The effects of modified interface agents on the bonding characteristics between customized cement adhesive for insulators and aluminum flanges

Abstract

Insulators are a composite structure composed of ceramic and aluminum flanges bonded together with cement adhesive, the strong bonding between cement adhesive and aluminum flanges is significant to ensure the normal operation of the ultra-high voltage transmission. However, the high alkalinity, low strength, high drying shrinkage, and weak interfacial adhesion between cement adhesive and aluminum flanges posed a big challenge to sound development of insulators, the related solution and research remained unknown. Therefore, the customized cement adhesive was prepared by Portland cement (OPC), sulphoaluminate cement (SAC) and mineral admixtures, and the effects of modified interface agents on the bonding characteristics between customized cement adhesive and aluminum flanges were investigated by FTIR, SEM and MIP. The findings revealed that an optimal customized cement adhesive could be obtained by adjusting a suitable ratio of OPC, SAC and mineral admixtures, 11d’s compressive strength of customized cement adhesive reached 89.3 MPa, the dry shrinkage rate at 28d decreased by 65.0 % than OPC, the pH reduce apparently at 11.52. The 11d interfacial bond strength using 45 % VAE and AA latex was 0.187 MPa and 0.276 MPa, which much higher than the blank sample as 0.055 MPa. The contact angles of 45 % VAE and AA latex decreases by 24.7 % and 35.0 % than asphalt. The modified interface agents could fill the large pores of cement adhesive, form a smooth and strong film in the binding structure. The polymer in the interface agent may chelate with Ca, Alor Fe further enhancing the cohesion.