Biaxiality ratio) of the homogenous and heterogeneous models. The heterogeneous simulation (in this case study) leads to approximately 70% reduction in the effective stress intensity factor. Furthermore, it was shown that the fracture trajectory of a simulative reflective cracking (SRC) test conducted on a real bilayer asphalt beam sample can be predicted well by modeling the beam layers as a heterogeneous two‐phase mixture.

Cracking behavior of asphalt pavement with a graded gravel layer based on computational granular mechanics

The reflective cracking is still a critical issue to be solved in the semi-rigid base asphalt pavements. In this study, the discrete element method (DEM) is used to study the reflection cracks of semi-rigid base asphalt pavement with a graded gravel interlayer at the meso level. The generation and development of internal meso cracks in asphalt pavements under vehicle loads were simulated and analyzed. The simulation results show that in the semi-rigid base asphalt pavement, the preset cracks extend from the tip to the surface layer and form reflective cracks in the direction of the oblique loading plate. With the increase in surface thickness, the development trend of the cracks slows down, and the total amount of meso cracks in the pavement decreases. The reflective cracking is reduced in the asphalt pavement with a graded crushed stone base, and the distribution position is relatively discrete. Under the same surface thickness, the number of meso cracks decreases with the thickness of the graded crushed stone base. It indicates that the graded gravel can effectively prevent the development of reflective cracking in asphalt pavements.

Assessment of Flexible Pavement Behavior Under Dynamic Earthquake Loading

Through cushioning the pressures caused from high traffic at prior asphalt, a reinforcing interlayer delays the formation of cracks at bitumen overlay. Experimental effort comprises of laboratory testing that better known behavior of sand as a subgrade and its impact on flexible pavement and base-course layer during earthquakes. The sand layer was 600 mm thick; the base was 200 mm thick, and the asphalt layer was constructed as a panel with dimensions of 300*300*50 mm, representing surface. These layers are put to the test with varied earthquake loading frequencies of 0.5, 1, and 1.5 Hz. Experiments were divided into two sections: one without geogrid and the other with geo-grid at center of -base and among base and sand. It was discovered that the frequency of ground movement causes cracks in the asphalt layer, which increases with shaking frequency and reduces with geogrid installation.

Field and Laboratory Assessment of Different Concrete Paving Materials Thermal Behavior

Impervious pavement surfaces within urban areas present serious environmental problems due to waterlogging, flooding and in particular, the urban heat island (UHI) phenomenon. Another issue that has recently been highlighted is user comfort in pedestrian and cycling areas. Materials that have potential for overcoming these issues include pervious concrete (PC), a new type of construction material with improved drainage properties and thermal properties. In this study, the thermal properties and behavior of commonly used concrete paving materials in urban areas (dense concrete (DC) and concrete pavers (P)) and pervious concrete (PC) paving flags were investigated and compared in terms of their thermal properties. Material behavior under different temperature conditions was investigated within laboratory research measuring thermal conductivity (λ) and the capacity for heating and cooling using infrared lamp. Complementary to laboratory tests, field research was conducted analyzing the surrounding conditions on pavement wearing course behavior under real weather conditions. Dense concrete paving material had the highest thermal conductivity coefficient and heat absorption capacity, and slowest heating and cooling speed, compared with the other paving materials. The results also highlighted the similar thermal properties of PC and P but with potentially improved user comfort for PC due to its draining properties. The base layer and surrounding characteristics had a significant influence on the thermal behavior of pavements, and future research should consider these parameters when addressing the UHI effect for different paving materials.

Transient Acoustic Wave Propagation Problems in Multilayered Pavement Using a Time Discontinuous Galerkin Finite Element Method

This paper presents a modified time discontinuous Galerkin finite element method (MDGFEM) for transient acoustic wave propagation problem of multilayered pavement. The pavement consists of cement concrete pavement, semi-rigid base, and natural soil. The multilayered pavement is modeled as poroelastic mediums and assumed to be water-saturated. The well-known generalized Biot’s theory is employed to describe the wave propagation problem. The present MDGFEM, based on the artificial damping scheme, employs the Hermite (P3) functions and the linear (P1) shape functions to interpolate the global nodal vector and its temporal gradient respectively in a time step. Numerical results of 1D and 2D problems show that the MDGFEM can filter out spurious numerical oscillations before and after waves, boundaries of the hole, and the interface between the layers more effectively for the propagation of acoustic waves in multilayered pavement. Compared with widely used time-continuous methods such as the Newmark method, the method proposed in this paper presents better capabilities in the fluid–structure interaction behavior of multilayer pavements and provides a more accurate solution, which contributes to the further development of non-destructive testing of multilayer pavement structures.

