Properties Of Pavement Research Articles

Trafik ve Yol Yüzeyi Özelliklerinin Katmanlı Kaplamaların Elastik Davranışına Etkisi

In this paper the overall elastic properties of different layered road pavements have been presented. Using micromechanical theory and the Voigt/Reuss and Hashin-Shtrikman bounds, all the elastic moduli that characterize the stiffness of the composite medium are determined. Following the Spanish Highway Administration classification of the pavement sections, this work presents in detail the effective elastic behavior of any of the cases covered by this document from their composition and the type of traffic. Although numerous experimental and laboratory works have been developed to study the mechanisms that govern different types of pavements, there are few works where they are explicitly determined. That is why the main novelty of this work consists in presenting analytical methods capable of quantifying the performance of the pavement based on the materials that compose it and the traffic loads to which it is subjected. The proposed scheme is implemented in some scenarios by showing the dependence of the different elastic modulus on the volume fraction of the different materials that made the layered composite pavement.

Effects of partial replacement of fine aggregates with crumb rubber on skid resistance and mechanical properties of cement concrete pavements

ABSTRACT This study analyses the skid resistance performance of rigid pavements by partially replacing fine aggregates with crumb rubber percentages in a laboratory setting. To achieve this objective, British pendulum testing is performed to examine the effects of crumb rubber on skid resistance in dry and wet conditions. In addition, mechanical properties such as compressive strength, tensile strength, and slump, are also investigated. Furthermore, a thorough literature review reveals that the relationship of skid resistance with mechanical properties is relatively scant, and a regression model is also missing that can predict skid resistance through these properties. To this end, this study presents empirical correlations, ascertaining a one-to-one relationship between skid resistance with mechanical properties. As different dosages of crumb rubber are used, this study also provides some guidelines on appropriate dosage of crumb rubber, keeping all the performance parameters in view. Findings of this study suggest that skid resistance is significantly enhanced when crumb rubber is added; however, it compromises the strength performance of rigid pavements. Therefore, an appropriate dosage of crumb rubber that balances them is required. Finally, correlations and models are evaluated and discussed in detail.

Performance of Asphalt Concrete Pavement Reinforced with High-Density Polyethylene Plastic Waste

This research investigates the possibility of using high-density polyethylene (HDPE) plastic waste to improve the properties of asphalt concrete pavement. HDPE plastic waste contents of 1, 3, 5, and 7% by aggregate weight were used. HDPE plastic waste=stabilized asphalt concrete pavement (HDPE-ACP) was evaluated by performance testing for stability, indirect tensile strength, resilient modulus (MR), and indirect tensile fatigue (ITF). In addition, microstructure, pavement age, and CO2 emissions savings analyses were conducted. The performance test results of the HDPE-ACP were better than those without HDPE plastic waste. The optimum HDPE plastic waste content was 5%, offering the maximum MR, ITF, and pavement age. Scanning electron microscope images showed that the excessive HDPE plastic waste content of 7% caused a surface rupture of the sample. Improvements in the pavement age of the HDPE-ACP samples were observed compared with the samples with no HDPE plastic waste. The highest pavement age of the HDPE-ACP sample was found at an HDPE plastic waste content of 5% by aggregate weight. The CO2 emissions savings of the sample was 67.85 kg CO2-e/m3 at the optimum HDPE plastic waste content.

A review of steel fiber’s potential use in Hot Mix Asphalt

The purpose of this paper is to overview the potential use of steel fibre in hot mix asphalt, explore the evolution of steel fibre reinforced asphalt concrete (SFRAC), highlights current trends in research and industry and recommend future areas of research. The study focus on the steel fibre industry and steel fibre generated from waste tyres applied in asphalt pavement. This review focuses on the use and performance of these fibres in altering the performance of asphalt pavements in terms of fibre concentration and fibre length, as well as the influence of steel fibre integration in asphalt pavements. According to the literature, the presence of steel fibre in asphalt pavements contributes significantly to the improvement of the properties studied, most noticeably durability. However, there are still few studies that provide conclusions about the relationship between fibre length and steel mixture concentration fibre in influencing the ability, strength, and durability properties of this asphalt concrete pavement. This review elevates awareness of the need of exploring the relationship between fibre length and morphological features in determining the bridging mechanism in asphalt concrete pavement composition.

