Effect of Carbon Nanotubes on the Chloride Penetration in Ultra-High-Performance Concrete

The improvement of Carbon Nanotubes (CNTs) addition on the properties of concrete has been recently investigated, e.g. mechanical properties and durability, but is rarely reported for Ultra-High-Performance Concrete (UHPC) with a very low water to binder ratio. This study evaluates the effect of CNTs on chloride penetration in UHPC and some mechanical properties of this material. The results of experimental tests show that the addition of CNTs in UHPC with contents from 0% to 0.5% by weight of binder in UHPC will reduce the workability of the concrete mixture, and not significantly improve the compressive strength of UHPC under both standard curing and heat curing conditions. However, the results showed that the addition of CNTs improves the dense microstructure of both the UHPC matrix and interfacial transition zone, and resulting in reducing the chloride penetration in UHPC. This is very important in cases of using UHPC for the constructions working under extreme conditions such as on a coastal, island, or underground structures with water erosion. © 2021, The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Switzerland AG.