超高韧性水泥基材料桥面连续构造的疲劳试验

Experimental Study of Fatigue Behavior of UltraHigh Toughness Concrete Used for Bridge Continuous Decks

摘要:

通过3个桥面连续构造节点的疲劳试验，分析不同材料（普通混凝土和超高韧性水泥基材料（UHTC））和配筋下桥面连续构造的疲劳性能.试验结果表明：在疲劳荷载作用下，UHTC材料表现出了明显的多缝开裂和延性破坏特征；在同等应力条件下，UHTC材料桥面连续构造节点的疲劳寿命是普通钢筋混凝土试件的3倍以上；相同荷载作用下，相比于普通混凝土，UHTC能有效减缓钢筋应变幅的增长，减缓桥面连续构造在疲劳荷载作用下的刚度退化，从而大大提高了桥面连续构造的疲劳寿命.

Abstract:

A novel high performance fiber reinforced concrete ultrahigh toughness concrete (UHTC) is expected to have promising applications in civil engineering due to its outstanding ductility. A series of fatigue tests were conducted on 3 continuous decks to study the fatigue properties of UHTC used as the structural joints in bridge continuous decks with different steel reinforcement ratios. The test results show that the UHTC specimens exhibit a significant multicracking behavior and good ductile failure characteristics under the fatigue load. The fatigue life of the UHTC continuous deck is more than three times that of the ordinary RC continuous deck at the same stress level. Under fatigue loading, the presence of UHTC can effectively reduce the increase of plastic strain in steel reinforcement, decrease the bending stiffness degradation, and improve the fatigue life of continuous deck structure.