- 程 俊1，劉加平1，張麗輝2
２０15年第12期
摘要
引用本文
摘 要：為探究含粗骨料超高性能混凝土單軸拉伸韌性及增強增韌機理，采用單軸拉伸法，研究含粗骨料超高性能混凝土的單軸拉伸性能；采用X射線計算機斷層掃描技術和圖像分析法，并引入纖維分散系數和纖維取向系數，對單軸拉伸試驗后超高性能混凝土中鋼纖維的真實分布進行表征；闡明了鋼纖維分布與粗骨料、鋼纖維分布與混凝土拉伸韌性之間的關系。試驗結果表明，鋼纖維以粗骨料為中心環繞分布；粗骨料對鋼纖維分布具有不利影響，粗骨料摻量越大，粒徑越大，纖維分散性越差，超高性能混凝土單軸拉伸韌性越低；鋼纖維分布與超高性能混凝土單軸拉伸強度及韌性密切相關，隨著纖維分散系數和取向系數的增大，超高性能混凝土單軸拉伸強度、韌性指數以及拉壓比相應增大，韌性增強。
Abstract: In order to investigate the properties of uniaxial tension and mechanism of strengthening and toughening of ultra-high performance concrete containing coarse aggregate, the method of uniaxial tension is used to study the toughness of uniaxial tension; the method of X-ray computed tomography and image analysis introducing fiber dispersion coefficient and fiber orientation factor, is used to study the true distribution of steel fiber in ultra-high performance concrete. It illustrates the relationship between steel fiber distribution and coarse aggregate, steel fiber distribution and uniaxial tensile toughness. The experimental results reveal that steel fibers take coarse aggregate as the center, surround distributing, coarse aggregate having adverse effects on the steel fiber distribution, the more of coarse aggregate content, the larger of particle size, the poorer of fiber dispersion, the lower of uniaxial tension toughness. Steel fiber distribution is closely related to uniaxial tensile strength and toughness of ultra-high performance concrete. With increasing of fiber dispersion coefficient and the orientation factor, uniaxial tensile strength, toughness index and tension and compression ratio are increased, the toughness of concrete reinforced.