Numerical evaluation of temporal moisture variations in unbound pavements with thin seals

The moisture condition of pavements is a crucial factor determining both their long-term and short-term performance in terms of the strength and stiffness of pavement materials. Unbound pavements with thin seals, the most common type of pavement in Australia and New Zealand, are vulnerable to moisture-related performance loss. Thin seals can be either bituminous or sprayed, the latter type being most common in Australia. This type of pavement can easily exchange moisture between the surrounding environment and the pavement structure, since the seal is relatively permeable. Therefore, changes in climatic factors such as precipitation, atmospheric temperature, evaporation, relative humidity and water table cause temporal moisture variations in pavement layers. These temporal moisture variations also affect performance losses. Hence, a reasonably accurate model is required to predict possible temporal moisture variation during service life in order to advance current Australian pavement design. This paper reports the development of a model to predict moisture conditions in terms of the degree of saturation (Sr), a critical parameter which determines rutting in the pavement layers of unbound pavements with sprayed seals. The model simulates the coupled moisture, vapour and heat flow through pavement layers in the middle section of the pavement, where the edge effects are not significant, employing 1-D numerical modelling. After validation of the model against some field data, the model was employed to analyse both the long-term and short-term hydraulic behaviour of pavements. Environmental factors substantially affect moisture conditions in the base and sub-base layers. Sensitivity analyses were performed to investigate the effects of the hydraulic properties of unbound granular materials (UGMs), the initial condition and the water table depth on long-term Sr and suction variation in unbound pavements with thin seals. It was found that the equilibrium moisture condition does not depend on the initial conditions, and the influence of the water table on subgrade equilibrium is significant only when the water table is within 6 m from the surface.

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.

Moisture influence on structural responses of pavement on expansive soils

Expansive soils are prone to heave and shrinkage due to changes in their natural moisture content. It would be helpful to predict distresses in pavement induced by heave/shrinkage because of long-term moisture variations in the subgrade considering specific environmental conditions. The virtual load method (VLM) has recently been developed to identify virtually distributed load that produces an equivalent deflection of the pavement caused by heave/shrinkage of expansive subgrade soils. In this research, a pavement section of interstate highway 220 (I-220) in Northern Louisiana is considered to implement the VLM and analyze structural behavior due to natural migration of water in unsaturated soil layers. Heave/shrinkage of the soils is computed from the predicted moisture content changes in subgrade using software VADOSE/W. In applying the Winkler’s model in the inverse theory to identify expansive soil-induced stresses in the pavement, a new iteration algorithm is proposed to consider the pavement-soil interaction. Special attention is drawn to the location of absolute maximum shear forces and bending moments in the pavement and their influences on the subgrade deformation. The effects of pavement stiffness and swelling pressure of the subgrade expansive soils are presented to understand the behavior of pavement on expansive soils.

Stiffness identification method for asphalt pavement layers and interfaces using monitoring data from built-in sensors

The bearing capacity of asphalt pavement gradually deteriorates due to repeated traffic loads. As the crucial mechanical index to evaluate the bearing capacity, the evolution of the stiffness of pavement layers and interfaces is necessary to be mastered. This paper proposes a stiffness identification method for the asphalt pavement layers and interfaces by using monitoring data from built-in sensors. First, the analytical solution of multi-layered elastic/viscoelastic medium with imperfect interlayer subjected to moving load is derived, and the theoretical relationship between stiffness and mechanical response can be obtained. The sensor layout is optimized on the basis of the theoretical relationship. Then, the stiffness identification method is developed, and its feasibility is theoretically explored through an example of three-layered elastic/viscoelastic medium. Finally, the proposed stiffness identification method is applied to a realistic asphalt pavement to validate its reliability. Results show that the proposed method can evaluate the stiffness of pavement layers (including elastic and viscoelastic properties) and interfaces. It is noteworthy that the stiffness identification method by using monitoring data from built-in sensors can be performed in real-time under each passing vehicle load, and is helpful to understand the damage behavior of pavement and guide maintenance decision-making.

