受火影响后无粘结预应力混凝土T梁的力学性能试验研究  

Experimental Study on Mechanical Properties of Unbonded Prestressed Concrete T Beams after Fire Exposure

作　　者：杭振园[1] 闻振菲 齐冠 吴颖峰[1] HANG Zhen-yuan;WEN Zhen-fei;QI Guan;WU Ying-feng(Zhejiang Institute of Communication,Hangzhou 311112,China)

机构地区：[1]浙江交通职业技术学院,浙江杭州311112

出　　处：《浙江交通职业技术学院学报》2023年第1期29-35,共7页Journal of Zhejiang Institute of Communications

基　　金：浙江省教育厅一般科研项目(Y202250046);浙江交通职业技术学院科研项目(2023KJ08);2021年度高校国内访问工程师“校企合作项目”(FG2021006)。

摘　　要：预应力混凝土(PC)梁因其较好的经济性和力学性能广泛应用于基础设施建设中,但针对无粘结预应力混凝土梁抗火性能的研究很少。通过对无粘结预应力混凝土T梁进行受火试验和理论分析,研究了受火时间和相关预应力损失对试件破坏模态、抗弯承载力以及抗弯刚度的影响。研究结果表明,火灾是导致试件力学性能劣化的重要,试件受火后,其弹性刚度下降明显,破坏模态也发生了明显的变化。在火灾发生时,钢绞线“弓弦效应”可以有效保证火灾后试件的极限抗弯承载力。Prestressed concrete(PC)beams are used in infrastructure construction because of their good economic and mechanical properties,but there are few studies on the fire resistance of unbonded prestressed concrete beams.Based on the fire test and theoretical analysis of unbonded prestressed concrete T beams,the influences of exposure time and prestress loss on the failure mode,flexural capacity and flexural stiffness of the specimens are studied.The results show that fire is an important factor leading to the deterioration of mechanical properties of specimens.After fire exposure,the initial flexural stiffness of the specimens decreases obviously,and the failure modes also change gradually.Due to the bowstring effect of the steel strands,the ultimate flexural capacity of specimens can be effectively guaranteed after fire disaster,thus there is no obvious downward trend for the ultimate flexural capacity.

关 键 词：预应力混凝土 无粘结钢绞线 受火试验 抗弯承载力 弓弦效应 

分 类 号：TU378.2[建筑科学—结构工程]