Durability performance of Palm Oil Fuel Ash-based Engineered Alkaline-activated Cementitious Composite (POFA-EACC) mortar in sulfate environment

• Published in: Construction & building materials 2017-01, Vol.131, p.229-244
• Main Authors: Salami, Babatunde Abiodun, Megat Johari, Megat Azmi, Ahmad, Zainal Arifin, Maslehuddin, Mohammad
• Format: Article
• Language: English
• Subjects: Analysis; Building materials durability; Cements (Building materials); Chemical properties; Compressive strength; Concrete curing; Mechanical properties
• ISSN: 0950-0618; 1879-0526
• DOI: 10.1016/j.conbuildmat.2016.11.048

•Engineered alkali-activated cementitious composites (EACC) was developed using 100% palm oil fuel ash (POFA).•Different sulfate solutions effect on POFA-EACC compressive strength was studied.•POFA-EACC has better durability performance with MgSO4(aq) solution than Na2SO4(q) solution. This paper presents an investigation into the durability performance of Palm Oil Fuel Ash-based Engineered Alkaline-activated Cementitious Composite (POFA-EACC) mortar exposed to sulfate environment. Cube specimens measuring 50mm×50mm×50mm were prepared from POFA-EACC and exposed to the sulfate solutions after one day of heat curing. The POFA-EACC mixtures were prepared with 100% POFA, 2% volume fraction of polyvinyl alcohol (PVA) fibres, alkali-activator (Na2SiO3(aq)/NaOH(aq)) ratios of 2.5 and different molarities (10, 12 and 14M) of NaOH(aq). Three salt solutions (5% Na2SO4(aq), 5% MgSO4(aq) and 2.5% Na2SO4(aq)+2.5% MgSO4(aq)) were used to study the resistance of the POFA-EACC mortar specimens to sulfate for 9months. Parameter used for the study are changes in weight, compressive strength and visual changes. SEM and XRD were employed to characterize and study changes in the microstructure of the exposed specimens. The results obtained from this study revealed that the specimens exposed to 5% MgSO4(aq) solution have better durability performance than the specimens exposed to 5% Na2SO4(aq).