Mechanical Performance Of Asphalt Mixtures Research Articles

Experimental investigation and evaluation of the compactness and moisture damage of asphalt mixes incorporating dune and river sand

Road construction is mainly based on the use of raw materials that must be in compliance with the standards, thus ensuring the quality and durability of the road. The use of dune sand and river sand in road geotechnics is an interesting subject. Both types of sand can be used in road construction and maintenance for a variety of applications. Dune sand is often appreciated for its uniform grain size and drainage capacity, while river sand can offer good mechanical strength. The majority of common bituminous mixes contain fillers made of quarry sand, whose amounts are difficult to regulate because of the variety of rock deposits and the conditions under which they are manufactured. In this paper, the compactness and moisture damage of asphalt mixes with two sand types, River sand (RS) with (0/4) size was sourced from the valley in the province of Medea (Algeria) and Dune Sand (DS) with a particle size of (0/0.5) was obtained from a dune in the Algerian province of Djelfa, were examined. Furthermore, a 100% replacement rate by weight of Crushed Sand (CS) with (0/3) mm size was used (quarry sand). The investigation employed a comprehensive approach, utilizing Marshall and gyratory shear compaction tests to assess compactness, while moisture damage was evaluated through rigorous water resistance testing and compressive strength methodology. The results of the study reveal a notable disparity in the mechanical performance of asphalt mixtures containing dune and river sand, showcasing diminished compactness and heightened susceptibility to moisture-induced damage when compared to alternative mix formulations. These findings underscore the critical role of sand type selection in asphalt mix design, emphasizing the need for careful consideration to optimize performance and durability.

The Consequences of Dimension Reduction for Open Graded Friction Course (OGFC) Asphalt Mixtures: Morphological Characteristics and Finite Element Model (FEM) Simulation

Asphalt mixtures exhibit complex mechanical behaviors due to their multiphase internal structures. To provide better characterizations of asphalt pavements under various forms of potential distress, a two-dimensional (2D) finite element simulation based on images of asphalt mixtures can be used to increase computational efficiency and reduce labor consumption. Nonetheless, using a representative image to eliminate the influence of dimension reduction from three dimensions to two dimensions is of great significance for attaining a reliable simulation result. Therefore, in this study, we investigated the consequence of dimension reduction for open-graded asphalt mixtures (denoted as OGFC-16), including a comprehensive characterization of these 2D models in terms of their morphologies and the similarities between them. This study aimed to reveal the variation in a 2D finite element simulation when applied to open-graded asphalt mixtures. Structural compositions, gradations, the aspect ratios of aggregates, and aggregate orientations were counted and calculated. In addition, the cosine similarity and structural similarity index measure (SSIM) were also calculated. Consequently, we performed a statistical analysis on the aforementioned indicators to quantitatively identify the discrepancy in the 2D images caused by dimension reduction. The results demonstrate that this 2D simulation might not be sufficient for representing the realistic mechanical performance of asphalt mixtures due to the remarkable variations in the image morphologies in different 2D images. However, the basic rules of stress behavior within structures can be accurately simulated. A compensative methodology for conducting a 2D simulation of open-graded asphalt mixtures should be based on a morphological characterization, considering structural compositions and the structural similarity index measure.

Influence of recycled rice husk ash filler on the mechanical performance of asphalt mixtures: A mortar scale analysis

Using industrial or agro-industrial wastes as alternative raw materials to manufacture asphalt mixtures brings advantages such as conserving natural resources and reducing environmental problems. Among these wastes are (a) rice husk ash (RHA) and (b) recycled rice husk ash (RRHA), obtained by controlled and uncontrolled combustion of rice husks, respectively. Previous studies have shown a high potential for RHA to be used as a filler in asphalt mixtures. However, the existing literature on RRHA usage and its corresponding applications is limited. Based on this background, the main objective of this study was to investigate the effects of RRHA when used as a filler on the mechanical properties of asphalt mortars/mixtures. For this purpose, the behavior of asphalt mortars (a combination of asphalt binder blended with sand and RRHA filler) was evaluated using the dynamic mechanical analyzer (DMA) with the three-point bending test. The test results suggest that RRHA reduces the workability and ductility of asphalt mortars. Furthermore, while RRHA indicated superior moisture-damage tolerance, brittle RRHA asphalt mortars with reduced fatigue strength were also produced. The optimum RRHA dosage for optimizing the asphalt mortar's mechanical properties/performance should not exceed 13.5% on the total weight of the mortar for the materials and test conditions. As a supplement to this study's findings, further research involving the combination of RRHA with conventional fillers and different materials (i.e., asphalt binders and aggregate types) is suggested to quantitatively assess the scaled-up mechanical performance of the asphalt mortars and their subsequent validation in asphalt mixtures.

