中文摘要：

对四面受火钢筋混凝土柱在经历不同加热温度（250℃，450℃，650℃）、不同冷却方式（喷水与自然冷却）情况下的力学性能进行了试验研究，分析了高温后冷却方式对钢筋混凝土柱耐火极限和承载力的影响．结果表明，受热温度和冷却方式对高温后钢筋混凝土柱的极限承载力有较大影响．随着温度的升高，钢筋混凝土柱的承载力逐渐降低，且不同的冷却方式对其承载力均有影响，与自冷柱相比，喷水冷却加剧了钢筋混凝土柱正截面承载能力的退化．

英文摘要：

The mechanical behaviors of RC columns subjected to fire on four sides were studied under different high temperatures （250℃, 450℃, 650℃ ） and cooling methods （by air and by water）. The effect of the cooling methods applied after high temperatures on the fire resistance and ultimate beating capacity of RC columns was analyzed. The test results indicate that the heating temperature and the cooling methods have a great influence on the ultimate load beating capacity of RC columns. With the increase of temperature, the ultimate load bearing capacity of RC colunms gradually decreases. Different cooling types all have an influence on the ultimate load beating capacity of RC columns. The ultimate load beating capacity of RC columns cooled by water is lower than that of RC columns cooled by air.