Improving the concrete compressive and flexural strength with a low fraction addition of carboxylated nitro-oxidized cellulose nanofibrils from banana rachis

Abstract

Conventionally, concrete strength depends on the bonding interface, especially in hydrated products such as calcium silicate hydrate (CSH). As a result, concrete is sensitive to tensile load. With its unique properties, a low fraction of carboxylated nitro-oxidized cellulose nanofibrils (NOCNF) from the banana rachis is employed to improve the mechanical performance of the concrete nanostructurally. Compressive and flexural strength using the NOCNF content at 0, 0.05, and 0.1 wt.%, cured for 7 and 28 days, were evaluated. Notably, the compressive strength increased by 16 % and the flexural strength by 13 % at 0.1 wt.% NOCNF compared to plain concrete after 28 days of curing. A low NOCNF fraction achieved a good, albeit impossible, performance with the microscale fibers. The nanostructured effect may hypothetically occur in two ways: excellent interaction between the NOCNF and the hydrated products, and carboxylic groups on the NOCNF surface that enhance cement hydration. These data are superior to those in the literature, particularly for small-diameter cellulose nanofibrils without carboxyl groups. As a sustainable nanocomponent, NOCNF could be a promising candidate to enhance concrete performance under mechanical loads