Ductility Test Research Articles

An approach to describe edge ductility

One of the challenges of utilizing advanced high-strength steels is their limited ability to withstand the forming of cut edges. Large production quantities of parts often lead to mechanical punching/shearing processes in blank preparation, providing a challenging starting point for forming processes. The most commonly used edge ductility test is the ISO 16630 hole-expansion test to describe stretch-flangeability properties. However, this method has been widely criticized for its large-scatter, unreliable results and the fact that it covers only a certain stress-strain state of cut edge forming. In addition, it does not provide enough data to be reliably used in forming simulations to predict edge failures. This paper presents an approach to create a more comprehensive way of describing overall edge ductility. Multiple edge forming test methods coupled with digital image correlation (DIC) were selected in order to investigate different edge loading scenarios in both open and closed trim line forming situations. Data regarding limiting local strain before cracking was collected for several steel grades, and results are gathered in 2D and 3D “Edge FLC”-figures. Attempts to utilize these results for simulation purposes are also presented. Results indicate that this approach can be useful to evaluate overall edge forming limits.

Composition and Evaluation on Road Performance of SBS/PTW High-Viscosity-Modified Asphalt and Its Mixtures for Ultrathin Overlays

As a highway pavement maintenance technology, the road performance of the ultra-thin overlay depends heavily on the performance of asphalt cement. For the preparation of high-performance-modified asphalt suitable for ultrathin overlay, the reactive blending technology was used based on SBS modified asphalt and combined with a penetration test, softening point test, ductility test, dynamic viscosity test, and viscous toughness test to study the optimal blending ratio of high-viscosity modified asphalt. Further, the rolling thin-film oven test (RTFOT), dynamic shear rheological (DSR) test, and Brookfield viscosity test are used to evaluate the technical properties of SBS/PTW modified asphalt under the best mixing ratio. Finally, the SMA-13 asphalt mixture was prepared with SBS/PTW high-viscosity modified asphalt and evaluated through a rutting test, low-temperature bending test, immersion Marshall test, freeze-thaw splitting test, structural depth test (TD), and British pendulum number (BPN) test. These results showed that the best blending mass ratio of high-viscosity modified asphalt is 6% SBS + 4% solubilizer + 0.2% PTW + 0.2% nano-ZnO. All technical property indexes of the prepared SBS/PTW high-viscosity modified asphalt meet the requirements of an ultra-thin overlay binder. The dynamic viscosity at 60°C reaches 64204 Pa·s, and the viscosity and toughness are 25.4 N·m and 20.9 N·m, respectively. SBS/PTW high-viscosity modified asphalt under dynamic shear rheology (DSR) test is classified as PG88 at high temperature. The rutting factor changes the smallest before and after aging, and it has excellent anti-aging performance. Furthermore, the asphalt mixture prepared by SBS/PTW high-viscosity modified asphalt has excellent high and low-temperature performance, water stability, and skid resistance performance. All properties meet the requirements of the ultra-thin overlay. This study demonstrated that the SBS/PTW high-viscosity modified asphalt possessed high viscosity properties, which can be used in the ultra-thin overlay and other highly demanding working environments.

Static Pullout Tests on Retrofitted Anchorage System in Concrete Using Supplementary Reinforcement

This paper presents experimental results of retrofitted anchorage system of structural concrete by using Post-Installation of Supplementary Anchorage (PISA) as a implicit strengthening measure and to improve the nonlinear performance of conventional anchorage system in hardened concrete. A total sixty specimens of M25 grade concrete (150x150x300mm) with two different size of rebar anchorage of 12mm, 16mm and five different configuration of conventional anchorage system was retrofitted by PISA technique is verified under direct tension pullout quasi static loads. The configuration of anchorage comprised by straight bar (A1), 90degree bend (A2), 180degree hook (A3), single head bar (A4) and double head bar (A5). The test parameters considered are bond strength, ductility, stiffness and bar-slip and test variables are configuration of anchorage, size of rebar and presence of supplementary steel. The obtained results validated by ANSYS modeling. This study concludes that a considerable improvement of nonlinear parameters such as ultimate load (3-8%), stiffness (4%-17%), ductility (16%-52%) and concrete contribution (6%-23%) by using PISA technique.

