高性能复合砂浆薄层加固RC梁的耐火极限试验研究

高性能复合砂浆钢筋网薄层(简称HPFL)加固混凝土构件是一种新型的加固方法,该方法采用的高性能复合砂浆为无机材料,具有众多优良特点。为研究HPFL加固RC梁在高温-外力共同作用时剪切销钉对界面粘结性能的影响,对6根三面U形(在梁的受拉面和侧面进行加固)加固RC梁进行了高温试验,所有加固试件分为三组,第一组两根试件未植入剪切销钉,第二组两根试件植入剪切销钉,剪切销钉间距较大,第三组两根试件也植入剪切销钉,剪切销钉间距较小。试验后,比较它们的耐火极限、跨中挠度和破坏形态,分析界面在高温时的破坏机理。试验结果说明:植入剪切销钉可以非常显著地改善界面在高温时的粘结性能,试件在高温时的耐火性能得到很大的提高。

EXPERIMENTAL INVESTIGATION ON DURATION OF FIRE RESISTANCE OF RC BEAM REINFORCED WITH HIGH-PERFORMANCE FERROCEMENT LAMINATE

High-performance ferrocement laminate(HPFL) is a new method to reinforce RC component. It adopts HPFL as inorganic material,and possesses numerous merits. In order to study the shear pins' impact on the interracial bonding properties at high-temperatures, the test include 6 RC beams strengthened with U-shaped HPFL (ferrocement was put onto the tension face and two profile faces) and 1 reference RC beam. All the beams strengthened with U-shaped HPFL are divided into three groups. The two beams strengthened with U-shapod HPFL in the first group without implanting shear pins. However, the two beams strengthened with U-shaped HPFL in the second group with shear pins by larger spacing. And the last two beams strengthened with U-shaped HPFL in the third group are also implanted with shear pins by smaller spacing. After the test, there is a comparison of their duration of fire resistance, deflection and destruction mode, and an analysis of the interface's failure mechanism is done at high-temperature. The results show that the implanted shear pin can significantly improve the interfacial bonding properties at high-temperature, and the strengthened beams' fire resistance at high-temperature has been greatly improved.