Aggregate Geometrical Features and Their Influence on the Surface Properties of Asphalt Pavement

Aggregate geometrical features directly affect asphalt pavement surface properties, which further affect the resistance to skidding of a road surface. In order to establish a relationship between the aggregate geometrical features and pavement surface properties, this paper employs an aggregate geometric characteristic evaluation system (AGCES) to describe the form property, angularity, and surface texture of aggregate particles. The geometrical feature parameters of 15 different aggregates were examined by AGCES and the corresponding surface properties of asphalt pavement prepared from the mentioned aggregates were evaluated by sand patch method, 2-Dimension Image-based Texture Analysis Method (2D-ITAM) and Walking Friction Tester (WFT), respectively. The relationships between the pavement surface property parameters and the aggregate geometric characteristic parameters studied were developed by the Levenberg-Marquarat and universal global optimization (LM-UGO). The results show that the calculated geometric characteristic parameters are in agreement with traditional manual measurement results. The pavement surface properties are significantly influenced by aggregate angularity and aggregate surface texture. Regression relationships were established to predict pavement surface properties from the aggregate geometrical features.

Evaluation of the optimum value of lightweight expanded clay aggregate incorporation into the roller-compacted concrete pavement through experimental measurement of mechanical and thermal properties

ABSTRACT The mechanical and thermal properties of roller compacted concrete pavement (RCCP) are considerably influenced by its aggregate. This study determined the optimum value of lightweight expanded clay aggregate (LECA) incorporation into the RCCP through the response surface methodology (RSM) with mechanical and thermal properties evaluation. LECA was replaced as coarse aggregate in different percentages of 25, 50, 75, and 100% (by volume) to develop lightweight and high-insulation capacity RCCP, which could be appropriate for cold climatic zones. Two different mixtures of RCCP with normal-weight aggregate comprising 12% and 15% cement were used as control mixtures. The results showed that incorporating LECA at any percentage in RCCP produced more workable concrete. The substitution of LECA in 25–100% decreased the density of RCCPs containing 12% and 15% cement about 8–24% and 7–23%, respectively, while the water absorption increased around 4–77% and 8–72%. The thermal conductivity of RCCPs decreased by increasing the LECA replacement as coarse aggregate. Also, the LECA replacement increment in RCCPs resulted in lower heat capacity values. Overall, it can be concluded that incorporating LECA in RCCP by around 37% as coarse aggregate would satisfy the standards in terms of fresh, mechanical, and thermal properties.

Changes in Pavement Properties due to Fiber Additives

Changes in Pavement Properties due to Fiber Additives

Impact of Crumb Rubber Concentration and Plastic Coated Aggregates on the Rheological Performance of Modified Bitumen Asphalt

The diminution of natural resource exploration, the retrieval of waste, and the structural modification of polymers by additives are the main contributions to sustainable development. The properties of bitumen are enhanced by the crumb rubber through effective bitumen modification techniques, which have environmental and economic advantages. In this study, plastic waste, plastic-coated aggregate (PCA), and bitumen were blended in order to enhance the engineering properties of the flexible pavement. In order to compute the composition of crumb rubber modified bitumen (CRMB), the adopted materials were subjected to the relevant experiments. PCA was a very effective material when compared to the standard bitumen road pavement. The recycling of waste crumb rubber and plastic was tested by adding them into the hot mix asphalt. The Marshall properties of standard (virgin) bituminous mix, CRMB grade 55, and plastic mix asphalt were studied in detail to explore the solutions for a sustainable environment. The comparison was performed between these two materials with the standard bitumen, which resulted in the CRMB and plastics being found as the most effective additions with robust properties such as low-cost material, high strength, long life usage, and un-harmful to nature. The optimal bitumen content was found to be 6.166%, 6.1%, and 5.833% for standard bitumen, crumb rubber modified bitumen, and plastic-coated aggregate, respectively.

