TL-4 Crash Test and Evaluation of Free-standing Single Slope Concrete Barrier with Cross-bolt Connection

TL-4 Crash Test and Evaluation of Free-standing Single Slope Concrete Barrier with Cross-bolt Connection
Author: Nauman Mansoor Sheikh
Publisher:
Total Pages: 52
Release: 2019
Genre: Automobiles
ISBN:

The purpose of the testing reported herein was to assess the performance of the free-standing single slope concrete barrier (SSCB) with cross-bolt connections according to the safety-performance evaluation guidelines included in American Association of State Highway and Transportation Officials' Manual for Assessing Safety Hardware (MASH) for Test Level Four (TL-4). The crash test performed was in accordance with MASH Test 4-12 criteria, which involves a 10000S single unit truck impacting the barrier at a target impact speed and angle of 56 mi/h and 15°, respectively. The free-standing SSCB with cross-bolt connection successfully contained and redirected the single unit truck. The barrier performed acceptably for MASH Test 4-12. The maximum dynamic and permanent barrier deflections were each 33.0 inches. In addition to the TL-4 crash test, researchers performed a detailed finite element analysis to determine the expected lateral deflection of the barrier under MASH Test 4-11 conditions, which involve impacting the barrier with a 2270P pickup truck vehicle with a target impact speed and angle of 62 mi/h and 25°, respectively. The maximum lateral barrier deflection for the pickup truck impact was estimated to be in the range of 12.5 inches to 16.8 inches.

Guardrail and Median Barrier Crashworthiness

Guardrail and Median Barrier Crashworthiness
Author: Malcolm H. Ray
Publisher:
Total Pages: 172
Release: 1997
Genre: Automobiles
ISBN:

This synthesis will be of interest to state department of transportation (DOT) roadway design, traffic, structural, maintenance, and research engineers and others concerned with highway safety issues. This synthesis describes the current state of the practice for the use of guardrails and median barriers and their crashworthiness. It includes information about the crashworthiness and typical applications of the most common, permanently installed, nonproprietary guardrail and median barrier systems used in the United States today. A significant amount of detail is included in the text to aid the design, selection, and locating processes for safe and effective guardrails and median barriers. The report presents data obtained from a review of the literature and a survey of state DOTs. The synthesis presents a description of the typical longitudinal barriers in use today, including drawings, the extent of their use, and the most recent testing on each guardrail and barrier system, with particular emphasis on NCHRP Report 230 and 350 requirements. In addition, it discusses the maintenance issues, cost constraints, and common problems with each type of barrier. The synthesis only discusses the crashworthiness of guardrails and median barriers; their transitions and terminals are not discussed.

Roadside Design Guide

Roadside Design Guide
Author: American Association of State Highway and Transportation Officials. Task Force for Roadside Safety
Publisher:
Total Pages: 560
Release: 1989
Genre: Roads
ISBN:

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

MASH TL-3 Evaluation of the Unreinforced, Single-slope Concrete Median Barrier
Author: Robert W. Bielenberg
Publisher:
Total Pages: 102
Release: 2018
Genre: Roads
ISBN:

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.

Aesthetic Concrete Barrier Design

Aesthetic Concrete Barrier Design
Author: Delbert Lance Bullard
Publisher: Transportation Research Board
Total Pages: 87
Release: 2006
Genre: Bridge railings
ISBN: 0309088496

This report contains guidelines for aesthetic treatment of concrete safety shape barriers. The report will be of particular interest to design and safety practitioners with responsibility for roadside safety improvements. The increasing application of context-sensitive design solutions for highway projects has created a national need for aesthetic improvement of typical highway features. Requests for concrete barrier treatments and bridge rails that contribute to the overall aesthetic experience are increasing. Concrete barriers (e.g., New Jersey, F-shapes, single-slope, and vertical-face designs) are often the barriers of choice in urban and suburban environments. Many transportation agencies and communities have expressed a desire for aesthetic treatments for these standard shapes. To date, there has been limited evaluation to determine which aesthetic treatments are safe and practical. Designers need guidance regarding the safety implications of aesthetic treatments for concrete barriers.

Development of a Low-profile to F-shape Transition Barrier Segment

Development of a Low-profile to F-shape Transition Barrier Segment
Author:
Publisher:
Total Pages: 106
Release: 2007
Genre: Roads
ISBN:

The purpose of the research reported herein was to develop a transition barrier segment that can be used to connect the low-profile barrier (LPCB(1)-92) to the standard height, F-shape portable concrete barrier (CSB-04). The design of the new transition barrier segment is such that no new hardware is required to connect the transition barrier segment to the low-profile barrier and the F-shape barrier. Researchers used computer simulations to evaluate the proposed design and to examine the location of critical impact points that were used in specifying impact conditions for a full-scale evaluation of the new design. Results of two full-scale tests coupled with results from the computer simulations show that the new transition barrier segment is ready for immediate implementation.