| dc.description.abstract | The use of precast concrete in construction is highly favored due to its many benefits, including improved quality control, reduced construction time, increased durability, and sustainability. In Oklahoma, post-tensioned slabs are commonly utilized in construction projects due to their resilience and capacity to withstand expansive soil movement. Nevertheless, when it comes to residential foundations, precast post-tensioned concrete slabs may present some limitations, such as challenges related to their
transportation and installation due to their weight.
The use of lightweight concrete (LWC) for precast slabs and structural elements has become increasingly popular due to its lower concrete density resulting from the use of lightweight aggregates. This not only makes transportation and installation more manageable but also enhances insulation. However, the use of lightweight concrete may result in reduced tension and shear strength, which could be addressed by incorporating post-tensioning. This research was conducted to identify the key factor in designing and producing a precast post-tensioned slab using LWC. The goal was to create a slab that can be manufactured off-site, transported to the job site, and positioned using a crane for lifting and a leveling mechanism for attachment to the foundation on site. This study consisted of four phases; the first phase involved reviewing previous research conducted on precast post-tensioned slabs made with LWC. In the second phase, a LWC mix was developed that could be used for the precast post-tensioned slabs cast in this project. The third phase focused on designing the slab using various methods and software. Finally, in the fourth and last phase of the research project tests were carried out on medium and large-scale specimens of the slab design developed in Phase 3, using the mix developed in Phase 2.
Valuable insights were gained from the research study results. First, it was confirmed that the final mix design developed during the study was feasible, performed as intended, and yielded positive results. Secondly, it was noted that while design software can be used to design structural elements, it is important to double-check reinforcement details for the sake of construction. Third, a preliminary design for precast post-tensioned slabs was carried out, and the medium specimen responded as expected without showing any cracks or excessive deflections, indicating the feasibility of this structural element. Finally, inadequate rigging led to inconclusive results for the large-scale specimen. | en_US |