An Easy Way To Determine The Flexural Quality Of Asphalt Is Using ASTM D113 – 07 and SNI 2432:2011

Asphalt is a material that has non-volatile properties and softens gradually when heated and functions as a binder for aggregates and as a surface covering material to make it impermeable to water. However, asphalt also has a weakness. Namely, it is easy to crack and be damaged when vehicles pass through the main road. To overcome cracked and worn roads, it is necessary to test the ductility of asphalt so that the road becomes flexible/plastic. This ductility test is very important because it greatly affects the pavement layer; Therefore, a ductility test is needed to determine the level of plasticity of an asphalt. The asphalt ductility test method refers to the specifications of ASTM D113 – 07 and SNI 2432:2011 with 3 samples of test objects and a test instrument called a ductilometer of type TAS – 250. Based on the ductility test, the asphalt ductility reaches an average elongation of 117.33 cm; This value indicates that the plasticity level of the asphalt has met the specifications and can be used in sustainable pavement construction layers because it has good plasticity.

Unlocking the Hidden Potential of Cosmetics Waste for Building Sustainable Green Pavements in the Future: A Case Study of Discarded Lipsticks.

This investigation is dedicated to unlocking the hidden potential of discarded cosmetics towards building green sustainable road pavements in the future. It is particularly aiming at exploring waste lipstick (WLS) as a high-quality functional additive for advanced asphalt mix technologies. To fuel this novel innovation, the effect of various WLS doses (e.g., 5, 10, and 15 wt.%) on the performance of base AP-5 asphalt cement was studied in detail. A wide array of cutting-edge analytical lab techniques was employed to inspect in-depth the physicochemical, microstructural, thermo-morphological, and rheological properties of resultant admixtures including: elemental analysis, Fourier transform-infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thin-layer chromatography-flame ionization detection (TLC-FID), scanning electron microscopy (SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), needle penetration, ring and ball softening point, Brookfield viscometer, ductility, and dynamic shear rheometer (DSR) tests. Unlike the unstable response of asphaltenes, the additive/artificial aging treatments increased the fraction of resins the most, and decreased that of aromatics; however, asphaltenes did not impair the saturates portion, according to Iatroscan research. FT-IR scan divulged that the WLS-asphalt interaction was physical rather than chemical. XRD diagnosis not only revealed an obvious correlation between the asphaltenes content and the fresh-binder crystallinity but also revealed the presence of fillers in the WLS, which may generate outstanding technical qualities to bituminous mixes. According to AFM/SEM analyses, the stepwise incorporation of WLS grew the magnitude of the “bee-shaped” microstructures and extended the roughness rate of unaged/aged binders. The prolonged consumption of the high thermal-stable additive caused a remarkable drop in the onset degradation and glass transition temperature of mixtures, thus enhancing their workability and low-temperature performance, according to TGA/DTGA/DSC data. The DSR and empirical rheological experiments demonstrated that the WLS could effectively lower the manufacturing and compaction temperatures of asphalt mixes and impart them with valuable anti-aging/fatigue-cracking assets. In a nutshell, the use of waste lipstick as an asphalt modifier is viable and cost-effective and could attenuate the pollution arisen from the beauty sector, while improving the performance of hot/warm asphalt mixes (HAM/WAM) and extending the service life of roadways.

Physical, Chemical and Thermal Properties of Palm Oil Boiler Ash/Rediset-Modified Asphalt Binder

The growth of the palm oil industry has resulted in an increase in the production of solid waste, created from the extraction of fresh fruit bunches, which can take the form of palm oil boiler ash (POBA). POBA can be used to modify asphalt binder and asphalt mixtures to reduce the harmful effect of this waste on the environment. The objective of each modification is to increase the strength, stiffness, durability, workability and constructability of asphalt mixtures while reducing the environmental effects. This study examines the physical and chemical properties of 60/70 penetration-grade asphalt binder, modified using POBA and warm mix asphalt (WMA) additive. Ranges of modified binder were prepared by adding 2% of the warm additive Rediset with different POBA contents (3%, 5%, 7% and 9%) throughout the wet mixing process. Physical properties of modified binder were obtained from penetration, softening point, ductility and rotational viscosity tests. Molecular components and structures of the modified binder were identified using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to determine the thermal properties of modified asphalt binder. The addition of 7% POBA in WMA binder showed the best characteristics in the tested consistency of its physical properties. As a modifier, POBA showed no chemical interaction with the molecules and structures of the asphalt binder and did not significantly change the physicochemical transitions. From the results, it can be concluded that using POBA in WMA binder for pavement construction is a viable option.

