High-Performance Semi-Flexible Pavement Coating Material with the Microscopic Interface Optimization

Abstract

This paper aims to optimize the asphalt-mortar interface characteristics of semi-flexible pavement coating material (SFPCM), three types of the interface modifiers, namely the silane coupling agent, carboxylated styrene-butadiene latex, and cationic emulsified asphalt, are selected to add into the cement mortar to optimize the asphalt-mortar interface. The microscopic characteristics of the asphalt-mortar interface and the macroscopic pavement performance of the SFPCM after the interface optimization are investigated to reveal the effect of interface modifiers and determine the best formula. Results show that: (1) The dry shrinkage of the cement mortar is increased with the increased dosage of the interface modifiers, while the strength is decreased accordingly; (2) the optimum dosages of the silane coupling agent, carboxylated styrene butadiene latex, and cationic emulsified asphalt are 0.5%, 10%, and 5%, respectively; (3) the microscopic asphalt-mortar interface characteristics of the SFPCM with different interface modifiers have significant differences; (4) the SFPCM with the cationic emulsified asphalt presents the best pavement performance, particularly the high-temperature stability. These results can be attributed to improve the pavement properties of SFPCM.

Cementitious Grouts Containing Irradiated Waste Polyethylene Terephthalate

“…In another study, three different interface optimizers (silane coupling agent, carboxyl styrene-butadiene latex, and cationic emulsified asphalt) were used with various percentages in cement grouts to improve the interfacial connection between the cement grout and asphalt in SFP mixtures. The results indicate that interface optimizers despite causing a reduction in strength properties of grout, greatly improves the interfacial connection of cement grout with asphalt as observed from microstructural analysis of mixtures as shown in Figure 6 [50]. These interface optimizers also show a positive effect in terms of crack resistance at low temperature, stability at high temperature, and moisture stability, particularly by cationic emulsified asphalt.…”

“…However, Figure 6. Microstructure of cement-asphalt interface modified with a silane coupling agent, carboxyl styrene-butadiene latex, and cationic emulsified asphalt [50].…”

Influential Factors and Evaluation Methods of the Performance of Grouted Semi-Flexible Pavement (GSP)—A Review

“…Polymers are the most traditional admixtures used in GSP, including latex, resin, SBS, styrene-butadiene rubber (SBR), and waste rubber [74,84]. Latex and resin are efficient to smooth the high rigidity of HCM and reinforce the tensile strength of the whole structure because of their hydrophilicity, which results in bonding at interfaces between materials [56,76]. However, they have little or no influence on the high-temperature performance of GSP.…”

“…Cationic CA efficiently increases the flexibility of grouting material, compared to anionic CA and average cement mortar [80]. In addition, CA (especially Cationic CA) has better cohesion with asphalt than average cement mortar, which can also act as a kind of interface modifier [76].…”

“…Despite advancement in anti-cracking resistance, CA-modified GSP will be inevitably sabotaged in both the compressive strength of grouting material and the rutting resistance of GSP. Accordingly, Xu et al, presents a method using SBS in OMA to offset the decrease in strength of CA-modified GSP [76].…”