Integrated composite wall with geopolymer permanent insulation formwork: Interface bonding behavior and mechanism

Abstract

Traditional external insulation engineering and formwork engineering in buildings are unable to meet the development needs of the construction industry under the current situation due to their complex construction processes, high environmental pollution, and insulation layers is prone to fire, peeling, and other diseases. Therefore, improving the technology of building external insulation engineering and formwork engineering scientifically and economically has become an urgent practical problem to be solved. This study developed an integrated composite wall with geopolymer insulation formwork based on alkali activation technology. The interface bonding performance between alkali-activated mortar (AAM) and building insulation materials (BIM), as well as between AAM and the post-cast normal concrete (NC) were examined by push-out test and single shear test, respectively. Among them, BIM includesd alkali-activated insulation materials (AAI) and traditional extruded polystyrene foam (XPS). Studied the enhancement effect and mechanism of interface treatment methods on two types of interfaces. The simplified models were proposed for the shear strength of AAM-NC interfaces with grooved treatment and crushed stone studs. The results showed that the interfacial bond strength of AAM-AAI was better than that of AAM-XPS, which was due to the more compact interface transition zone of AAM-AAI. The grooved treatment had a positive improvement effect on the shear strength of AAM-AAI and AAM-NC interfaces, increasing by 16.59%∼167.32% and 21.03%∼42.06%, respectively. Adding crushed stone studs and installing connectors can improve the bonding performance of AAM-NC interface by 19.63%∼42.99%. In addition, the proposed simplified models have high consistency between the predicted results and test results, which can provide good reference value for engineering design.