Application of nanoindentation in asphalt material aging and characterization of actual pavement aging

The aging of asphalt pavements has a serious impact on their road performance and service life., Therefore, it is necessary to characterise the aging behaviour of the actual pavement in service. The aging behaviour of asphalt pavements is difficult to characterise accurately due to the macroscopic nature of the aging indicators obtained by conventional testing methods. Nanoindentation (NI), as an emerging microscopic tool, has been increasingly used in the field of asphalt materials. It is necessary to verify the accuracy of nanoindentation in characterising the aging behaviour of asphalt materials. In this paper, a total of ten samples were selected for testing, corresponding to five states of aging for styrene-butadiene-styrene (SBS) modified and matrix asphalt respectively. The effects of aging on the micro-modulus and viscoelastic properties of the asphalt mastic samples were mainly characterised by means of nanoindentation. This is combined with Dynamic Shear Rheometer(DSR) frequency sweep tests and an attempt to establish a relationship between DSR and NI. Macroscopic characterisation of the aging behaviour of asphalt mastic is achieved. On this basis, the aging behaviour of the actual pavement was characterised using nanoindentation. The results show that the creep compliance of the asphalt mastic back-calculated by the DSR complex shear modulus is in good agreement with the nanoindentation creep compliance results. The accuracy of the nanoindentation characterisation of the aging performance is thus verified. The closer the aging of the actual pavement to the road surface the more pronounced the aging becomes.

An approach to investigate the supplementary inconsistency between time series data for predicting road pavement performance models

ABSTRACT Road agencies commonly face high level complexity of comprehensive pavement maintenance scheduling complications. This could be due to uncertainty of some parameters that substance in the predicting models. Disregarding this uncertainty of such parameters in the road maintenance scheduling problems may lead to imprecise solutions and unreliable road conditions. Frequently time series data that have a hierarchical structure are used for predicting road surface or pavement structure distresses models. However, further realistic and accurate predicted models are those consider supplementary inconsistency between time series data with utilising a predictive approach that imposes knowledge of the input parameters. The purpose of this study is to test this theory by comparing the predictions of models developed using two approaches and their accuracies in utilising the same data. These approaches are the traditional regression model (TRM) with only one level of heterogeneity approach and the hierarchical regression model (HRM) with many levels of heterogeneities approach. A Metro North Western (MNW) urban road network in Victoria (Australia) was considered as the case study for this study investigation where covering the condition of approximately 305 Km of asphalt surfaced pavements. By considering the structure of time series data, the study revealed that more accurate models could predict the pavement behaviour, the deterioration rate, and significantly influenced parameters. In addition, the study highlighted that it is essential to deliberate and process the hierarchical structure of datasets to consider the observed and unobserved heterogeneities in time series data for developing any pavement performance model using either deterministic or probabilistic prediction approaches. Multiple simulation scenarios have been performed for both approaches and the HRM approach shows more reasonable outputs. For predicted deterministic SIR models, road intervention (SIR ≥ 20) are triggered at age 12.5 when using TRM approach and at age 10.5 when using HRM approach. For predicted probabilistic SIR models, the surface condition of a section with SIR weighted average condition values of 2 is triggered at age 17.5 when using TRM approach and at age 10.5 when using HRM approach. This also refers to earlier maintenance scheduling is required when using the later approach because it deals confidentially with each road sections time series data. In that regard, ignoring the uncertainty in time series data of such factors in the road surfacing maintenance scheduling problems may lead to suboptimal solutions and unstable pavement conditions.

SUBSTITUSI LIMBAH PLASTIK “HDPE” SEBAGAI PASIR TERHADAP STABILITAS DAN KELELEHAN BETON ASPAL

In fact, plastic waste after being used becomes trash and makes the environment dirty. There are many ways to make waste useful by recycling, using it for decoration and so on. Much plastic waste is applied to concrete mixtures and pavement mixtures as a substitute for sand. The use of plastic scraps as sand is applied to the pavement layer of Hotmix to increase the value of road stability, flexibility and resistance to fatiq. Plastic wastehdpe will be used on the LASTON AC-WC pavement type. Pavement for class I roads, with pavement criteria referring to the Marshall Method. Sand quality from Lumajang and gravel from Pasuruan. The design with variations of 4.5%, 5%, 5.5%, 6% plastic is replaced by 0%, 5%, 10%, 15% and 20% for sand size Ø 2.36 mm. The parameters that are reviewed are the stability and melting as well as the optimum level of asphalt, then a conclusion is drawn whether they meet the existing hypothesis. This research is continuation of 2017 research. Follow up, will be carried out further research (year 2020), with variations of plastic waste and a review of other mechanical properties in terms of the effect of addition on flexible pavement behavior. Keywords: HDPE plastics, hotmix, laston, stability, flow and KAO

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.

