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This study investigates the combined impact of Trinidad Lake Asphalt (TLA) and styrene–isoprene–styrene (SIS) on the performance of PG 64-22 asphalt binder. The study specifically examines how the addition of TLA and SIS affects the stiffness, viscoelastic properties, and ability to resist deformation of the asphalt binder, using the Superpave test method. The findings demonstrate that the addition of SIS improves the ability to withstand deformation, with the best results seen in the mixture containing 20% TLA and 5% SIS. This blend achieves a harmonious combination of stiffness, pliability, and ease of use. Increasing the SIS content to 10% and combining it with a 20% TLA greatly enhances resistance to rutting, but it also decreases workability. In addition, a mixture consisting of 10% TLA and 10% SIS provides excellent resistance to fatigue and possesses viscoelastic properties that are well suited for reducing oxidative aging and cracking. Although SIS typically enhances the performance of binders, an excessive quantity can result in unwanted rigidity, requiring meticulous optimization. The results highlight the importance of customizing TLA–SIS combinations according to specific environmental conditions in order to optimize advantages. Subsequent studies should investigate the prolonged impacts and alternative combinations of additives to further improve the performance of binders. [ABSTRACT FROM AUTHOR]

This study investigates the combined impact of Trinidad Lake Asphalt (TLA) and styrene–isoprene–styrene (SIS) on the performance of PG 64-22 asphalt binder. The study specifically examines how the addition of TLA and SIS affects the stiffness, viscoelastic properties, and ability to resist deformation of the asphalt binder, using the Superpave test method. The findings demonstrate that the addition of SIS improves the ability to withstand deformation, with the best results seen in the mixture containing 20% TLA and 5% SIS. This blend achieves a harmonious combination of stiffness, pliability, and ease of use. Increasing the SIS content to 10% and combining it with a 20% TLA greatly enhances resistance to rutting, but it also decreases workability. In addition, a mixture consisting of 10% TLA and 10% SIS provides excellent resistance to fatigue and possesses viscoelastic properties that are well suited for reducing oxidative aging and cracking. Although SIS typically enhances the performance of binders, an excessive quantity can result in unwanted rigidity, requiring meticulous optimization. The results highlight the importance of customizing TLA–SIS combinations according to specific environmental conditions in order to optimize advantages. Subsequent studies should investigate the prolonged impacts and alternative combinations of additives to further improve the performance of binders.

Rutting of asphalt pavement occurs earlier and is more serious under the increasingly heavy traffic load conditions that can be found in subtropical monsoon climate regions. High modulus asphalt concrete (HMAC) with excellent anti-rutting and anti-fatigue properties is generally used to mitigate this issue. Given the relatively high cost of the additives used in this type of asphalt, in this study the feasibility of using recycled asphalt mixture (RAP) and Trinidad lake asphalt (TLA) for the preparation of HMAC is considered. The mineral composition of the RAP is first analyzed, then the TLA modified asphalt with different levels of RAP content is used to assess the effect of RAP on the performance of the mixture. Finally, the high-temperature rheological properties of extracted bitumen and the adhesion characteristic between mineral and bitumen are analyzed. The results show that after RAP combustion, the yellowish and greyish minerals display different alkalinity values, while the greyish mineral exhibits an improved ability to combine with bitumen. Thus, RAP can significantly enhance the high-temperature rutting resistance of TLA modified asphalt mixtures. The aged bitumen in RAP makes the mixed binder harder and improves its rheological properties at high temperatures. [ABSTRACT FROM AUTHOR]

Asphalt materials have a very wide range of applications in roads, but with the increase of traffic pressure and the intensification of cracking and rutting in traditional asphalt pavements, there is an urgent need to further improve the performance of asphalt materials. In this paper, composite asphalt materials containing 10%, 20%, and 30% trinidad lake asphalt (TLA) and 0%, 2%, 3%, and 4% styrene-butadiene rubber (SBR) were prepared. Their basic properties and the properties of the mixes used for road rehabilitation were analyzed. It was found that the addition of TLA and SBR caused a decrease in the penetration degree of the material, but significantly increased the softening point of the material, TLA was detrimental to the ductility of the material, and SBR could improve the ductility. From the analysis of the performance of road rehabilitation mixes, the comprehensive performance of 20% TLA+3% SBR was good, its dynamic stability reached 3,712.66 times/mm, its water stability was also good, and its stiffness modulus was 3,332.64 MPa. The results prove the improvement of TLA and SBR for asphalt performance, and this method can be applied in practical projects. [ABSTRACT FROM AUTHOR]

