Analysis of the performance and mechanism of desulfurized rubber and low‐density polyethylene compound‐modified asphalt

Abstract

Desulfurized rubber (DR) and low-density polyethylene (LDPE) were used to modify bitumen. The basic physical properties, rheological properties, chemical composition, thermogravimetric behavior, and morphological characteristics were determined and evaluated to analyze the performance and mechanism of DR and LDPE compound-modified asphalt. A series of experiments (e.g., conventional test methods, rotational viscosity, storage stability, and dynamic shear rheometer tests), Fourier transform infrared spectroscopy, thermogravimetric analysis-differential scanning calorimetry, fluorescence microscopy, and atomic force microscopy were conducted. The results revealed that DR-modified asphalt (DRMA) had increases in the penetration, ductility, softening point, and penetration index by 30.2, 22.3, 3.5, and 11.1%, respectively, over the crumb rubber-modified asphalt (CRMA). The compatibility between the asphalt and modifier is better for DRMA than for CRMA. These findings indicate that DRMA has a better pavement performance than CRMA. Furthermore, compared with DR-modified bitumen, LDPE inclusions increased the value of G*/sin δ by at least 75.9% and improved the thermal properties. Morphological observations confirmed that the DR/LDPE additives were better dispersed than crumb rubber and formed a more homogeneous phase separation in the asphalt.

Investigation of physiochemical and rheological properties of waste cooking oil/SBS/EVA composite modified petroleum asphalt

“…In order to better explore the FTIR difference among these samples, both indexes named carbonyl index ( I CO ) and sulfoxide index ( I SO ) proposed by Liu et al . were used.…”

“…The morphologies of the surfaces of the materials and the mechanical properties of the materials can be explored using AFM, which is a nondestructive imaging tool . To date, AFM has proven to be an effective and repeatable method for characterizing the surface microstructures of asphalt binders . Loeber et al .…”

“…33 To date, AFM has proven to be an effective and repeatable method for characterizing the surface microstructures of asphalt binders. [34][35][36][37][38] Loeber et al first used AFM to research the surface characteristics of asphalt binders and first reported a "bee-shaped" or "bee-like" microstructure. 39,40 In general, the nanostructure of asphalt includes two-phase states: the dispersed phase represented by a "bee-like" structure and the continuous phase represented by light components.…”

Evaluation of polyphosphoric acid on the performance of polymer modified asphalt binders

“…However, with rapidly growing traffic, some pavement problems such as rutting, cracking, and spalling occurred in the early stages . In order to ensure and enhance the pavement quality, some admixtures were added into asphalt such as styrene–butadiene–styrene (SBS), crumb rubber (CR), and styrene butadiene rubber (SBR). Benefiting from the excellent performances, SBS is the most widely modifier for asphalt in China, and, SBR is often used to improve asphalt performance .…”

Waste plastics in asphalt concrete: A review

“…[60] Desulfurizing the rubber was shown to improve this measurement in rubber mixtures with virgin LDPE, again attributed to better dispersion of the filler. [61] As noted elsewhere, the G*/sin δ parameter is not a very good predictor of rutting performance. Another test for asphalt binder, namely multiple stress creep recovery, has much better correlation.…”