Evaluation on the Performance of Hydraulic Bitumen Binders under High and Low Temperatures for Pumped Storage Power Station Projects.

The high and low-temperature performance of five hydraulic bitumen binders was evaluated using the dynamic shear rheometer (DSR) test, infrared spectrum test and direct tensile (DT) test. These hydraulic bitumen binders were respectively applied for several pumped storage power stations (PSPS) projects that were constructed or under construction. In order to relate the bitumen performance to the mixture performance, the slope flow test, three-point bending test and thermal stress restrained specimen test were carried out on hydraulic asphalt mixtures. The test results indicated the DSR rheological master curves can well distinguish the difference of each bitumen binder as well as the effect of polymer modification. Phase angle master curves, black diagrams and infrared spectra all indicated that several penetration-grade hydraulic bitumen binders were not virgin bitumen binders but were modified with relatively lower SBS polymer content when compared with traditional SBS-modified bitumen. When selecting the commonly used Karamay SG70 hydraulic bitumen as a reference, the normal SBS-modified bitumen was superior to other bitumen in terms of low- and high-temperature performance. Several slightly SBS-modified bitumen binders did not always show consistent results, which indicated that slightly modified bitumen may not really have the desired performance as expected. Therefore, SBS-modified bitumen will be more promising when dealing with extremely low or high temperatures. Bitumen performance was well compared with the mixture performance by using the bitumen creep, relaxation and tensile failure strain corresponding to the asphalt concrete slope flow, the maximum bending strain and the failure temperature, respectively. Compared with the traditional penetration, softening point and ductility test, it indicated that the DSR rheological test, creep test, direct tensile test and stress relaxation test can be used as more powerful tools for the characterization and optimization of hydraulic bitumen binders.

Effects of tetraethyl orthosilicate on rheological behaviors of crumb rubber modified asphalt

The purpose of this work is to study the rheology, fatigue properties and physical changes of crumb rubber modified asphalt (CRMA) after pretreatment of rubber crumbs with tetraethyl orthosilicate (TEOS). Six weight ratios of TEOS to crumb rubber, 0%, 15%, 20%, 25%, 35%, and 50%, were chosen to prepare modified crumb rubber (CR) and use it to prepare CRMA. The effects of TEOS on the physical properties of CRMA were analyzed through softening point, penetration and ductility tests. Mechanical tests including multiple stress creep and recovery (MSCR) test, temperature sweep test, and linear amplitude sweep (LAS) test were conducted to evaluate rheological properties and fatigue resistance. The results show that TEOS addition can effectively improve the physical properties, rheological properties and high temperature stability of CRMA. However, the excessive addition of TEOS can decrease rheological properties and fatigue life of rubber-modified asphalt. The results of temperature scanning test and MSCR test show that CRMA has the best G* and δ under the condition that TEOS content is 25% of CR mass; and it has optimal non-recoverable creep compliance (J(nr)) and percentage of recovery (R%). LAS test results indicate that CRMA has better fatigue life when TEOS content is 25% of CR.

Physical properties of palm oil boiler ash modified bitumen with Rediset

This study examines the physical properties of a 60/70 penetration grade bitumen modified using warm mix asphalt (WMA) additive, Rediset and palm oil boiler ash (POBA) as a modifier. Modified binders were prepared by adding 2% of Rediset with different POBA contents (3, 5, 7, and 9%) through wet mixing process. Physical properties of modified bituminous binder were obtained from penetration, softening point, rotational viscosity and ductility tests. The addition of 7% POBA in WMA binder has the best characteristics in term of its physical properties. The penetration values, softening point temperatures and ductility characteristics show inconsistent patterns. However, the rotational viscosity of each combination had decreased with the increment of temperature even though the trend was not significantly constant. Penetration index (PI) showed an increment with 3 and 5% and decrement pattern on 7 and 9% as well as penetration viscosity number (PVN) showing an inconsistent decrement with the addition of POBA. From the results, it can be concluded that using POBA in WMA binder for pavement construction is a viable option and can be further investigated.

