Performance Of Bituminous Mixtures Research Articles

Road Performance and Self-Healing Property of Bituminous Mixture Containing Urea-Formaldehyde Microcapsules.

Urea-formaldehyde (UF) is a common shell material for self-healing microcapsules; however, the influence of urea-formaldehyde microcapsules (UFMs) on the road performance of bituminous mixtures and the sensitivity of their healing abilities remains unclear. In this paper, UFMs were prepared via in situ polymerization (ISP), followed by an investigation into the road performance of UFM self-healing bituminous mixtures through various tests, including wheel tracking, immersed Marshall, freeze-thaw splitting, low-temperature bending, and three-point bending fatigue tests. Subsequently, the impact of the damage degree, healing duration, and temperature on the self-healing property was discussed. The results indicated that incorporating 3 wt% UFMs into bitumen significantly improved the high-temperature stability and fatigue resistance of the bituminous mixture; for example, its dynamic stability and fatigue life could be increased by about 16.5% and 10%, respectively. However, it diminished the thermal crack resistance, as evidenced by decreases in bending tensile strength and strain by 3.7% and 10.1%, respectively. And it did not markedly improve the moisture susceptibility. Additionally, the maximum improvement observed in the healing rate was about 9%. Furthermore, the healing duration and temperature positively influenced the bituminous mixture's self-healing, whereas the degree of damage exerted a negative impact, with a relatively significant effect.

Characteristics of Oil Palm Fruit Ash as Binder in Asphaltic Concrete

In order to reduce energy and natural resource consumption during road construction, the sustainability concept needs to be seriously addressed. Oil Palm Fruit Ash (OPFA) is one of the by-products of palm oil production that are typically disposed of in landfills as a result of the growing number of plantations in Malaysia, particularly in Sarawak. Due to the fact that OPFA is known as biomass with pozzolanic qualities (siliceous material), this study was carried out to examine the applicability of OPFA with varying concentrations (0% - 40%) by weight as a modifier in bitumen grade 60/70. Based on the results of the laboratory testing, it was discovered that the modified bitumen provided greater resistance to rutting, temperature, and skid resistance on the bituminous mixture (AC20) compared to the control sample. The 40% OPFA modified samples had the greatest resilient modulus test value, measuring 10992 MPa at 25 °C and 2936 MPa at 40 °C, respectively. In addition, the combination containing 40% OPFA produced the lowest deformation value in the dynamic creep test, which was only 0.20mm, while producing 83.63 skid numbers in the skid resistance test. OPFA can be utilized as a binder modifier to improve the performance of bituminous mixture, which indirectly supports the sustainable development goals (SDGs) concept in road construction, as this study conclusively demonstrated.

Uncovering the Hidden Value of Waste Cow Bones Towards their Use as a Sustainable Biofiller for Hot-Mix Asphalt Paving Applications

This work is aimed at uncovering the hidden value of waste cow bones towards their use as a sustainable biofiller for hot-mix asphalt (HMA) paving applications. To do so, the effect of various contents of calcined cow bone powder (e.g., 5, 10, and 15 wt. % CBP) on the AP-5 bitumen performance was investigated. Numerous lab techniques were adopted to assess the physicochemical attributes of finished filler-asphalt mastics, namely: elemental analysis, Fourier transform-infrared spectroscopy (FT-IR), thin-layer chromatography-flame ionization detection (TLC-FID), needle penetration, ring and ball softening point, Brookfield viscometer, and ductility. Iatroscan analysis revealed that the CBP treatment did not alter the saturates but induced an increase in the fractions of aromatics/asphaltenes and a decrease in the resins. The FT-IR scan highlighted that the CBP–binder interactions were mainly governed by physical mechanisms rather than chemical ones. The empirical methods showed that the CBP incorporation enhanced the stiffness/hardness, the consistency, as well as the high-temperature performance of bituminous mixtures. Overall, the use of waste cow bones as a green biofiller is viable and profitable, and it has the potential to reduce the environmental pollution caused by the livestock industry while also improving the performance of hot-asphalt mixes and extending the pavement life at a low cost.

