While polymer concrete channels have been the favoured drainage channels, polypropylene is the clearly the superior channel for many reasons.
Polypropylene channels guarantee an optimal and aesthetically satisfying result in all projects that require an easy to install and durable solution.
Ease of Installation & Reduction of Installation Costs
Plastic channels can be easily installed on site due to the characteristics of polypropylene that make installation lightweight, easy to transport and handle. Concrete channels are much heavier than polypropylene ones and are therefore more likely to have a significant impact on labour and transport costs.
For example, based on the same performances, a drainage channel made of polypropylene, class D400 with an internal section of 200x200mm has a weight of approximately 22kg, while a concrete channel can weigh up to 130kg. This also leads to the use of equipment for the transportation and laying of concrete channels, which contributes to the increase in costs.
Polypropylene channels can be installed directly by the workforce; and with ease.
Increased Internal Roughness
In the previous paragraph we discussed the channels comparison with the same performance but not with the same size. For what reason?
The reason for this is simple: when compared to concrete or concrete-polymer channels, polypropylene channels have less internal roughness, which allows more water to be transported with the same internal cross-sectional area
In hydraulics, coefficients associated with the internal roughness of the walls are used, and among these we can find “Gauckler-Strickler”, “Bazin”, “Manning” or “Kutter”. As expressed in the table below, polypropylene performs significantly better than other materials from which drainage channels are commonly manufactured. For example, taking the Gauckler-Strickler coefficient as a reference, PP has an index of 95 compared to 70 for cement and 80 for concrete-polymer.
Resistance to Chemicals
As SAB have pointed out in their article on rainwater drainage channels in service stations and forecourts, chemical resistance is an important element to evaluate when considering the replacement of existing channels. Extending the useful life of the drainage system decreases the chances of an emergency intervention to replace or repair drainage channels that have been installed previously.
An example of this type of intervention was the installation of Sabdrain channels in petrol stations in Jordan for three major fuel distribution players: JoPetrol, Total and Al Manaseer. The project involved about 2,000 metres of drainage system and the proximity of Gersa’s stations next to Hadrian’s Arch, a historical and artistic beauty dated back to 130 AD, made the success of the project even more relevant and significant.
Initially, petrol stations used concrete channels in order to optimise material costs. However, this solution soon led to a serious problem with the rapid deterioration of the channels. This has led to the replacement of the channels and therefore to the choice towards the SAB polypropylene channels for the reasons expressed above in this article.