A Study of Mechanical Properties and Frost Resistance of High-Performance Concrete Repair Materials Doped with Carbon Nano-Fibers

LI Changhui; XUE Wenchao; QI Lin; LIU Lingzhi; WANG Daotong

doi:10.3969/j.issn.2097-1915.2025.02.014

Abstract：This article introduces a repair material being characteristic of high-performance concrete doped with vapor grown carbon nano-fiber reinforcement(VGCF)and carbon nano-tubes(CNT)for runway.That material of adding nano-fibers to concrete can improve its mechanical properties and endurance is a well-known fact.However,the uneven distribution of nano-fibers in the cement matrix can lead to a de-crease in performance.The article focuses on the adaptability of repair materials and cement-based pave-ment materials,and analyzes the influence of carbon nano-fiber materials on the micro mechanism of con-crete reinforcement.Mix proportion tests are conducted by doping carbon nano-fibers with different mass fractions in concrete,and the compressive strength,bonding strength,mass loss rate under freeze-thaw cycles,and bonding strength loss rate are measured respectively.The research shows that when the CNT104 content is 0.1%,the compressive strength and bonding strength of concrete are 60.6 MPa and 11.3 MPa respectively,and the 150 freeze-thaw cycles being over,the mass loss is minimum.When the content of CNT107 is 0.15%,the compressive strength and bonding strength are fairly good,i.e.59.1 MPa and 11.5 MPa respectively.When the content reaches 0.2%,the mass loss is minimal after 150 freeze-thaw cycles.When the VGCF content is 0.15%,the concrete reaches its maximum compressive strength and bonding strength,i.e.68.0 MPa and 18.6 MPa respectively.At the same time,the concrete with different contents of VGCF shows better frost resistance.At a content of 0.15%,the quality loss rate of concrete after freeze-thaw cycles is the lowest.After 150 freeze-thaw cycles,the bond strength is measured again.By comparing before and after freeze-thaw,it is found that the decrease rate of bond strength with 0.15%VGCF added is 32.79%,which is the lowest among all groups.The results indicate that taking UHPC mixed with 0.15%VGCF as runway repair material,its fairly good adaptability to ce-ment-based pavement materials is very protruding.