Cyclic tests on composite plate shear walls–concrete encased before and after fire exposure

Cyclic lateral loading tests were conducted on six composite plate shear walls–concrete encased and two conventionally reinforced concrete walls. The composite plate shear walls–concrete encased were constructed using high-performance concrete and different steel configurations with a same steel content ratio. These walls were divided into two batches. Three composite plate shear walls–concrete encased and one conventional wall were first exposed to the ISO 834 standard fire before the cyclic tests. To their comparison, the other four walls were only tested under the cyclic loading at room temperature. During the fire tests, the four walls experienced the spalling of concrete. The composite plate shear walls–concrete encased suffered more explosive spalling than the conventional wall. After the fire tests, all walls were tested under the cyclic loading. Based on the test results, analysis and discussions were made on the lateral load, lateral stiffness, and energy dissipation ability of walls. The difference was identified between the behavior of composite plate shear walls–concrete encased and that of conventional wall. Moreover, the influences of fire exposure were analyzed on seismic behavior of shear walls. Generally, the high temperatures reduce the yield, peak, and ultimate loads of walls and degrade the lateral stiffness. No significant difference can be found in energy dissipation ability between the heated and unheated walls before the drift ratio 1/120