Mechanical Properties of Cold Mix Asphalt (CMA) Mixed with Recycled Asphalt Pavement

From the perspective of sustainability and environmental concerns, the use of cold-mix asphalt (CMA) and recycled asphalt pavement (RAP) is more advantageous than the use of hot mix asphalt (HMA) and warm mix asphalt (WMA). Some researchers used a mixture of CMA and RAP to improve the mechanical properties of pavement and made it more economical. However, only a few studies have focused on using a high content of RAP—particularly 100% RAP—as the virgin aggregate. Therefore, this study aims to analyse cold-mix asphalt (CMA) using 100% recycled asphalt pavement (RAP) instead of virgin aggregate raw materials and to determine the best mixture for the production of environmentally friendly asphalt. It is necessary to investigate the performance of CMA mixed with RAP in terms of the resilient modulus, indirect tensile strength, fatigue and rutting resistance. In this study, the percentage of bitumen emulsions added is 2%, 2.5%, 3%, 3.5%, and 4%, along with 100% RAP material. The results indicate that the fatigue life of the RAP mixture increased by 49.34% with the addition of bitumen emulsion (BE) from 2% to 4%, while the wheel tracking test experienced a decrease in rutting depth along with an increase in BE dose of 4%, which was 9 mm. The mixture containing 4% asphalt emulsion has the best performance. The results suggested that increasing the BE dosage increases the resistance against rutting and fatigue.

Inner dimension detection of open and buried crack in asphalt pavement based on Rayleigh wave method

In this paper, the finite element models of asphalt pavement with open vertical/inclined crack and buried vertical crack were established, and the propagation route and energy distribution of Rayleigh wave near the cracks were researched. Propagation time difference method was put forward to calculate the inner depth and angle of open inclined crack and horizontal position of buried vertical crack. The relationship between normalized depth (ND) and displacement attenuation coefficient (DAC) indexes of open and buried vertical cracks were studied further, and the displacement attenuation method for back calculating the depth of open vertical crack and buried depth and horizontal position of buried crack was established. On-site detection was carried out and the applicability of above methods were researched. The viscoelastic property of asphalt pavement can be eliminated by detecting in low environment temperature, while the attenuation correction method was put forward to reduce the influence of heterogeneous property in on-site detecting. Results show that for slender vertical cracks, the crack width and depth have little influence on DAC-ND curve. When DAC value is 0.1, the wavelength corresponding to the center frequency of Rayleigh wave basically equals to the crack depth. For buried vertical crack, DAC-ND curves obtained by changing buried depth and changing center frequency are basically consistence when DAC value is lower than 0.8. The theoretical feasibility of propagation time difference method was confirmed, but the error amplification is severe. Vertical displacement attenuation method has much higher on-site detection accuracy in crack inner depth detection.

Effect of Steel Wool and Graphite on the Electrical Conductivity and Pavement Properties of Asphalt Mixture

Effect of Steel Wool and Graphite on the Electrical Conductivity and Pavement Properties of Asphalt Mixture

Pavement Properties and Predictive Durability Analysis of Asphalt Mixtures.

The actual lifetimes of many highways are lower than that expected based on the initial pavement design, which brings increasingly prohibitive costs of pavement maintenance and repair. Although many works have been done, the real service lifetimes are still disappointing, and the researchers are also trying their best to increase the projects’ life span. In this study, to comprehensively predict the durability and lifetime of newly designed asphalt mixture structures, an asphalt pavement project consisting of three hot mix asphalt (HMA) mixtures were evaluated. The mixtures were constructed in the pavement project of the Weiwu expressway in Gansu Province. Pavement properties of the asphalt mixtures, rutting and temperature fatigue factors of the dynamic modulus are discussed. The fatigue resistance is supposed to improve on increasing the vehicles’ speed below the freezing point, which may be more suitable for applications in expressways. Meanwhile, the lifetime is measured according to the number of fatigue axle loads calculated, which were corrected between the specimens in the lab and the field core samples. Durability analysis prediction can be obtained based on the fatigue lifetime predictive model accordingly, which can provide more information about the fatigue lifetime and the rehabilitation planning of existing pavements in the future accordingly.

