Internal carbonation curing base on molecular sieve: Influence and mechanism on cement-based materials

Carbonation curing of cement-based materials can not only store CO2, but also improve the mechanics and durability. But there are still many problems limiting its application. For example, the water cement ratio should be low, the carbonation reaction only occurs at the surface and the high-pressure curing equipment is hard to be used in-situ. In this paper, the molecular sieve adsorbed CO2 was adopted as internal carbonation curing agent to investigate its influence and mechanism on the strength of cement-based materials. And the mechanism was investigated through the methods including X-Ray Diffraction and scanning electron microscope. Results indicated that under the action of internal carbonation curing agent, the strength of the cement paste at 3d, 7d and 28d increased by 22.5%, 18.6% and 12.8%, respectively. It would provide more possibilities for in-situ application of carbonation curing on cement-based materials which cannot be achieved by conventional carbonation curing.