Identifying the Long-Term Thermal Storage Stability of SBS-Polymer-Modified Asphalt, including Physical Indexes, Rheological Properties, and Micro-Structures Characteristics

Abstract

The thermal storage stability of styrene–butadiene–styrene tri-block copolymer modified bitumen (SBSPMB) is the key to avoid performance attenuation during storage and transportation in pavement engineering. However, existing evaluation index softening point difference within 48 h (ΔSP48) cannot effectively distinguish this attenuation of SBSPMB. Thus, conventional physical indexes, rheological properties, and micro-structure characteristics of SBSPMB during a 10-day storage were investigated in this research. Results showed that during long-term thermal storage under 163 °C for 10 days, penetration, ductility, softening point, recovery rate (R%), and anti-rutting factor (G*/sinδ) were decayed with storage time increasing. This outcome was ascribed to the phase separation of SBS, which mainly occurred after a 4-day storage. However, ΔSP48 after a 6-day storage met the specification requirements (i.e., below 2.5 °C). Thus, the attenuation degree of asphalt performance in field storage was not effectively characterized by ΔSP48 alone. Results from network strength (I) and SBS swelling degree tests revealed that the primary cause was SBS degradation and base asphalt aging. Moreover, conventional indexes, including penetration, ductility, and softening point, were used to build a prediction model for rheological properties after long-term storage using partial least squares regression model, which can effectively predict I, R, Jnr, G*/sinδ, and SBS amount. Correlation coefficient is above 0.8. G*/sinδ and I at the top and bottom storage locations had high coefficient with SBS amount. Thus, phase separation of SBSPMB should be evaluated during thermal storage.

Reutilization of crystalline waste plastics for modified asphalt using twin‐screw extrusion: Polyethylene and polypropylene as typical subjects

“…The segregation index ( S ) was measured to investigate the storage stability of modified asphalts, which was defined as follows. where T 1 is the softening point value at the upper end of segregated aluminum tube, T 2 is the softening point value at the lower section of segregated aluminum tube 28 …”

Research on the Skidding Resistance and Attenuation Characteristics of Asphalt Pavement Based on Image Recognition-Analysis Strategy

“…Wu et al [23] analyzed the attenuation of asphalt mixtures under various loading numbers and deduced the attenuation mechanism of skidding resistance. Wang et al [24] established a grey model based on three-dimensional texture by quadratic fitting, which is beneficial for an in-depth analysis of the anti-skidding attenuation properties of asphalt pavement. Hu et al [25] established a prediction model of friction coefficient based on improved grey wolf optimization (IGWO) and natural gradient boosting (NGBoost) to forecast the skidding resistance.…”

The Modification Mechanism, Evaluation Method, and Construction Technology of Direct-to-Plant SBS Modifiers in Asphalt Mixture: A Review

“…One is the separation of the SBS modifier during high-temperature storage and transportation, and the second is the fracture and degradation of SBS molecules at high temperatures during processing. After the SBS-modified asphalt is processed, during transport and paving, affected by time and temperature, the softening point and ductility will continue to decay [10,11]. The construction process is becoming richer and richer with the increasing variety of modifiers.…”

“…In France, RP modifiers were developed to significantly improve the rutting resistance of asphalt pavements. In 1992, specifications for producing and con-structing direct-to-plant high-modulus asphalt mixtures were developed [11,12]. In Japan, TPS direct-to-plant modifiers suitable for drainage pavements were developed, which can significantly improve the strength and durability of asphalt mixtures [13].…”