Evolution of selective absorption for bitumen from Basic Oxygen Furnace Slag (BOF) during aging and rejuvenation in bituminous mixtures

• Three layers of bituminous films at different stages of aging and rejuvenation were obtained by staged extraction method. • The selective absorption of bitumen by BOF is significantly higher than that by natural aggregate. The selective absorption of bitumen by aggregates exhibits a time-dependent effect. • The selective absorption of bitumen by aggregates is most significant during the short-term aging process. • Bitumen delamination occurs due to selective absorption of bitumen by aggregates, resulting in little effect on the road performance of bituminous mixtures. The selective absorption of bitumen by BOF has been systematically studied by previous scholars. However, there is still a lack of research on the selective absorption of bitumen by BOF at different aging stages. Hence, this issue deserves systematic investigation. Also in order to understand how to improve the pavement performance of BOF based bituminous pavement, this study is designed to explore the selective absorption behavior of BOF to bitumen components at different aging and rejuvenation stages. The protocols of short-term aging, PAV aging, and second PAV aging were subjected to specimens to simulate different service time of bituminous pavement. The complex modulus, phase angle, chemical composition and four component contents of different stages and layers of bituminous samples were analyzed by dynamic shear rheometer and Fourier infrared spectroscopy and thin layer chromatography with flame ionization detection. The road performance of the bituminous mixtures at different stages was also investigated. The results show that the BOF and natural aggregates all reveal selective absorption of bitumen, while BOF demonstrates a more significant effect for bitumen than natural aggregates. The selective absorption of bitumen by aggregates exhibits a time-dependent effect, resulting in the strongest selective absorption at the stage of short-term aging. Bitumen layers display multi layered system due to selective absorption of bitumen by aggregates, while effects insignificantly on the road performance of bituminous mixtures. The decrease in the ability of adhesion for bitumen due to aging is the key factor affecting performance of bituminous mixtures.

Use of Tensile Creep Test (TCT) for evaluation of low temperature performance of bituminous mixtures used for bridge pavement

Use of Tensile Creep Test (TCT) for evaluation of low temperature performance of bituminous mixtures used for bridge pavement

Mechanism and Performance of Bituminous Mixture Using 100% Content RAP with Bio-Rejuvenated Additive (BRA).

The low RAP content, hot mixing conditions, and the addition of a high ratio of new bitumen and aggregates result in low economic and environmental benefits for current regeneration technologies. A bio-rejuvenated additive (BRA) that can fully (100%) regenerate the RAP without heating is proposed in this paper. To reveal the mechanisms of BRA-rejuvenated RAP, the effects of BRA on the chemical structure and molecular weight of the RAP were investigated using Fourier-transform infrared spectroscopy and gel permeation chromatography. The mechanical performance and water damage resistance of BRA-rejuvenated RAP were studied. Low contents of new bitumen or epoxy resin were suggested to increase the mechanical performance of 100% RAP. The results show that the 1.5% BRA-rejuvenated RAP had the best mechanical performance. The blending of BRA with recycled RAP is a completely physical process, without any chemical reactions. The molecular weight of BRA is lower than that of bitumen; it can substantially increase the content of light components in aged bitumen, and play the role of adjusting and restoring the balance of the components of aged bitumen. The mechanical performance of BRA-rejuvenated RAP is enhanced significantly by adding low dosages of new bitumen or epoxy resin.

Advantages Of Filler And Surfactant Additive To Improve Moisture Sensitivity Of Hot Mix Asphalt Mixtures.

This research investigated the effect of mineral composition of aggregate on moisture sensitivity of bituminous mixtures and explored the benefits of hydrated lime filler and Wetfix BE surfactant additive to improve the resistance of the mix against moisture sensitivity. Basalt, quartzite, and limestone aggregates were selected based on their different mineralogy and 70 -100 penetration graded bitumen binders used during the study. Four laboratory tests the rolling bottle, shaking abrasion, pull-off tensile strength and indirect tensile strength tests were applied to study the effects of aggregate minerals and benefits of hydrated lime and Wetfix BE. Statistical analysis using Two-way ANOVA test conducted for each test to check the outcome significance. Results from each test revealed that mineral composition of aggregate have significant effects on the moisture resistance performance of bituminous mixtures and hydrated lime filler and Wetfix BE surfactant additives have advantages to improve the performance of bituminous mixture against moisture sensitivity and improves the long-term performance of asphalt mix.

