About the author:

CCCC Road & Bridge Transportation Technology Co., Ltd., Beijing 101300, China

Abstract:

To enhance the compressive and flexural strength of concrete for highway bridge deckpavement, a series of tests were conducted on mix proportion design, steel fiber content,water reducerselection, and binder material ratio of ultra,high performance concrete （ UHPC） to investigate theinfluence of different factors on its performance and determine the optimal mix proportion. The resultsindicate that the steel fiber content significantly affects the mechanical properties of UHPC. Anappropriate amount of steel fiber effectively improves its compressive and flexural strength,with theoptimal content being 51kg / m3. The addition of polycarboxylate superplasticizer notably enhances theworkability of the UHPC mixture, reduces cohesiveness, and increases the flow spread,with the optimalcontent being 4kg / m3. In the binder material ratio, partially replacing cement with an appropriate amountof mineral powder and fly ash positively influences both the mechanical properties and flowability ofUHPC. The optimal ratio is cement ∶ mineral powder ∶ fly ash = 400 ∶ 60 ∶ 40kg / m3. Based on theoptimal mix proportion, the initial flow spread of UHPC reaches 625mm, and the 3,day, 7,day, and 28,day compressive strengths are 97.45, 107.51, 134.42MPa, respectively. The mixture exhibits suitableviscosity and good leveling performance, meeting the requirements for highway engineering applications.