16′ Radius Guardrail with 3:1 Slope – TL2 Short Radius Guardrail

Report Number(s): 0-6913-R1

Description: A 31-inch tall short radius system was developed and tested per MASH TL-2 modified conditions, by increasing the impact angle to 25° from 15°, and is considered MASH complaint per the MASH evaluation criteria. This new short radius system requires a thrie-beam guardrail system constructed along the primary roadway that transitioned to a section of bridge parapet. The thrie-beam is curved at the nose section and then is attached to a w-beam rail via an asymmetric thrie to w-beam connector. The w-beam rail is attached with a TxDOT GF (31) DAT-14 terminal at the secondary roadway end. The curved 25-ft arc length thrie-beam section was rolled to a 16-ft inside radius, and it has 11-inch long slots on the nose section of the curved thrie-rail. Six sand drums were strategically placed on the inboard, field side of the installation between posts 9 and 15 as illustrated in the test installation drawings. The impact performance of the short radius guardrail system with a 3H:1V slope was evaluated using modified MASH Tests 2-33, 2-32 2-31, 2-35, and 2-34 that were conducted successfully. For Test Nos. 469137-3-1 and -3-2 (MASH 2-33 and 2-32), standard BCT Anchor Cables (FCA01) measuring 6 ft-6¾ inches end to end, inclusive of terminal fittings, were used. Due to the cables being longer than required, the Guardrail Anchor Brackets (FPA01) were repositioned and attached to the thrie-beam with four bolts instead of eight. For Test Nos. 469138-3-3, -3-4, and 469138-3-5 (MASH 2-31, 2-35, and 2-34, respectively), modified BCT Anchor Cables measuring 5 ft-5 inches end to end, inclusive of terminal fittings, were used. These shortened cables allowed the Guardrail Anchor Brackets (FPA01) to attach to the thrie-beam with eight bolts.

Test Level: 2

MASH Test Number: 2-31, 2-32, 2-33, 2-34, 2-35

Proprietary/Non-proprietary: Non-proprietary

Pass/Fail: Pass

Evaluation: Testing + Engineering Analysis

Sponsor: Texas Department of Transportation