Development and seismic damage assessment of alkali-activated non-formwork insulation composite shear wall

The current external insulation system is prone to varying degrees of cracking and fall off during earthquake events, which can lead to a series of consequences, such as building energy consumption, function loss, and casualties. This study proposed three types of alkali-activated non-formwork insulation composite walls for the first time, and proposed corresponding structural form and preparation techniques. The synergistic performance of alkali-activated non-formwork external insulation system and reinforced concrete (RC) wall under earthquake action was investigated, and compared with the current insulation composite wall. This provided valuable insights into the impact of alkali-activated non-formwork external insulation system on the seismic performance of composite walls. A seismic damage assessment method for alkali-activated non-formwork insulation composite walls was proposed, and a quantitative relationship between seismic damage level, damage index, and residual drift limit value was established. The test results showed that the alkali-activated non-formwork insulation system can work in synergy with RC walls, significantly reducing the degree of RC wall damage without affecting the seismic bearing capacity and deformation performance of RC wall. The seismic damage model proposed based on residual displacement had good applicability, which fully reflects the phenomenon of performance degradation of specimens after experiencing failures such as concrete fall off and longitudinal reinforcement buckling. The development rate of the damage index of the current external insulation system was higher than that of RC walls, while the development rate of the damage index of the alkali-activated non-formwork external insulation system lagged behind that of RC walls.