PERFORMANCE EVALUATION OF ETHYLENE-VINYL ACETATE MODIFIED BITUMEN AND MIXTURES

Interconnectivity necessitates the use of transportation facilities and infrastructure. All highway design agencies seek acceptable, long-lasting, and cost-effective strategies while designing these facilities. The traffic demands on roads are much higher than they have been in the past. Increased traffic loads, larger traffic volumes, and insufficient maintenance have all contributed to serious road surface distress (e.g., rutting and cracking) due to rapid development. As conventional asphalt combinations are unable to withstand high axle loads and tire pressures, interest in polymer-modified asphalt has grown. Polymer modification of asphalt is one of the most effective ways to improve asphalt qualities. The practical temperature range of binders is greatly expanded by polymers. The inclusion of the polymer can considerably improve the binder qualities by increasing the stiffness of the bitumen and enhancing its temperature susceptibility, enabling the building of safer roads and lower maintenance costs. This research presents a laboratory investigation of the Ethylene Vinyl Acetate (EVA) polymer-modified bitumen. NHA-B gradation, PARCO 60/70 grade bitumen, and EVA polymer of TPI Polene Public Company Limited were used. Penetration, softening point, ductility, and viscosity tests were used to evaluate the conventional properties of the asphalt binders. Three different percentages of polymers were used i.e., 2%, 4%, and 6%. The impact of the EVA polymer on permanent deformation and moisture susceptibility was investigated. A double wheel tracker (DWT) was used to quantify permanent deformation (rutting), and a Universal Testing Machine (UTM) was used to examine moisture susceptibility using an Indirect Tensile Strength (ITS) test. For different percentages of bitumen volumetric properties according to Marshall Mix Design procedure were measured, and then Optimum Bitumen Content (OBC) was evaluated. Performance tests were performed using above mentioned percentages of EVA. The rutting potential of mixes was improved by the addition of EVA as compared to control asphalt mixes. The same effect of the polymer was on the moisture susceptibility of the prepared samples. This showed that EVA polymer can be used in flexible pavements to reduce permanent deformation and high-temperature problems.

Modification mechanism and enhanced low-temperature performance of asphalt mixtures with graphene-modified phase-change microcapsules

This study explored the modification mechanism of adding commercial graphene (CG) to microcapsule wall materials of the prepared modified phase-change microcapsules (MFPCM) and the modified asphalt. To this end, different amounts of CG and melamine formaldehyde (MF) resin were used as microcapsule wall materials (with n-tetradecane as the core material) to prepare graphene-modified phase-change microcapsule (CGMFPCM) specimens. The microstructure and properties of MFPCM specimens with different contents of CG were also characterized via a differential scanning calorimeter (DSC), simultaneous thermal analyzer, scanning electron microscope (SEM), and Fourier-transform infrared (FT-IR) spectrometer. Next, the asphalt specimens modified by n-tetradecane, MFPCM, and CGMFPCM with different contents were prepared by the high-speed shearing method. The conventional performances of the modified asphalt specimens were assessed via penetration, softening point, and ductility tests, while their microstructure and performance were investigated by SEM, FT-IR spectrometer, and DSC. The thermodynamic characteristics of both base and modified asphalt specimens were measured via a conductometer. No chemical reactions between the added CG and core or wall materials of MFPCM were revealed. After adding CG, CGMFPCM specimens combined high heat conductivity of CG and phase change performance of MFPCM. Adding 0.45% CG to MFPCM enhanced its thermal efficiency without harming its thermal stability. The modification of base asphalt by phase-change materials was reduced to its physical modification, implying that phase-change materials were simply dispersed in the base asphalt with no chemical reactions. High-temperature heating and high-speed shearing in the preparation of modified asphalt reduced the effective content of phase-change materials. Both microscopic and macroscopic test results confirmed that the low-temperature performance of asphalt was improved after adding CGMFPCM.

