Experimental Evaluation of Foam-Void Double-Tees

Abstract

Gross vehicular weight restrictions limit the shipping of typical pre-stressed concrete double-tees (DT) for parking decks to one member per trip. The objective of this study is to reduce the self-weight of these members to facilitate two-at-a-time shipping, and thus enable lower shipping costs and reduced environmental footprint. In this research, two 35 foot-long DT members were fabricated and tested to study strategies for reducing self-weight. Foam boards were placed inside the stems of the DT members to produce foam-void double-tees (FVDT). One inch and two inch-thick foam boards were used along with normal and semi-light weight concretes. The two FVDT members were cut length-wise through the top flanges to create four unique single-tee specimens, which were then load tested to evaluate structural capacity and behavior. This thesis discusses the experimental setup and results of flexural testing and shear testing. The test results demonstrated that the presence of foam boards had negligible effect on flexural performance; each of the foam-void specimens supported an experimental moment that was greater than the calculated nominal moment capacity and the shear capacity was more than that expected demand for a typical parking garage DT. Furthermore, cracking near the edges of the foam voids was not an issue under service or higher loads

    Similar works