Introduction: Piping Choices and Their Impact
Today, plastic stormwater pipes are emerging as the preferred choice of stormwater pipes over concrete pipes. This blog aims to delve into the compelling advantages of plastic over concrete and why it’s becoming the go-to for sustainable stormwater management.
Advantages of Plastic Stormwater Pipes
Over the past few years plastic pipes have been getting used and implemented by many industries, in some cases they are even more widespread then concrete pipes. Why is plastic gaining popularity over concrete? Here are the reasons:
Durability and Longevity
Plastic pipes are resistant to wear and tear, offering extended life spans. Unlike concrete, which are brittle and prone to damage and cracking over time. Plastic have inherent flexibility which improves durability. Plastic pipes also have a service life of over 100 years which is a significant advantage.
One of the salient advantages of plastic stormwater pipes over their concrete counterparts lies in their weight. Plastic pipes are approximately 94% lighter than concrete pipes. This significant weight differential not only simplifies transportation and handling logistics but also expedites installation processes.
Corrosion, particularly rust formation, poses a formidable challenge in the realm of stormwater management systems to concrete pipes. When concrete pipes are exposed to certain aggressive environmental conditions or caustic stormwater runoff, they can corrode over time. Such degradation can impair the structural integrity of the pipe, potentially leading to cracks, leaks, or even catastrophic failures.
Plastic stormwater pipes stand out prominently in this context due to their innate corrosion resistance. Unlike concrete or metal pipes, plastic pipes remain unaffected by:
- Chemical Interactions: Many stormwater runoffs contain chemicals that can react with concrete or metal pipes. Plastic pipes, by virtue of their non-reactive nature, are impervious to most of these chemicals.
- Environmental Factors: Fluctuating pH levels, sulfates, and other corrosive agents prevalent in certain soils or waters have minimal effect on the integrity of plastic pipes, ensuring longevity.
Advantages Stemming from Corrosion Resistance:
- Longevity and Durability: The inherent resistance to corrosion means plastic pipes often outlast their concrete counterparts, reducing the need for frequent replacements or repairs.
- Reduced Maintenance: With little to no risk of corrosion, the maintenance overhead associated with plastic pipes is substantially lower.
- Optimal Flow Rate: Absence of corrosion ensures that the internal surface remains smooth, reducing friction and maintaining efficient water flow.
In instances where existing concrete pipes exhibit signs of corrosion or structural damage, one effective remediation strategy involves the insertion of a plastic lining within the pipe. This not only provides a corrosion-resistant barrier but also extends the service life of the existing infrastructure without necessitating complete pipe replacement.
In the era of sustainable development, environmental considerations play a pivotal role in infrastructure decisions. When analyzing the environmental footprint of stormwater management systems, plastic stormwater pipes present several advantages over their concrete counterparts.
Reduced Carbon Footprint:
- Manufacturing Process: The energy consumption in the production of plastic pipes is generally lower compared to the energy-intensive process of producing concrete pipes. This results in a lower carbon footprint for plastic pipe production.
- Transportation: Due to their lighter weight, transporting plastic pipes requires less energy compared to concrete pipes. This further reduces greenhouse gas emissions associated with their distribution.
- Material Usage: The manufacturing of plastic pipes typically requires less raw material by volume than concrete pipes, ensuring more efficient use of resources.
- Water Consumption: The production of concrete is water-intensive. Opting for plastic pipes can lead to a significant reduction in water usage in the manufacturing phase.
Longevity and Waste Minimization:
- Durability: Plastic’s resistance to corrosion ensures a longer lifespan, reducing the frequency of replacements and, consequently, the waste generated.
- Recyclability: Modern plastic pipes, especially those made from HDPE or PVC, can be recycled, thus reducing landfill waste and promoting circular economy principles.
Reduced Ecological Disruption:
- Installation: The lighter weight and ease of installation of plastic pipes often means less invasive construction methods, resulting in minimal disruption to local ecosystems.
- Leachate Concerns: Concrete can sometimes leach alkaline substances into the surrounding environment, potentially affecting soil pH and aquatic life. Plastic pipes don’t have this concern.
Installation and Maintenance
Our Plasdrain™ pipes are flexible pipes designed for controlled deflection under vertical soil loads.
