Two vehicles totaled Heat at Pentecost: "Blow-up" on the A13 occurred on an older section of highway

The heat on Whit Monday led to a so-called "blow-up" on the A13 highway, with two vehicles suffering a total loss. The danger exists when old concrete slabs are covered with asphalt.

The heat on Whit Monday led to a so-called "blow-up" on the A13 between Sennwald and Haag in the direction of Sargans, as first reported by "20 Minuten". The highway was closed in the affected section and two cars were totaled. Traffic was only able to resume on Tuesday morning.

There is a risk of a blow-up when older concrete slabs are covered with asphalt. This was the case on the A13 near Sennwald, as media spokesman Florian Schneider from the St. Gallen cantonal police confirmed to the "Liechtensteiner Vaterland " newspaper. According to the report, concrete slabs were initially installed in the area of the A13, but these were covered over a few years ago.

What is a blow-up?

A blow-up occurs when the concrete slabs expand in the heat and the tension cannot be relieved. The dark asphalt also heats up and transfers the heat to the concrete slabs. If expansion joints are also blocked, the slabs push upwards and can cause the road surface to crack explosively.

According to the Federal Roads Office (Astra), there are other sections in Switzerland with this type of mixed construction. As Astra spokesperson Thomas Rohrbach told the Tages-Anzeiger newspaper, there are still "a few kilometers of older sections of the national road network". According to the Federal Office, sections of the A6 between Bern and Thun are affected, and the section of the A13 on Whit Monday was also known and documented.

A major repair project is currently underway between Haag and Oberriet. However, according to Rohrbach, the actual construction work has "not yet been finalized". It also remains to be seen whether and in what form the old concrete slabs will be removed.