Ceramics-Silikáty 67, (3) 306 - 318 (2023)

In this paper, sulfoaluminate cement (SAC) is modified with a Polyvinyl alcohol (PVA) powder to prepare a repair mortar for repairing buildings with clay bricks, in addition, the adhesion and durability were studied. The experimental results show that the PVA powder-modified sulfoaluminate cement repair mortar has excellent durability and adhesion with the clay brick. At the same time, it was found that the PVA modified sulfoaluminate cement can reduce the drying shrinkage and the cracks in the bonding interface, which is beneficial to improve the adhesion. In addition, the PVA powder can reduce the total porosity of the mortar, but the increase in the capillary porosity is unfavourable to the durability of the mortar. However, the durability results show that the PVA powder effectively improves the water permeability resistance, frost resistance and sulfate corrosion resistance of the SAC repair mortar and the interface between the SAC repair mortar and clay brick. Nevertheless, under a high-temperature environment, the compressive strength and tensile bond strength of the repair mortar decreased rapidly, and also decreased with an increase in the PVA content.