新型正交异性钢板-STC组合桥面结构研究与应用

The Research and Application of Super Toughness Concrete on Composite Deck Structure

为综合解决钢桥面体系中正交异性钢桥面结构疲劳开裂和沥青混凝土铺装层易损两种病害问题,本文提出了新型正交异性钢板—超高韧性混凝土(STC)组合桥面结构,基于广东省肇庆市马房大桥,开展了新型正交异性钢板—STC组合桥面结构足尺模型试验。试验结果表明,STC具有良好的抗拉性能,其最大拉应变达到955με而未出现开裂,因而能够适应马房大桥上的受力状态。2011年,新型正交异性钢板—STC组合桥面结构成功应用于马房大桥第11跨,各道施工工序均方便可行,且现浇的STC层经高温蒸汽养护后,未出现任何收缩裂缝。同时,实桥检测表明,增设STC层后,桥面系的局部刚度显著提高,车载引起桥面系构件中的局部应力降低了80%—92%,将有助于提高桥面系的抗疲劳寿命。

In order to deal with fatigue cracking of orthotropic steel deck （OSD） and to diminish dam- ages with asphalt concrete pavement on steel deck, a new orthotropic steel deck-super toughness concrete （STC） composite deck system was proposed in this article. Based on the Mafang Bridge, a steel box girder bridge in Guangdong province of China, a full-scale model experiment was performed. Experiment result shows that the STC exhibited superior tensile performance, as it didn＇t crack even though the maximum tensile strain in the STC layer reached to 955 p.e, which means that the STC layer will withstand disad- vantageous mechanical state on steel bridge decks. In 2011, the new OSD-STC composite deck was initial- ly applied on the 1 lth span of the Mafang Bridge. All of the construction processes were practical. Impor- tantly, the cast in situ STC layer didn＇t crack after applied with hot steam treatment. Moreover, field in- spections show that vehicle-induced stress in OSD components decreased 80%-92%, which is extremely helpful to extend fatigue life of OSD.