MASH CRASH TESTING AND EVALUATION OF THE MGS WITH REDUCED POST SPACING (Quarter Post Spacing)

Report Number(s): 610211-01

Description: The 181 ft-3-inch-long test installation was comprised of a 31-inch high, 12-gauge, 4‑space, W‑beam guardrail system. The W-beam rail was supported by wide-flange posts with 14-inch-tall wood blockouts. A TxDOT DAT terminated each end of the guardrail system. Beginning with the upstream DAT, there were three distinct sections of the installation:

1. a 37 ft-6-inch-long section (posts 3 through 9) with post spacing at 75 inches;
2. a 75 ft-0-inch-long section (posts 9 through 57) with quarter post spacing at 18¾ inches; and
3. a 43 ft-9-inch-long section (posts 57 through 64) with post spacing at 75 inches.

In the full post spacing sections, a 10-inch button-head guardrail bolt secured each blockout to a post. In the quarter post spacing section, the bolts secured the rail only at half post spacing. Therefore, no additional slots were cut in the W-beam rail. Additionally, the quarter post spacing section did not have posts bolted to the rail at splice locations. In the full-post spacing sections, the W-beam rails were spliced at midspan between the posts. The wide-flange posts were embedded 40 inches deep in drilled holes that were backfilled with crushed limestone base and compacted to meet MASH strength requirements.

Test Level: 3

MASH Test Number: 3-11, 3-10

Proprietary/Non-proprietary: Non-proprietary

Pass/Fail: Pass

Evaluation: Full-Scale Crash Testing

Sponsor: Roadside Safety Pooled Fund