鋼筋混凝土版穿孔剪力拉力側 火害行為研究

Abstract

本研究擬針對鋼筋混凝土版版柱接頭區，進行耐火性能試驗。利用高溫環境溫度變化下，採用不同鋼筋比、混凝土強度及火害延時等變數，並以相當於最大服務載重的力量加載於試體進行試驗。量測鋼筋混凝土版溫度分佈情形、載重-位移關係、溫度-位移關係、耐火時效，以了解鋼筋混凝土版之貫穿剪力行為，受拉面加熱之貫穿剪力耐火時效遠小於在壓力面加熱，也沒有爆裂行為發生。

由本試驗結果顯示增加拉力鋼筋比可以增加常溫貫穿剪力強度，受火害時高鋼筋比強度下降速度較快，試體受火害延時二小時的殘餘強度高於火害延時三小時。

This research was conducted to investigate the punching shear behavior of concrete slab-column joints with different steel ratio, concrete strength and fire duration under maximum service load at elevated temperatures. The distribution of temperature inside the slab and the deflection of slab were measured in the progress tests. Then we can find the behavior of concrete slab-column joints at elevated temperatures.

From the test results, increasing steel ratio can increase the punching shear strength at room temperature. The strength of specimen with high steel ratio decreases faster than the one with low steel ratio at elevated temperature. The residual strength of the fire duration for two hours is higher than the fire duration for three hours. The fire resistance capacity of punching shear wish is subjected elevated temperatures on tension side is higher than there specimens subjected elevated temperatures on the compression side. NO spalling were fund in the tests.