Effect of Filler and Binder Contents on Air Voids in Hot-Mix Asphalt for Road Pavement Construction

Filler and binder make up a small proportion of bituminous mixtures, hence they are considered as important ingredients of mixtures. Sometimes due to equipment error during production, some mixtures retain extra or a reduced amount of filler or binder as compared to the design mix formula. It is thought that the poor performance of bituminous mixtures is a result of inadequate proportioning of materials and the use of inappropriate compaction tools. This study was intended to appreciate the influence of contents of filler and binder in relation to durability in asphalt mixtures. Filler used was crushed stone passing 0.075 mm sieve, while the binder was 35/50 penetration grade. Several trial mixes were prepared following Ugandan specifications for Road and Bridge Works, and the Asphalt Institute in MS-2. Marshall design method was used, studying volumetric properties with an average stability value of 22.3 kN, average flow value of 3.7 mm, VA of 4.4%, VFB of 69.3%, and VMA of 14.2%. Also, compaction of mixtures to assess its performance at optimum filler and binder contents was done. Compaction was done using an Automatic Impact Hammer, a Vibrating Hammer, and a Superpave Gyratory compactor aimed at simulating secondary compaction by traffic and assessing the retained air voids which was 3.3%, 1.3%, and 0.7% respectively. Generally, in bituminous mixtures when a vibrating hammer or a gyratory compactor is recommended for compaction, coarser mixes would be the best choice.

The Influence of Reclaimed Asphalt Pavement on the Mechanical Performance of Bituminous Mixtures. An Analysis at the Mortar Scale

The main characteristics of bituminous mixtures manufactured with a considerable amount of reclaimed asphalt pavement (RAP), compared to conventional mixtures, are a reduction in workability, an increase in stiffness, and a loss of ductility, due to the presence of the aged bitumen contained in the RAP particles. To minimize these impacts, softer binders or rejuvenators are commonly used in the design of these mixtures in order to restore part of the ductility lost and to reduce the stiffness. In spite of previous investigations demonstrating that the mortar plays an essential role in the workability, long-term performance, and durability of bituminous mixtures (where cracking, cohesion, and adhesion problems all start at this scale), not many studies have assessed the impacts caused by the presence of RAP. In response to this, the present paper analyzes the workability, fatigue performance, and water sensitivity of bituminous mortars containing different amounts of RAP (from 0% to 100%) and rejuvenators. Mortar specimens were compacted using a gyratory compactor and studied via dynamic mechanical analysis under three point bending configuration. The results demonstrated that the presence of RAP reduces the workability and ductility of asphalt mortars. However, it also causes an increase in their stiffness, which induces a more elastic response and causes an increase in their resistance to fatigue, which could compensate for the loss of ductility. This aspect, together with the low water sensitivity shown, when using Portland cement as an active filler, would make it possible to produce asphalt materials with high RAP contents with a similar long-term mechanical performance as traditional ones. In addition, the use of rejuvenators was demonstrated to effectively correct the negative workability and ductility impacts caused by using RAP, without affecting the fatigue resistance and material adhesion/cohesion.

Comparison of binder and mixture tests to characterize permanent deformation of elastomer and terpolymer modified binders

Elastomers, plastomers, and Reactive Ethylene Terpolymers (RETs) are some of the most commonly used polymers for modification of bitumen. Each type of modifier can have a considerably different influence on the rheological behavior of the binders and therefore, the performance of bituminous mixtures in pavements. In this study, for comparing the effect of different modifiers on the resistance to permanent deformation of asphalt binders, two elastomer-modified binders, and two RET-modified binders were evaluated using laboratory characterization tests. In order to have a comparison between the different modifiers, all the modified binders were prepared using the same base binder. A range of binder and mixture characterization tests were conducted including the Superpave high-temperature Performance Grading (PG) test, Multiple Stress Creep and Recovery test (MSCR) and steady shear tests on the binders, and flow number, flow time and dry rut wheel tests on the mixtures. Each binder characterization test was found to yield a different ranking of binders with respect to their resistance to permanent deformation. However, the results from mixture characterization tests were more conclusive; all tests on mixtures yielded nearly identical ranking of binders. When the results of binder and mixture characterization tests were compared, viscosity from steady shear tests was found to correlate the most with the permanent deformation observed in the mixture characterization tests.