Influence of void content on noise reduction characteristics of different asphalt mixtures using meso-structural analysis

In order to study the noise reduction behavior of asphalt pavements with different void contents, a two-dimensional (2D) level acoustic-structure coupled sound absorption model was constructed. The sound absorption effects of asphalt mixtures with different void ratios were qualitatively analyzed, and the variation law of their absorption coefficients was obtained. At the same time, the influence of void characteristics on noise reduction was analyzed using the meso-structure. The results show that: with the increase of the void ratio of asphalt mixture, the total area of voids in the specimen section increases; the number of voids in the specimen section decreases, while the average equivalent diameter of the voids increases; the fractal dimension of the voids in the section increases; the anti-dispersion ability and noise reduction effect of the asphalt mixture increase. The prediction model of sound absorption coefficient established in the study could predict the sound absorption coefficient of asphalt mixture, which provides a reference for practical application.

Mesoscopic asphalt pavement response analysis using a random aggregate generation-based concurrent multiscale method

Asphalt concrete (AC) layers in asphalt pavements are heterogeneous, but they are generally deemed as homogeneous in engineering practice, which cannot realistically reflect the complex mechanical behavior of asphalt pavement, particularly at finer scales. To resolve this problem, the present study developed a random aggregate generation-based concurrent multiscale method to simulate the mechanical response of asphalt pavement using ABAQUS software. In this method, the mesoscopic structure of AC with a 60 cm length was simulated in the vicinity of tire loading by a random aggregate generation method and embedded into a macroscale pavement model. To account for the effects of pavement structure and environmental factors, three thicknesses of AC layer (10 cm, 15 cm and 20 cm), two types of pavement structures respectively with a cement-treated base (CTB) and a granular base (GB), and two pavement temperatures (5 and 35℃) were adopted in the simulation. The maximum principal stress (MPS) values of fine aggregate matrix (FAM) within the region of interest were sorted and the values at the percentiles of 10%, 20%, …, 90%, 100% were extracted. Besides, the number of the elements with top 1% MPS values were evaluated. Specific statistical analysis was performed on these values to investigate potential damage behavior of the AC layer. The results showed that the MPS at the percentile of 100% is at least three times that at the percentile of 90%, which indicates considerable stress concentrations at the narrow gaps between coarse aggregates. Top-down cracking could be the main cracking pattern for the CTB and GB pavement at low temperatures, and bottom-up cracking may be the main damage mode for the GB pavement at high temperatures. Increasing the thickness of the AC layer may effectively reduce the stress level at top of the AC layer for the CTB pavement at low temperatures.

Review of Runway Pavement Monitoring

Research on runway pavement is very local, meaning that it is strongly influenced by the quality of the material, the quality of implementation in the field and the climate in which the runway is built. In Indonesia, there are not many runway pavement studies. On the other hand, most airports in Indonesia only have one runway. If there is any damage, the airport should be closed. Based on these conditions, it is necessary to research the behaviour of runway pavement. On the other hand, research on runway pavement has been widely carried out in several developed countries. This study examines various existing studies to be used as a methodology in similar research in Indonesia. A review of the runway behaviour research is carried out by identifying the methodology related to using sensors to describe the pavement reaction in accepting the load. These methods were evaluated to assess their possible application in Indonesia. With the obtained results related to the pavement behaviour monitoring method, it is hoped to provide an initial step to identify runway pavement behaviour in Indonesia.

Behaviour of Steel Fibre Reinforced Concrete Pavements on A Single Fibre Level

Concrete is a popular construction material used all around the globe. It is strong in compression and weak in tension. To mitigate this tensile weakness, various reinforcement methods have been used over the years, of these, fibre reinforced concrete (FRC) has gained popularity. Fibres not only improve the tensile strength of the concrete matrix, but also control crack propagation through crack bridging action. The goal of this study is to investigate the long-term behaviour of FRC pavements through conduction of static and fatigue meso-scale level tests using different steel fibres. To achieve this goal, the influence of different fibre geometries and embedment angles on the pull-out behaviour of fibres in FRC was investigated first. This was carried out by examining 60mm Dramix 3D steel and 5D steel fibres at single fibre level. The embedment depth was kept constant at half the fibre length, and the fibre embedment angles were tested at 0°, 15° and 30°. The average maximum pull-out load, Amax, was determined first through static tests then fatigue tests were carried out using 85% of the Amax value on pre-damaged samples. These tests indicated that an increase in fibre embedment angle and number of hooks leads to additional anchorage of the fibre. Fibre pull-out was found to be the dominant fibre failure mechanism for the static single fibre pull-out tests (SFPTs).