Crash Testing and Evaluation of W-Beam Guardrail on Box Culvert (405160-5-1)

The primary objective of this project was to test and evaluate a guardrail design with standard post spacing for use across low-fill box culverts in accordance with NCHRP Report 350 TL-3. A second objective of this project, was to develop a W 6x9 post with welded base plate detail for use with an epoxy anchoring system that simplifies installation. Posts anchored to a simulated concrete box culvert using the Hilti RE500 Epoxy anchoring system were evaluated through pendulum testing. The strength of the base plate, post welds, and anchoring system was sufficient to result in plastic failure of the posts under an impact load. The W 6x9 post and anchorage detail was subsequently incorporated into the full-scale crash test installation. NCHRP Report 350 test 3-11 was performed to evaluate the guardrail system across low-fill culvert. The W-beam rail element was ruptured by the impact from the vehicle. Even though the rail element was ruptured, the vehicle was contained and redirected without penetrating, underriding, or overriding the installation. The rail element ruptured after the vehicle was redirected and while it was exiting out of the barrier system. Based on the review of all available test data, the W-Beam Guardrail on Box Culvert met the required criteria for TL-3 according to the specifications for the NCHRP Report 350 test 3-11. The adhesive anchoring system worked as designed with the new W 6x9 post and welded baseplate detail. No damage to the deck or failure of the adhesive anchors was observed. The new adhesive anchoring system is considered suitable for implementation as an alternative to through-bolted anchorage in successfully crash tested guardrail systems designed for use across low-fill culverts.