Study on the Properties of Cement-Based Cementitious Materials Modified by Nano-CaCO₃

Abstract

The effects of Nano-CaCO3 on the physical, mechanical properties and durability of cement-based materials were investigated in this paper. The mechanical property, durability and SEM microscopic tests of test blocks with different Nano-CaCO3 content were carried out. Results showed that Nano-CaCO3 could improve the flexural strength, compressive strength and impermeability of cement-based materials. When the content of Nano-CaCO3 is 2.0%, the strengthening effect of Nano-CaCO3 on the cement-based materials was optimized, and the flexural strength of cement-based materials after 3 d, 7 d and 28 d increased by 12.6%, 18% and 32.4%, respectively, compared with the reference group. When the content of Nano-CaCO3 exceeded 2.0%, the flexural strength of cement-based materials begins to decline with the increase of Nano-CaCO3 content. Similarly, when the content of Nano-CaCO3 reached 2.0%, the impermeability of the cement-based materials was also optimized, and the permeability height of the base group could be increases by 41.4%. At the early stage of hydration, the exothermic rate of cement with 2.0% Nano-CaCO3 content was higher than that of other contents. When the content of Nano-CaCO3 increased from 0 to 2.0%, the hydration exothermic rate increased gradually with the increase of Nano-CaCO3 content.

Keywords

• durability
• microstructure
• hydration
• multiscale
• bending toughness