Pile Guide Part 1 – Load Bearing Piles

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Introduction

Piles can be categorized in two main types: load bearing piles and sheet piles. There are numerous types of load bearing piles. The below illustration shows a pile classification system based on type of material, configuration, installation technique and equipment used for installation. Load bearing piles can also be classified based on their method of load transfer from the pile to the soil mass. Load transfer can be by friction, toe bearing or a combination.

Steel Piles

General Information:

• Among all piling materials steel piles are allotted the highest allowable unit working stresses, but not necessarily the highest in proportion to the ultimate strength of the material.
• Steel piles are generally considered to be high capacity piles but have been historically used for a wide range of loadings.

Steel H-Piles

General Information:

• H-piles are a specially designed sub-group of wide flange shapes with equal thickness in the web and flanges.
• The depth of the section is approximately equal to the width. H-piles are hot rolled from ingots on the same type mill used to manufacture wide flange structural shapes.
• Are versatile and can be used for both friction and end bearing applications.
• Are manufactured as a finished product, which can be driven with standard equipment.
• Can be considered for a design load between 80 kips (356 kN) and 500 kips ( kN).
• They function most efficiently for end-bearing or partial end- bearing applications.
• Are a standard in many states for highway bridge piers and abutments where the job sites are remote

Advantages:

• High individual load capacity when driven to bear on or in hard or dense materials.
• Ready availability; can be installed with standard driving equipment; lengths can be easily extended or reduced to the job requirements.
• Compact shape with low displacement – minimum disturbance to adjacent piles or structures; able to penetrate where many other types could not.
• High bending strength for applications involving lateral loads. Readily driven on a batter if required.
• Good tension piles for uplift – constant cross- section, plus steel is best material for tensile strength.

Disadvantages:

• Relatively higher cost unless efficiently loaded.
• Inability to inspect the physical condition after driving (an advantage for closed ended tubular piles)
• Non-constant radius of gyration (an advantage of pipe piles for certain situations).
• Corrosion problems in certain environmental situations if unprotected.

H-Piles as End-Bearing Piles:

• H-piles are most efficient when they can be driven to refusal or practical refusal on rock, or into dense materials overlying rock. The pile functions as a short column, hence the rock may be stronger than the steel for the maximum design load that can be applied.

H-Piles as Friction Piles:

• While many meters of H-piles have been driven for friction applications, they are non-displacement piles and tend to drive further in loose sands and silty sand. There may be good reasons however to select H-piles for this use if, for example, a significant scour depth is computed for a bridge pier abutment.

H-Piles as Soldier Beams:

• One common application of H-piles is their use as soldier beams for retaining walls. These retaining walls can be either permanent or temporary for excavations and braced cuts.
• Typically, the H-piles are driven on 6’ – 8’ (1.8 – 2.4 m) centers in a row with the flanges facing each other. The lagging – either concrete or timber – is then stacked with the ends of the flanges facing the webs. The flanges of the H-piles thus retain the lagging.
• Cross bracing (in the case of braced cuts) or tieback systems can be used to provide additional lateral support for higher walls or loads.
• H-piles also are used in conjunction with sheeting to form high-modulus walls; as discussed in the Pile Buck Sheet Piling Design Manual.

Steel Pipe Piles

General Information:

• Pipe piles usually consist of seamless, welded or spiral welded steel pipes of wall thickness in the range of 0.109” to 2.500” (2.8 – 63.5 mm).
• The piles are available in 8” (203.2 mm) to 48” ( mm) diameters.
• Common sizes of pipe piles can be considered for loads between 60 kips (267 kN) to over 400 kips ( kN).
• Pipe also provides a strong casing for concrete fill where underground pressures are high.
• Pipe piles may be driven with an open end or a closed end.

