The 2in1 Method – An enhanced way to use temporary safety barriers

DELTA BLOC is enhancing the applicability of permanent safety barriers, providing a holistically approached solution for cost reduction in the renovation and widening of motorways.

There are premium safety barriers on the market for every application. For temporary applications the DELTA BLOC® systems DB 50SL and DB 65S with their slim and light design have been successfully installed on numerous sites all over the world. Currently, for permanent installations rigid concrete barriers with the containment level H2 are the prime choice in many countries. If in situ concrete barrier systems are used, the much discussed and questionable impact behaviour of passenger vehicles is accepted because of the low manufacturing costs. Modern precast concrete systems also provide rigid impact behaviour in class H2, but they provide an enhanced passenger protection with the proven impact severity level of ASI B.

In many cases, old steel systems on central reservations are replaced by inexpensive in situ concrete barriers. Temporary safety barriers are required for the duration of the construction work. This results in extra expenses for transportation, rental or purchase on top of the manufacturing costs of in situ concrete barriers. The good news: These costs can be completely eliminated by using the new 2in1 safety barriers.

Cost reduction through the use of 2in1 safety barriers

2in1 safety barriers are systems that can be used in both application areas – temporary and permanent. This provides a high cost reduction potential by eliminating the need for transportation, renting or purchasing temporary work zone protection. Due to the elimination of transportation the carbon footprint of the whole construction site is improved significantly. The permanent vehicle restraint system which is required in any case is also used to protect the work zone during the construction phase. An installation team installs approx. the length of 120 meters in one hour. At the end of the construction phase the system is shifted into the final position as a permanent installation. The fast installation and repositioning of the safety barriers are of decisive importance. Modern precast concrete systems meet these requirements due to their modular design. Attention has to be paid to the fact that crash tests according to EN 1317 are required to prove the performance of both, temporary and permanent systems. A CE certification according to EN 1317-5 is compulsory.

Temporary use with low working width – permanent functionality without displacement

DELTA BLOC® offers several systems with dual applicability in its DB 80 series. As temporary safety barriers these systems provide containment the T3 and N2 with working widths W2 and W3 in moveable installation. In the permanent application, depending on design and use, these systems show their true performance spectrum with the containment of level H2. New possibilities of element stabilization by anchoring or embedding provide break-through protection and vehicle redirection without element displacement at low impact severity. This way the systems DB 80E, DB 80AS-E and DB 80AS-A reach the performance classes of H2 W1 ASI B on roads and bridges.

As a matter of fact, the 2in1 method with dual precast concrete safety barriers kills two birds with one stone. The cost reduction potential is considerable and obvious.

Application example: Motorway A8 and A3 near Würzburg (Germany)

The example of the German motorway A8 and A3 show how the dual application of safety barriers works. During the construction work the DB 80F elements with the performance class T1 W1 ASI A and T3 W2 ASI A were used as a temporary safety barrier system. After the construction work the elements were rearranged to their final position and fixed in place with steel anchors. As a permanent safety barrier they now are performing in class H2 W3 ASI B.

Auteur: Redactie Infrasite