Application of sealants in pavement crack and joint sealing

Sealant is widely recognized as a cost-effective solution for pavement crack and joint sealing. However, the application of sealant requires consideration of material properties and environmental conditions. This paper reviews various sealants used in pavement maintenance, focusing on the composition, preparation, and properties of asphalt-based and polymer-based sealants. Owing to the favorable mechanical properties, epoxy resins, polyurethanes, and silicones can not only serve as modifiers in modified asphalt but also function independently as sealants. The review compares traditional sealing construction methods, and highlights the benefits of automated techniques that improve safety and efficiency. However, automated technology still has the potential to achieve superior performance and lower costs. The study also examines sealant failures, identifying adhesion and cohesion failures as the primary modes, and compares the temperature sensitivity of cohesive strength and adhesive strength. Effective sealants must demonstrate flexibility and resistance to cracking. Generally, asphalt-based sealants show better stress relaxation compared to silicone sealants, particularly at lower temperatures. Additionally, anti-aging and waterproofing properties are critical considerations, with asphalt-based sealants generally offering superior waterproof performance but becoming harder and more brittle over time. This review provides practical guidance for selecting pavement sealants by considering material properties, environmental conditions, and specific project needs.