Lightweight High Performance Concrete Bulb T Beams With Self Consolidating Concrete In A Bridge Structure

Lightweight high-performance concrete (LWHPC) with a pozzolan (fly ash or silica fume) or slag cement is expected to provide high strength and high durability with reduced dead load. Reduced dead load may provide savings in the substructure elements. Self-consolidating concrete (SCC) is a new technology with a very high level of workability as it easily fills formwork under the influence of its own mass, typically without any additional consolidation energy. In this study, self-consolidating LWHPC with slag cement was used in the prestressed bulb-T beams for the bridge on Route 17 over Route 15/29 in Fauquier County, Virginia. The deck has LWHPC with slag cement. The bridge has two spans, each 128 ft long. Test beams 65 ft long with the same cross section as the actual beams were cast and tested prior to the fabrication of the bridge beams. The LWHPC provided satisfactory strength and permeability in the test beams and bridge beams that were also SCC. The bridge deck concrete had satisfactory strength and durability with no cracks after two winters. The study recommends that lightweight SCCs with pozzolans or slag cement be considered in beams when there are long spans, poor soil conditions, and congested reinforcement. It is also recommended that lightweight concretes be considered for reducing deck cracking.