Portland State University. Department of Civil & Environmental Engineering
Date of Award
Master of Science (M.S.) in Civil & Environmental Engineering
Civil and Environmental Engineering
1 online resource (ix, 95 pages)
Insulating concrete forms -- Testing, Walls -- Design and construction, Structural dynamics, Reinforced concrete construction, Recycled products
Insulated concrete forms (ICFs) are green building components that are primarily used for residential wall construction. Unlike most polystyrene based ICF variants, the Faswall ICFs used in these experiments were significantly denser because they were made from recycled wood particles and cement. The current design approach for structures constructed with this type of wall form only allows the designer to consider the contribution of the reinforced concrete cores. Previous research has shown that this approach may be conservative. This project experimentally evaluated the lateral structural response of these types of grid ICF walls under increasing amplitude of in-plane cyclic loading. Two different height-to-length (aspect) ratios (approximately 2:1 and 1:1) were investigated, as was the effect of simultaneous gravity load. Furthermore, the reinforced concrete grid was exposed for each aspect ratio in order to examine the contribution of the ICF blocks to the lateral response. Analyses of hysteretic behaviors and failure modes indicated conservatism in the current design approach for estimating lateral strength and ignoring the beneficial contribution of the ICF blocks to overall performance. The presence of the wall forms increased the lateral shear capacity of the walls by an average of 42% (compared to the walls with forms removed), while also increasing the deformation capacity by an average of 102%. Furthermore, by considering an additional gravity load of 10 kips-per-lineal-foot (klf), the shear resistance of the walls increased by 32% (versus walls only subjected to self-weight), on average, and the deformation capacity of the walls increased by an average of 19%. Comparisons of the experimental results to several design equations led to the recommendation of a design equation that was previously accepted for another type of ICF system.
Garth, John Stuart, "Experimental Investigation of Lateral Cyclic Behavior of Wood-Based Screen-Grid Insulated Concrete Form Walls" (2014). Dissertations and Theses. Paper 1857.