Asphalt Concrete Mixes Research Articles

A performance study on asphalt concrete mixes with different waste materials as modifiers in pavement application

A performance study on asphalt concrete mixes with different waste materials as modifiers in pavement application

Investigation on the effect of moisture induced damage on asphaltic concrete mix incorporating waste concrete aggregates

Recycling waste materials, such as partial replacement of WCA for natural aggregates in hot-mix asphalt, could be an option for addressing problems such as environmental pollution and the increasing demand for natural resources. Due to continual development and renovation in the construction industry, the generation of concrete waste has become one of the major challenges. Consequently, the purpose of this study was to develop an asphalt mix design utilizing waste concrete aggregate (WCA) as a partial substitute for natural aggregates (NA). The ratios of WCA10:NA90 and WCA30:NA70 are utilised to design the asphalt mixtures. In this study, asphalt mixtures containing 10 and 30 percent WCA are referred as WCA10 and WCA30, respectively. The density-voids analysis enables the determination of the optimum asphalt content that satisfies the criteria of the Malaysian Public Works Department (PWD). Results indicates that the criteria and design parameters of both mix conforms to the PWD specifications. The optimum asphalt content determined for both WCA10 and WCA30 asphalt mix is 5.7 and 5.8 percent respectively. The moisture sensitivity test is then performed on both WCA10 and WCA30 asphalt mixtures to determine how susceptible these mixtures are to moisture-induced damage. The tensile strength ratio (TSR) for WCA10 and WCA30 asphalt mixtures is 83.6 and 97.4 percent, respectively, which is greater than the minimal requirement of 80%. This investigation revealed that the use of WCA in hot-mix asphalt satisfies the moisture susceptibility requirements.

Effect of nanomaterials on the durability of hot mix asphalt

Traffic volume and loads have increased significantly in recent years, coupled with the high summer temperature and the low temperature in winter, premature failure in asphalt concrete pavement becomes the main challenge for pavement construction companies and engineers. The use of modifiers in asphalt concrete mixes become of considerable interest in the improvement of pavement performance and service life. With the advent and evolvement in nanotechnology, many researchers focused on how these materials could serve in rising the serviceability of pavement in terms of reducing rutting, fatigue cracking as well as moisture induced damage. In this study, nanomaterials, including nano silica (NS), nano carbonate calcium (NCC), nano clay (NC), and nano platelet hydroxyapatite (NP), were used to examine the prospect of enhancing the durability and resilience of asphalt mixtures. Specifically, this study aimed to evaluate the effect of adding nanomaterials as a modifier to the bitumen on the Marshall properties, resilient modulus as well as the durability of the asphalt concrete mixture, which was assessed for moisture susceptibility using indirect tensile strength (ITS) and permanent deformation using the uniaxial repeated load test. The investigated nanomaterial dosages were as follows; NS (1, 3 and 5%), NCC (2, 4 and 6%), NC (3, 5 and 7%), and NP (2, 4 and 6%), by weight of asphalt cement. The results were compared with the control mix (CM), i.e., an unmodified mix. The results revealed that nanomaterials significantly improved the properties of asphalt concrete. Also, this work provides a basis for producing more durable mixtures with higher resistance to distress.

Sustainable recycling of polyethylene waste through utilization in asphalt paving applications

One the enormous amount of waste polyethylene (PE) materials amassing in Iraq is posing an expensive landfill and disposal issue. The current study examines the potential for employing PE as a partial replacement for environmentally friendly pavement construction. Different amounts of PE were used to partially replace asphalt cement (3 %, 6 %, 9 %, and 12 % by weight). The PE-substituted asphalt (PESA) binders were subjected to the rheological and compatibility properties. Additionally, two asphalt concrete (AC) mixtures-one control and one PEAC-were created for the mechanical and durability experiments. Among the parameters assessed during the tests are the following: adhesion to a variety of substrates and substrate surfaces; elongation at room temperature (aging index); flexibility at elevated temperatures (cracking index); temperature susceptibility; compatibility; and the extensional viscosity of the PESA binder as well as the extensional viscosity of the PESA-mixture (PESAM). Furthermore, the mechanical and durability properties of AC and PEAC mixes were examined using the Marshall stability, Marshall quotient, static indirect tensile strength at 25 and 60°C, tensile strength ratio, and resilient modulus 25°C tests. Results show that PESA binder outperforms virgin asphalt binder in terms of cracking and temperature resistance. PEAC mixture exhibits higher stability, indirect tensile strength, moisture resistance and resilient modulus than AC mixture. According to standard and durability testing, replacing virgin binder with six percent PE can be recyclable and suitable for use as sustainable material for paving applications.

