STRUCTURAL CHARACTERISTICS OF LOAD BEARING STRAW BALE CONSTRUCTION

Abstract

Environmental protection has become a topic that people attach great importance to in the new era, and reducing carbon emissions has become one of its important indicators. The construction industry occupies a major position in terms of energy consumption and carbon emissions, especially in terms of building materials. The production and use of steel and cement have resulted in a large amount of carbon emissions. Under the trend of energy conservation and emission reduction, people realize the charm of biological resources. As a by-product of crops, wheat and other cereal straw can significantly reduce carbon emissions by storing biochar through photosynthesis during the growth stage. Secondly, its good thermal insulation also greatly reduces the energy consumption of the temperature control system in the building. In many countries, straw has been used in construction for more than a hundred years, and the use of straw in the construction industry has considerable commercial value.
However, the development of straw bale construction has been relatively slow. There is limited knowledge about the structural capabilities, durability and resistance of straw bale buildings to corrosion and insect infestation in hot and humid environments. Moreover, there is a lack of specifications to guide the construction of straw bale buildings and a lack of standards for straw bale building construction technology, which makes the safety of the buildings unclear and there are barriers to acceptance at the public level.
The aim of this doctoral thesis is to conduct a more detailed and comprehensive study of the current situation of straw bale construction. Tests were conducted on full-scale straw bale walls to evaluate their structural performance under vertical and lateral loads. Afterwards, through vertical load experiments on single-package wide walls, the effects of wall slenderness ratio and concentric and eccentric loads on the wall bearing capacity were explored. And the bonding between straw and plaster and the vertical load pass path in the wall were analysed.
This research project mainly verified the conclusion that plaster coat improves the bearing capacity of strawbale construction and reduces the structural bearing capacity under vertical eccentric load. It was also found that the wall height (wall slenderness ratio) has little effect on the vertical bearing capacity of the strawbale construction. We also designed new experiments to test the bonding of straw and plaster, and analysed that straw and plaster coat previously conducted force transmission in the form of shear force. It is hoped that through this series of experiments, the knowledge and understanding of strawbale construction could be expanded, and more complete technical indicators can be provided, so that strawbale construction could be more widely used in the future.

Date of Award	27 Mar 2024
Original language	English
Awarding Institution	University of Bath
Supervisor	Peter Walker (Supervisor) & Dan Maskell (Supervisor)