Wood concrete skyscrapers

Multi-storey buildings in timber have gained increased interest with the development of cross laminated timber products. A wide variety of CLT-elements is currently on the market, most characterized by a fixed width and lengths of up to 16-20 meters. Thickness generally is limited for technical reasons to approximately 350 mm. Even though no product standard is available yet, multi-storey buildings have been realized with CLT in a number of countries, showing the potential of the product. A multi-storey building with seven storeys was tested for earthquake resistance by CNR-Ivalsa in 2007 in Japan. A further development in this field is the development of mixed structures, such as wood-concrete skyscrapers. Depending on the conditions, very tall buildings can be built, mainly made out of timber. With the right combination of other materials such as concrete, skyscrapers can be designed using a system of outriggers and tensile elements in the facade with a combination of CLT-panels. In this paper, some basic concepts are presented, as well as a number of advantages using such combinations, including positive effects on crane times and building economics. The main market of such buildings is thought to be in rapid developing countries such as China and India, where cities show rapid growth and demand for environmentally friendly housing is on the rise.