Enhancement of mechanical properties, durability and service life of low carbon cement paste with super low w/c ratio by incorporating carbon fiber

Abstract

The high strength and durability of cement-based materials are pivotal for energy conservation and carbon emission reduction. By employing solid water mixing technology, a cement-based material with a significantly high compressive strength was developed. However, the concurrent increase in brittleness prompted the exploration of carbon fiber as a potential bridging agent to improve toughness. This paper investigates the role of carbon fiber reinforcement in enhancing the mechanical properties, durability, and service life of cement paste with a super low water-to-cement (w/c) ratio. The results demonstrated that the addition of 0.3 vol% carbon fiber led to an 18.4 % increase in 28-day flexural strength compared to the control group, as well as a 15.3 % increase in flexural compression ratio. Furthermore, under the same carbon fiber content, the drying shrinkage rate after 150-day exhibited a decrease of 20.3 %, and there was a notable decrease of 35.80 % in compressive strength loss rate after 200 freezing-thawing cycles. Service life was significantly improved. It showed that carbon fiber could improve the toughness and durability of hardened cement paste.