Experimental Study on the Dynamic Modulus of an Asphalt Roadbed Grouting Mixture under the Influence of Complex and Multiple Factors

Abstract

After long-term service, the ground will experience settlement and the stability of the roadbed will be lost. In order to effectively reinforce the roadbed, an asphalt roadbed grouting mixture has been applied to the filling of the roadbed. The rotary compaction method was used to prepare different gradation types of lime composite-modified oil sludge pyrolysis residue asphalt, mixtures Sup13, Sup19, and Sup25. This article takes the dynamic modulus of an asphalt roadbed grouting mixture as the mechanical index, and the uniaxial compression dynamic modulus test is carried out on three kinds of rotary compaction asphalt mixtures, Sup13, Sup19, and Sup25. The dynamic modulus master curves of different gradation composite-modified oil sludge pyrolysis residue asphalt mixtures are fitted to study the dynamic modulus of asphalt mixtures under different nominal maximum particle sizes, loading frequencies, and temperatures. The results show that (1) The dynamic modulus of different gradation composite-modified oil sludge pyrolysis residue asphalt mixtures increases with the decrease in temperature and the increase in frequency; (2) when other conditions are the same, the compound-modified asphalt mixture’s dynamic modulus decreases significantly under low-frequency and high-temperature conditions; (3) in the range of 4.4–37.8 °C and medium loading frequency, the dynamic modulus of the compound-modified asphalt mixture is more affected by temperature and loading frequency; (4) in the low-temperature and high-frequency range, the compound-modified asphalt mixture with a larger nominal maximum particle size has a higher dynamic modulus, and the asphalt mixture with better stability of skeleton structure has a higher dynamic modulus. The research results of this article will provide scientific guidance for the study of the mechanical properties of asphalt roadbed grouting mixtures.