Road Safety Barriers with Short Elements of Lightweight Concrete

Concrete road safety barriers have been employed broadly in Italy, beginning from the 1980s, particularly on the highways and freeways. The safety barrier homologation and design standards, have not precisely determined, in particular for concrete barriers, specific fields of application or modality of installation. Sometimes such barriers have been judged too much rigid and, therefore, inadequate to pass the crash tests conducted with the lightweight vehicle. There wasn’t any change or new design (cross section shape and size) in the last 20 years, so, for all these reasons it is interesting to investigate the possibility to achieve, with concrete barriers, better overall performances (containment of the heavy vehicles and lower accelerations on the occupants of the lightweight vehicles). In this sense, a proposal regarding the design of these modular systems is to use lightweight concrete and make the element shorter than the one usually adopted in Italy. In such way, the higher lateral deformability of this barrier could lead to a greater dissipation of energy, with the resulting decrease of the dynamic effects for the users, maintaining a good containment capability in the high energy crash tests. In this paper this new design is evaluated with “virtual” crash tests, carried out with a finite element code, LSDYNA. The model has been previously validated by comparing the result of a real crash test (using the existing Italian concrete barrier design) with the “virtual” crash test performed in the same conditions.