Round Wood Post W-Beam Guardrail

Report Number(s): 0-6946-R2

Description: The test installation consisted of a 31-inch tall W-beam guardrail with round wood posts (posts 3 through 28) installed in MASH compacted soil, with a TxDOT downstream anchor terminal (DAT) [GF (31) DAT-14] on each end, for a total installation length of 181 ft-3 inches. Modified wood blockouts (similar to PDB01) for round wood posts were installed on posts 3 through 28 using 18-inch long guardrail bolts, USS flat washers, and recessed guardrail nuts (FBB04). Standard 12-gauge W-beam guardrail (type RWM04a) was used in the system. The top of the W-beam was 31 inches above grade, and the guardrail splices were located mid-span between every other post. Posts were equally spaced at 6 ft-3 inches. Guardrail posts 3 through 28 were nominal 7-inch diameter, 6 ft-3 inch–long (including a rounded top) round wood guardrail line posts. The wood blockouts nominally measured 14 inches tall × 6 inches wide × 8 inches deep, including a routered 3½-inch radius on the post side. These posts were installed 40 inches deep in drilled holes that were backfilled and compacted with soil meeting Grading B of AASHTO standard specification M147-65(2004) “Materials for Aggregate and Soil Aggregate Subbase, Base and Surface Courses.” Each TxDOT GF (31) DAT-14 terminal was 9 ft-4½ inches long as measured from their anchor posts to the W-beam splice between posts 2 and 3 and posts 28 and 29, respectively.

Test Level: 3

MASH Test Number: 3-11

Proprietary/Non-proprietary: Non-proprietary

Pass/Fail: Fail

Evaluation: Full-Scale Crash Testing

Sponsor: Texas Department of Transportation