The acid and chloride permeability resistance of masonry cement plaster mortar incorporating high-volume fly ash content

Abstract

The utilization of masonry cement mortar has been on the rise in recent years, gradually supplanting the traditional use of lime and Portland cement in plastering applications. Masonry cement mortar is favored for its enhanced workability; however, it remains vulnerable to environmental factors, and there is a dearth of information regarding the durability assessment of masonry cement plaster mortar. While incorporating fly ash in mortars is a common practice, it is often paired with Ordinary Portland Cement as the primary binding agent. This research project was devised to investigate the performance characteristics of masonry cement plaster mortar infused with varying levels of fly ash. The control specimen was systematically replaced with fly ash in 10% weight increments, up to 50%. Evaluations were conducted immediately in its fresh state, and assessments of strength and durability were extended over 360 days. Scanning Electron Microscope (SEM) and X-Ray diffraction analysis (XRD) were used as characterization techniques. The outcomes of the study were noteworthy. Mortars containing 30% or more ash exhibited a significant 15% enhancement in flow and an impressive 88% increase in compressive strength compared to plain mortar. The durability assessment revealed that masonry cement mortar incorporating 40% and 50% fly ash displayed nearly 14 times greater resistance to chloride penetration and maintained its strength when exposed to acidic solutions. This underscores the dual benefits of this material, enhancing the aesthetics of buildings and fortifying them against external chemical attacks that can compromise the integrity of concrete and bricks.