Extending the modified steel slag cement into the hydrophobic and anti-icing application

Abstract

Steel slag cement is commonly used as a non-load-bearing building material because of its low long-term strength. To promote its large-scale recycling, the new application of steel slag cement is significantly attractive. In this study, a new type of hydrophobic steel slag cement modified by Polydimethylsiloxane (PDMS) was prepared. α-C2S, β-C2S, C3A, C3S, C4AF, Aft, and CH were found in the samples by XRD. The Rietveld refinement technique was used to quantitatively analyze the content of hydration products. SEM and EDS analysis revealed the effect of PDMS and steel slag on the morphology of hydration products. The increase in the steel slag content, resulted in a smoother the surface due to the decrease in hydration products. It was found that PDMS covered the surface of hydration products, resulting in excellent hydrophobic properties. FTIR and XPS analysis showed that the main reason for the good hydrophobicity of the sample was that PDMS crosslinked on the surface of cement particles and filled the pores. With hydrophobic modification, the contact angle could reach 143.7°. The hydrophobically modified cement exhibited excellent self-cleaning ability, low water absorption, good photothermal properties, remarkable anti-icing properties, certain mechanical strength and high durability.