Correlation between Deformation and Volumetric Characteristics in the Aging Condition of Hot Mix Asphalt

The surface layer of pavement structures tends to experience a decrease in performance as its service life approaches. Generally, this decrease in performance is caused by aggregate degradation and aging of the asphalt binder, which can be caused by traffic loads or weather exposure. The mechanical performance of asphalt mixtures is due to the effects of aggregate degradation, which was simulated by reducing the coarse aggregate fraction and adding medium and fine aggregate fractions. The asphalt aging process simulates changes in binder characteristics by adding RAP binder to Pen 60/70 asphalt. Hot mix asphalt (HMA) with new material (SA-1) as a control for degradation simulation (SA-2, SA-3 and SA-4). Marshall test results show that aggregate degradation significantly causes a decrease in voids in the mixture (VIM) and voids in mineral aggregate (VMA), as well as an increase in voids filled with asphalt (VFA). WTM test results show that HMA degradation causes an increase in rutting depth, which increases the deformation rate and decreases dynamic stability. The correlation results between WTM and Marshall tests show a negative exponential relationship between VIM and VMA with deformation and a positive exponential relationship between VFA and asphalt mixture deformation.

Red mud application as filler in asphalt mixtures production

Red mud is the solid waste from bauxite processing during aluminium production. Its inadequate disposal causes social, economic and environmental prejudices. The industrial solid waste insertion evaluation in the production chain is beneficial and necessary. This work aims to evaluate the mechanical performance of asphalt mixtures produced with red mud as filling material. Asphalt mixtures with 5% and 7% red mud were produced, and permanent deformation and moisture-induced damage tests were carried out. A mixture without red mud addition (control) was produced for comparison. The results showed that the mixtures with red mud presented permanent deformation resistance greater than the control one, with more than 40% reduction in rutting deformation. The moisture damage did not significantly affect the mixtures tested. The red mud application as a filler in asphalt mixtures is viable and can be an alternative to reduce the damage such a waste can cause to the environment.

Mechanical performance of asphalt mixture containing eco-friendly additive by recycling PET

The reason for conducting this research was to examine asphalt mixtures and the influence of additives obtained from recycled Polyethylene Terephthalate (PET) on their mechanical properties. Due to this, after the chemical recycling of PET, the substance resulting from the chemical reaction was added to the asphalt binder in different contents. In order to evaluate the mechanical performance of mixtures containing additives, a variety of different mechanical tests were carried out. In order to accomplish this goal, tests including dynamic creep, indirect tensile strength (ITS), and indirect tensile modulus (IDTM) were carried out to determine rutting, moisture susceptibility, and resilient modulus, respectively. The SCB test is used to determine how well a material resists cracking when subjected to low temperatures. The results showed that the addition of an additive derived from recycled PET could increase the rutting resistance, significantly improve resistance against moisture damage and increase cracking resistance at low temperatures. In accordance with the findings of the indirect tensile strength tests, indirect tensile modulus and SCB was the best performance related to the asphalt mixture containing 2% recycled PET. However, this result was different in the dynamic creep test, and the asphalt mixture containing 1% additive showed the best performance. The results of data analysis with one-way analysis of variance showed that all the data obtained in this study are statistically significant considering the confidence factor of 95%, so it can be said that the addition of recycled PET additive has a significant effect on the mechanical properties of the asphalt mixture.

Influence of aging, RAP content, and recycling agent on the performance of asphalt mixtures.

A great complexity limits its use as the degree of aging of the asphalt binder of the RAP is a determinant for the interaction with the new binder and recycling agents to design asphalt mixtures with reclaimed asphalt pavement (RAP). One of the ways to analyze the level of interaction between the aged binder and the recycling agent is through the analysis of the performance of the mixtures after the accelerated aging of the samples in the laboratory. Thus, this paper evaluated the mechanical performance of asphalt mixtures with high contents of RAP (50%, 75%, and 100%) and organic type recycling agents (residual engine oil) and surfactant (ADCAP WM), submitted to aging protocols short and long term. The data obtained verified the feasibility of adding up to 75% of RAP in the recycled mixtures. However, detailed monitoring of its execution and performance throughout its useful life is necessary. Fatigue and flexural fracture data were highly altered by aging conditioning, evidencing the reduction in the performance of the compositions of the recycled mixtures. The statistical test showed significance for the parameters RAP content and type/content of the recycling agent used. In addition, there was an increase in the deformation capacity and better resistance to aging and cracking with the incorporation of the surfactant recycling agent.

