Precast/Prestressed Girder Help

STRAND PATTERN

Figure 3, “Strand Pattern at Midspan,” on page 36 shows the assumed strand pattern for the 27 strands in the bottom of the beam. All strands are straight.

FIGURE 3. Strand Pattern at Midspan

For 27 strands, the distance between the center of gravity of the strands and the bottom fiber of the beam at midspan, ybs, is

= 23 × 2 × 0.75 + 4 × 0.75 27 × 0.75 = 2.30 i n

Strand eccentricity at midspan, ec, is

y b y b s = 20.78 2.30 = 18.48 i n