局部替换钢纤维细石混凝土的桥面连续板抗弯性能试验研究

Experimental study on flexural mechanical performance of bridge deck continuous slabs with local replacement of steel fiber reinforced concrete with fine aggregate

对9块局部替换钢纤维细石混凝土和3块普通混凝土桥面连续板的缩尺试件进行了四点抗弯力学性能试验研究。通过改变桥面连续板中部区域钢纤维细石混凝土的替换宽度和配筋率,对桥面连续板的破坏特征、承载能力、刚度及延性、中和轴高度变化、钢筋应变等力学性能进行了研究与分析。结果表明,经局部钢纤维细石混凝土增强后的桥面连续板,其抗弯强度、刚度和延性明显增强。钢纤维细石混凝土能有效改善桥面连续板的协同变形能力,延缓桥面连续板开裂和界面中和轴上升。配筋率显著影响桥面连续板的承载力,随着配筋率的增大,试件的刚度和开裂荷载随之增加,延性随之出现降低。此外,钢纤维细石混凝土替换宽度的改变对试件整体性能影响规律不显著。

The four-point flexural mechanical performances of nine local replacement steel fiber reinforced concrete with fine aggregates(SFRC-FA)and three ordinary concrete continuous slabs on bridge deck were studied.By changing the steel fiber ratio and replacement width of SFRC-FA in the middle of the continuous slabs,the mechanical properties of specimens,such as failure characteristics,flexural strength,stiffness and ductility,reinforcement strain and height change of neutralization axis,were studied and analyzed.The results show that the flexural strength,stiffness and ductility of the continuous slabs reinforced with SFRC-FA are obviously enhanced.SFRC-FA can effectively improve the cooperative deformation ability of the continuous slab of the bridge deck,delay the cracking of the slab and the rising of the neutral axis.Furthermore,the steel fiber ratio significantly affects the bearing capacity of specimens.With the increment of reinforcement ratio,the stiffness and cracking load of the continuous slabs increase,and the ductility decreases.In addition,it is found that changing the replacement width of SFRC-FA has no significant effect on the performance of the specimens.