Creep, shrinkage and mechanical properties of concrete reinforced with different types of carbon nanotubes

This study investigates the influence of incorporating different types of carbon nanotubes (CNTs) on the long-term creep and shrinkage of concrete. Concretes were produced with 0.05-0.5% of unfunctionalized and functionalized CNTs of distinct aspect ratios and water to cement ratios of 0.35-0.55. The influence of CNTs on main fresh and mechanical properties was also analysed. The incorporation of CNTs were able to improve the compressive strength up to 21%, but only slightly increased the modulus of elasticity. Long time-dependent shrinkage and creep of CNT-reinforced concrete were reduced up to 15% and 18% as compared to reference concrete, respectively. Early shrinkage could be reduced up to 54%. CNTs of different aspect ratio equally affected creep, but CNTs of lower aspect ratio were more effective in shrinkage reduction. (C) 2018 Elsevier Ltd. All rights reserved.