Advantages:

• Wide selection of sizes and thicknesses available to choose from.
• Delivery is excellent since there are many manufacturers and distributors; popular sizes are stocked.
• Standard sizes of pipe pile can be driven with conventional driving equipment. Light wall pipe makes an efficient shell for concrete fill when mandrel-driven.
• Pipe piles driven open-end to rock, cleaned, inspected and filled with concrete can resist very high individual loads.
• Pipe piles with wall thickness over about 1/8”
(3.2 mm) and filled with concrete are treated
as a composite pile with both the steel and the concrete sharing the applied load. The advantages of both steel and concrete are enjoyed.
• Pipe piles can be inspected for material damage and curvature prior to acceptance.
• They can be readily spliced to extend lengths, resist hard driving, and drive straighter because of their constant radius of gyration. They make a more efficient column where unsupported length and large loads are design requirements.

Disadvantages:

• Open-end pipe piles are not as favorable as H-piles for non-displacement applications since the plug of soil inside the pipe also offers resistance to penetration.
• Closed-end they are full displacement piles with certain potential problems associated with displacement.
• They may not be price-competitive with other displacement piles.

Closed Ended Pipe Piles:

• A closed ended pipe pile may be filled with concrete or left unfilled.
• They may be filled with a structural shape such as an H-section in addition to the concrete and socketed into bedrock (rock socketed piles).
• If bearing capacity from the entire pile toe area is required, the pile toe should be closed with a plate or a conical tip.
• Mandrels are usually not used for driving pipe piles, which are generally driven from the pile head.
• When the end of a pipe pile is equipped with a closure device, the pile becomes a displacement pile and functions well as a friction pile particularly in loose sands.
• When driven open or closed end it can also function as a high capacity end-bearing pile.

Open Ended Pipe Piles:

• Open-ended pipe piles are driven when hard driving, caused by the presence of debris, small boulders and the like is anticipated.
• The pipe can be fitted with a special driving shoe, which adds steel thickness at the toe to reduce stresses and damage.
• Open-ended pipe piles may also be partially socketed into rock at site of steeply sloping bedrock or where pile fixity at the toe is a design requirement.
• Pipe piles driven open-end may be filled with concrete after cleaning out the plug, back filled with sand, or the plug ignored.
• This type of pile is also common in the installation of offshore oil platforms, whether driven from the surface or underwater. In these applications, they primarily are designed for uplift loads due to wave or wind action on the structure.
• Open ended pipe piles are recommended where the pile or pile group is to be subjected to horizontal loads and bending moments such as vessel impact and scour on large structures such as bridges.

RR Piles:

• A special type of pipe pile is the RR pile, manufactured by Makela Metals.
• These can be formed into sectional pile systems by mechanical joints.
• They are used as toe-bearing piles in the repair of buildings, as supports under machine bases, and for house foundations.
• Light installation equipment, the cost-effective use of material and versatility of application are benefits offered by RR piles.
• RR piles are spliced using friction joints, so no welding is required for splicing.

Concrete Piles

General Information:

• Concrete piles utilize concrete as the main structural material for compressive loads; however, concrete is deficient in resistance to tensile load. Therefore, when a concrete pile is subject to direct tension or bending, steel must be added to resist these stresses.
• Concrete piles are classified as pre-cast or cast-in- place depending on the method of manufacture. Pre- cast piles are formed in a casting bed, cured, and then driven into place.

Cast-In-Place Concrete Piles

General Information:

• Cast-in-place piles are, as the name implies, cast in a pre-formed excavation at the project site and hence the concrete is not subjected to driving forces.
• In general, cast-in-place concrete piles are installed by placing concrete in an excavated hole in the ground. In some cases the hole is lined with a steel shell or casing which may be temporary or permanent.
• Steel pipe piles, when filled with concrete, can be classified under this category.
• Predetermination of pile lengths is not as critical as for precast concrete piling, since required pile lengths can be easily changed during installation.
• Cast-in-place concrete piles can be installed with or without a mandrel, depending upon the wall thickness of the pile.

Raymond Step Taper Piles

General Information:

• The most popular of the mandrel-driven type piles, consisting of a tapered steel shell to be installed with the aid of an internal mandrel. After withdrawing the mandrel, the shell is then filled with concrete to complete the pile.

