Enhancing fresh properties and strength of concrete with a pre-dispersed carbon nanotube liquid admixture

Abstract This study evaluated the effects of a pre-dispersed carbon nanotube (CNT) liquid admixture on the fresh and hardened performance of CNT-reinforced concrete (CNTRC) dosed at 2.5, 5 and 10% (bwoc), using high-early strength (HE) and Portland cement (OPC) binders. The effect of mixing time, admixture dosage and water-to-binder ratio sensitivity on rheology, bleed and compressive strength after 1-, 7- and 28-days’ curing of CNTRC mixes were assessed, addressing a knowledge gap in workability and early-age performance of the concrete nanocomposite. 10% admixture addition imparted significant strength enhancements at 1 day – up to 40% with OPC, 46% with HE binders – and 28 days – up to 21% for OPC and 37% for HE binders. Results highlighted the benefits of an extended mixing time upon improved CNT homogenisation, compressive strength and reduced bleed. This research demonstrates the significant, applications-ready benefits to early-age and 28-day concrete performance with a pre-dispersed CNT liquid admixture.