DSpace@MIT

Thesis (M. Eng.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 41).Executive Summary: The BubbleDeck® slab is a revolutionary biaxial concrete floor system developed in Europe. High-density polyethylene hollow spheres replace the ineffective concrete in the center of the slab, thus decreasing the dead weight and increasing the efficiency of the floor. These biaxial slabs have many advantages over a conventional solid concrete slab: lower total cost, reduced material use, enhanced structural efficiency, decreased construction time, and is a green technology. Through tests, models and analysis from a variety of institutions, BubbleDeck® was proven to be superior to the traditional solid concrete slab. The reduced dead load makes the long-term response more economical for the building while offsetting the slightly increased deflection of the slab. However, the shear and punching shear resistance of the BubbleDeck floor is significantly less than a solid deck since resistance is directly related to the depth of concrete. Design reduction factors have been suggested to compensate for these differences in strength. This system is certified in the Netherlands, the United Kingdom, Denmark and Germany. In this investigation, after verifying the validity of the prior research through a finite element analysis of an office floor in SAP2000, the BubbleDeck® slab was tested for a pedestrian bridge deck. Bridge design is dominated by the dead weight of the structure and by concentrated stresses from vehicular traffic. This new slab can solve both of these problems by reducing weight with the plastic spheres and by applying it to a pedestrian bridge to limit the high stresses. A set of bridge decks were modeled and analyzed in SAP2000 for this study.