Strength properties of roller compacted concrete pavement (RCCP) under different curing methods

The curing of roller compacted concrete (RCC) pavements requires much more attention and importance than conventional concrete pavements due to its very dry consistency. This research was conducted to determine the effects of different curing types and their application times on mechanical properties of RCC. In addition, the effects on physical properties of RCC were determined in the study, as well. In the experimental study, 4 different curing types as the curing compound, burlap, membrane and water that have been widely used in the market, were applied for 15, 30, and 60 min and immediately after casting. Compressive strength, flexural strength, weight loss, ultrasonic pulse velocity and rebound hammer tests were applied to determine the physical and mechanical properties of RCC specimens. According to the results, the best curing method for compressive and flexural strengths of RCC was determined as water curing, providing approximately 29% and 34% increase in strength compared to uncured mixtures, respectively. In terms of weight loss, the best result was obtained with water curing, increasing the amount of moisture, unlike other curing methods.

Asphalt Mixture with Scrap Tire Rubber and Nylon Fiber from Waste Tires: Laboratory Performance and Preliminary M-E Design Analysis

Scrap tire rubber and nylon fiber are waste materials that could potentially be recycled and used to improve the mechanical properties of asphalt pavement. The objective of this research was to investigate the properties of scrap tire rubber and nylon fiber (R-F) modified warm mix asphalt mixture (WMA). The high-temperature performance was estimated by the Hamburg wheel-tracking testing (HWTT) device. The low-temperature cracking performance was evaluated by the disk-shaped compact tension (DCT) test and the indirect tensile strength (IDT) test. The stress and strain relationship was assessed by the dynamic modulus test at various temperatures and frequencies. The extracted asphalt binder was evaluated by the dynamic shear rheometer (DSR). Pavement distresses were predicted by pavement mechanistic-empirical (M-E) analysis. The test results showed that: (1) The R-F modified WMA had better high-temperature rutting performance. The dynamic modulus of conventional hot mix asphalt mixture (HMA) was 21.8%~103% lower than R-F modified WMA at high temperatures. The wheel passes and stripping point of R-F modified WMA were 2.17 and 5.8 times higher than those of conventional HMA, respectively. Moreover, the R-F modified warm mix asphalt had a higher rutting index than the original asphalt. (2) R-F modified WMA had better cracking resistance at a low temperature. The failure energy of the R-F modified WMA was 24.3% higher than the conventional HMA, and the fracture energy of the R-F modified WMA was 7.7% higher than the conventional HMA. (3) The pavement distress prediction results showed the same trend compared with the laboratory testing performance in that the R-F modified WMA helped to improve the IRI, AC cracking, and rutting performance compared with the conventional HMA. In summary, R-F modified WMA can be applied in pavement construction.

Mechanical and hydraulic compatibility of RAP with geosynthetics used in MSE walls

Mechanical and hydraulic properties of recycled asphalt pavement (RAP) as backfill in mechanically stabilized earth (MSE) walls were evaluated. Woven and nonwoven geotextiles and uniaxial and biaxial geogrids were used as reinforcements. Results of interface direct shear tests showed that the interface friction angle (δ) of RAP-geogrid was higher than that of RAP-geotextile. On average, the δ for RAP-biaxial geogrid was 15% higher than δ for RAP-uniaxial geogrid. For geotextile reinforcement, the δ for RAP-woven geotextile was 20% higher than δ for RAP-nonwoven geotextile. Compaction of RAP at elevated temperatures only slightly affected δ. Pullout capacities of RAP-uniaxial geogrid and RAP-woven geotextile are comparable to those of sand-uniaxial geogrid at different overburden pressures. The compacted RAP reinforced with uniaxial geogrid, however, exhibited significant creep strains at a range of sustained pullout forces that led to failure of the RAP-uniaxial geogrid. Reducing the pullout capacity by 40% is recommended for design to reduce the potential of creep failure. Long-term filtration tests showed that in all cases RAP-geosynthetic systems were able to drain freely and this behavior could be predicted with the existing clogging criteria that have been previously developed for sands and gravels.

Backcasting and forecasting stabilized soil mechanical properties for mechanistic-empirical pavement design

The ability to reliably forecast or backcast mechanical properties of chemically stabilized soils to use as design inputs (e.g. Mechanistic-Empirical Pavement Design Guide) is not readily available. In this paper, seven data sets comprised of 1642 laboratory specimens and 206 field cores were used to calibrate numerical relationships from literature to backcast and forecast mechanical properties of chemically stabilized soil commonly used in Mississippi pavements. When relationships from literature were compared to Mississippi materials, unconfined compressive strength (UCS) was underpredicted; however, when regression parameters were optimized to the data sets, prediction accuracy increased and were on average within 89–99% of actual UCS values. Equations were also shown to provide reasonable estimates of elastic modulus (E) and indirect tensile strength (IDT) when parameters were optimized. Accelerated curing to replicate later life pavement properties in laboratory specimens as well as field cores were compared to relationships from literature to determine their applicability to later life mechanical properties. Literature equations calibrated using laboratory cured specimens predicted mechanical properties within the range of properties reported from cores. Based on this analysis, a set of recommended regression parameters are given that are optimized for common Mississippi materials.

