1. Preface
SSP have been on the market for approximately 100 years and have become a cornerstone in civil engineering. They are well-known and widely used in various applications, from coastal protection to foundation construction. Their reliability and durability have made them the number one choice in many engineering projects around the world.
However, in recent years, VSP have started to gain increasing popularity, despite having been on the market for nearly 40 years. This growing interest is due to their unique properties, which make them an attractive alternative to traditional SSP. Their lightness, corrosion resistance, and ease of installation are just a few of the advantages that attract engineers and investors to choose VSP, especially when utilizing in seawall, bulkhead, and cut-off wall construction.
In this document, VI SEM will compare SSP and VSP, analyzing their characteristics, applications, and benefits. This way, engineers and industry specialists will be able to make more informed decisions about choosing the right sheet piles for their projects.
2. Content
2.1. Material characteristics
SSP are made from high-quality steel, characterized by exceptional strength and durability. Below are the most important technical parameters and their significance:
+ Tensile Strength: Steel has a tensile strength ranging from 340-580 MPa (megapascals), which means it can withstand large loads without breaking.
+ Young’s Modulus: For steel, the Young’s modulus is approximately 210 GPa (gigapascals). This is a measure of the material’s stiffness: the higher the value, the lower the deformation under load.
These properties make steel the ideal material for heavy civil engineering applications, such as the construction of bridges, foundations, and coastal protection. Its exceptional resistance to bending allows SSP to withstand the greatest mechanical challenges, providing stability and safety to structures.
However, in marine applications or brackish water environments, SSP are exposed continuously to natural influences, most especially saline water and oxygen, making them highly vulnerable to corrosion. The corrosion rates applied to the steelwork structure are in accordance with the recommendations of “The Corrosion and Protection of Steel Piling Products: An Overview, March 2011, TATA Steel” for tropical locations”. Accordingly which Corrosion rates on unprotected steel averages from 0.015mm to 0.39mm per year depending on exposure zones as showed in following table.
Corrosion zone | Corrosion rate |
Buried zone | 0,015 mm/year/side |
Immersion zone | 0,02 mm/year/side |
Low water zone | 0,10 mm/year/side |
Tidal zone | 0,04 mm/year/side |
Splash zone | 0,39 mm/year/side |
VSP made from polyvinyl chloride (PVC), offer a different set of advantages that make them increasingly popular in various applications. The key technical parameters of VSP are as follows:
+ Tensile Strength: This is approximately 40-46 MPa, a significantly lower value compared to steel, meaning that VSP are not designed for large mechanical loads.
+ Young’s Modulus: For PVC, the Young’s modulus is approximately 2.3-3 GPa, indicating greater flexibility and lower deformation compared to steel.
Despite their lower mechanical strength, VSP stand out for their exceptional resistance to corrosion, chemicals, and biological degradation. This makes them an excellent choice in environments where steel is subject to rapid wear, such as marine environments, brackish water environments or contact with aggressive substances. Further, VSP is manufactured with special compounds for resistance to harmful ultraviolet rays
2.2. Unit weight
The density of steel material is 7,85 ton/cu.m, meanwhile the density of PVC just 1,45 ton/cu.m. Therefore, the VSP can be up to >70% lighter than SSP materials (example the unit weight of 1 m of SSP type SP-III (W=400mm, H=125mm, t=13mm) is 60,0kg but unit weight of VSP type SU457 (W=442mm, H=152mm, t=6,3mm) just 7,1kg; the unit weight of 1 m of SSP type SP-IIIw (W=600mm, H=180mm, t=13,4mm) is 81,6kg the but unit weight of VSP type SU622 (W=606mm, H=230mm, t=9,0mm) just 13,5kg), making it easier to handle, transport and installation.
2.3. Cost
SSP
The cost for SSP is generally higher due to the material and manufacturing processes. Additionally, the transportation and installation of SSP can be costly due to their weight and the need for specialized equipment. Maintenance is also a significant cost, especially in environments exposed to corrosion, where regular coatings or galvanization may be necessary.
VSP
VSP offer significant savings compared to SSP. Here are some key aspects that influence the financial benefits:
+ Product Cost: Basing on market prices, the unit price for each meter of VSP just equivalent 50-60% of SSP price with similar section size, making them more attractive for many construction projects.
+ Transportation: Due to their lower weight, it was easier to transport to the project site, or more panels can be loaded into trucks for the same weight as SSP, lead of significantly more economical and straightforward. Their lower weight also reduces logistical costs and environmental impact.
+ Installation: The installation of VSP is less complicated and less costly. They can be installed using lighter equipment, further reducing costs.
+ Maintenance: One of the greatest advantages of VSP is their resistance to corrosion and biological degradation. This means they do not require costly maintenance or corrosion protection, resulting in significant long-term savings.
2.4. Other advantage of VSP in compare with other sheet pile
Longer Service Life and Sustainability
Mainly due to its superior corrosion and chemical resistance, VSP can be designed and installed with the confidence on its performance for 50 years and beyond. Vinyl has a long shelf life which means natural elements like the sun, wind, and water are not likely to break it down as quickly as other materials. With the relentless radiant energy from the sun, combined with the surrounding’s harsh elements, walls made from materials other than vinyl will eventually rot, corrode, or become a habitat or for marine-boring critters like small mollusks and crustaceans. They are also fire resistant and proven to possess adequate resistance against creep under sustained load.
Consistency of Appearance
Wood fades, paint chips, and steel rusts over time. With VSP, this problem is virtually eliminated maintaining its lasting & aesthetic look for long period of time.
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