Durability of Slag–Cement Paste Containing Polyaluminum Chloride

Abstract

The effect of polyaluminum chloride (PAC) on the durability, microstructure, and corrosion sensitivity of slag–cement pastes was investigated in this research. Various experimental tests were performed to assess the mechanical properties (compressive strength test), durability (rapid chloride migration test, water permeability test, capillary water absorption test, chloride binding test, accelerated carbonation test), microstructure (scanning electron microscopy, X-ray diffraction, mercury intrusion porosimetry), and corrosion sensitivity (accelerated corrosion sensitivity, initial chloride concentration). Experimental results showed that adding 1.5% PAC increased compressive strength by 77.0%, 53.8%, and 19.4% at 3, 7, and 28 days. Resistance to chloride migration, water permeation, capillary water absorption, and carbonation was improved. These results were consistent with the microstructural analysis, which showed that adding PAC facilitated the formation of Friedel’s salt and development of pore structure, which was the key factor for the improved durability of the slag–cement paste. Adding 1.5% PAC had a limited influence on the corrosion sensitivity despite introducing the additional chloride ions into the system. These results promote the further practical application of PAC.