Dynamic Viscosity Standard of High Viscosity Modified Asphalt Considering Temperature and Load Coupling Effect

Abstract

The anti-ravelling and anti-rutting performances of porous asphalt pavement are significantly affected by dynamic viscosity of high viscosity modified asphalt. Climatic and traffic conditions vary greatly due to the vast territory of China, and dynamic viscosity standard has not been recommended up to now aiming at different temperature and load conditions. The influence of high viscosity additive dosage on key property indexes was firstly analysed for asphalt and asphalt mixture, and appropriate dosage was recommended. The dynamic stability changing law of porous asphalt mixture was revealed under different temperature, load and their coupling conditions. Multiple regression relation of them was established. Finally dynamic viscosity standard was proposed considering temperature/load coupling effect. The research results show that when high viscosity additive dosage exceeds 10% for 70# base asphalt, the increasing trend of dynamic viscosity becomes slowing down. Semi-logarithmic relations of dynamic stability with ravelling loss, Marshall stability were respectively found, and double-logarithmic relation of that with dynamic viscosity was found. The appropriate dosage of high viscosity additive is recommended as 12%. Based on multiple regression formula of dynamic stability with dynamic viscosity, temperature and load, the lower limit of 60°C dynamic viscosity is recommended as 50000Pa•s for normal region, 100000Pa•s for heavy-load region, 200000Pa•s for high-temperature region, and 400000Pa•s for heavy-load & high-temperature region.

Performance and Mechanism of High-Viscosity and High-Elasticity Bitumen (HVE-MB) Modified with Five Additives

“…Zhou et al [23] mixed SBS, stabilizer, plasticizer, and tracking resin in the original bitumen to manufacture the HVM bitumen with good performance for the porous asphalt pavement. Li et al [24] analyzed the contents of high viscosity additive on crucial properties of bitumen and bituminous mixtures. For 70 # original bitumen, the dynamic viscosity increases slowly when the content of high viscosity additive is higher than 10%.…”

Analysis of Coupling Effect and Heavy Load of High-Temperature Stability of Asphalt Mixture

“…According to the test results obtained under conditions of different temperatures and loads and the two synchronous conditions, Shi Liwan analyzed the developing rules and established the relationship between the rutting evaluation index and test conditions [13]. By analyzing the influence of high viscosity additive dosage on key property indices, Li and others recommended appropriate dosage and dynamic viscosity standards aimed at different temperatures and load conditions and found a double-logarithmic relation of dynamic stability with dynamic viscosity [14]. Dai and others analyzed the sensitivity of dynamic creep permanent deformation parameters to dynamic stability and concluded that the viscosity coefficient η 1 was positively correlated with the change of dynamic stability(DS) and most sensitive to DS [15].…”