Development and engineering application of rapid hardening UHPC for emergency repair and reinforcement in cold winter regions
LYU Hao
LI Siqi
LI Kuan
Abstract：In order to prepare rapid hardening UHPC for emergency repair and reinforcement in cold winter regions,the effects of retarder and steel fiber content on the working and mechanical properties of UHPC were discussed.The results show that the higher the dosage of retarder,the longer the setting time of UHPC and the lower the loss of expansion.When the dosage of retarder is 0.75%,the comprehensive performance of UHPC is the best,the 4 h and 24 h compressive strength are 50 MPa and 82 MPa,re-spectively;while 4 h and 24 h bonding strength are 2.8 MPa and 4.7 MPa,respectively.With the increase of steel fiber content,the bonding strength and flexural toughness of UHPC increase.The 28 d bond strength and flexural strength of UHPC with 1.5%steel fiber content were 9.5 MPa and 22.6 MPa,respectively,and the strength improvement was not significant with the increase of steel fiber content.The durability of UHPC is much better than that of C50 steel fiber reinforced concrete by frost resistance and chloride ion migration coefficient test,which is suitable for emergency repair and reinforcement in cold winter regions.Combined with the concrete replacement engineering application of Heha high-speed expansion joint anchoring area in Heilongjiang Province,the rapid hardening UHPC can be opened to traffic 4 h after pouring,and there is no damage phenomenon after two years of operation through freeze-thaw and deicing salt environment.
Keywords：rapid hardening UHPCemergency repair and reinforcementflexural toughnessdurabilityfreeze-thaw cycle
Publication Date：2026-01-25
Online Publishing Date：2026-03-17(First online date of this platform, not the publication date of the document)
Pages：5( 43-47 )