Recently the Irish Farmers Journal visited Corbett Concrete Products Ltd to find out more about the manufacturing process of concrete culverts used to make underpasses for farmers. Corbetts supplied the concrete culverts used in the recently completed underpass on the well-known Browne family farm in Killeagh, Co Cork, which was featured in the Irish Farmers Journal. The underpass was installed by Mulcahy Steel Ltd.

Another concrete manufacturing company was reported in error as supplying the culverts for the Browne farm in the article. Concrete culverts have become popular in the last five to 10 years because they provide a safe method of moving livestock under public roads.

Michael Corbett says they started producing culverts in 2009. The process for making a culvert begins with the tying of steel to form a cage. This is then placed into moulds, which have been sprayed with a releasing agent. Spacers have already been fitted to ensure even cover of concrete. The moulds are filled with concrete and vibrated.

Twelve hours later, the culvert is removed by the gantry crane and stored in the maturing area for more than 28 days. From this area, culverts are loaded and transported to a prepared site.

Michael says that all their culverts are made to European specification (en 1990, en 1991-2, en-1992-2), which are the relevant Irish annexes for the Eurocodes. Depending on size, culverts vary in price from €1,150 to €2,000 per linear metre. “In recent years, some customers are requesting a wider culvert (5m) to facilitate the inflow/outflow of cows from robotic milking systems,” according to Michael.