The invention relates to the technical field of building
expansion joint sealing composite materials, in particular to a building
expansion joint sealing
composite material and a preparation method and application thereof. The preparation method comprises the following steps: mixing an
epoxy resin precursor containing disulfide bonds and
polyurethane containing disulfide bonds to obtain a
polyurethane-
epoxy resin matrix with an interpenetrating
network structure; a Na source, an Nb source, a Ba source, a Ti source, a Sn source, a Sr source and a Zr source are mixed to prepare the
sodium niobate leadless piezoelectric
ceramic with piezoelectric performance. The preparation method comprises the following steps: modifying
sodium niobate lead-free piezoelectric
ceramic by adopting
dopamine hydrochloride to obtain polydopamine modified
sodium niobate lead-free piezoelectric
ceramic; and mixing the polydopamine modified
sodium niobate lead-free piezoelectric ceramic, the
polyurethane-
epoxy resin matrix and the aminated
carbon nanotube, and curing to obtain the building
expansion joint sealing
composite material. The building expansion joint sealing
composite material has excellent mechanical properties and
bonding strength, has good damping performance in a wide temperature range, and solves the problems in the prior art.