HDPE-lined Box Culverts

Most COPREM concrete products are immune to attack by aggressive elements in the environment. However, some applications may require additional protection - e.g. when conveyed liquids may develop sulphuric acid within the system. For several years now we have been producing precast concrete products with an HDPE (High-Density Polyethylene) lining system that guarantees absolute absence of cracks and infiltration, and resistance to chemical agents - maintaining the basic characteristics of the concrete pipe intact.

 

The choice of High-Density Polyethylene was made because of its peculiar characteristics, i.e. resistance to chemical attack of saline, acid and alkaline solutions, as well as to solvents such as alcohol, esters and ketones. It resists in environments from ph 2 to ph 12 withstanding the possible evaporation of sulphates and sulphides.

Another important characteristic is the preservation of the characteristics over time. Even after years of operation, for example in the drainage system, this product preserves the design parameters (K coefficient in the Manning-Strickler formula). Other materials instead tend to degrade, putting the system in critical conditions, with all the negative consequences for the health of citizens.

Our technicians have designed the welding of a safety band on the joint, which is carried out by our staff with a patent issued by the Italian Welding Institute of Genoa. With this system we are able to guarantee the perfect tightness of our pipelines, which can be used both in case of small pressures and in case of crossing areas with water draining wells serving public aqueducts.
 

The box culvert is distinguished by its versatility of use. It is used both for the transport of clear or waste water (especially for channelling surface water that has to pass under roads, motorways and railways) and in the new technology called Technological Tunnel.

In the transport of surface water, the standard box culvert is generally used with an internal epoxy coating of variable thickness. The tightness (not under pressure) of the joint is guaranteed by butyl seal to be applied during installation.
However, today we face new requirements in terms of tightness. In some recent situations, the butyl seal does not meet the client's requirements anymore.
Moreover, the box culvert is starting to be used as an alternative to the classic circular pipe. For this reason it must guarantee the same performance in terms of resistance to chemical attack and abrasion, and at the same time give a guarantee of tightness of the joint equal to that of circular pipes.

In order to give a positive answer to these requests, the idea was to protect the inner surface of the box culvert with a High Density Polyethylene liner of variable thickness to improve the performance of the concrete.
The liner is supplied by one of the largest plastics production companies, and has a thickness ranging from 1.5 to 5 mm. Our advanced production plants, together with our specialised workers, guarantee the highest quality products.

 

COPREM has always been working to meet the needs of its customers, scrupulously complying with the law and regulations in force. All production complies with the technical standards in force, in particular the prefabricated boxes are CE marked in accordance with the provisions of Regulation 305-11 EU and the relative harmonised reference standard UNI EN 14844:2012 and comply with the requirements of Ministerial Decree 17-01-18 "Technical standards for construction".

We produce the reinforcing bar with double electrowelded mesh and additional shaped reinforcement rods, or with longitudinal distribution bars, a secondary distribution reinforcement able to guarantee, in all phases of prefabrication, the maintenance of the required iron covers and a real distribution of the structural warps.

They are not to be considered similar to the reinforcement elements of alternative devices such as steel chains, cables or wires. Alternative solutions consisting of a flexible reinforcement bar in which distribution warps are not foreseen and where the main warps are simply connected to a chain system are not suitable. These systems do not guarantee at all the respect of the parameters and the possible breaks of these chains in the casting phases could lead to the realisation of portions of products without reinforcement.

From what has been stated above, the role of the potential buyer is considered fundamental, who, also through the work of the Designer and the Works Manager, must carefully evaluate the characteristics declared by the manufacturer so that all legal and regulatory requirements are really complied with. COPREM has always been working to meet the needs of its customers by scrupulously complying with the law and regulations in force.

 

flexible rebar without secondary distribution rebar