Microscopic Analysis of Activated Crumb Rubber and Its Effect on Mechanical Performance of Asphalt Mixtures Using Dry Process

Microscopic Analysis of Activated Crumb Rubber and Its Effect on Mechanical Performance of Asphalt Mixtures Using Dry Process

Mechanical performance of cup lump rubber modified asphalt mixtures incorporating polyphosphoric acid

Natural rubber (NR) producing countries face rubber production and price fluctuations. NR production's high cost and low market price have produced an extensive demand for alternative applications of NR. This paper examined the influence of cup lump rubber (CLR) and polyphosphoric acid (PPA) on the mechanical performance of asphalt mixtures. The five modified blends were selected for the hot mix asphalt (HMA) performance analysis. The results revealed that the CLR increasing content in the bitumen ultimately increases the optimum bitumen content (OBC) for the asphalt mixture. There is a significant difference in the base mixture OBC (5.19 %) compared to the cup lump rubber-modified bitumens (CLRMBs). The CLRMB6 + 0.5PPA asphalt mixture OBC was 5.32 %, which is higher among all the mixtures. The rutting findings demonstrated that the control mixture exhibited the highest strain of 1.71 %, followed by CLRMB6 with 1.43 %, CLRMB3 + 0.5PPA with 1.1 %, CLRMB9 with 0.7 %, and CLRMB6 + 0.5PPA with the lowest strain of 0.47 %. The creep stiffness modulus of all mixtures met the minimum requirement of ≥75 MPa. The results implied that the CLR and the PPA displayed incredible potential to improve the asphalt mixture's resilient modulus (MR). The CLRMB9 resilient modulus increased significantly by 22 % compared to the control mixture. The CLRMB6 + 0.5PPA has a higher MR of 5210 MPa than the other modified mixtures and the control mixture with 3521 Ma. Thus, the study's findings suggest that the CLR, in conjunction with the 0.5PPA exhibits a decisive effect on the asphalt mixture performance and could be beneficial as a sustainable material in the pavement industry.

Feasibility of Concurrent Improvement of Pollutants-Absorption Ability from Surface Runoff and Mechanical Performance of Asphalt Mixtures by Using Photocatalytic Nanomodified Porous Asphalt

Feasibility of Concurrent Improvement of Pollutants-Absorption Ability from Surface Runoff and Mechanical Performance of Asphalt Mixtures by Using Photocatalytic Nanomodified Porous Asphalt

Effect of synthetic fibers on the mechanical performance of asphalt mixture: A review

Effect of synthetic fibers on the mechanical performance of asphalt mixture: A review

Experimental and Machine Learning Approach to Investigate the Mechanical Performance of Asphalt Mixtures with Silica Fume Filler

This study explores the potential in substituting ordinary Portland cement (OPC) with industrial waste silica fume (SF) as a mineral filler in asphalt mixtures (AM) for flexible road pavements. The Marshall and indirect tensile strength tests were used to evaluate the mechanical resistance and durability of the AMs for different SF and OPC ratios. To develop predictive models of the key mechanical and volumetric parameters, the experimental data were analyzed using artificial neural networks (ANN) with three different activation functions and leave-one-out cross-validation as a resampling method. The addition of SF resulted in a performance comparable to, or slightly better than, OPC-based mixtures, with a maximum indirect tensile strength of 1044.45 kPa at 5% bitumen content. The ANN modeling was highly successful, partly due to an interpolation-based data augmentation strategy, with a correlation coefficient RCV of 0.9988.

