style="text-align: left;">At the Vienna airport an extension to the runway was constructed as a prestressed concrete pavement. This runway extension measured approximately 3,280 ft. by 147 ft. 6 in. A new taxiway approximately 3,609 ft. by 73 ft. 8 in. and a parking apron for jets 1,425 ft. by 172 ft. were also constructed of prestressed concrete. The slabs for these areas were constructed in sections. The thickness of these slabs was 6 in. and each section had a width of 24 ft. 8 in. and was from 328 ft. to 410 ft. long. (Fig. 1.) Pretensioning was applied in the longitudinal direction. In the transverse direction the slab as posttensioned with cables consisting of 24 wires, each encased in conduit tubing. The wires have a diameter of approximately 5/32 in., a yield stress of 206,000 psi and a tensile strength of 241,500 psi. The initial prestress was 227 psi in the longitudinal direction and 142 psi in the transverse direction. Both prestressed reinforcement lies in the center of the slab (Fig. 2). In the longitudinal direction 80 wires are placed in two layers. The transverse elements are spaced app. 9 ft. apart. Per 1 sq. yd. of concrete slab approximately 6% lb. of wire was used.
展开▼
