High-Temperature Performance Evaluation of a Novel Graphene-Based Aerogel

Evaluation of high temperature performance of asphalt mastic sealing layer for hydraulic engineering

In order to study the high temperature performance of LM-S modified asphalt mixture and SBS modified asphalt mixture, repeated loading creep test was used to study the influence of temperature and deviatoric stress on the axial permanent deformation of the two kinds of asphalt mixture. At the same time, Permanent deformation, ε@5000, flow number FN and creep rate were select to evaluation of high temperature performance from different directions. The results show that the ε@5000 and creep rate are failed in the condition of high temperature and large deviatoric stress, so it hast widely practicable. The flow number FN is also limited by the conditions, which leads to the distortion of the flow number at lower temperature and smaller deviatoric stress so it is not easy to direct used as the evaluation index. Axial permanent deformation can reflect the permanent deformation in different cycles which is an excellent index to evaluate the high temperature performance of the two kinds of asphalt mixture, it is recommended to use axial permanent deformation to compare the LM-S modified asphalt mixture and SBS modified asphalt mixture The experimental results show that the axial permanent deformation of the LM-S modified asphalt mixture is always less than that of SBS modified asphalt mixture,it indicating that the high temperature rutting resistance of the LM-S modified asphalt mixture is better than that of SBS modified asphalt mixture.

Novel rejuvenators for sustainable recycling of aged SBS modified bitumen: Performance evaluation and reactive mechanism analysis

Evaluation of high temperature performance of SBS-modified asphalt mixture was presented. Both wheel loaded method and creep method were adopted for two different mixtures and two kinds of specimens with different height, and corresponding indicators were measured. Meanwhile, the correlation between these indicators was thoroughly analyzed and two kinds of mixtures were compared. The experimental results show that there is a good linear relationship between LWT indicators and CT indicators for M-13, while a relatively poor relationship for M-25, especially that between dynamic stiffness and static stiffness and that between dynamic stability and static creep stiffness. Besides, logarithmic relationship between DS and RD has a higher determination coefficient than that for linear relationship. Thus, multi-index evaluation should be taken for synthetically assessing high temperature performance of asphalt mixture.

: A new test rig is designed to evaluate the start-stop cyclic durability of high-temperature solid lubricant coatings applied to foil thrust bearing systems. This test rig also allows the characterization of low speed thrust bearing performance, augmenting existing high speed test capabilities. The Low-Speed Thrust Bearing Rig is designed to test foil thrust bearings at speeds up to 21,000 rpm and temperatures up to 540 deg C (1000 deg F), with variable thrust loads. Thrust bearings can be subjected to tens of thousand of start-stop cycles to simulate decades of service in a turbomachinery application. Initial testing has validated the rig capabilities by subjecting a bearing and thrust runner to more than two thousand start/stop cycles at a temperature of 430 deg C (800 deg F).

Evaluation of high temperature performance of SBS + Gilsonite modified binder

Structure and properties of cast Al–Si based alloy with Zr–V–Ti additions and its evaluation of high temperature performance

To study the influence of temperature and reclaimed asphalt pavement (RAP) content (0%, 30%, 50%, and 70%) on the high-temperature performance and anti-reflection cracking performance of warm-mix recycled asphalt mixture, triaxial repeated creep tests and overlay tests (OT) based on digital image correlation technology (DIC) were used to analyze the high temperature and anti-reflection cracking performance of recycled asphalt mixtures. Based on the improved Burgers model, a permanent deformation (PD) model was established to evaluate the high-temperature performance of recycled asphalt mixtures. The anti-reflection cracking performance of recycled asphalt was quantitatively analyzed from macro and meso perspectives by using a macro index (load loss rate) and a meso index (vertical strain density DE). In addition, a reflection cracking damage model was developed by cumulative load loss rate relative change rate, and the fractal characteristics of reflection cracks were studied according to the fractal theory. The results show that with an increase in RAP content, the anti-deformation ability of a recycled asphalt mixture is enhanced, and the anti-reflection cracking performance becomes worse. However, with an increase in temperature, the anti-deformation ability of recycled asphalt mixture is weakened, and the anti-reflection cracking performance is enhanced. A PD mechanical model can well describe the high-temperature deformation resistance of recycled asphalt mixtures. The established reflection cracking damage model has high fitting accuracy and accurately describes the reflection cracking damage evolution process of recycled asphalt mixture. In addition, the analysis of the fractal characteristics of reflection cracks shows that the reflection cracks of a recycled asphalt mixture have fractal characteristics of statistical significance. DIC technology can be used to evaluate the anti-reflection cracking performance of recycled asphalt mixtures qualitatively and quantitatively from the mesoscopic perspective, which makes up for the current deficiency in macroscopic evaluation.