Advantages:

• Versatility, a wide range of configurations and variations are possible to accommodate different loads and soil conditions.
• Drivability, the heavy mandrel permits the use of lighter hammers for more effective driving and development of the geotechnical capacity.
• Internal inspection is possible after driving and before concreting.
• Installation is made without damage to the working pile since driving is done on the mandrel and not on the concrete.
• A range of pile capacities is possible from medium to very high.
• Shape characteristics: the configuration is that of a true displacement pile combined with the taper to develop capacity of the soil-pile system in shorter lengths than other types, particularly in loose granular soils.
• The pile shell insures that the hole is secure against soil intrusion.

Disadvantages:

• Displacement piles are particularly vulnerable to pile heave in plastic soils. This condition should be monitored closely.
• Thin gauge shells are vulnerable to damage where underground debris or boulders are encountered.
• Splicing to extend lengths is difficult.
• Shells are vulnerable to collapse from excessive earth or hydrostatic pressure, and special measures must be taken in those situations.

Monotube Piles

General Information:

• Monotube piles are a proprietary pile shell, which is rigid enough to be head driven. The rigidity is obtained by use of heavy gauge steel (3 to 9 gauge), which is longitudinally ribbed or “ fluted” during the cold forming process.
• The basic shell is tapered with tips of about 8” (203.2 mm) diameter and butts 12” (304.8 mm) to 18” (457.2 mm). L
• Lengths range from 10’ (3.05 m) to 75’ (22.9 m).
• Extensions to the tip sections are made with straight-sided tubes up to 40’ (12 m) long.
• After installation, the shell is filled with concrete.
• Monotubes compete with lighter wall pipe piles, and mandrel-driven cast-in-place piles for both friction and end-bearing applications. They are designed assuming both the concrete and steel support the applied load.

Compacted Concrete Piles

General Information:

• The method utilizes a heavy, removable pipe shell and a charge of special mix concrete. Special equipment has been devised to handle the pipe and a heavy drop hammer, which rams the dry- mix concrete into the soil inside the pipe. As the mix descends it pulls the pipe with it.
• When the desired elevation is reached, the pipe is restrained and the concrete mix is pounded out the base where it forms a compact bulb. The pile shell is then rammed in on head of the bulb terminating at the surface.
• This pile is most suited for granular soils and has developed working load capacities of over 300 kips ( kN). These piles experience the same general problems as augered piles and they generally are no longer than 40’ (12 m).

Composite Splices

General Information:

• Piles, which combine two types of piles in a single length, are classified as composite piles.
• A very common type of composite pile is a prestressed concrete pile combined with an H-pile “stinger.” This provides both toe protection and penetration assistance for the pile.
• If required a very high capacity composite pile can be formed from a pipe pile that is driven or drilled to rock, cleaned out and socketed into the rock. A steel core section is added and the pipe filled with concrete.
• These piles are quite expensive but some building codes permit very high loads on this pile because of the controlled conditions under which it is installed.

Drilled-In Caissons

General Information:

• Drilled-in Caissons are drilled shafts, which use a driven casing, either permanently or more typically temporarily.
• The caisson can be driven with an impact or vibratory hammer, depending upon the soil conditions.
• Use of a vibratory hammer simplifies removal of the casing.
• Design considerations are the same as those for drilled shafts.

Precast and Prestressed Concrete Piles

General Information:

• Frequently such piles are cast with a hollow core to reduce weight, in which case the head and toe of the pile are solid.
• The hollow core may be used for placing instrumentation during construction or for determining pile damage.
• Precast concrete piles are usually of constant cross section but may have a tapered tip.
• Concrete piles are considered non-corrosive but can be damaged by direct chemical attack (e.g., from organic soil, industrial wastes to organic fills), electrolytic action (chemical or stray direct currents), or oxidation.
• Requirements for precast concrete piles generally apply equally to prestressed units, except reinforcement.
• Such piles must be designed and installed in accordance with the general provisions for piling.
• Precast piles must be proportioned, reinforced, cast, cured, handled and driven to resist the stress induced by handling and driving as well as by structural loads.
• Handling equipment shall be constructed to equalize the reactions on multiple lines of pile pickups.

