A new pavement crack repair sealant with two-way shape memory effect

Abstract

To address the challenge of sealant debonding due to cyclic temperature variations, a new pavement crack repair sealant which can achieve two-way shape memory deformation is developed. The developed crack sealant is a shape memory liquid crystal elastomer (SMLCE), designed to exhibit the deformation characteristics of heat contraction and cold expansion. First, the material composition and preparation process of the developed SMLCE are given. Thermodynamic properties, phase transition temperatures and molecular structures are analyzed based on DSC and FITR. The effects of the crosslinker and chain extender ratios and the key preparation processes on the two-way shape memory deformation and mechanical performance of SMLCE are systematically analyzed. Based on the analysis, the optimum ratio of SMLCE is determined to be 1:15 and the optimum secondary crosslinking preparation process is 150% orientation stretching. Under the optimal solution, the developed SMLCE can achieve the multiple two-way shape memory reversible deformation with a maximum 46% deformation in the temperature range of -20°C∼120°C. At the same time, the developed SMLCE has excellent mechanical properties, with a tensile strength of 20.7Mpa and an elongation at break of 322%. It also exhibits good low-temperature deformation capabilities at -10°C and above. Finally, the suitability and application potential of the developed two-way SMLCE as a pavement crack sealant are assessed. The developed SMLCE has good adaptability in most climate zones, which indicates its great potential as a pavement crack sealant. This research provides a new way for the pavement crack repair.