Characterisation of asphalt binder modified with ethylene–propylene–diene–monomer (EPDM) rubber waste from automobile industry

Ethylene–propylene–diene–monomer (EPDM) is a high-quality synthetic rubber widely used in non-tyre automotive parts. Waste EPDM rubber is generated at several industries, manufacturing units, and automobile repair/service stations. The present study aims at the evaluation of asphalt binders and mixes with waste EPDM as a modifier. Modification was attempted with four EPDM contents (2%, 4%, 6% and 8% by binder weight). Storage stability was checked for the modified blends with and without a crosslinking agent (sulphur). Binder characterisation was done through penetration, softening point, temperature and frequency sweeps, master curve, multiple stress creep recovery, Burger’s model fit, and binder yield energy tests. Performance of bituminous mixtures with EPDM-modified binders was also evaluated through Hamburg wheel tracking, stiffness modulus, and indirect tensile strength tests. The incorporation of EPDM enhanced the rutting and fatigue performance of the binder. Mixtures showed better stiffness, rutting resistance and tensile strength compared to those with control mixes.

Effects of Composite Warm Mix Additive (CAR) on the Physical and Rheological Performance of Bitumen and the Pavement Performance of Its Concrete.

Warm mix asphalt received increasing attention in recent years, and this technology aims to increase the fluidity of bitumen in the process of mixing and construction. To characterize the physical and rheological properties of bitumen and the pavement performance of bituminous mixtures, it was modified by a composite additive Rediset. Rediset consists of both the cationic surfactants and organic additive-based rheology modifiers. Commonly used materials such as Pen 60/80 bitumen and bituminous concrete (AC-20) were selected. The results show that Rediset can improve the penetration and softening point of the bitumen, making the bitumen stiffer and harder. All Rediset-modified bituminous concretes are in the same low-temperature performance grade (PG) as the bitumen without Rediset. Although Rediset can decrease the rutting and crack resistance of Rediset-modified bituminous concrete, all the Rediset-modified bituminous concrete with less than 2% Rediset still satisfied the requirement of the maximum bending strain being higher than 2000 με, and the dynamic stability of Rediset-modified bituminous concrete with 3% Rediset was still higher than 1000 cycles/mm. The cationic surfactants in the Rediset can play the role of an anti-stripping agent and improve the adhesion between the interfaces of the aggregate and bituminous binder, which enhances the moisture resistance of Rediset-modified bituminous concrete.

A multi-criteria decision-making analysis for the selection of fibres aimed at reinforcing asphalt concrete mixtures

ABSTRACT In the last few years, fibers have been proposed as one of the most important additives for the development of reinforced asphalt mixtures. The optimal fiber selection is a very complex task, as an extensive range of criteria and alternatives have to be taken into account. Decision support systems have been applied in the construction sector, but not for selecting fibers for bituminous mixtures. To fill this gap, two Multi-Criteria Decision-Making Analysis methodologies for the selection of the best fiber to be used in Asphalt Concretes are presented in this paper. The Weighted Aggregate Sum Product Assessment (WASPAS) methodology and the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) integrated with Fuzzy Analytic Hierarchy Process (FAHP) are used to evaluate the effect of various types of fibers on the mechanical performance of bituminous mixtures. Given the uncertainty involved, a stochastic simulation is proposed using the Monte Carlo method. A statistical analysis is carried out to verify the results obtained. Both methods of multi-criteria analysis were effective, with TOPSIS being slightly more conservative in the assignment of performance scores. Synthetic fibers proved to be a suitable option as did fibers with high tensile strength and elastic modulus.

