Influence of Nano-SiO2 and Nano-CaCO3 on the Mechanical Properties of Concrete with Different Strength Grades

The flow ability, mechanical properties and microstructure of concrete with different strength grades affected by nano-SiO2 and nano-CaCO3 was studied. The experiment results showed that the strength of concrete at early age was increased by adding the nano-materials if the strength grade of concrete was not high. But the strength at the age of 28 days was not affected a lot by adding these nano-materials. On the other hand, it was not useful to the strength if the strength grade of concrete was high.