Research on methods for effective use of machines in kit in construction and repair of asphalt concrete pavement

This paper develops a methodology for studying the effective use of asphalt paving and transport machines, the main determining parameters of which are the cost and productivity of transporting and laying asphalt concrete mix. An algorithm has been developed for optimizing the operational performance of a set of asphalt paving and transport machines in the construction and repair of roads.

Data mining and forecasting of pavement strength depending on the composition of asphalt concrete mix

The article substantiates the need for widespread introduction of computer technology and information systems in the mix production process at ACF and their quality control, which is determined by the presence of a significant number of control objects, a large array of monitored indicators, high labor and material costs of testing, low efficiency and quality of processing complex multidimensional data. It is proposed to use Data Mining methods for intelligent data analysis and prediction of pavement durability depending on the composition of asphalt mix which enable to solve the tasks of classification, regression, clustering and forecasting using artificial intelligence methods. The algorithm of intellectual data analysis and prediction of durability of the mix depending on its composition is offered and the actions at each its stage, using additional methods of data analysis, are described. The example of real raw data processing obtained from the quality control laboratory of one of the asphalt plants using Data Mining tools of STATISTICA package according to the developed algorithm is given. The prospects of using modern data processing technologies in the field of asphalt concrete quality control are evaluated. It is shown that to assess the quality of the mix and pavement durability, it is necessary to move to complex quality indicators, taking into account pavement operating conditions.

Fatigue Prediction Model and Stiffness Modulus for Semi-Flexible Pavement Surfacing Using Irradiated Waste Polyethylene Terephthalate-Based Cement Grouts

Semi-flexible pavement surfacing, or grouted macadam, is an alternative to conventional flexible and rigid pavement. It is constructed by injecting cementitious grout into the voids of an open-graded asphalt surfacing. The cement used in cementitious grouts has adverse environmental effects because of the carbon dioxide emission in cement production. The objective of this study was to investigate the potential of using irradiated waste polyethylene terephthalate (PET) and fly ash (FA) as a (partial) cement replacement in cementitious grouts for semi-flexible pavement surfacing. This study sought to assess the stiffness modulus and fatigue properties of the semi-flexible specimens prepared with control grout, regular PET (2.57% PET + 10% FA) and irradiated PET (4.75% PET + 10% FA)-based grouts and compares the stiffness modulus and fatigue properties of semi-flexible specimens with the conventional hot mix asphalt (HMA) concrete. The semi-flexible surfacing specimens showed superior performance, higher stiffness modulus, and better fatigue life than the hot mix asphalt. The difference in fatigue cycles was apparent at lower stress ratios of 25 and 30%. The semi-flexible pavement mixtures exceeded 100,000 cycles at the lowest stress ratio of 25%, while the HMA fatigue cycles were less than 100,000 cycles. Furthermore, the semi-flexible specimen with irradiated PET (which contain a higher amount of waste PET than the regular PET) showed similar stiffness modulus and fatigue life as the specimens with regular PET and control grout. The irradiation technique offers a sustainable solution for recycling higher amounts of waste PET in highway materials for semi-flexible pavement surfacing.

The Evaluation of Physical and Mechanical Properties of Synthetic Polymer Modified Hot and Warm Mix Asphalt

The application of polymer in an asphalt concrete (AC) mixture has reached wide popularity lately to deal with the increasing demand for higher quality roads with heavier traffic loading. Ethylene-vinyl acetate (EVA), classified as a thermoplastic, is currently one of the most popular polymers employed. This research attempts to evaluate the effect of adding EVA by means of the dry method, namely by pouring the additive directly into the mixture, which produces both hot and warm Polymer-Modified Asphalt Concrete (PMAC) mix. FTIR result indicates the polymer as a thermoplastic material. Moreover, the volumetric and mechanical properties of the mixture were examined through the density and semi-circular bending (SCB) tests. The outcomes show that the inclusion of the polymer could slightly modify the density and VMA of the AC mix. Meanwhile, the tensile strength, fracture energy, crack resistance index (CRI), and flexibility index (FI) results describe substantial enhancement brought by the polymer, with a generally increasing trend up 200% of the control mix. Conclusively, the application of polymer could enhance the physical and mechanical properties of hot and warm AC mixes with the optimum dosages of 5 and 6%. Additionally, the properties of warm PMA are somewhat comparable to the regular hot AC mix.