Increasing the content of reclaimed asphalt pavement material (RAP) in hot-mix recycled asphalt mixture (RHMA) with a satisfactory performance has been a hot topic in recent years. In this study, the performances of Trinidad lake asphalt (TLA), virgin asphalt binder, and aged asphalt binder were first compared, and then the modification mechanism of TLA on virgin asphalt and aged asphalt was explored. Furthermore, the RHMA was designed in accordance with the French norm NF P 98-140 containing 50% and 100% RAP, and their high-temperature stability, low-temperature cracking resistance, and fatigue performances were tested to be compared with the conventional dense gradation AC-20 asphalt mixture. The results show that the addition of TLA changes the component proportion of virgin asphalt binder, but no new functional groups are produced. The hard asphalt binder modified by TLA has a better rutting resistance, while the fatigue and cracking resistance is lower, compared to both aged and virgin asphalt. The high-modulus design concept of RHMA is a promising way to increase the RAP content in RHMA with acceptable performance. Generally, the RHMA with 50% RAP has similar properties to AC-20. And, when the RAP content reaches 100%, the high- and low-temperature performance and anti-fatigue performance of RHMA are better than AC-20 mixture. Thus, recycling aged asphalt using hard asphalt binder for hot-mixing recycled asphalt mixture to increase the RAP content is feasible. [ABSTRACT FROM AUTHOR]

Based on the evaluation index test and contact angle adhesion test of the composite modified asphalt penetration system, the high-low temperature performance, segregation, construction and workability of TLA/SBR modified asphalt were evaluated, road performance and fatigue resistance of TLA/SBR modified asphalt mixture were verified by indoor road performance test and cantilever beam fatigue test. The results show that the addition of TLA can significantly improve the softening point, viscosity and surface energy of SBR modified asphalt, and improve the adhesion of composite modified asphalt. The addition of SBR ensures that TLA can have sufficient low temperature ductility. The addition of TLA significantly improves the high temperature performance and water stability of SBR modified asphalt mixture. SBR modifier makes up for the low temperature performance defects of TLA modified asphalt mixture. TLA/SBR composite modified asphalt mixture has excellent comprehensive road performance and fatigue resistance. The recommended TLA dosage is 20%~30%, and SBR dosage is 3.5%~4.5%. [ABSTRACT FROM AUTHOR]

Mastic asphalt (MA) has been recognized as one of the most deformation-resistant and thus durable materials for bridge pavement. The performance properties of MA are highly dependent on the physical and rheological properties of the binder applied in the MA mixture. To modify the binder properties to obtain the expected performance of the MA mixture, Trinidad Lake Asphalt (TLA) is often applied. In this study, the TLA-modified binders to be used in mastic asphalt bridge pavement systems were evaluated to develop the optimum material combination using conventional and performance-related testing. Physical and rheological tests were carried out on TLA-modified binders with the different modifier content in the range of 10–50% on a weight basis. The tests revealed that the TLA modifier addition to the 35/50 base bitumen should be close to the value of 20%. Higher concentrations of TLA may make the binder very stiff and could induce low-temperature cracks in mastic asphalt. [ABSTRACT FROM AUTHOR]

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Increasing the content of reclaimed asphalt pavement material (RAP) in hot-mix recycled asphalt mixture (RHMA) with a satisfactory performance has been a hot topic in recent years. In this study, the performances of Trinidad lake asphalt (TLA), virgin asphalt binder, and aged asphalt binder were first compared, and then the modification mechanism of TLA on virgin asphalt and aged asphalt was explored. Furthermore, the RHMA was designed in accordance with the French norm NF P 98-140 containing 50% and 100% RAP, and their high-temperature stability, low-temperature cracking resistance, and fatigue performances were tested to be compared with the conventional dense gradation AC-20 asphalt mixture. The results show that the addition of TLA changes the component proportion of virgin asphalt binder, but no new functional groups are produced. The hard asphalt binder modified by TLA has a better rutting resistance, while the fatigue and cracking resistance is lower, compared to both aged and virgin asphalt. The high-modulus design concept of RHMA is a promising way to increase the RAP content in RHMA with acceptable performance. Generally, the RHMA with 50% RAP has similar properties to AC-20. And, when the RAP content reaches 100%, the high- and low-temperature performance and anti-fatigue performance of RHMA are better than AC-20 mixture. Thus, recycling aged asphalt using hard asphalt binder for hot-mixing recycled asphalt mixture to increase the RAP content is feasible.

