Researchers from the Concrete Structure Technology research group of the Polytechnic University of Catalonia have worked with the industry to design and build a prototype of a concrete crash barrier for interurban roads that reduces the degree of severity of vehicle impact in accidents, and therefore the injury to vehicle occupants.
The new crash barrier design is not only safer, but also cheaper and more environmentally friendly than existing solutions because it reduces the amount of concrete needed by up to 10 per cent, preventing 6.6 tonnes of carbon dioxide emissions for every kilometre of barrier.
The new in-situ crash barrier , with its high resistance to impact, also reduces maintenance costs during its useful life, which is estimated to be 100 years. The barrier prototype has already been installed in various parts of Spain, and will continue to be rolled out in 2017.
Roadway departure crashes are the most common road accident and their consequences are the most severe. On interurban roads, a high percentage of fatal incidents occur when the vehicle leaves the road.
Crash barriers or restraint systems designed to reduce this kind of accident can be made of metal, precast or in situ concrete, masonry and even wood. These systems serve to “restrain” vehicles by preventing them from crossing over into the opposite lane into oncoming traffic, instead redirecting them and acting as shock absorbers in the case of impact.
While only metal and precast concrete crash barriers meet the impact severity index criteria in European standard EN 1317, metal crash barriers have several drawbacks. Firstly, they need to be repaired after an accident, which has an effect on traffic. They also have high maintenance costs.
The researchers from the Polytechnic University of Catalonia worked with companies in the industry to design a new, continuous in-situ concrete crash barrier. Compared to existing barriers, these new barriers reduce the severity of injuries in accident victims after they crash into them. The researchers achieved this by optimising the length of transitions - that is, the spaces between one barrier and the next, and by adjusting the reinforced concrete material, and adapting direct contact or friction with the ground.
The shape of the barrier has been optimised to ensure that vehicles can be redirected gradually and smoothly, improving driver control of the vehicle and preventing them from swerving into opposite or adjacent lanes.
Due to the reduced concrete material required to manufacture them, the new barriers are more competitively priced than precast concrete ones. They also require virtually no maintenance, because they do not need to be removed after a car accident, which means there are no disruptions to traffic when they need to be repaired, unlike existing metal barriers.