Effects of natural zeolite replacement on the properties of superhydrophobic mortar

Abstract

A superhydrophobic mortar containing zeolite was fabricated by using natural zeolite as an cement replacement material and stearic acid as hydrophobic additive. The addition of natural zeolite improves the microstructures of superhydrophobic mortars, enhancing its water-repellency and anti-corrosion property. • The superhydrophobic mortar containing natural zeolite was fabricated. • The addition of natural zeolite improves the microstructures of superhydrophobic mortars. • The WCA decreases first and then increases with the increase of zeolite replacement amount. • Effects of different zeolite content on water absorption and corrosion resistance were studied. Natural zeolite is one of the most commonly used cement replacement materials for fabricating concrete. However, the hydrophilicity of the concrete containing natural zeolite makes water and corrosive media easily penetrate into concrete through pores. Here, a superhydrophobic mortar containing zeolite with water-repellency and anti-corrosion property was fabricated by using natural zeolite as an eco-friendly cement replacement material and stearic acid as low surface energy additive. The effects of different zeolite replacement on the microstructures, wettability, water absorption, anti-corrosion performance and compressive strength of superhydrophobic mortar were studied. The addition of natural zeolite improves the microstructures of superhydrophobic mortars. As the zeolite replacement increases, the water contact angle of the superhydrophobic mortars decreases first and then increases, but it always keeps above 150°. The addition of zeolite reduces the water absorption and improves the anti-corrosion performance of superhydrophobic mortar. The water absorption of superhydrophobic mortar with 15% zeolite replacement is only 0.61%. Moreover, the compressive strength increases by 14 % for 15% zeolite replacement. This study can decrease the consumption of cement, reducing the environmental burden caused by the use of cement, and provide a valuable idea for the eco-friendly fabrication of superhydrophobic cement-based materials.