This thesis presents the results from in-plane cyclic testing of a reinforced cob wall. Cob is an earthen building material composed of sand, clay, straw and water. Cob is typically constructed with no steel reinforcement; however, the California Building Code requires reinforcement in all buildings for resisting seismic forces. The purpose of this thesis is to provide additional technical data to integrate cob into the building code. Test results are reported for a 7’ x 8’ x 14” wall with two layers of welded wire steel reinforcement constructed on a reinforced concrete foundation. In-plane cyclic loading was performed on the wall up to a maximum displacement of 3.5 in. Compression tests of sixteen 3.5” x 3.5” cubes were conducted to determine the compressive strength and the modulus of elasticity of cob. Results provide observed performance, displacement components, yielding points and seismic response modification factors. A numerical model was developed to conduct a parametric study considering the variation of several material and structural properties. In addition, discussion of material properties and recommendations for future work are included.

This thesis investigates full-scale pipe stem reinforced cob walls under in-plane cyclic shear loads. Cob is the combination of clay subsoils, sand, straw and water that is built in lifts to produce monolithic walls. There is insufficient amount of information on cob as a building material in today’s age. The prior research that exists has examined varying straw content and type, water content, and mixture ratios to determine their effect on strength. There is currently one report that analyzes full-scale cob walls under in-plane loading. This thesis looks to iterate the full-scale tests and specifically studies the effect of reinforcement on cob walls. Concurrent to this research, another thesis was written that investigates a full-scale wire mesh reinforced cob wall under in-plane cyclic shear loads. From the data collected, a shear failure was suggested for the stem pipe wall. There appeared to be a large amount of ductility from the data and the cracks formed. Ductility, a seismic response modification factor (R-Factor) and stiffness were calculated using the yield point and ultimate loads.Iterations of this research and those performed in the past can be helpful in integrating cob in to the California Building Code.

Achieving a transition to sustainability and decrease the environmental impact of building is part of Sweden's sustainability goals. Authorities and policy makers have a big responsibility to promote and facilitate this transition, but how this is to be achieved is not as readily answered. Using the multi-level perspective on socio-technical transitions, this thesis investigates the conditions for sustainability transitions in Swedish building by learning from the case of earthen and straw home builders. Qualitative mixed methods research, including questionnaires and semi-structured interviews was carried out to explore drivers and barriers for innovative sustainable building in Sweden. Findings suggest that there are barriers for innovative sustainable building in Sweden that might slow down the sustainability transition process, not in terms of regulation but in practices and norms in the current socio-technical regime.