Reinforced Concrete Piles

General Information:

• These piles are manufactured from concrete and have reinforcement consisting of a steel rebar cage consisting of several longitudinal bars and lateral or tie steel in the form of individual hoops or a spiral.
• Reinforced concrete piles as compared to prestressed piles are more susceptible to damage during handling and driving because of tensile stresses.
• These piles are easier to splice than the prestressed piles and are used where possibilities of variable pile lengths exist.
• These piles are best suited for friction piles in sand, gravel and clays. Typically, the maximum length allowed is 50’.

Prestressed Concrete Piles

General Information:

• This pile consists of a configuration similar to a conventional reinforced concrete pile except the prestressing steel replaces the longitudinal reinforcing steel.
• The prestressing steel may be in the form of strands or wires and is placed in tension.
• The prestressing steel is enclosed in a conventional steel spiral.
• Such piles can usually be made lighter and longer than normally reinforced concrete piles of the same rigidity.
• Pretensioned piles are usually cast full length in permanent casting beds.
• Post-tensioned piles are usually manufactured in sections and assembled and prestressed to the required pile lengths at the manufacturing plant or on the job site.
• The primary advantage of prestressed concrete piles versus conventional reinforced concrete piles is durability.
• Since the concrete is under continuous compression, hairline cracks are kept tightly closed and thus prestressed piles are usually more durable than conventionally reinforced piles.
• Another advantage of prestressing (compression) is that the tensile stresses, which can develop in the concrete under certain driving conditions, are less critical.
• These piles are best suited for friction piles in sand, gravel, and clays.

Prestressed Cylinder Piles

General Information:

• Prestressed cylinder piles are post-tensioned piles that are spun cast in sections, bonded with a plastic joint compound, and then post-tensioned in lengths containing several segments.
• Special concrete is cast by a process unique to cylinder piles that achieves high density and low porosity.
• The pile is virtually impervious to moisture.
• Generally, cylinder piles are used for marine structures or dry land trestles.
• The piles typically extend above ground and are designed to resist a combination of axial and lateral loads.
• They are available in diameters of 36” (914.4 mm) to 90” ( mm).

Timber Piles

General Information:

• Two species account for over 90% of the usage—Southern pine and Douglas fir. Southern pine is grown mainly in the southern United States and consists of four sub-species: longleaf, loblolly, slash and short leaf. Douglas fir is a product of the Northwest Coast with the preferred product for piling identified as “Coastal” Douglas fir.
• Some specialty timber is imported from the tropics for marine piling applications. Greenheart, imported from South America, is one such species. It features high strength and superior resistance to decay and to attack by marine borer organisms.
• Timber piles are processed as clean-peeled (all outer bark and 80% of inner bark removed) rough peeled (all outer bark removed) and un-peeled (all bark retained). Piles that are to be further treated with preservatives must be clean-peeled.
• Timber piles are frequently installed un-peeled and untreated. These are generally for use in temporary structures or installations with a planned short-service life. However, the majority of timber piles are now treated with wood preserving chemicals to extend their life.
• Sawed timbers are very rarely used for piling, therefore timber piles are always round and tapered, which is an efficient shape for a pile.

Quality:

• Timber for piling should be of sound wood and free from decay and insect damage. Other possible defects are identified as follows:
  • A check is a separation of the wood extending across the growth rings from the surface toward the centre but not completely across the section. A check should not extend any further than the pitch (centre core).
  • A shake is a circumferential separation of the rings of growth. The lengths of shakes in the head of the pile are limited.
  • A split is a lengthwise separation of the wood across the growth rings but extending from one surface to the other. Splits may not be any longer than the diameter of the head.
  • Knots are, of course, the source of limbs, which have been trimmed from the trunk. Restrictions are imposed on the sizes and depth of knots based on being classed as “sound” or “unsound.”
  • Straightness requires that a straight line from center of head to center of toe must lie entirely within the pile body.

Advantages:

• Low cost, per ton of capacity.
• Dependable, renewable supply – available in a range of lengths and sizes.
• Long history of successful application to low and medium unit loads.
• Easily handled and driven with conventional equipment.
• Tapered shape and full displacement characteristics advantageous for developing soil capacity in shorter lengths.
• Strength in tension and bending applications.

