Six full-scale vehicle crash tests were conducted on guardrail systems to evaluate the effectiveness of substituting timber posts for the standard 315.7 steel posts specified in a current guardrail standard. Results of the tests indicate that timber is a suitable post material for the "weak-post" concept. Although there was some difficulty in determining the proper rail attachment to the post, solutions to the problem are suggested in this report. the timber post design calls for a 12-gage flexural beam mounted on 6- by 7-in. Or 5 1/2-in. Diameter pine posts spaced at 12.5-ft centres. A 1/4-in. Diameter steel bolt and a pipe insert provide proper attachment of rail to post. The sixth test of the series provided an evaluation of the effectiveness of a continuous installation composed of the new timber weak-post system and the department's strong-post system. The test results indicated that the transition design between the two systems was satisfactory, but design changes could improve performance. (Author/publisher)
Abstract
