Nanomaterials in ultra-high-performance concrete (UHPC)-A review

This paper presents a state-of-the-art review of the utilization of nanomaterials in ultra-high-performance concrete (UHPC). First, various types of nanomaterials currently available for use in UHPC are summarized and their geometric and physical properties are analyzed. Then, the effects of nanomaterials on the packing density and fresh properties of UHPC are addressed. The hydration kinetics and mechanical properties of UHPC, such as the interfacial bonding, compressive strength, tensile and flexural responses, and nano-mechanical properties, are analyzed according to the nanomaterial type and dosage. Based on the data acquisition and analysis, the optimal dosages of nanomaterials for strength enhancements of UHPC are suggested. The influence of nanomaterials on the durability-related properties, such as the porosity, water sorptivity and permeability, sulfate attack, abrasion resistance, corrosion resistance, freeze-thaw resistance, fatigue performance, and shrinkage, are also investigated. Finally, nanomaterial-based functional UHPCs with electrical, self-sensing, and electromagnetic shielding properties are reviewed and discussed.