MASH CRASH TESTING AND EVALUATION OF THE MGS WITH REDUCED POST SPACING (Half Post Spacing and Shortened Block outs)

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 72-inch wide-flange posts with timber blockouts. TxDOT DATs 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 33) with half post spacing at 37½-inches; and
3. a 43 ft-9-inch-long section (posts 33 through 40) with post spacing at 75 inches.

A 10-inch button-head guardrail bolt secured each blockout to a post except where a post was located at a rail splices.  Standard 14-inch-tall wood blockouts were installed on posts 3 through 8 and 34 through 40 (full post spacing sections). Shortened 10-inch-tall wood blockouts were installed on posts 9 through 33 (half post spacing section). 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

Proprietary/Non-proprietary: Non-proprietary

Pass/Fail: Pass

Evaluation: Testing + Engineering Analysis

Sponsor: Roadside Safety Pooled Fund