What is the minimum length of cast-in-place concrete barrier before requiring a barrier design with an independent foundation?
What is the minimum length of TL-3 cast-in-place concrete barrier before requiring a barrier design with an independent foundation?
We have experienced barrier impacts at or near the end of a barrier causing the barrier to rotate back and exposing the parapet causing a blunt end impact. We have recently modified our Standards to strengthen the barrier end sections to ensure the barrier will not fail if impacted at or near the end as shown within the attached document.
Now the question has come up, what is the minimum length of CIP barrier placed on each pavement type to ensure the barrier will not fail during impact? Be it barrier placed on a concrete roadway panel (see figure 1) or placed on asphalt pavement / 4 inch thick barrier pad (see figure 2).
Figure 3 is what we use for a 30ft long CIP barrier with independent foundation placed next to a structure.