Characterization of waste cooking oil and waste engine oil on physical properties of aged bitumen

Waste cooking oil (WCO) and waste engine oil (WEO) have been generated in huge quantities in recent years as a result of the improvement of society's living standards and the advancement of automobiles and The molecular structure of WCO and WEO is similar to bitumen, indicating their potential for usage in highway construction to mitigate the hardening effect of recovered asphalt pavement materials. In this study, five different ratios of WCO and WEO were blended with VG40 grade bitumen under ageing conditions in accordance with the adaptability of the paving bitumen specification (IS 73: 2013). The waste oil treated samples were artificially short-aged by means of the thin film oven test. The penetration, softening point, viscosity, temperature sensitivity, penetration ageing ratio, and ductility tests were used to evaluate the physical performance parameters of the WCO and WEO modified bitumen.The results of the tests reveal that the blending of WCO and WEO with neat bitumen softens the workability of aged bitumen. The physical properties of aged bitumen improved when treated with WEO as compared to when treated with WCO. Based on the results of the analyses and the overall ranking, it has been found that a blend of 3 percent WEO and 3 percent WCO resulted in the most significant improvement in bitumen modification. Significant differences were observed when waste oil was blended with a higher percentage, resulting in a change in the grade of bitumen.

Modification Mechanism and Rheological Properties of Emulsified Asphalt Evaporative Residues Reinforced by Coupling-Modified Fiber

In order to solve the problems of the smooth surface of basalt fiber and its weak interfacial adhesion with emulsified asphalt cold recycled mixture, a silane coupling agent (KH550) was used to treat the surface of basalt fiber and the effects of treatment concentration and soaking time on fiber modification were studied. The influence of silane coupling-modified basalt fiber (MBF) on the rheological properties of emulsified asphalt evaporation residue was studied at high and low temperatures using three routine index tests: a dynamic shear rheological test (DSR), a bending beam rheological test (BBR), and a force ductility test. The elemental changes of the fiber before and after modification and the microstructure of the emulsified asphalt evaporation residue with the coupling-modified fiber were analyzed by Fourier infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray energy dispersive spectroscopy (EDS), which is used to study the modification mechanism of emulsified asphalt evaporation residue reinforced by coupling-modified fiber. The results indicate that the concentration and soaking time of the silane coupling agent have a great influence on the surface morphology and mechanical properties of the fiber, and that the optimal treatment concentration is 1.0% and the optimal soaking time is 60 min. The addition of coupling-modified fibers can reduce the phase angle and unrecoverable creep compliance of emulsified asphalt evaporation residue, increase the rutting factor and creep recovery rate, and improve the elastic recovery ability and permanent deformation resistance. However, excessive fiber will weaken the ductility of emulsified asphalt at low temperatures. The appropriate content of silane coupling-modified fiber (MBF) is 1.5%. After silane coupling modification, the fiber surface becomes rough and cohesion is enhanced between the fiber and the emulsified asphalt base. Silane coupling-modified basalt fiber (MBF) acts as reinforcement for stability and bridging cracks.

Rheological evaluation of asphalt binder modified by amorphous poly alpha olefin (APAO)

This study examined the effect of amorphous poly alpha olefin (APAO) on the rheological behavior of asphalt binder. In order to modify asphalt binder, several percentages of APAO (0, 2, 4, 6, 8%, and 10% by the weight of asphalt binder) were used. The penetration grade, softening point, ductility, and viscosity tests were performed. Also, the multiple stress creep recovery (MSCR) and linear amplitude sweep (LAS) tests were conducted to evaluate the rutting and fatigue behavior of asphalt binder. The storage stability test was implemented to measure the ability of modified asphalt binder against separation. Based on the results, using APAO reduced the penetration grade and increased the softening point due, maybe, to the asphalt binder stiffening. The PI values increased with the addition of APAO, which indicated that the temperature susceptibility of all modified asphalt samples was reduced compared to the base asphalt binder. The increase in the viscosity of virgin asphalt binder due to APAO addition caused the mixture placement/compaction operations to become harder. The G*/sinδ parameter for all types of pre-post-aging RTFO asphalt binders was improved for APAO-modified asphalt binder, meaning that the latter stiffened and thus increased the respective rutting resistance of mixtures. The low-temperature performance of asphalt binder indicated that the stiffness of asphalt sample increased with an increase in the APAO percentage, which indicates that the addition of APAO improved the cracking potential of modified asphalt binders and had negative effects on the asphalt binders. The storage stability test results indicated that the phase separation of asphalt binder was related to the APAO content. Results revealed, ignoring the levels of stress, that using APAO reduced the non-recoverable creep compliance (Jnr) value of virgin asphalt binder, indicating the production of an asphalt binder benefitting higher rutting resistance with APAO modification. APAO increased the %R of asphalt binder. Based on the LAS test results, the addition of APAO led to an increase in the fatigue life of asphalt binders, and by increasing the additive content, the fatigue life increased. The FTIR analysis indicated that no chemical interaction was observed between asphalt binder and APAO.