Experimental Evaluation of Rutting Resistance of Sugar Cane Bagasse Ash Modified Asphalt Mixture

Abstract: Bagasse ash (BA) was used as filler in hot mix asphalt. Mineral fillers in asphalt concrete mixes have a significant influence on asphalt concrete performance. Although mineral filler is just a minor percentage of the total performance of asphalt concrete, it plays a critical function. Bagasse Ash (BA) was utilized as a filler ingredient to test and assess the performance of asphalt concrete. BA was used in variable ratios to replace Stone Dust (SD) in road construction. Filler was used in varying quantities (4%, 5.5%, and 6.5%). Furthermore, BA is used to replace the traditional SD filler in partial replacements of 10%, and 20%, as well as full replacement of SD. The Marshall Mix Design Method was used with three different amounts of bitumen, namely 4%, 4.3%, and 4.6%. By using National Highway Authority’s (NHA) general criteria for Optimum Binder Content, a total of 108 samples were produced. The prepared mixes showed good outcomes, and the majority of them passed the NHA's main requirements. Some of the mixtures do not meet the VMA and VFA requirements given in MS-2 Asphalt Institute 2014. Two forms of performance testing are the Dynamic Modulus Test and the Wheel Tracking. A total of twelve OBC samples are evaluated for wheel tracking and dynamic modulus. Bagasse Ash has been tested in the lab and found to be capable of being used as filler in both partial and full replacement of conventional stone dust filler.

Artificial Neural Network Modeling of Theoretical Maximum Specific Gravity for Asphalt Concrete Mix

Artificial Neural Network Modeling of Theoretical Maximum Specific Gravity for Asphalt Concrete Mix

A Comprehensive Review on the Effect of Filler Materials on Engineering Properties of Asphalt Concrete Mixes

The effect of filler materials on the properties of bituminous concrete was reviewed in this paper. Flexible pavement layer is made up of asphalt concrete. It is the commonest type of pavement in the world. Asphalt concrete contains aggregates, bitumen binder and fillers. The Asphalt concrete has voids which needs to be filled for better performance of its functions. Fillers help to fill voids and change the physical and chemical properties of asphalt concrete and bitumen combines with filler to forms mastic that holds the aggregates together. Asphalt Institute recommended 4-8% fillers for use. The recent developments in technology is geared towards the use waste materials as fillers in concrete production. It was revealed in this review that Marble dust and Calcium Carbide Residue (CCR) can be used in bituminous mix as alternative to conventional fillers in asphalt mixes. The waste bagasse and coconut peat fillers give mastic viscosity similar to limestone filler but higher than granite filler. Concrete dust and brick dust as fillers in bituminous mix improve flow value, Marshall stability and physical characteristic of bitumen. The conclusion of this review analysis shows that fillers in bituminous mix reduces the problem associated with waste disposal and high concentration of calcium carbonate in waste ash can help to reduce rutting and moisture damage potentials.

Performance Evaluation of High Modulus Asphalt Concrete (HMAC) Prepared Using Asphaltenes-Modified Binders

