Boron nitride nanosheet as a promising reinforcement for cementitious composites

Boron nitride nanosheet (BNNS) is a good candidate for cement paste to improve the weak interlayer bonding strength in three-dimensional (3D) concrete printing. In addition, the increased viscosity with the addition of BNNS leads to enhanced shear performance, which can help to tackle the problems of poor stability and eccentricity. To understand the reinforcing role of BNNS, the investigation of shear properties in BNNS-tobermorite composite is carried out using molecular dynamics simulations. The microstructure is characterized to show the good matching between BNNS and tobermorite. The improvement of BNNS in the shear modulus of BNNS-tobermorite composite and the load transfer between BNNS and tobermorite is also quantified. The results provide an in-depth understanding of the enhancing mechanism of BNNS in the shear properties of tobermorite composite, which envisions the promising application of BNNS in 3D printed concrete.