Investigation on optimal lightweight expanded clay aggregate concrete at high temperature based on deep neural network

Abstract

This study explores the effects of mixture design parameters on the residual mechanical properties of lightweight expanded clay aggregate (LECA) concrete exposed to elevated temperatures. A total of 30 lightweight concrete mixtures were cast and exposed to three elevated temperatures, namely 250°C, 500°C, and 700°C. The test variables comprised the LECA percentage used as partial volume substitution for natural sand (0%, 25%, 50%, 75%, and 100%), silica fume partial replacement for cement by weight (5%, 7.5%, 10%, 12.5%, and 15%), cement content (300, 400, 500, 600, and 700 kg/m3), and different water‐to‐cement (W/C) ratios (0.25, 0.313, 0.375, 0.438, and 0.5). The compressive and indirect tensile strengths were measured before and after exposure to elevated temperatures. The results indicate that the lightweight concretes incorporating higher contents of cement and silica fume and made with lower W/C ratio exhibited higher initial mechanical properties yet incurred more significant drop in mechanical properties after exposure to 500°C and 750°C.

Predicting stress-strain behavior of normal weight and lightweight aggregate concrete exposed to high temperature using LSTM recurrent neural network

“…It can be seen from Figure 13 that the strains at peak stress of all the specimens are approximately 170% of those at ambient temperature exposure, when the exposure temperature rises to 250°C. With a larger increase in the exposure temperature, the failure strain (peak stress related strain) increases significantly, such that it becomes approximately 230% at 500°C of exposure temperature in comparison to that observed for the equivalent specimens exposed to room temperature The escalation of failure strain at 500°C exposure temperature could be attributed to the material constituents softening under heating, as well as the cement paste-aggregate thermal incompatibility [8]. The failure strain of the specimen increases 330% compared to the room temperature when the temperature rises up to 750°C.…”

“…In addition, LWAC has better thermal performance than the normal-weight concrete (NWAC) because of the higher heat resistance and porous structure of the lightweight aggregates compared to their normal-weight counterpart. Thus, its application can significantly reduce the energy consumption in buildings [6][7][8].…”

Artificial neural network evaluation of concrete performance exposed to elevated temperature with destructive–non-destructive tests

“…The most important mineral forming the essence of kaolin is kaolinite (Al 2 Si 2 O 5 (OH) 4 ). Kaolinite is a clay mineral composed of aluminum hydrosilicate composition [14,15]. Metakaolin is a highly fine reactive alumino-silicate pozzolan obtained by firing and then grinding purified kaolin or kaolinite clays at a certain temperature range [26].…”

“…Thus, undesirable structural damages occur in the structure by negatively affecting the mechanical properties of the concrete. The degree to which concrete is affected by temperature varies according to the components it contains [14,15,60]. According to the thermal conductivity of the components used in concrete at elevated temperatures, deterioration and fragmentation occur.…”

Assessment of the Durability Against a Chemical Attack of Fiber-Reinforced Lightweight Pouzzolanic Concrete under the Effect of Temperature

“…LWC has good fire resistance due to its lower thermal conductivity, which helps to slow the spread of fire within a building. This can improve the safety of the building occupants in the event of a fire [3][4][5][6]. Despite being lightweight, LWC can be just as durable as traditional concrete.…”