Mastic asphalt (MA) has been recognized as one of the most deformation-resistant and thus durable materials for bridge pavement. The performance properties of MA are highly dependent on the physical and rheological properties of the binder applied in the MA mixture. To modify the binder properties to obtain the expected performance of the MA mixture, Trinidad Lake Asphalt (TLA) is often applied. In this study, the TLA-modified binders to be used in mastic asphalt bridge pavement systems were evaluated to develop the optimum material combination using conventional and performance-related testing. Physical and rheological tests were carried out on TLA-modified binders with the different modifier content in the range of 10–50% on a weight basis. The tests revealed that the TLA modifier addition to the 35/50 base bitumen should be close to the value of 20%. Higher concentrations of TLA may make the binder very stiff and could induce low-temperature cracks in mastic asphalt.

Copyright of New Building Materials / Xinxing Jianzhu Cailiao is the property of New Building Materials Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to improve the low-temperature cracking resistance and durability of high-modulus asphalt mixture, this article proposes the use of Trinidad Lake Asphalt (TLA) and polyester fibre complex methods to obtain high-modulus asphalt mixture, based on indoor accelerated load, low bending temperature, freeze-thaw splitting and APA fatigue test to study the influence of TLA content on permanent deformation resistance performance, water stability, low-temperature crack resistance and fatigue resistance of high-modulus asphalt mixtures. Meanwhile, it reveals the mechanism of the TLA and polyester fibre composite modified on high-modulus asphalt mixture and recommends the best solution of high-modulus asphalt complex is 30% TLA + 3‰ polyester fibre. [ABSTRACT FROM AUTHOR]

The reuse of waste crumb rubber (CR) (used tyres) and Polyethylene Terephthalate (PET) (plastic beverage bottles) is of particular interest in Trinidad and Tobago since present disposal techniques presents environmental and health challenges. The results of this study investigating the influence of PET and CR on the performance characteristics of the HMA2 pavement design using Trinidad Lake Asphalt (TLA) and Trinidad Petroleum Bitumen (TPB) filled an information gap as no previous studies utilizing these indigenous asphaltic materials exist. Existing information using asphaltic materials other than TLA and TPB are irrelevant as variations in performance characteristics due to the addition of polymeric additives can vary from asphalt to asphalt due to differences in source and chemical composition of the parent binder. The results of this study show that a 6% CR and PET addition achieved the highest performance advantage demonstrated by an increase in the Marshall Quotient of between 21-22% and an insignificant decrease in the Bulk Specific Gravity (0.2%) compared to the unmodified blend. The improvement in the mechanical properties and the performance of the modified pavement materials observed is evidence of the useful effects of these waste materials in road paving design and offer a beneficial strategy for the reuse of these waste materials. [ABSTRACT FROM AUTHOR]

Gussasphalt has been widely used as a surfacing material for long-span steel bridge decks. While most existing studies focus on the engineering properties of gussasphalt mixtures, this study aims to design gussasphalt mixtures using Trinidad Lake Asphalt (TLA) based on the mechanical performance of gussasphalt binders, mastics and mixtures. Three base asphalts (the styrene-butadienestyrene modified asphalt, the Pen 20/40 and Pen 60/80) and four dosages of TLA (20%, 30%, 40% and 50%) were used to prepare gussasphalt binders. The performance of Pen 20/40 with 30% TLA was found to be a qualified design according to the penetration, softening point and ductility of the gussasphalt binder and the dynamic shear properties of gussasphalt mortar. Afterward, optimum binder-aggregate ratio of 8.75% was obtained based on workability, high temperature performance, and low temperature performance. Lastly, the mechanical response of the gussasphalt mixture to dynamic loading was analysed using the dynamic frequency sweep test and triaxial repeated load permanent deformation test. The findings also indicated that the SBS modified asphalt binder may be not suitable as the base asphalt of gussasphalt. The cumulative strain level of gussasphalt mixture in triaxial loading linearly increased with respect to load stress, but exponentially increased with respect to testing temperature. [ABSTRACT FROM AUTHOR]

