Laboratory Investigation of Lignocellulosic Biomass as Performance Improver for Bituminous Materials

Abstract

Lignocellulosic biomass has gained increasing attention as a performance modifier for bituminous material due to the vast amount available, its low cost and its potential to improve the durability of pavement. However, a comprehensive study concerning both the binder and mixture performance of modified bituminous material with lignocellulose is still limited. This research aims to evaluate the feasibility of applying lignocellulose as bitumen modifier by rheological, chemical and mechanical tests. To this end, two lignocellulosic biomass modified bituminous binders and corresponding mixtures were prepared and tested. The chemical characterization revealed the interaction between lignocellulosic biomass and bitumen fractions. Rheological test results have shown that lignocellulosic modifiers improve the overall performance of bituminous binder at high, intermediate and low temperatures. The findings obtained by mixture mechanical tests were identical to the binder test results, proving the positive effect of lignocellulosic biomass on overall paving performance of bituminous materials. Although lignocellulosic modifier slightly deteriorates the bitumen workability, the modified bitumen still meets the viscosity requirements mentioned in Superpave specification. This paper suggests that lignocellulosic biomass is a promising modifier for bituminous materials with both engineering and economic merits. Future study will focus on field validation and life cycle assessment of bituminous pavement with lignocellulosic biomass.

Effect of Lignin Modifier on Engineering Performance of Bituminous Binder and Mixture

“…Meanwhile, the close results in high frequencies showed that the negligible effect in low-temperature performance of test binders with lignin. This finding supports past works conducted by Wang [ 47 ]. By comparison, lignin from wood chips had a slight improvement in high-temperature performance than that of lignin from corncobs.…”

“…The fatigue life (N ƒ ) results reflect that the high strain applied to the bitumen binders reduced the fatigue life regardless of whether the lignin was used and whatever the sources of lignin were. The higher value of the cycles to fatigue (N ƒ ) is, the worse fatigue resistance the test binder owns [ 47 ]. According to Figure 6 , Pen60/70 was responsible for the higher cycles and the application of lignin reduced the values of N ƒ at both strain levels.…”

“…After soaking in hot water for 48 h, the flow value of mixtures using LMA was universally lower than Pen60/70, although the flow values of LMA mixtures after water soaking for 30 min were slightly higher than that of Pen60/70 mixtures, their differences were not significant. The higher Marshall Stability and the lower flow value is, the better performance at higher service temperatures the mixture has [ 47 ]. The Marshall stability and flow value test results indicate the positive effects on the permanent deformation resistance of Pen60/70 brought by lignin.…”

“…The long-term aging group was put in a constant temperature oven (85 °C) for the five-day aging process, mimicking the aging conditions of a pavement after the construction of five to ten years of service life. ITSM Ratio (ITSMR) was employed as an indicator of the aging sensitivity of test samples, ITSMR equals to the ratio of the ITSM after and before the long-term aging and was calculated by following equation [ 47 ]. where ITSM after aging is the ITSM after the long-term aging and ITSM before aging is the ITSM before the long-term aging.…”

Leaf litter lignin degradation in response to understory vegetation removal in a Masson pine plantation

“…Lignin, one of the most abundant organic substances, can be used in a variety of applications in daily life (Alinejad et al, 2019; Wang, Cai, Zhang, Xu, & Yu, 2019). As a recalcitrant component in plants, however, lignin not only plays a vital role in strengthening plant structure (Su et al, 2019) but also regulates the plant litter decomposition rate because it is difficult to degrade and surrounds labile litter components in the cell wall, preventing their release (Melillo, Aber, & Muratore, 1982; He et al, 2016).…”