Effects of Alkylamines-Based and Polyalkylene Glycol-Based Bonding Enhancers on the Performance of Asphalt Binders

The premature deterioration of asphalt pavements usually occurs due to different moisture damage mechanisms resulting in stripping, ravelling, potholes, and disintegration without proper treatment. Numerous efforts have been taken into consideration to improve the bonding between materials, hence prolonging the pavement life. This study evaluates the performance of asphalt binders incorporating Alkylamines-based (ALM) and Polyalkylene Glycol-based (PLG) bonding enhancers. Each bonding enhancer at 0.5% and 1.0% based on the weight of asphalt binder was separately blended with the conventional asphalt binder 60/70 penetration grade using a high shear mixer at 1000 rpm for 30 minutes at 160°C. The physical and rheological properties of modified binders were evaluated through penetration value, softening point, ductility, elastic recovery, rotational viscosity (RV), and dynamic shear rheometer (DSR) tests. Overall, additions of ALM and PLG show identical penetration grade compared to the control sample. Both ALM and PLG showcase a higher ductility and elastic recovery than the neat binder. The DSR test indicates the incorporation of bonding enhancers improves the modified binders’ rutting performance. While the application of ALM at 0.5% dosage increased the binder failure temperature out of all the tested samples, where the failure temperature is at 70°C, compared to others at 64°C. Studies at mastics and mixture levels should be conducted to appropriately understand the effect of bonding enhancer on the bituminous materials.

Study on the Physical, Chemical and Nano-Microstructure Characteristics of Asphalt Mixed with Recycled Eggshell Waste

Green economy is a major them of sustainable development. The application of biological waste in engineering is conducive to green development. This study reveals the effect of recycled eggshell waste on the physical and chemical properties as well as nano-microstructure characteristics of asphalt. The hardness, thermal stability and ductility of asphalt were explored by the penetration, softening point and ductility tests. The distribution and relative content of protons in asphalt were revealed by nuclear magnetic resonance hydrogen spectrum (1H-NMR). The microscopic characteristics of the particle morphology and surface structure of the eggshell powder were explored by scanning electron microscopy (SEM). An atomic force microscope (AFM) was used to analyze the evolution laws of asphalt nano-microstructures. The experiment results indicate that (1) the eggshell waste increases the hardness, thermal stability and reduces the ductility of asphalt; (2) the chemical environment in which the protons of the eggshell waste asphalt are located and the H index have no obvious changes; (3) the eggshell powder is characterized by a rough, wrinkled, porous and loosened structure; (4) the nano-microstructure of eggshell waste asphalt exhibits “bee-like structures”, and the different proportion of eggshell waste changes the maturity, size and quantity of the “bee-like structures” and roughness, which can be attributed to the interaction of the asphaltene-waxiness system.

A new approach to enhance the reclaimed asphalt pavement features: role of maltene as a rejuvenator

The properties of aged asphalt can be renewed using rejuvenating agents. Rejuvenators can improve the performance of reclaimed asphalt pavement (RAP) by reducing the asphaltene-to-maltene ratio back to their initial state. This study assessed the function of maltene as a rejuvenator to renew aged asphalt. Penetration, softening point, ductility and viscosity tests were performed to determine the ideal maltene content to be incorporated into RAP. The rejuvenated asphalt samples were evaluated using rolling thin film oven (RTFO), dynamic shear rheometer (DSR), bending beam rheometer (BBR), Fourier transform infrared (FTIR), thermogravimetric (TGA) and atomic force microscopy (AFM) measurements. The outcomes were compared with virgin and aged asphalts. Both oxygenated groups and asphaltene content decreased by adding 12% maltene. Essentially, DSR, BBR, TGA, and AFM analyses divulged the comparable performance of rejuvenated asphalt with virgin asphalt, signifying the potency of maltene for practical applications.

