Using Carbon Nanotube Enriched Liquid Additive Technology To Improve Concrete Durability and Design Life Contributing As a Sustainable Solution : Tasha Eagle

Using Carbon Nanotube enriched liquid additive technology to improve concrete durability and design life, contributing as a sustainable solution.

Tasha Eagle1,

1 Product Segment Specialist & BDM, FOSROC

ABSTRACT

Carbon nanotube (CNT) enriched liquid additives, when used in the design and construction of concrete result in improved durability and strength. Nanoparticles serve as nucleation sites during cement hydration to help create a denser, cement paste composition. Australian trials have yielded increases between 10Mpa – 20Mpa, equaling ~10% - 30% improvements in compressive strength gains as tested to AS1012.9 2014. Reducing the permeability of the concrete, the CNT dispersed additive significantly reduced chloride diffusion coefficient results in one laboratory and one field trial in Australia, tested at 37% and 33% reduced permeability per Method NT Build 443 1995-II. Using service life prediction modelling, this determined a design life extension of 8 and 19 years respectively. Georgia’s Dept. of Transport achieved increased abrasion resistance to ~50% and compressive strength increases by more than 25% per ASTM C779, proc. C, and ASTM C39, respectively. A trafficable concrete drainage project, in a flood zone, subject to abrasive conditions including salts and chlorides, placed concrete drain sections with and without CNT additive in the concrete. The result was a tensile strength increase of ~22% and abrasion resistance 40%, and after 36 months in service it showed no cracks or pitting vs. the control mix which cracked (>0.3mm) and was deeply pitted. By reducing the slab thickness by 19mm on a USA project, a saving of 430m3 of concrete and 155 ton of CO₂ omissions in reduced cement use alone, was realised. Benefits of CNT technology in concrete will be detailed further in this paper.