Value-added application of waste PET based additives in bituminous mixtures containing high percentage of reclaimed asphalt pavement (RAP)

Abstract The use of reclaimed asphalt pavement (RAP) in road pavement construction has been widely encouraged due to its environmental and economic benefits. However, the percentage of RAP is usually capped at low percentages as studies have shown that a high percentage of RAP might be detrimental to overall pavement performance. Recent research has shown that the addition of waste plastic materials such as Polyethylene Terephthalate (PET) or their functionalized additives into asphalt pavement may potentially improve the durability of pavement and also help alleviate the environmental problems caused by plastic. The main objective of this study is to investigate the feasibility of using the additives, derived from waste PET through an aminolysis process, to improve the performance of bituminous mixtures containing RAP, by characterising the binder properties. To achieve this objective, binder samples composed of virgin bitumen, aged bitumen at various percentages, and PET derived additives, were prepared. These samples were then characterized through various laboratory tests, including dynamic shear rheometer, bending beam rheometer, moisture susceptibility, infrared red spectroscopy and fluorescence microscopy tests. The results indicated that the samples containing RAP and PET derived additives provided better overall performance compared to the conventional binder, increasing the rutting resistance by at least 15% and fatigue cracking resistance by up to 60%. Usage of such waste PET based additives as an additive for RAP mixtures represents an approach to deal with a relevant recycling problem while simultaneously recovering two value-added materials.

Influence of Environmental Conditions on the Performance of Bituminous Mixtures

Abstract Aging and moisture damage are considered as major environmental factors which affect the performance of bituminous mixtures. This study investigated the effect of aging and moisture invasion on the performance of bituminous mixtures in terms of tensile strength and rutting resistance. Two different types of aggregates sources and one unmodified bituminous binder with and without warm additive were used. Bituminous mixtures were subjected to two levels of aging conditions (short-term and long-term aged) and two levels of moisture conditions (1 and 3 freeze-thaw cycles). A total of 24 different combinations were investigated for tensile strength and permanent deformation characteristics. Mineralogical investigations characterized the crushed stone as calcareous and bank run as siliceous aggregates. Results from this study demonstrate that levels of aging had a significant impact on the tensile strength of bituminous mixtures with warm mix additive as compared to conventional bituminous mixtures. Fracture work density, a surrogate cracking parameter was able to adequately capture the influence of aggregate mineralogy on the moisture susceptibility of long term aged mixtures. In addition, moisture conditioning was found to influence fracture work density of mixtures more than aging. Further, the rutting resistance of mixtures was determined in terms of flow numbers obtained using Francken model. In general, the rutting resistance of conventional mixtures was relatively higher than a mixture with warm mix additive. As expected, the flow number of conventional mixtures increased with aging and further reduced with moisture conditioning. Interestingly, the flow numbers of bituminous mixtures with warm mix additive was not negatively impacted by moisture at short term aged conditions. However, flow number of both mixtures after long term aging exhibited a similar trend. Additionally, statistical analysis showed that an increase in freeze-thaw cycles from one to three did not significantly impact the tensile characteristics of the mixtures.

Fatigue performance of bituminous mixtures made with recycled concrete aggregates and waste tire rubber

Fatigue cracking is one of the main hot-mix asphalt (HMA) failure modes. The current laboratory investigation analyses the fatigue performance of HMA made with recycled concrete aggregates (RCA). An HMA type AC 22 bin S made with 0%, 35% and 42% of RCA was tested in the indirect tensile fatigue test (ITFT) device. Three constant stress levels, ranging from 150kPa to 350kPa were used. Mixtures were manufactured at the optimum bitumen content using two types of bitumen: a B35/50 penetration grade bitumen and a 10% waste tire rubber modified bitumen, BC35/50. This investigation demonstrates the beneficial effect on fatigue life of the incorporation of RCA. Additionally, the use of crumb rubber could lead to RCA bituminous mixtures with higher fatigue life in medium traffic roads.