Performance evaluation of high-elastic/salt-storage asphalt mixture modified with Mafilon and rubber particles

Evaluation of the terminal blend crumb rubber/SBS composite modified asphalt

The morphological characteristics of aggregate include outline shape, angularity, and surface texture, which determine the mutual extrusion and friction between aggregates, and significantly affect the performance of asphalt pavement. At present, the research on the morphological characteristics of coarse aggregate is mainly focused on indoor visual identification technology (AIMS, XCT, etc.), in which the applicability of the proposed aggregate shape characterization index is weak, and these instruments could not serve the practical engineering well. In this article, the Coarse Aggregate Morphological Identification System (CAMIS) is developed based on computer vision technology, and the system can recognize the shape features of aggregates above 2.36 mm particle size and carry out uninterrupted feeding and removal based on the mechanical arm system, which can realize large sample detection. Based on CAMIS aggregate identification system and laboratory tests (rutting test, dynamic modulus test, and penetration shear test), the shape identification and performance test of aggregate samples from construction site are carried out, and an aggregate performance evaluation index, CEI, suitable for high-temperature areas is proposed in combination with the improved response surface method. The processing parameters of vertical shaft impact aggregate crusher are optimized based on the CEI index, and the recommended processing parameters are verified by laboratory tests. The results show that the morphological characteristics of coarse aggregate affect the high temperature performance in order angularity, needle flake, axial coefficient, and convexity. The combination of processing parameters of vertical axis impact crusher is recommended to be of 45 m/s rotational speed, 3 t/h feed quantity, and 30% air intake. Verified by laboratory tests, the aggregate identification system CAMIS developed in this article and the proposed aggregate performance evaluation index, CEI, are highly reliable.

Assessment of testing methods for higher temperature performance of emulsified asphalt

In Europe, bitumen classification has traditionally relied on empirical tests, namely penetration and the Ring and Ball softening point, originally developed for unmodified binders and considered insufficient for modern modified binders. As an alternative, a rheology-based method, the Bitumen Typisierungs Schnell Verfahren (BTSV) rapid bitumen categorization method, has been developed in Germany to characterize high service temperature performance, with performance requirements introduced in 2025 in the German specifications. In this study, the performance of five bitumen types commonly used in Hungarian road construction was investigated using the BTSV method. During testing, the softening temperature corresponding to a rheological threshold value of G* = 15.0 kPa (TBTSV) and the phase angle (δBTSV) were determined. TBTSV is defined as the temperature corresponding to G* = 15 kPa, representing the softening state, while δBTSV reflects the viscoelastic balance between elastic and viscous behaviour. The objective of this study is to evaluate the high-temperature performance of commonly used Hungarian bituminous binders using the BTSV method and to compare the results with traditional empirical parameters and German classification systems. A total of 137 binder samples from production control were tested and analysed, including paving-grade, SBS-modified, and chemically stabilized rubber-modified binders. Statistical evaluation included mean values and 95% confidence intervals. For rubber-modified bitumens, the recoverable, insoluble rubber content was determined using the Soxhlet extraction method. Based on the results, it can be concluded that with increasing rubber content, the TBTSV value shows an increasing trend, while the δBTSV value decreases. As discussed in the paper, a strong linear relationship was observed between the investigated parameters in the TBTSV–δBTSV diagram, with a coefficient of determination of R2 = 0.99.

High temperature performance evaluation of bio-oil modified asphalt binders using the DSR and MSCR tests

Impacts on asphalt mixture’s high temperature performance with PR series additives added by means of rutting test and Repeated Shear Test (Constant Height) (RSCH) were investigated. The analytic results of the two tests show that (1) rutting test is not suitable for the high temperature performance evaluation of asphalt mixture with PR series additives added for the reason of the conflict between dynamic stability and rut depth; (2) the results of RSCH, such as K1 K2, N and γ, show very well consistency which is suitable for the high temperature performance evaluation of asphalt mixture with PR series additives added. The results of RSCH show that asphalt mixture with PR PLASTS (PR.S) added has the best performance, the PR FLEX MODULE (PR.M) one is the next and the original one is the worst for the high temperature anti-shear performance.