Effect of Adhesives on the Structural Performance of Timber-Framed Joints for Sustainable Civil Engineering Construction

The need for infrastructural growth in developing countries has increased exponentially consequent to the rapid rise in population. This in turn, has increased the demand for prominent building materials like cement, which is mainly used in concrete construction. With the global cement production crossing 4.1 billion metric tons which releases about 7% of total carbon dioxide to atmosphere, it has become indispensable to promote such a construction material that is sustainable and also, at the same time cost effective. Timber provides a viable alternative in this regard, due to its eco-friendly, energy efficient and light weight qualities, thereby, making it ideal as a building material. Timber framed structures have been used in seismically susceptible regions since times, with connections being the most vulnerable elements that govern the integrity and safety of such systems under diverse loading actions. Although, the behavior of timber framed structures has been studied by many researchers by testing full-scale-connections with the aim to establish consistent design provisions on the same, however, much emphasis in this approach has focused only on a particular connection configuration, with no attempt being made for optimizing the joints through innovative detailing. To address this concern, a comparative study to evaluate the performance of various full-scale timber frame Nailed connections (Bridled Tenon, Cross Halved, Dovetail Halved and Mortise Tenon) supplemented by adhesive with respect to Nailed-Only counterparts, under tensile loading, has been investigated in this paper. The test results have been used to calculate stiffness, load capacity and ductility in both the connection forms (with and without adhesion) which in turn have been compared to other joint profiles along with the observed failure modes. The experimental outcomes showed incorporation of adhesive to be an effective and economical technique in significantly enhancing the performance of different connections considered in this study. Thus, this research is novel as it attempts not only to explore and improve the behavior of various timber framed joints in a logically sequential manner, but also, provides a sustainable alternative to the contemporary building materials, thereby, making it eco-friendly in its approach.