CORROSION RESISTANCE and WATER RESISTANCEResists a broad range of chemicals and unaffected by water
FRP systems are water tight and Protectors systems have an external resin rich water tight penetration barrier
Subject to oxidation and corrosion which otherwise requires galvanisation for many complications – a expensive and difficult process.Can cause galvanic corrosionTypically made from only a single or small range of polyethylene resins, HDPE lacks the ability to be optimized for severe chemical environments and efflucentConcrete is a porous material allowing water to penetrate the surface. Even with sealants concrete can leak
Concrete often uses steel rebar for reinforcement and the rebar is susceptible to rust from water permeating the surface.
STRENGTHGram for Gram stronger than Steel and aluminium
Compressive strength – 206.5MPa (LW)
Flexural Strength – 206.5MPa (LW)
Ultimate stress –
Yield Strength – 248.22MPa
Higher tensile strength and higher tensile modulus
Yield Strength – 241.325MPa
Higher tensile strength and higher tensile modulus
Ultimate Stress = 23MPa
Degrades over time, although initial strength of system is greater
High compressive strength, but low tensile strength – reinforcement available. Ultimate strength dependant on water-cement ratio
Modulus of ElasticityHoop Modulus = 27.58GPa
Axial Modulus = 12.4GPa
200GPa69 GPaHDPE Modulus = 0.69GPa
HDPE has higher in ground deflection and pipe bending.
Requires piping supports in some installations
Dependant on modulus of elasticity of aggregate, matric and rebar (if any)
Usually between 30-50GPa
Pressure DesignDesigns at minimum a 6:1 safety factor ratio in pressure situationsLower safety factor in designs causing extreme occasions to be big issue for HDPEN/A
WEIGHTWeights 25% of steels and 70% of aluminiumDue to high weight often requires lifting apparatus where it would not be require for FRP, lowering costs33% of the weight of steelDensity = 970 kg/m3
Hence is a lighter weight per cubic metre than FRP
Density of 2400kg/m^3, roughly twice the weight per cubic metre than FRP, pound for pound stronger than Concrete
ELECTRICAL CONDUCTIVITYNon conductiveRequires grounding due to high conductivity Requires grounding due to high conductivity Non conductiveN/A
THERMAL CONDUCTIVITYGood insulator with low thermal conductivity
Thermal conductivity
50.2 W/m
thermal conductivity
Low thermal coefficient of expansion
23.4 m/m/C *10^-6 K
Generally considered to be ¬ 0.5 W/mK0.04W/mK – 0.07W/mK, usually N/A property
Thermal expansion and contractionLower thermal expansion, with 1/10th of the expansion and contraction of HDPE
Low thermal coefficient of expansion
12.6 – 14.4 m/m/C *10^-6
Low thermal coefficient of expansion
13.5 – 14.4 m/m/C *10^-6 K
Low thermal coefficient of expansion
23.4 m/m/C *10^-6 K
HDPE tends to lose its mechanical properties drastically at 22 degrees. Becomes not recommended when the temperature exceeds 80 degrees.
12 x 10-5 cm/(cm °C)
Concrete expands and contracts regularly with temperate cause cracks to appear and corrosion.
OPERATING AND DESIGN TEMPERATURESFRPs mechanical properties do not degrade until roughly 83-105 CELCIUSHDPE tends to lose its mechanical properties drastically at 22 degrees. Becomes not recommended when the temperature exceeds 80 degrees.
IMPACT RESISTANCEWill not permanently deform under impactCan permanently deformCan permanently DeformRequires a high force o cause impact damage, but once concrete is damaged due to brittle nature permanent deformation occurs
COSTLower installation costs, less maintenance, longer product life cause lower lifespan costLower initial material costs, ,high installation and maintenance costs. Part Price comparable to FRPCheaper than FRP, similar lifetime costs – lifespan usually just as long under low load conditionsLower initial material costs, ,high installation and maintenance costs.
LifespanGuaranteed to last 75years, lifespan can be up to 150 yearsIn the case of underground steel installations, steel tanks usually last roughly 10-15 years before replacement – dependant on many factorsRoughly similar to FRP, due to low strength cannot be used in high load situations15-50 year expected lifespan, depending on environment.
MANUFACTURE AND FABRICATIONCan be easily manufactured, easy of complex shapes, can be fabricated with simple carpenters tools. No torches or torches requiredOften requires welding and cutting tools, with heavy equipment requiring special processes. Good machinabilityCan be manufactured to smaller diameters with HDPE being quicker to produce – uses more complex processes to create such as rotatory mouldingConcrete must be built as separate sections for ease of delivery and installation, hence joints provides weaknesses even with additional sealants. More complex systems are required in manufacture of concrete assemblies.
INSTALLATION FRP is simple to install, requiring minimal machinery operation and usually light crane systems. Due to the lightweight nature of FRP installation, transportation and the preassembled nature of the systems installation is usually quick and simpleDue to the weight of steel, systems are usually requiring heavy machinery, the likes which would not be necessary for FRP Comparable weight and usual thin sheet nature of Aluminium has comparable installation ease to FRP, with reductions in strengthComparable to FRPRequires step by step installation on site as concrete systems have to be poured and set. Requires more transportation increasing time and expenses.
MAINTENANCEMaintenance is simple with the interior coating and smooth layer make removal of sludge simple and easy and maintenance requires minimal effort. Comparable to FRP
Much more difficult in all stages of maintenance to deal with, more difficult to clean and maintain requiring higher frequency and increased cost over the life of the system.