Integrally hydrophobic cementitious composites made with waste amorphous carbon powder

Abstract

Amorphous carbon powder (ACP) is a hydrophobic by-product material from refining waste materials of paraffin production factory. ACP effects on permeability and mechanical properties of cementitious composites were investigated. A range of properties of modified cement paste and concrete including hydrophobicity, workability, porosity, compressive strength, transport properties comprising sorptivity, water absorption, water desorption rate and electrical resistivity were studied. Results showed that incorporation of 15% ACP by weight of cement reduces water absorption, sorptivity and electrical conductivity of cement paste by 23%, 86% and 65%, respectively. Sorptivity and electrical conductivity of modified concrete samples by 20% ACP by weight of cement, were reduced by 60% and 30%, respectively. Adding ACP to paste samples resulted in higher compressive strength through lowering porosity. However, in the case of concrete, no significant change was observed. It was demonstrated that ACP could reduce the wettability of cementitious composites by refining the pores and altering the hydrophobicity characteristics of cementitious composites.