Abstract High strength, extended fatigue life, and improvement in rutting resistance are the main advantages of using high modulus asphalt concrete as a base course material in the pavement structure. The primary goal of this paper was to investigate the performance properties of the high modulus base course using different asphaltenes-modified binders. A crude oil binder and two different asphalt binders from Alberta oil sands sources were used to prepare the mixtures. To prepare hard-grade asphalt binders, all binders were modified using asphaltenes, a waste byproduct of the deasphalting of Alberta oil sands. The performance grades of the modified and unmodified binders were determined, and a mix design was developed for the high modulus asphalt concrete mixes. To evaluate the performance properties of high modulus asphalt concrete mixes composed of unmodified and asphaltenes-modified binders, Hamburg wheel tracking, dynamic modulus and flow number, and indirect tensile strength at low temperature were conducted. The high-temperature performance test results, including Hamburg wheel tracking and flow number tests, indicated that asphaltenes-modified mixtures show higher resistance to permanent deformation. However, the indirect tensile strength test results at low temperature showed higher tensile strength and lower fracture energy for the asphaltenes-modified mixtures compared with the unmodified samples. Moreover, according to the dynamic modulus test results, the asphaltenes-modified mixtures exhibited higher modulus values (stiffness) than the unmodified samples at different loading frequencies compared with the unmodified samples.

Laboratory Evaluation of ESGFIBER in Asphalt Paving Mixture.

The global desire to improve the performance of road pavements and move towards a sustainable transportation system has immensely encouraged the usage of fibers in asphalt paving materials. In this study, glass fibers trademarked as ESGFIBER produced by the ESG Industry company Limited from Daejeon, Korea were added in dense-graded asphalt mix. The purpose of this study was to evaluate effects that fibers have on volumetric properties, mechanical properties, and long-term performance of asphalt concrete mixes. ESGFIBER were mixed together with aggregates and asphalt binder in asphalt mix and five different asphalt mixes with different dosage of fibers were evaluated in this study. The Marshall mix design method was used for designing all asphalt mixes, and laboratory tests indirect tensile strength test, deformation strength test and Hamburg wheel tracking test were conducted to evaluate moisture susceptibility, fatigue cracking behavior and rutting resistance of asphalt concrete mixes. The results showed that when ESGFIBER were added in asphalt mix moisture susceptibility, fatigue cracking and rutting resistance were both improved. The usage of ESGFIBER in asphalt concrete mixes can be very beneficial since the mechanical and long-term performance were improved upon the addition of fibers.

Direct tensile test evaluation and characterization for mechanical and rheological properties of polymer modified hot mix asphalt concrete

AbstractUsing polymer to modify asphalt binder for better performance has become popular in pavement engineering, for which to evaluate the effect of polymer addition on the properties of the asphalt concrete is essential for mix design. Conventional mechanical test methods, primarily using bending of beams and indirect splitting, are not only materially and timely costly and labor intensive but also provide no direct information for the viscoelastic and rheological characteristics of the materials. This paper reports a study using direct tensile test (DTT) to evaluate the effect of polymer on both mechanical and rheological properties of modified asphalt concrete. Two types of polymers, which are styrene‐butadiene‐styrene (SBS), and a mixture of SBS and polyvinyl chloride (PVC), were investigated on two mixes using fine and coarse aggregates, respectively. It has been found that SBS generates improvement for both mechanical and rheological properties of hot mix asphalt concrete. However, using a hybrid mixture of SBS and PVC shows that PVC can further improve the mechanical properties, but deteriorate the toughness of the asphalt concrete. At the end, a simple quadric polynomial model has been proposed to characterize the combined SBS and PVC effects for the sake of the guidance for mix design.

Characterisation of asphalt concrete mixes with municipal solid waste incineration fly ash used as fine aggregates substitution

ABSTRACT Characteristics of dynamic modulus (|E*|) and phase angle are necessary to determine the response of bituminous mixtures. Limited regressions are available in the literature for phase angle prediction. This research focuses on the effect of using municipal solid waste incineration (MSWI) fly ash as fine aggregates substitution on the performance of HMA mixes. Therefore, (MSWI) fly ash was incorporated in bituminous mixtures in five substitution percentages (0%, 5%, 10%, 25% and 50%). Mix design was conducted according to Superpave mix design method to find the optimum binder content of the various mixes. Two predictive models were used to better fit the phase angle mastercurvesand reduce the deviation at higher and lower limits of the frequency loading. The results indicated that the absorption of binder increased with higher substitution percentages. Similarly, higher voids in mineral aggregates and voids filled with asphalt values were observed with higher replacement percentages. The incorporation of (MSWI) fly ash affected the mixture's stiffness. Lower (|E*|) values were observed for all mixes as compared to the control mix. Mixes with MSWI fly ash developed lower and higher phase angle values as compared to the conventional mix depending on the percentage of replacement and the frequency range.