Morphological characteristics of mineral filler and their influence on active adhesion between aggregates and bitumen

Mineral filler has a significant effect on the service performance of asphalt pavement. This study used morphological analysis and active adhesion test to explore the relationship between morphologies of filler and pavement properties. Limestone fillers with different morphologies were prepared by four crush methods for adhesion analysis of aggregates-bitumen interface. The coating ratios were calculated by image analysis and volumetric analysis, used to represent the active adhesion properties. The results show that the roundness of jaw-crushed filler is the smallest, and it can be attributed to the heavier force of jaw crusher than the other three methods. There is no evidence that the crush methods contribute directly to the angularity of filler. Furthermore, a close negative linear relationship was found between the roundness of fillers and adhesion properties. The recommended angularity and roundness of mineral filler should be less than 0.895 and less than 0.515, respectively, to ensure a well-accepted active adhesion between aggregates and bitumen materials.

POLYMERIC MODIFIERS FOR BITUMINOUS BINDERS

Polymer-modified binders (PMB) have found wide application in improving the durability and performance properties of asphalt pavement. To establish the prospects for modifying bituminous binders with polymers, it is necessary to study the basic physical and chemical characteristics of these materials. This paper presents the results of studying the main structural and thermophysical properties of polyethylene terephthalic waste. It was revealed that the presence of functional groups and the corresponding thermal characteristics of the polymer waste open the possibility of using them as modifiers in road construction.

Experimental Investigation on the Mechanical Properties of Polypropylene Hybrid Fiber-Reinforced Roller-Compacted Concrete Pavements

To explore the effect of multi-scale polypropylene fiber (PPF) hybridization on the mechanical properties of roller-compacted concrete (RCC), the early-age (3, 7, 14, 28 days) compressive strength, splitting tensile strength and uniaxial tensile test of RCC reinforced with micro-, macro- and hybrid polypropylene fibers were investigated. Then, the tensile stress–strain curve of polypropylene fiber-reinforced roller-compacted concrete (PFRCC) and the corresponding tensile parameters were obtained. The uniaxial tensile constitutive equation of PFRCC and fiber hybrid effect function was also proposed. Finally, the enhancement mechanism of fiber hybridization on mechanical properties of RCC was analyzed. The results indicated that the strength and toughness of PFRCC improved with the incorporation of PPF, showing obvious plastic failure characteristics of PFRCC. Before curing the concrete for 7 days, micro-PPF played a major role in strengthening RCC, while macro-PPF played a major role in reinforcing concrete after that. Moreover, the tensile strength and toughness indexes of multi-scale PFRCC performed the best, indicating the positive hybridization of three types of PPF. The proposed PFRCC uniaxial tensile constitutive equation and fiber hybrid effect function based on existing researches were also well matched with the experimental results.

A review on the utilization of waste material in asphalt pavements.

Recycling of waste and disposal has become a vital environmental issue that creates serious concern worldwide. The use of waste material in pavement structure is one of the essential initiative for the future towards sustainable environment. This study imparts a review on waste materials such as plastic waste, crumb rubber, glass fibre, steel slag, crushed concrete and Low Density Polyethylene (LDPE) and their use in asphalt pavements. The waste materials act as modifiers and have the capability to upgrade the performance of pavement and provide green technology with eco-friendly environment. Utilization of waste material as an asphalt binder enhanced the engineering properties of asphalt pavements. It may be regarded as a smart strategy for sustainable development as it is cost-effective, economical, efficiency and productivity. Moreover, it approached to minimize the pollution. Further, many researchers have investigated the outcomes of asphalt pavement with waste and observed that it achieved the properties and performance of asphalt mixtures while reducing pavement damage, failure and deformation.