Search

ABSTRACT Recent impetus on utilization of different types of nanomaterials for modification of asphalt binders has motivated the authors to undertake the present study. The present study evaluated the rutting, [...]

ABSTRACTThis research work aimed to evaluate the effect of CNT on the performance of asphaltic mixture. CNT-asphalt binder composite was initially prepared at different CNT dosages (0%, 0.4%, 0.75%, 1.5%, and 2.25% by the weight of asphalt binder). The effect of CNT on the workability of asphaltic mixture was evaluated with the help of compaction data. The change in compaction densification index indicated that such an addition will have a negative impact on the workability of asphaltic mixture. Similarly, the strain response and flow number obtained from the dynamic creep test at 50°C indicated that the addition of CNT will help in improving the rutting performance. Likewise, the variation of Tensile Strength Ratio (TSR) value indicated that the moisture damage resistivity potential of asphaltic mixture can be improved with the addition of CNT. Finally, intermediate temperature performance was evaluated using indirect tensile fatigue and indirect tensile test-based cracking tolerance index. The variation of different parameters from the above approaches indicated that CNT can help in improving the intermediate temperature performance of asphaltic mixture.

This article aimed at providing comprehensive information on the use of nanomaterial in asphalt binder and mixes based on an exhaustive review of the literature. The complete literature review can broadly be perceived into three different segments. The first segment of this review discusses (a) the need of nanomaterial, and (b) different types of nanomaterials with their respective characteristics. The second segment of this review work discusses about the various functional aspects which have been reported to have an important role on or before construction of asphaltic layer, i.e. (a) mixing of nanomaterials with asphalt binder, (b) nanomaterial dispersion into asphalt binder matrix, and (c) high-temperature storage stability of binary composite (asphalt binder and nanomaterial) and triple composite (asphalt binder, polymer additive and nanomaterial) under high-temperature condition. Among different types of mixing approach, use of a high shear mixer and ultra-sonication individually or in combination has been reported in the literature for an efficient way for dispersion of nanomaterial in an asphalt binder matrix. To evaluate mixing of nanomaterial in asphalt binder matrix, different microscopic approach such as X-Ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Atomic Force Microscopy (AFM) has been recommended in the literature. The third segment emphasises on the effect of nanomaterial addition on performance-based parameters for (a) aging resistivity potential, (b) moisture damage resistivity potential, (c) intermediate, (d) high, and (e) low-temperature performance. The review of the literature showed that the addition of nanomaterial to asphalt binder not only improves the aging resistivity potential of asphalt binder but also improves the moisture damage resistivity potential, high, and intermediate temperature performance of asphalt binder and mixes. However, the mixed response was observed from the review of literature for the corresponding effect of nanomaterial on low-temperature performance parameters.

Organo-modified nanoclay has got considerable attention in recent years to improve the performance of asphalt binders. However, various aspects such as rutting performance using Multiple Stress Creep Recovery (MSCR) test, fatigue performance using Linear Amplitude Sweep (LAS) test and ageing resistivity potential using advanced rheological parameter are still unexplored for better rheological characterisation. The present study deals with rutting, ageing resistivity potential and fatigue performance of asphalt binder (AC-10) modified with organo-modified nanoclay (CL-30B). Different percentages (0, 2, 4 and 6% by weight of binder) of CL-30B were mixed with AC-10 using a high-shear mixer. Different rheological studies, such as Brookfield viscosity, Superpave performance grading, time–temperature sweep, MSCR and LAS tests, were conducted on CL-30B-modified asphalt binders. Effects of CL-30B on performance were observed to be predominant in intermediate to high-temperature range as obtained from the master curve. The ageing resistivity of asphalt binder increased with the addition of CL-30B. The Superpave rutting parameter (G*/Sinδ) increased and non-recoverable creep compliance (Jnr) estimated from MSCR decreased with inclusion of CL-30B, indicating a better rutting performance of asphalt binders. The number of cycles to fatigue estimated from the LAS test showed improvement in fatigue performance of asphalt binder with addition of CL-30B. The high-temperature performance grade of CL-30B-modified binder was found to be higher compared to virgin binder. The relationship between Jnrand G*/Sinδ, and recovery (R) and storage modulus (G′) parameters are presented in this paper. In addition, ranking of asphalt binder based on various parameters (i.e. G*/Sinδ, AI, Jnr, R, Nf) is discussed in this paper.