Performance Evaluation of Steel Slag Asphalt Mixtures for Sustainable Road Pavement Rehabilitation

The demand for more sustainable transport infrastructure has led to a broader acceptance of waste materials in pavements. An excellent example of this trend is the incorporation of steel slag aggregates (SSA) in asphalt mixtures. This work evaluates the mechanical performance of asphalt mixtures that include SSA in their composition. Asphalt mixtures were evaluated through laboratory tests for affinity between binder and aggregate, Marshall and volumetric properties, stiffness, resistance to fatigue, permanent deformation, and water sensitivity. Two rates of SSA incorporation—20% and 35%—were considered. In general, results indicated that incorporating SSA has not impaired the behavior of the asphalt mixtures. In some cases, the presence of SSA has improved mechanical performance. It was the case of the resistance to permanent deformation, stability, flow, and water sensitivity. This work confirms the suitability of the SSA application in asphalt mixtures beyond the benefit of promoting industrial waste in pavement engineering.

Alternative Fillers in Asphalt Concrete Mixtures: Laboratory Investigation and Machine Learning Modeling towards Mechanical Performance Prediction.

In recent years, due to the reduction in available natural resources, the attention of many researchers has been focused on the reuse of recycled materials and industrial waste in common engineering applications. This paper discusses the feasibility of using seven different materials as alternative fillers instead of ordinary Portland cement (OPC) in road pavement base layers: namely rice husk ash (RHA), brick dust (BD), marble dust (MD), stone dust (SD), fly ash (FA), limestone dust (LD), and silica fume (SF). To exclusively evaluate the effect that selected fillers had on the mechanical performance of asphalt mixtures, we carried out Marshall, indirect tensile strength, moisture susceptibility, and Cantabro abrasion loss tests on specimens in which only the filler type and its percentage varied while keeping constant all the remaining design parameters. Experimental findings showed that all mixtures, except those prepared with 4% RHA or MD, met the requirements of Indian standards with respect to air voids, Marshall stability and quotient. LD and SF mixtures provided slightly better mechanical strength and durability than OPC ones, proving they can be successfully recycled as filler in asphalt mixtures. Furthermore, a Machine Learning methodology based on laboratory results was developed. A decision tree Categorical Boosting approach allowed the main mechanical properties of the investigated mixtures to be predicted on the basis of the main compositional variables, with a mean Pearson correlation and a mean coefficient of determination equal to 0.9724 and 0.9374, respectively.

Mechanical performance under dynamic loading of rubberized asphalt mixtures with highly-porous vesicular aggregate

In volcanic regions, the use of certain abundant aggregates of scoriaceous nature with high porosity to manufacture bituminous paving mixtures is a major problem due to the excessive heterogeneity, absorption and limited strength of these aggregates. Consequently, the properties of the mixtures often do not meet technical specifications. The aim of this research is to study the improvement of the mechanical performance of asphalt mixtures with these residual volcanic aggregates by using binders modified with rubber from end-of-life tyres, since environmental and economic requirements make it necessary to reuse both types of waste. Laboratory studies determining the compactability, dynamic stiffness, fatigue resistance and elastic constants have made it possible to characterise the mechanical performance of these mixtures during production and in service, and to compare them with conventional mixtures. It was found that the use of tyre rubber modified bitumen makes compaction somewhat more difficult, but reduces the particle size degradation of the porous aggregates and improves the mixture performance and durability, showing higher stiffness moduli and increased resistance to fatigue.

Mechanical performance of asphalt mixture composed of asphalt binder modified with sunflower oil

Warm Mix Asphalt (WMA) refers to a variety of asphalt mixtures produced at lower temperatures than those conventionally used to produce hot mixture asphalt. These reductions in the production temperatures provide social, economic, and environmental gains. This study aimed to investigate the mechanical properties of asphalt mixtures composed of asphalt binders modified with sunflower oil at the addition contents of 1%, 2%, and 3%. Indirect tensile strength, resilient modulus, water sensitivity, dynamic modulus, rutting resistance, and fatigue life of the asphalt mixtures were evaluated. Results showed that the mechanical performance of asphalt mixtures composed of oil-modified asphalt binder decreased compared to that of the mixture with neat asphalt binder, even though all of them are suitable for application in surface courses according to the current technical requirements for asphalt concretes. However, asphalt mixtures with sunflower oil-modified binders presented enhances in adhesion, which indicates less susceptibility to moisture than their equivalent non-modified.

