Multiscale dynamic fracture behavior of the carbon nanotube reinforced concrete under impact loading

•Multiscale simulation of dynamic fracture of CNT-reinforced concrete.•The mechanical behavior of CNT is obtained through the molecular dynamics.•The numerical simulation of the CNT-reinforced cement is compared with the experimental results.•The fracture energy of the CNT-reinforced sample is substantially increased.•The depth of projectile penetration is significantly reduced.

In this paper, the impact behavior of the carbon nanotube reinforced concrete is investigated through the multiscale simulation. At the nano scale, properties of carbon nanotubes are determined through the molecular dynamics simulation. Afterwards, a finite element based hydration model of the cement is adopted to disperse the CNTs on the surface of the cement. At the meso scale, the concrete is simulated by considering all three phases including, cement, aggregates and interfacial transition zone (ITZ), to obtain a homogenized response. Finally, at the macro scale, the homogenized response is used to find the behavior of CNT-reinforced concrete under impact loading. The results indicate that less damaged areas are generated in the CNT-reinforced concrete model. It responses with higher resistance and energy absorption capacity, which results in considerable reduction of the penetration depth to contain a projectile.