Disadvantages:

• Cannot be spliced to extend lengths.
• More vulnerable to driving damage.
• Vulnerable to deterioration from a number of natural sources unless effective protection is provided.
• Restrictive properties regarding strength, sizes and lengths.

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What is the typical wall thickness of steel pipes?

Pipe piles usually consist of seamless, welded or spiral welded steel pipes of wall thickness in the range of 0.109” to 2.500” (2.8 – 63.5 mm).

When do you use compacted concrete piles?

Compacted concrete pile is most suited for granular soils and has developed working load capacities of over 300 kips ( kN). These piles experience the same general problems as augered piles and they generally are no longer than 40’ (12 m).

Utilities—we don't always think about what runs beneath our feet, diverting water and sewer systems. But the use of proper storm sewers and culverts is essential to keep our cities functioning, clean, and safe.

Whether handling amounts of waste, accommodating sudden onsets of water runoff and flooding, or carrying water into agricultural sectors to irrigate crops, utilities are the veins beneath a city's concrete surface.

One of the most commonly used types of pipe is Reinforced Concrete Pipe, or RCP.

Reinforced concrete has been a common material for pipelines and water conveyance systems for centuries.

Concrete itself has been used as a construction material for even longer—a couple of thousand years, in fact. RCP is a sustainable product with a proven lifespan of more than 100+ years. This is why it is often the product of choice by specifiers and builders.

RCP is a type of piping used for directing the flow of liquids or water underground.

These pipes are typically used in roadway and site development, as they are designed to convey a very large amount of liquid volume and built to withstand environmental stressors.

Because of Reinforced Concrete Pipe's (RCP)

•   Strength
•   Reliability

This piping is ideal for infrastructure projects such as storm sewer conduits—RCP can handle large amounts of any runoff, flooding, or storm surges, safely diverting it from city or industry sectors.

Due to its innate resilience, RCP remains strong even through disruptive events and stressors. RCP has impressive durability, sustainability, and proven 100 year lifespan, allowing installations to remain functional and effective for many years.
This means that residents and road users will not be disturbed by unnecessary infrastructure rehabilitation or pipe replacement.

Where is RCP Used?

RCP is a go-to for any utility project because it is one of the strongest and most durable building materials available.

Because of RCP's proven lifespan, often lasting more than 100 years, uses of concrete pipe include all types of major projects, such as:

Culverts

Sanitary Sewers

Storm Sewers

Contractors, engineers, and transportation departments across the country can rely on RCP to be the most durable selection in pipelines that last for well over a century. They can trust RCP's structure, rigidity, resilience, and dependability for many years.

What makes RCP?

RCP is constructed from concrete materials, as the name suggests. More specifically, the concrete materials tend to be,

Locally sourced
for each production location

Using
aggregates

Cementitious
materials

Domestic
steel reinforcement

As much eco-friendly
material possible

RCP is resilient and sustainable, leaving a lighter carbon footprint and minimal negative environmental impact than other pipe materials such as plastic.

What is RCP's Lifespan?

Concrete pipe is proven to have an incredibly long lifespan—you can expect RCP to last at least 100 years.

Because of RCP's inherent strength, durability, sustainability, and resilience to environmental factors, it will last well into the future.

RCP can handle both large liquid volumes and external loads, therefore the extensive lifespan of RCP means less disruption to its environment and roadway users, as the pipeline won't have to be replaced or repaired as frequently as other pipe materials. RCP is resilient even through disruptive events and can resist many different types of stressors.

Unsurprisingly, concrete is not a new invention. Ancient cultures like the Egyptians and Romans utilized concrete thousands of years ago. So, it's no wonder that we have learned to depend on concrete products for many construction needs and critical infrastructure projects.

The Origins of Concrete

One of the first recorded applications of what we now call concrete can be traced back to the Roman Empire, around the 2nd century BC. They began mixing volcanic ash, lime, and aggregates to create Opus Caementicium, the first truly effective concrete.

Volcanic Ash Lime Aggregates

Opus Caementicium The first truly effective concrete

From this original concrete mixture, the Romans were able to mix a variant, known as Pozzulana, that performed incredibly well when submerged in sea water. Caesarea Maritima

The earliest known example of underwater concrete technology

Pozzuolana's use in building the seaport of Caesarea Maritima is the earliest known example of underwater concrete technology.