Effect of Recycled Shell Waste as a Modifier on the High- and Low-Temperature Rheological Properties of Asphalt

The deteriorating ecological environment and the concept of sustainable development have highlighted the importance of waste reuse. This article investigates the performance changes resulting from the incorporation of shellac into asphalt binders. Seashell powder-modified asphalt was prepared with 5%, 10%, and 15% admixture using the high-speed shear method. The microstructure of the seashell powder was observed by scanning electron microscope test (SEM); the physical-phase analysis of the seashell powder was carried out using an X-ray diffraction (XRD) test; the surface characteristics and pore structure of shellac were analyzed by the specific surface area Brunauer-Emmett-Teller (BET) test; and Fourier infrared spectroscopy (FTIR) qualitatively analyzed the composition and changes of functional groups of seashell powder-modified asphalt. The conventional performance index of seashell powder asphalt was analyzed by penetration, softening point, and ductility (5 °C) tests; the effect of seashell powder on asphalt binder was studied using a dynamic shear rheometer (DSR) and bending beam rheometer (BBR) at high and low temperatures, respectively. The results indicate the following: seashell powder is a coarse, porous, and angular CaCO3 bio-material; seashell powder and the asphalt binder represent a stable physical mixture of modified properties; seashell powder improves the consistency, hardness, and high-temperature performance of the asphalt binder but weakens the low-temperature performance of it; seashell powder enhances the elasticity, recovery performance, and permanent deformation resistance of asphalt binders and improves high-temperature rheological properties; finally, seashell powder has a minimal effect on the crack resistance of asphalt binders at very low temperatures. In summary, the use of waste seashells for recycling as bio-modifiers for asphalt binders is a practical approach.

Effect of the binary compound method of TOR promoting dissolution and NaOH solution surface treatment on the performance of rubber asphalt

In view of the problems of poor high-temperature storage stability, high viscosity and easy segregation of rubber powder modified asphalt, the rubber asphalt was prepared using a binary combination of surface treatment crumb rubber powder (CRP) in NaOH solution and a doped trans-polyoctenamer rubber reactant (TOR). Through asphalt softening point, penetration, ductility and segregation tests, a reasonable concentration of 2% NaOH for surface treatment of CRP and an optimum content of 4.5% for TOR were determined. The microscopic mechanism of NaOH and TOR on rubber asphalt was analyzed by tests such as scanning electron microscopy and infrared spectroscopy, and the performance of binary compound modified asphalt (NT-RA) was analyzed using segregation test, bending beam rheometer (BBR), dynamic shear rheology (DSR) and Brinell rotational viscosity test. The results show that NaOH solution could remove impurities on the surface of CRP and improve the interfacial adhesion state between asphalt, and TOR can promote the dissolution of CRP in asphalt. The binary compound action significantly improves the storage stability, low-temperature performance and high-temperature performance of rubber asphalt, and effectively reduces the viscosity of rubber asphalt.

Experimental investigation on the performance of bone glue and crumb rubber compound modified asphalt

Bone glue (BG) and crumb rubber (CR), as waste derivatives, have the advantages of low cost, green, and extensive sources. At present, the research and application of BG in road engineering are still insufficient, and there are few studies on using the combination of BG and CR for asphalt modification. Thus, this work studied the effect of BG and CR composite modification on the performance of asphalt. A series of conventional tests and rheological tests, including penetration, softening point, phase separation, temperature sweep (TS), multiple stress creep and recovery (MSCR), were used to evaluate high-temperature properties. Bending beam rheological (BBR) test and ductility test were carried out to assess the low-temperature characteristics of composite modified asphalt. Finally, the microstructure of composite modified asphalt was studied by fluorescence microscope (FM). The functional groups referring to the chemical components present of BG/CR composite modified asphalt were identified through Fourier transform infrared (FTIR) spectroscopy. It can be found from the results that the penetration decreases, and the softening point and ductility increase. Moreover, the combination of BG and CR increases the rutting factor, recovery rate, and creep rate. Besides, this composite material decreases the creep modulus and non-recoverable creep compliance. Furthermore, it was found that blending BG and CR into asphalt can enhance its high- and low-temperature characteristics. In addition, BG significantly enhances the CR-modified asphalt's storage stability, and the BG/CR modifier is uniformly and stably dispersed in the matrix asphalt. FT-IR results showed that the composite modification between BG, CR, and asphalt matrix is a physical process.