Properties and durability of partially replaced cement-based composite mortars co-using powders of a nanosilica superplasticiser and finely ground plastic waste

Abstract

This paper was about an experimental work on properties and durability of partially replaced cement-based composite mortars. Substitutions equal to 0, 2, 4 and 6% of finely ground polyethylene (PE) in association with a 3% nanosilica superplasticiser (SP) were used to cast the composite mortars. Fresh properties concerned setting as well as compressive strength versus porosity accessible to water whereas hardened durability properties were investigated by carbonation according to FT-IR, chloride corrosion of reinforcement, total chloride ion content, steel bars losses of mass and nitric acid attack. The superplasticiser and polyethylene powder inhibited the hydration of the cement while the compressive strength decreased with the rise of the polyethylene content but remained higher than the control mortar one for a (PE) content not exceeding 4%. Composite mortars were less porous and experienced a 2.08% average porosity. Under carbonation, composite mortars exhibited similar performance with the control mortar while corrosion and steel bar mass losses readings revealed the passive condition of the composite mortars and a total chloride content less than 0.4%. Composite mortars demonstrated better resistance to nitric acid attack with (PE) content increase. Correlation of the SEM images and X-ray evidence with the experimental records may be an indication of the feasibility of providing composite mortars with an optimal 2% (PE) for concrete constructions under severe environmental conditions.