Thermal Properties of Hydrated Lime-Modified Asphalt Concrete and Modelling Evaluation for Their Effect on the Constructed Pavements in Service

Flexible pavements are subjected to three main distress types: fatigue crack, thermal crack, and permanent deformation. Under severe climate conditions, thermal cracking particularly contributes largely to a considerable scale of premature deterioration of pavement infrastructure worldwide. This challenge is especially relevant for Europe, as weather conditions vary significantly throughout the year. Hydrated lime (HL) has been recognized as an effective additive to improve the mechanical properties of asphalt concrete for pavement applications. Previous research has found that a replacement of conventional limestone dust filler using hydrated lime at 2.5% of the total weight of aggregates generated an optimum improvement in the mechanical properties of the asphalt concrete mixes used for all three purposed layers (i.e., wearing, levelling, and base) at atmospheric temperatures from mild to relatively high. This paper reports on a continuous experimental test for the thermal properties of the optimized hydrated lime-modified mixes. The experiment together with that conducted before provides the required data to characterize the thermomechanical constitutive relations of the optimized hydrated lime-modified mixes. The obtained thermal and mechanical properties thereafter were implemented in a numerical modelling study for a scenario involving pavement exposed to coupled thermal and traffic service conditions. The study has demonstrated that using HL in mineral filler enhances the thermal properties of asphalt concrete, which, however, showed little influence on the local temperature profiles within the pavement structure. The thermal effect is pronounced under the coupled thermomechanical conditions for a pavement exposed to both traffic and climatic impacts. The HL pavement has about 1.5% less deformation, and 39% less stress level under traffic loading only, but the thermal effect increases the maximum total internal tensile stress level by 26% in the HL pavement in winter season. The modelling analysis has shown that the local maximum tensile stress dominates in the surface region of the HL pavement. It will help to reduce the workload of crack repairing and in long term help on saving costs and efforts of maintenance.

Influence of Corn Cob Ash as a Filler Material in Asphalt Concrete Mixes

Influence of Corn Cob Ash as a Filler Material in Asphalt Concrete Mixes

Improvements to the Duplicate Shear Test (DST) Device for Measuring the Fundamental Shear Properties of Asphalt Concrete Mixes

Improvements to the Duplicate Shear Test (DST) Device for Measuring the Fundamental Shear Properties of Asphalt Concrete Mixes

Size Effect of Hydrated Lime on the Mechanical Performance of Asphalt Concrete

Despite widespread agreement on the beneficial nature of hydrated lime (HL) addition to asphalt concrete mixes, understanding of the effect of HL particle size is still limited. Previous investigations have focused mainly on two different size comparisons, and so certain guidance for a practical application cannot yet be produced. This study investigates three distinct sizes of HL, in the range of regular, nano, and sub-nano scales, for their effects on the properties of modified asphalt concretes. Five different percentages of HL as a partial replacement of ordinary limestone filler in asphalt concrete mixes were studied for wearing course application purposes. Experimental tests were conducted to evaluate the mechanical properties, including resistance to plastic flow, volumetric properties, moisture susceptibility, resilient modulus, and permanent deformation. The results revealed that a positive correlation exists between the mechanical properties and the fineness of HL particle sizes.

A REVIEW ON EFFECT OF SOLID WASTE FILLERS ON ASPHALT MASTIC AND ASPHALT MIXTURE

The pavement works consumes more of natural resources through which depletion take place due to continuous consumption. So, it is required to regulate the usage of natural material and recommended to use some alternate materials in the form of replacement. Conventional fillers that are used in asphalt mix are stone dust, limestone, Portland cement, etc. In order to regulate usage of these materials utilization of waste/by-products as a filler such as marble dust, calcium carbide residue (CCR), Fly-Ash, brick dust, etc. In this review analysis the effect of solid waste products as fillers in asphalt concrete mixes and asphalt mastics were elaborated by means of mechanical properties, rheological properties and performance properties like resistance against rutting, cracking and fatigue. As a result, from various research works, the improvement in performance and properties of asphalt mastic and asphalt mixes were observed with utilization of solid waste mineral fillers. KEYWORDS: Asphalt Mastic, Asphalt Mix, filler, CCR, Marble Dust