Performance evolution, decision-making analysis of alkali- activated mortar and interface splitting tensile behavior with ordinary concrete

Abstract

In the context of sustainable development, permanent formwork as a new type of structural function formwork has gradually become the mainstream development trend in the construction industry. However, the current research work lacks sufficient evidence to confirm the possibility of alkali-activated materials (AAM) as permanent formworks. Based on blast furnace slag and waste photovoltaic glass, a new AAM was developed to prepare green permanent building formwork. The fluidity, mechanical properties and drying shrinkage of AAM were systematically studied, taking into account the influence of sand-binder ratio (s/b). TOPSIS (Technology for Order Preference by Similarity to Ideal Solution) evaluation results show that AAM with s/b of 1.25 shows excellent comprehensive performance. Based on the above results and distinguishing existing technologies, 12 new forms were designed for AAM-ordinary concrete (OC) interface. The splitting tensile strength, failure form and bond mechanism of AAM-OC interface were studied, and the effects of interface agent, grooving form, crushed stone stud (CSS) and embedded parts were considered. It is found that the maximum bond strength of AAM-OC interface can reach 2.79 MPa, which provides direct evidence for the possibility of AAM as a permanent building formwork. Triangular groove and paving a small amount of CSS have a negative effect on the bond strength of AAM-OC interface, indicating that improper treatment of AAM-OC interface will increase its defects. Other interface treatment methods can improve the bond strength of AAM-OC interface in varying degrees, and the maximum increase rate can reach 33.49%. The interface failure form show that AAM-OC interface has good compatibility. The microscopic morphology test results provide favorable evidence for the above he above discussion results. This study shows that AAM has potential application prospects in preparing permanent formworks.