Residual properties of three-span continuous reinforced concrete slabs subjected to different compartment fires

Abstract

Residual properties of three-span continuous reinforced concrete slabs subjected to different compartment fires', Engineering Structures.

Post-fire behaviour of continuous reinforced concrete slabs under different fire conditions

“…Similar to the observations in Ref. [26], severe post-cooling spallings (with the concrete falling into pieces) occurred prior to the residual test due to the moisture absorbed by the calcareous aggregate (rehydration). Compared to thermal-hygral or thermal-mechanical spalling [40], the post-cooling spalling was much slower, but it continued up to the beginning of the residual test (approximately 2 months).…”

“…As discussed in Ref. [26], the average concrete (steel) temperatures on the bottom and top surfaces of the heated spans were 828 (781) °C and 254 (497) °C, respectively. Note that, as indicated in Fig.…”

“…This is an important shortcoming of the available literature data, as different compartment fires frequently occur in modern buildings [22][23][24][25]. Thus, Wang et al [26] investigated the post-fire residual behaviour of five continuous reinforced concrete slabs (named Slabs S1-PF to S5-PF) under various fire scenarios in the spans. The results indicate that the residual material properties of heated compartments and concrete spalling significantly affect the ultimate load and failure mode of the fire-damaged continuous RC slabs.…”

“…Apart from the experimental studies, the theoretical methods need to be developed to assess the residual strength of the fire-damaged concrete slabs, particularly the residual bearing capacity and failure criteria [26]. At present, several theoretical methods [3,16,[28][29][30][31][32][33][34] were developed to predict the bearing capacity of simply supported two-way concrete slabs at ambient and elevated temperatures.…”

“…In those developed methods, different flexural failure modes were proposed to predict the bearing capacities of concrete slabs at large deflections (considering tensile membrane action). However, for fire-damaged concrete slabs, another failure mode, such as the punching shear failure, should be considered because of the material strength degradation and the decreased thickness of slabs resulted from concrete spalling [26].…”