Influence of unserviceable tires’ rubber on the mechanical performance of hot mix asphalt

This work aimed to optimize the production of hot mix asphalt (HMA) from the use of asphalt-rubber. For that, the mechanical performance of asphalt mixtures produced with different binders was evaluated: commercial asphalt-rubber (AR08), asphalt crumb rubber 10% (AR10) and 15% (AR15), and conventional asphalt (PEN 50-70). For the composition of these mixtures, the optimum asphalt contents were defined by the Marshall design. To carry out the mechanical tests, specimens molded with Marshall and Superpave compactors were tested. From the results obtained, it was verified that AR08 and AR10 asphaltic mixtures, compacted with Superpave, carried out the best mechanical performance. However, the AR08 binder is already available on the market, which facilitates its usage in paving works

Characterisation of modified asphalt mixtures with lignin of pinus and eucalyptus woods

ABSTRACT Lignin is a natural polymer that has antioxidant properties. However, a supplied lignin’s physical, chemical, and rheological behaviour will differ from the source. Thus, the objective of this work was to investigate the mechanical performance of asphalt mixtures produced with asphalt binders modified by lignins at the contents of 0, 3, 6, and 9%, from pinus and eucalyptus sawdust. The mixtures were evaluated by performing the Splitting Tensile Strength Test, Lottman, Resilient Modulus, and Dynamic Modulus. The results pointed to lignin, both tested, as a good natural polymer due to the increase in resilience of the asphalt mixtures and reduction of susceptibility to moisture for the proposed contents. Therefore, it is suitable for field use. Lignin can be identified as a residual modifier that can provide longer service life to asphalt coatings, presenting itself as an alternative modifier to the synthetic elastomeric polymers. The addition of 3% pinus lignin presented the best mechanical performance, followed by the addition of 9% eucalyptus lignin.

Indices relation and statistical probability analysis of physical and mechanical performance of asphalt mixtures

Rutting deformation is one of the most prominent diseases in asphalt pavement’s early damage. In this paper, it analyzes the relation and their distribution law between Marshall stability and the physical and mechanical indices of asphalt mixtures based upon a correlation analysis and statistical principles, which is to find the reasonable range of rutting performance design parameters of asphalt pavement. The results showed that the asphalt mixture’s stability increased with the increase in bulk volume relative density and asphalt saturation, but decreased with the increase in the percent of air-voids and the voids in the mineral aggregate. The optimal fitting function of bulk volume relative density and asphalt saturation for AC-13 asphalt mixture follows a Weibull distribution, that of Marshall stability and air-voids follows a Gamma distribution, and that of percent voids in the mineral aggregate and flow value follows a Lognormal distribution. For a GAM-16 asphalt mixture, the optimal fitting function of bulk volume relative density and Marshall stability follows the Weibull distribution, the optimal fitting function of air-voids follows a Gamma distribution, that of flow value and percent voids in the mineral aggregate follows a Lognormal distribution, and asphalt saturation follows a Normal distribution. It is recommended that AC-13 asphalt mixtures’bulk volume relative density ranges from 2.27～2.38 g·cm3, the air-voids ranges from 3.4～6.0%, and GAM-16 asphalt mixtures’bulk volume relative density ranges from 2.29～2.37 g·cm3, the voids in mineral aggregate ranges from 17～18.17%, the asphalt saturation ranges from 75～82.13%, which can provide a reference for in-depth understanding of the deformation characteristics and construction of highways’ pavement in similar areas.

Effect of Different Types of "Dry Way" Additions in Porous Asphalt Mixtures.

Polymers are widely used to improve the mechanical performance of asphalt mixtures. Among them, styrene butadiene styrene (SBS) is the most commonly used, especially in the wet modification of virgin bitumen. This method, which is extensively utilized, has several advantages, but also some disadvantages, concerning its performance (such as the risk of instability or a lack of homogeneity) and logistical management (such as the need for special equipment, the transport of materials, and the dependence on the refinery that modifies the bitumen). This paper analyses the use of the most conventional types of polymers (two types of SBS, one type of BS, and rubber from end-of-life tires), dry added, as an alternative method. They have been used in porous asphalt mixtures. This type of bituminous mixture is usually designed with commercial polymer-modified bitumen, due to the mechanical requirements, and it is very sensitive to the properties of the binder used. The mechanical behavior of experimental porous asphalt mixtures has been significantly improved, especially in the case of SBS, although the performance did not reach that of commercial polymer-modified bitumen. The results have shown that the dry method is a suitable and feasible option to manufacture modified mixtures, especially considering its advantages, from a logistical viewpoint, in comparison with the wet method.