During the last three decades there has been increasing concern within the scientific community about the effects of indoor air quality on health. Changes in building design devised to improve energy efficiency and has induced that modern homes and offices are frequently more airtight than older structures. Furthermore advances in construction technology have caused an extensive use of synthetic building materials. The construction process and the production of building materials not only consume the most energy they also have a big impact on the Global Warming Potential. While these improvements have led to more comfortable buildings with lower running costs, they also provide indoor environments in which contaminants are readily produced and may build up to much higher concentrations than outside. Because about 80-90% of our time is spent indoors, where we are exposed to chemical and biological contaminants and possibly carcinogens, the Indoor Environmental Quality plays an increasing role. The aim of this study was to develop building components out of sustainable natural materials for modular building concepts with regard to the Indoor Environmental Quality such as the air quality and the indoor climate, the temperature and humidity. To guarantee high Indoor Air Quality a mechanical ventilation system is part of the construction. It has to ensure a controlled air change with a minimum of dissipation of energy. Building parts were assembled to meet high energy efficiency Standards. For the construction parts wood, hemp, sheep wool and clay were used to meet the settled requirements. As a first result of this study two modular buildings were erected, in which the indoor air quality and the construction physics will be monitored in the next few years for generating valuable data.
The thermal refurbishment of the building stock is one of the most fundamental challenges of sustainable urban development. Particularly the use of natural and local materials gets an increasing relevance, regarding the embodied energy. The focus of this work is the development of systematised solutions for thermal refurbishment with...
The goal of this study is to determine the shear and tension resistance capacity of a tenon connector made out of beech plywood for the connection of cross laminated timber wall elements. To determine the tensile and shear capacity of the connector according to EN 26 891 [1], tensile and shear tests were performed on cross laminated timber elements with thicknesses of 100 mm, 150mm and 180 mm which were connected with the pin connector. The sample set consisted of 36 test specimens of which were 18 tensile specimens and 18 shear specimens. For each test series, three tensile and three shear tests with the top layer parallel and perpendicular to the load direction were performed. The test specimens were stored for four weeks in normal climate at 20 ° C and 65% relative humidity before they were tested. The shear and tension capacity shows a substantially linear behaviour by increasing the length of the connector. In the tensile tests a transverse tension failure happened in the transverse layer. In the shear tests a plastic failure of the beech plywood connector happened.
