为研究不同再生骨料取代率混凝土柱的耐火性能,进行了3个足尺再生混凝土柱在竖向荷载和温度场耦合作用下的升温耐火试验.其中,2个试件再生粗骨料取代率为100％,细骨料为天然砂的半再生混凝土柱;1个试件为再生粗、细骨料取代率均为100％的全再生混凝土柱.在试验基础上,比较分析了各试件的截面温度变化、耐火极限、轴向变形、侧向挠度和破坏形态.研究表明:相同轴压比条件下,半再生混凝土柱的耐火极限随着混凝土强度的提高而降低;混凝土强度变化对温度场分布规律影响较小;半再生混凝土柱与全再生混凝土柱相比,混凝土材料性能退化较慢,耐火性能较好.%In order to investigate the fire resistant performance of the recycled concrete columns with different replacement rate of recycled aggregate;three full-sized recycled concrete columns were designed and tested under high temperature and unchanged vertical load. Two of the specimens were made from recycled concrete with 100% of recycled coarse aggregate and 100% of natural fine aggregate;which was called 50% recycled aggregate concrete. The other one was made from recycled concrete with 100% of recycled coarse aggregate and 100% of recycled fine aggregate;which was called 100% recycled aggregate concrete here. Based on the experimental study;several parameters were comparatively analyzed;including the temperature variation at the cross section;fire endurance;vertical displacement;lateral deflection;and failure modes of specimens. Results show that the fire resistant endurance for recycled coarse aggregate concrete column decreases with the concrete strength increases. The concrete compressive strength has little infuence on the temperature field of columns. Compared to the column with 100% recycled aggregate concrete;the column with 50% recycled aggregate concrete has better fire resistant performance and its material property deteriorates more slowly.
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