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.
In recent years, global climate change has caused worldwide trends in science and industry toward a focus on the development of modern technologies with reduced environmental impact, including reduced CO2 emissions into the atmosphere. The technology for producing asphalt mixtures (AM) at lower temperatures (WMA—warm asphalt mix) using zeolite materials for the bitumen foaming process fits perfectly into these trends. Therefore, towards the development of this technology, the research presented in this paper presents the modification process of zeolite NaP1 from fly ash with silanes of different chemical structures (TEOS, MPTS, TESPT) and their application in the foaming process of bitumen modified with polymers (PMB 45/80-55). The scope of the work includes two main novelty elements: (1) the use of zeolite–silane composites in bitumen foaming and (2) polymer-modified bitumen foaming. Chemical characterisation carried out by EDS-XRF, FTIR, and XPS analysis clearly demonstrated the success of the zeolite matrix modification process, which directly resulted in textural changes. Simultaneously, mineralogical analysis carried out by XRD showed the complete retention of the initial phase composition of zeolite matrix. Further studies have shown that the application of zeolite–oxide composites results in less PMB 45/80-55 stiffening without imposing negative effects on its softening point and dynamic viscosity.
Mastic asphalt (MA) has been particularly popular in recent years for bridge pavements due to many advantages such as easy application, good waterproofing properties, and high durability. However, the drawback of mastic asphalt in comparison to other asphalt mixtures is its lower resistance to permanent deformation. Trinidad Lake Asphalt (TLA) is often applied to make mastic asphalt resistant to permanent deformation. Practical experience demonstrates that serious failures may occur if MA pavement design and materials selection is not taken into account sufficiently. Therefore in this study, the influence of two parameters: zero shear viscosity (ZSV) of TLA-modified binder and mastic composition described by the filler–binder ratio, on the permanent deformation resistance of the MA mixture was evaluated. The primary purpose of determining the ZSV of the TLA-modified binders was to evaluate the rutting potential of the binders. The permanent deformation (rutting) resistance of the MA mixtures was evaluated based on static and dynamic indentation tests. The optimum content of TLA in the base bitumen and the optimum filler–binder ratio in the MA mixture were obtained based on multiple performance evaluations for modified binder, mastic and MA mixtures, i.e., 20% and 4.0, respectively.
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.
Mastyks asfaltowy ma duży wpływ na właściwości mieszanki mineralno-asfaltowej. O jego cechach decydują nie tylko właściwości poszczególnych składników, ale także wzajemne proporcje między nimi – głównie stosunek wypełniacz/lepiszcze. Do oceny mastyksu można stosować te same metody badań, co do oceny asfaltów drogowych, traktując go jako lepiszcze o bardzo dużej lepkości. Wyniki badań mogą posłużyć do wstępnego projektowania składu mieszanki asfaltu lanego, zwłaszcza w kontekście trwałości nawierzchni na obiektach mostowych, gdzie asfalt lany stanowi warstwę ochronną izolacji. W artykule przedstawiono wyniki badań ciągliwości mastyksu i odporności na deformacje trwałe asfaltu lanego, zawierających asfalt drogowy 35/50 zmodyfikowany dodatkiem asfaltu naturalnego Trinidad Epuré. Celem przeprowadzonych badań było ustalenie wpływu stosunku wypełniacz/lepiszcze oraz dodatku asfaltu naturalnego na umowną energię rozciągania w badaniu ciągliwości, a także określenie korelacji pomiędzy właściwościami mastyksu zawierającego zmodyfikowane lepiszcze a cechami mieszanki asfaltu lanego.
The mastic asphalt mixture (MA) is one of the first mineral and asphalt mixtures used in history. Its composition and structure allow it (the mixture) to be produced both in industrial conditions (in mineral and asphalt mixing plants) and in field conditions—in mobile boilers (especially when the produced mixture is used to repair damaged surface). The high proportion of the sand fraction makes the mixture highly workable, allowing it to be laid/incorporated without special equipment. MA, however, also has some drawbacks. The asphalt content is higher than in other mixtures, which can make it prone to plastic deformation. Mastic asphalt requires higher processing temperatures than other “hot” mixtures. Mastic asphalt mixtures are installed as road pavement layers and, because of their high density, as the protective layer on roof felt isolation on bridge decks. The high temperature of embedding creates a risk of damaging the roof felt, as its typical temperature resistance is lower than 180 °C, whereas the temperature of the mastic asphalt mixture is higher. The use of zeolites can enable reconciliation of technological requirements of mastic asphalt and asphalt roof isolation. The mixes MA 8 and MA 11 containing 0 and 5% of two types of zeolites and asphalt binders 35/50 or elastomer-SBS-modified asphalt binder PMB 25/55-60 were used in the research. Laboratory tests revealed that the addition of a 5% amount of zeolite by asphalt mass makes it possible to reduce the mastic asphalt laying temperature by up to 30 °C, which seems to be very important from ecological, economical, and pavement durability points of view.