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MASH TL-3 Evaluation of the Unreinforced, Single-Slope Concrete Median Barrier

REPORT NUMBER

TRP-03-388-18

AUTHORS

Bob Bielenberg, Ronald Faller, Kellon Ronspies

PUBLICATION DATE

2018-11-19

ABSTRACT

The Ohio Department of Transportation (ODOT) requested an evaluation of an unreinforced, single-slope concrete median barrier capable of satisfying Test Level 3 (TL-3) safety requirements found in the Manual for Assessing Safety Hardware, Second Edition (MASH 2016). The barrier was designed with a height of 42 in. (1,067 mm), a base width of 28 in. (711 mm), and top width of 12 in. (305 mm). The tarmac surface was milled down 1 in. (25 mm) to accommodate the barrier and asphalt pad. The barrier was cast in place using concrete with a minimum compressive strength of 4,000 psi (27.6 MPa). Expansion joints were installed in 20-ft (6.1-m) intervals to simulate cracking and potential barrier discontinuities. An asphalt pad, installed on the milled surface using a tack coat, functioned as the barrier keyway and extended 96 in. (2,438 mm) from the traffic and back sides of the barrier. Previous testing of similar single-slope concrete barriers indicated that only one full-scale crash test (MASH test designation no. 3-11) was needed to satisfy TL-3 criteria. During the test, the 5,001-lb (2,268-kg) pickup impacted the installation at a speed of 62.8 mph (101.0 km/h) and at an angle of 24.9 degrees for an impact severity of 116.3 kip-ft (157.7 kJ). The vehicle was safely contained and redirected, and the test satisfied safety performance evaluation criteria of test designation no. 3-11 found in MASH 2016.