Design of an Advanced MASH TL-3 Portable Barrier
REPORT NUMBER
TRP-03-500-25
AUTHORS
Bob Bielenberg, Ronald Faller, Scott Rosenbaugh, Andrew Loken
PUBLICATION DATE
2025-12-17
ABSTRACT
This research effort focused on developing a new MASH Test Level 3 (TL-3) portable barrier system to address limitations of existing designs, including excessive dynamic deflection and compromised vehicle stability. The objective was to create a barrier that improved safety performance while simplifying installation, reducing reliance on connection hardware, and providing durability suitable for long-term service.
The project began with a review of concepts from an initial feasibility study and relevant design criteria. After criteria were established, project sponsors identified a near-vertical portable concrete barrier (PCB) composed of staggered, interlocking segments as the preferred option. This concept was selected for its ease of installation and potential to substantially reduce dynamic deflection during impacts. An initial design was developed and evaluated using LS-DYNA simulation to estimate safety performance and guide refinements. Analyses examined reinforcement configurations, barrier segment length, and the effect of longitudinal gaps between segments. Results indicated that the interlocking PCB concept could meet MASH TL-3 requirements while reducing dynamic deflection below 24 in. An optimal reinforcement layout was identified to provide adequate strength, limit damage, and enhance durability. An 8-ft segment length was selected as a balance between deflection control and horizontal curvature needs, and end gaps up to 1 in were found to pose no safety concerns.
Additional refinements incorporated drainage features, lifting hardware, anchorage options, and improved constructability based on fabricator input. Full design details were completed, and prototype segments were fabricated. A follow-on study will conduct full-scale MASH Tests 3-10 and 3-11, with results to be reported separately.
The project began with a review of concepts from an initial feasibility study and relevant design criteria. After criteria were established, project sponsors identified a near-vertical portable concrete barrier (PCB) composed of staggered, interlocking segments as the preferred option. This concept was selected for its ease of installation and potential to substantially reduce dynamic deflection during impacts. An initial design was developed and evaluated using LS-DYNA simulation to estimate safety performance and guide refinements. Analyses examined reinforcement configurations, barrier segment length, and the effect of longitudinal gaps between segments. Results indicated that the interlocking PCB concept could meet MASH TL-3 requirements while reducing dynamic deflection below 24 in. An optimal reinforcement layout was identified to provide adequate strength, limit damage, and enhance durability. An 8-ft segment length was selected as a balance between deflection control and horizontal curvature needs, and end gaps up to 1 in were found to pose no safety concerns.
Additional refinements incorporated drainage features, lifting hardware, anchorage options, and improved constructability based on fabricator input. Full design details were completed, and prototype segments were fabricated. A follow-on study will conduct full-scale MASH Tests 3-10 and 3-11, with results to be reported separately.
KEYWORDS
Highway Safety, Roadside Appurtenances, MASH, Portable Barrier, LS-DYNA
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