An Experimental Study on the Adhesion Performance of SSG Sealant to Timber and its Application in Mock-Up Assemblies

Abstract

In recent years, the Japanese architectural industry has seen a growing trend toward timber construction, driven by increasing environmental awareness. However, despite the use of timber in structural elements, aluminium sash frames remain prevalent in many buildings. This study aims to develop a durable, all-timber sash system by focusing on the Structural Silicone Glazing (SSG) method. The method allows timber components to be used without direct exposure to outdoor conditions, thereby enhancing durability. This research investigates the adhesion performance of SSG sealant on timber. Initially, adhesion tests were conducted on various timber specifications to identify optimal candidates. Subsequently, residual adhesion performances were investigated on selected specimens pre-treated by several artificial aging methods. Experimental validation was performed using a full-scale specimen. A timber SSG unit (GW2940×GH805) was installed in a wind pressure chamber. The unit was subjected to 2.2 million cycles +1 kPa wind pressure, followed by a single application of ±4.5 kPa. After testing, the specimens were extracted from the unit for adhesion tests to assess residual performance. Additionally, full-scale mock-ups of arches and a circular shape were fabricated. CNC machining enabled the precise shaping of timber to match the edge curve of glass, which confirmed the feasibility of producing timber SSG units with complex geometries[A1.1][A1.2]. These results demonstrate the feasibility of applying SSG to timber sash systems with appropriate material selection.