The improper disposal of used frying oil (UFO) presents numerous ecological, environmental and municipal problems. Of great concern is the resultant blockage of municipal drainage systems and water treatment facilities, harm to wildlife when they become coated in it and detriment to aquatic life and ecosystems due to the depletion of the oxygen content in water bodies such as rivers and lakes that have become contaminated. Statistics show that in Trinidad and Tobago, in excess of one million liters of used cooking oil is collected annually from various restaurant chains. This paper investigated the potential of using UFO as a performance enhancing additive for road paving applications utilizing Trinidad Lake Asphalt (TLA) and Trinidad Petroleum Bitumen (TPB) as a mitigation strategy for improper UFO disposal. Modified blends containing various additions of UFO (2-10% wt) were prepared for the TLA and TPB asphaltic binders. Results demonstrated in terms of stiffness, increasing the dosage of UFO in TLA and TPB base binders resulted in a gradual decrease in stiffness (G* value decreased). In terms of elasticity, increasing the dosage of the UFO additive in TLA resulted in a general decrease in the elasticity of the blends indicated by an increase in phase angle or phase lag ( δ). Increasing dosages of the UFO additive in TPB resulted in a significant decrease in δ where the most elastic blend was at the 6% UFO level. TLA and UFO-TLA modified blends exhibited significantly lower values of δ and higher values of G* confirming the superiority of the TLA material. Incorporation of the UFO in the blends led to a decrease in the rutting resistance and increase in the fatigue cracking resistance (decrease in G*/sin δ and G*sin δ, respectively). This study highlighted the potential for the reuse of UFO as an asphalt modifier capable of producing customized UFO modified asphaltic blends for special applications and confirms its feasibility as an environmentally attractive means of reusing the waste/hazardous UFO material locally. [ABSTRACT FROM AUTHOR]

Trinidad lake asphalt (TLA) modified bitumen was prepared to study effect on aging properties and study modification mechanism. The aged blend was prepared by thin film oven test (TFOT), pressure aging vessel (PAV) and ultraviolet (UV) radiation, respectively. Morphology characteristics of modified bitumen were investigated by infrared spectra (IR) and atomic force microscope (AFM). The retained penetration (RP) can be increased while viscosity aged index (VAI) and softening point increment (Δ S ) get decreased after aging simulation. It indicated the addition of TLA can effectively ameliorate aging resistance of thermal-oxidative and UV-aging. The susceptible degree of softening point ratio was higher than Δ S but lower than RP. From IR spectra, there are no new absorption peaks added for TLA addition and the modification was mainly physical. Investigation of AFM showed that addition of TLA change the intersection effect between asphaltene and other bitumen components to form the more stable system. Besides, the association effect of the dispersed phase improved system rigidity, softening point and viscosity. [ABSTRACT FROM AUTHOR]

Trinidad lake asphalt (TLA) has been utilized as a modifier to blend with conventional petroleum bitumen for road and bridge applications where highly stable surfacings are required. The aim of this work was to evaluate the effect of TLA on rheological properties of Trinidad lake modified asphalt (TLMA). The critical content of TLA in the modified blend by weight was determined as the interaction of mineral particles occurred. Test results showed that TLA stiffened asphalts, but the degree of stiffening varied significantly with the TLA concentration levels. An increase in complex modulus (G*) and elastic response (δ) resulting from the introduction of TLA to asphalt binders had the potential benefit of improving resistance to rutting. In addition, zero shear viscosities (ZSVs) obtained from the Cross model were equal to the low shear viscosities (LSVs) at a frequency of 0.05Hz, while the ZSVs from the Carreau model were close to the LSVs at 0.1Hz. Steady state viscosities (SSVs), having the lowest values, approximately equaled the LSVs at 0.5Hz. The concentration of TLA was recommended to be in the range of 20-33% by the weight of naturally modified asphalt according to the SSV stiffening effect. [ABSTRACT FROM AUTHOR]

The application of various modifiers has emerged in recent years to improve conventional petroleum-based bitumen properties. The natural asphalt called Trinidad Lake Asphalt (TLA) has been applied very often due to its consistent properties, high viscosity and density, and superior rheological properties, and effective blending with other bitumen. However, most studies on TLA-modified binders always focused on physical and rheological properties in the original (unaged) condition, but the details about aging properties are often neglected. This study aimed to investigate the effect of short-term aging on the physical and rheological characteristics of the 35/50 base bitumen modified by the addition of two different TLA contents. The conventional physical tests and dynamic shear rheological tests were undertaken before and after aging to measure the penetration and softening point, complex shear modulus, and phase angle of the modified binders, as well as to calculate the zero shear viscosity using the Cross model fitting procedure. Based on the results of the above-mentioned comprehensive testing, the effect of aging on TLA-modified binder properties was evaluated using aging indices, as well as a direct comparison of results. The tests revealed that the short-term aging of TLA-modified binders did not worsen or reduce the pavement resistance to permanent deformation or the load-bearing capacity of the asphalt mixture. [ABSTRACT FROM AUTHOR]