Application of rejuvenators and virgin bitumen to restore physical and rheological properties of RAP binder

Both chemical and rheological aspects of aged bitumen in reclaimed asphalt pavement (RAP) material play an important role in the final performance of bituminous mixtures containing recycled asphalt material. This must be especially considered in the case of pavements containing high RAP content. The use of rejuvenators and/or virgin bitumen in recycled mixtures helps improving the properties of aged bitumen. This research study investigates RAP oxidised bitumen and its possible rejuvenation with virgin bitumen and addition of various additives as rejuvenator agents. Tests were conducted to analyse the chemical, rheological and physical behaviours of several binder mixes before and after laboratory ageing processes. Long-term ageing of rejuvenated binder mixes was also investigated to assess the effectiveness of rejuvenation over time. The results showed that the addition of virgin bitumen and rejuvenators could improve the performance of oxidised bitumen and increase its resistance to further ageing.

Ageing and temperature effect on the fatigue performance of bituminous mixtures

The ageing of asphalt mixes, together with their exposure to low temperatures, causes a progressive increase of cracking. In this paper, the effect of ageing and temperature on the fatigue of asphalt concretes made with two types of binders, conventional (50/70) and polymer modified bitumen (PMB), is studied. For this purpose, specimens previously subjected to an accelerated laboratory ageing process were tested by a strain sweep test at different temperatures (-5ºC, 5ºC and 20°C). Results were compared with the obtained from the unaged specimens showing the relative importance of ageing, temperature and type of bitumen on the parameters that determine the fatigue life of the mixture. The mixtures behaviour becomes more brittle with ageing and the decrease of temperature. However, ageing hardly has an effect on fatigue at lower temperatures. In general, mixtures made with polymer modified bitumen have a better fatigue performance to ageing and temperature.

Investigation on rheological performance of sulphur modified bitumen (SMB) binders

In order to enhance the properties of base bitumen so as to improve the performance of bituminous mixture, it has been a common practice to modify the bitumen by adding some modifiers. Sulphur has been reported to be an effective extender for conventional bitumen. This study was attempted to develop a modified binder in the laboratory using VG-30 bitumen with sulphur (S) and study the effects of ‘S’ on the viscosity, rheological, penetration index and storage stability with effects of short and long term aging. The rheological study includes rutting, fatigue, master curve and Multiple Stress Creep Recovery (MSCR) test using Dynamic Shear Rheometer (DSR). It is observed that the modification of VG-30 with 2% of ‘S’ by weight at 140°C temperature for about 60min, resulted in homogeneous modified bitumen binder. The Superpave rutting parameter (G∗/Sinδ) and MSCR test results showed that, SMB-2S (VG-30+2% S) and SMB-3S (VG-30+3% S) binder exhibited better rut resistance performance, especially at high temperature. However, SMB-2S showed relatively lower value of Superpave fatigue factor and aging index value than SMB-3S, implying superior performance in fatigue and aging resistance behavior, respectively. Storage stability test results showed that modification with 2% S possessed better compatibility in bitumen matrix. Thus, it can be stated that the SMB-2S showed superior rheological and storage stability properties that can satisfy the requirements for resisting the rutting and fatigue cracking.

Performance evaluation of crumb rubber and paraffin modified stone mastic asphalt

Recently, crumb rubber (CR) obtained from waste tires and Fischer–Tropsch paraffin are mostly used in bitumen modification to improve the performance of bituminous mixtures. Each of these additives affects the different properties of mixtures. There are limited studies in the literature about the combined usage of additive in the same mixture to utilize the different characteristics. In this study, the stability, stiffness, fatigue resistance, permanent deformation resistance, and moisture susceptibility characteristics of the stone mastic asphalt prepared with the bitumen modified with CR and paraffin were examined and compared with the control mixture. It was determined that CR-modified mixtures showed significantly more elastic characteristics. The mixture in which the 10% CR and 3% paraffin were used together gave better results in terms of moisture susceptibility and fatigue resistance when compared with the control mixture. It was determined that the use of paraffin together with CR contributed to the improved performance, and was in accordance with the CR in terms of mechanical characteristics of stone mastic asphalt.