Properties and modification mechanisms of nano-zirconia filled reactive powder concrete

Abstract

The mechanical and electrical properties of reactive powder concrete (RPC) with nano-ZrO 2 (NZ) are investigated in this research. The reinforcing mechanisms of NZ to RPC are studied through thermogravimetry (TG) analysis, scanning electron microscope (SEM) observation and X-Ray powder diffraction (XRD) analysis. Research results indicate that the NZ has obvious modifying effect to RPC. The flexural, compressive and splitting strengths of RPC with NZ at curing age of 28 days achieve increases of 36.6%/4.19 MPa, 16.3%/16.18 MPa and 34.0%/1.08 MPa, respectively, compared to plain RPC. The addition of NZ makes a 20% decrease in the electrical conductivity of RPC. The NZ does not accelerate the hydration process of RPC. However, the microstructures of NZ filled RPC are denser than that of plain RPC. This leads to the reduction of the growth space of calcium hydroxide (CH) crystals, thus the size of CH crystals is reduced. Furthermore, NZ can reduce CH crystal orientation to improve the microstructures of the composites.

A Critical Review on Effect of Nanomaterials on Workability and Mechanical Properties of High‐Performance Concrete

“…Test data show that the compressive strength of concrete increases gradually when the content of NPOFA is as high as 30%. Ruan et al [125] and Han et al [126] found that the mechanical properties of RPC with NZ at a curing age of 28 days improve the compressive strength in comparison with plain RPC.…”

Influence of ZrO2 Nanoparticles on the Microstructural Development of Cement Mortars with Limestone Aggregates

“…Zirconium oxide nanoparticles have also been added in reactive powder concretes (RPC); several works showed that zirconium oxide nanoparticles do not accelerate the hydration process of RPCs, however, they can make the hydration products distribution more uniform, restricting the growth space of CH crystals, obtaining denser microstructures of these concretes. It has also been reported that high contents of zirconium oxide nanoparticles can contribute to better mechanical properties (up to 3% by weight), however, in the absence of a good dispersion, they can agglomerate and weaken the reinforcing effect [22,23].…”

Graphene-engineered cementitious composites

“…As the filler becomes smaller, it is surprisingly found that the addition of these tiny fillers can not only improve the mechanical properties and durability of cementitious materials but also endue them with such functionalities as electrical, thermal, and electromagnetic properties. 4 –9 It is reported that the compressive strength of concrete can be increased up to 70% by incorporating nano-silicon dioxide particles. 10 The addition of 5% nano-aluminum oxide can enhance the elasticity modulus of cementitious composites up to 143%.…”