These loads are then transferred to the soil in the side support zone. The Australian Standard
AS/NZS 2566.2 “Buried flexible pipelines – Part 2 Installation” provides detailed information on
appropriate methods for ensuring the side support zone is correctly constructed, which is of
critical importance. Key aspects from AS2566.2 are included in the following. Our resistance to corrosion also ensures minimal maintenance.
The Composition of Pipes: Plastic vs. Concrete
Understanding the battle between plastic and concrete begins by peering into their past.
Brief History of Pipe Materials
Concrete pipes have had their roots in ancient civilizations, whereas plastic emerged during the 20th century. A matter of tradition vs. innovation, wouldn’t you say?
The Basic Make-Up of Plastic and Concrete Pipes
Concrete, a composite material, primarily consists of aggregate bonded with fluid cement. On the other hand, plastic pipes, often made of polyvinyl chloride (PVC) or polyethylene, are more versatile and flexible.
Real-world Scenarios: Success Stories with Plastic Pipes
From urban cities to remote villages, the shift to plastic is evident. Many municipalities have reported fewer blockages, leakages, and maintenance calls since making the switch.
Fernlea Estate – City of Casey
Symon Bros Constructions performed the civil construction works at 75 Tuckers Road Clyde
within the City of Casey district to create the Fernlea Estate. During Stage 1B of this project a
combination of both concrete and corrugated plastic stormwater drainage pipes were installed.
The council specified the backfill and embedment material to be full 3% Cement Treated 20 mm
crushed rock back fill to 1/3 of the pipe’s diameter above the pipe.
It was suggested that CCTV inspections be performed prior to practical completion of the
project to ensure the stormwater drainage system was performing and if any damage had
occurred to the stormwater piping system during construction works.
Jetstream Services performed the CCTV inspection of all drainage infrastructure which involved
both a visual inspection from the CCTV unit and a deflection assessment obtaining datum levels
at selected chainage locations.
Pipe sizes and pipe types evaluated were:
- 300mm both concrete and corrugated plastic
- 375mm corrugated plastic only
- 450mm both concrete and corrugated plastic
- 525mm both concrete and corrugated plastic
- 600mm corrugated plastic only
- 675mm concrete only
- 750mm concrete only
- 900mm concrete only
Interestingly the results showed numerous locations of circumferential surface or simple
cracking in the concrete piping installed. In the corrugated plastic piping installed, no cracking
nor signs of adverse performance were identified. The only observation being a build-up of
concrete deposits in the invert of one section.
The following photographs extracted from the detailed reports summarise the observations
from both piping alternatives.
Repairing concrete pipe cracking
The solution to repair cracking of concrete piping is to reline with a plastic polymer relining
solution. The concrete has failed and so a plastic solution is included to solve the problem.
Image 13: Concrete 300 pipe circumferential surface crack, width 1mm, from 2 to 5 o’clock
Image 14: Concrete 300 pipe circumferential surface crack, width 1mm, from 2 to 10 o’clock
Image 15: Plastic corrugated pipe showing the only observation of note as deposits in the
invert, being hard compacted concrete material. Obstruction: <5%, from 5 to 6 o’clock. No
cracking, no damage in any section of corrugated plastic piping.
Why the Shift is Inevitable and Necessary
For sustainable urban planning, the choice of materials is crucial. Plastic pipes offer a combination of durability, cost-effectiveness, and environmental benefits that concrete struggles to match.
Conclusion: The Future of Stormwater Piping
Concrete had its era, but it’s time for plastic to shine. As cities grow and the need for efficient stormwater systems increases, plastic pipes are set to lead the charge. After all, progress means adapting to the best, right?
- Are plastic pipes safe for drinking water?
Yes, many plastic pipes are designed specifically for potable water and meet safety standards.
- How long do plastic stormwater pipes last?
They can last over 100 years with minimal maintenance.
- Can concrete pipes be replaced with plastic pipes in existing systems?
Yes, many cities are gradually replacing older concrete pipes with more efficient plastic ones.
- Do plastic pipes harm the environment?
Plasdrain pipes are recyclable and often have a lower environmental impact than concrete during production.
- What is the best type of plastic used in stormwater pipes?
Polypropylene plastic (PP) is the best type of plastic to use for non-pressure pipe applications which is what Plasdrain pipes implements.