The biggest part of my design has to provide with shelter from rain and give sitting area. Also I need it to occur some aging process changes. The material has to be available in great sizes and appropriate strength. A glulam seems to fit perfectly.
Glue-laminated wood (or glulam) is comprised of many small chips of wood glued together in diffrent directions to create a girder or other structural members. The diffrent orientations of these wood pieces provide greater strength than a single piece of wood of the same size and also allow for sizes and lengths unlimited by log sizes. The wood is fully sea- soned (dried) before being laminated to ensure a high-quality member. Glulams are specified by their quality and size much like typical timber. High-quality glulams will use a specific type of wood and have a greater strenght or size. The development of glulams was a significant advancement in the twentieth century wood construction industry, allowing for longer spans and for shapes that the natural material cannot provide.
Example of use:
My design consists of three parts and two of them are going to be made of cor ten. I chose that material because of its ability to age along with time by showing the rust on the surface.
Weather-resistant steel works by controlling the rate at which oxygen in the atmosphere can react with the surface of the metal. Iron and steel both rust in the presence of air and water, resulting in the product of corrosion - rust, iron oxide. Non-weather-resisting steels have a relatively porous oxide layer, which can hold moisture and promote further corrosion. After a certain time (dependent on conditions), this rust layer will delaminate from the surface of the metal, exposing the surface and causing more damage. Rusting rates seen on a graph would appear as a series of curves approximating to a straight line.
Cor-Ten is the primary brand name for corrosion resistant products that were developed by United States Steel Corp. Cor-Ten has subsequently been licensed to be produced by other steel producers. There are basically two types of Cor-Ten that are most prevalent, Cor-Ten A (generally up to 12mm thick) and Cor-Ten B (generally 15mm thick and above).
Weathering steel is popularly used in outdoor sculptures. I present some example of use of cor ten:
Weakness of COR-TEN:
Using weathering steel in construction presents several challenges. Ensuring that weld-points weather at the same rate as the other materials may require special welding techniques or material. Weathering steel is not rustproof in itself. If water is allowed to accumulate in pockets, those areas will experience higher corrosion rates, so provision for drainage must be made. Weathering steel is sensitive to salt-laden air environments. In such environments, it is possible that the protective patina may not stabilize but instead continue to corrode.
All those seeming weaknesses turn into advantage in the way I need it in my project. I like it being imperfect and can experience higher corrosion rates. The aging will be visible for human eye more likely.