The Original Concrete Piping Systems

The first underground application of pipes and culverts to manage water and sewer flow is also attributed to the Romans. When ancient Rome became too overpopulated for a surface sewer ditch system, work was begun on a massive underground concrete culvert and pipe system that drained local marshes to remove the waste of Rome and carry it into the River Tiber.

Cloacae Maxima

Rome's main sewer system

And so, the Cloacae Maxima (lit. “Greatest Sewer”) was constructed around 300 BC as Rome's main sewer system.

The eleven aqueducts that fed water into the city were also harnessed to help flush out the system, and separate pipes were installed to channel this fresh water to various public fountains.

Today, portions of such Roman concrete masterpieces are still standing and in use—parts of the Cloacae Maxima are visible, as are the underwater concrete ramparts at Caesarea Maritima.

Some two thousand years later, these concrete structures remain sturdy even with continuous exposure to water and liquid erosion.

The Evolution of Concrete Use

John Smeaton discovered a more efficient way to produce hydraulic lime for cement

In more modern times, a major breakthrough was made in when John Smeaton discovered a more efficient way to produce hydraulic lime for cement, using clay that contained limestone.

Invention of Cement

Joseph Aspdin invented Portland cement.

First apartment built

First apartment building using steel-reinforced concrete was built in Paris.

The number of large-scale concrete projects increased

The Hoover Dam and Grand Coulee Dam also joined the ranks of large-scale concrete projects in .

First Uses of Concrete Pipe

The earliest recorded use of concrete pipe

But the first appearance of modern-day concrete sewer systems in the USA came about during the mid-19th century. In Mohawk, N.Y. The earliest recorded use of concrete pipe was installed as a sewer system in . In close succession, other east coast cities began to install concrete pipelines throughout the second half of the 19th century, with many of these pipelines still in use today.

Sorry, your browser does not support inline SVG. Joseph Monier created wire-enforced concrete & attained his first patent for iron-reinforced concrete

In the s, a French gardener and inventor named Joseph Monier created wire-enforced concrete when he was experimenting with building a stronger type of pot to withstand plant root pressure. He presented his invention at the Paris Exposition of , and obtained his first patent for iron-reinforced concrete on July 16th, .

More patents followed in the next few years

Further patents followed, including iron-reinforced concrete pipes and basins in , iron-reinforced concrete panels for building façades in , and reinforced concrete beams in .

Other development breakthroughs in concrete pipe include the very first reinforced concrete pipes

Other development breakthroughs in concrete pipe include the very first reinforced concrete pipes, incorporated in

• France in
• America in
• Australia in

Of course, these early instances of RCP were much different than what we use today. The early process of constructing a large reinforced concrete sewer via open trench and concrete poured directly in place and cured onsite.

The origin of the method of casting concrete pipe

Later, during the s, as sturdier motorized vehicles became more prevalent in the industrial sector, reinforced concrete pipes were no longer cast and cured at the jobsite, but were transported from regional casting factories to the site.

In modern construction methods, though RCP is still used for many of the same applications such as water drainage and sewer systems, the process is more streamlined. Because concrete is the most durable and strong building material on the market today, RCP can be found in countless infrastructure and drainage projects.

Applications in City Planning

City sewer systems are one of the essential planning aspects of any metropolis. Sewage is a guaranteed waste product in any community, and city planners have to take this into account to ensure the sanitation of the city and the safety of its residents.

Because RCP is known for sturdiness, high joint performance, and resilience; entrusting drainage and runoff management to this product is the best option for storm sewers and construction applications.

RCP is ideal for conveying liquids, it remains strong through disruptive events and external stressors, and lasts for decades—up to 100+ years, and can serve for even longer under the right conditions.

100+ yrs

Under normal usage

150 yrs

Under right conditions and usage

Due to this lifespan and resiliency, the integrity of roadways and infrastructure is maintained without the need for unnecessary overhaul and repairs.

Storm drains are another crucial factor in city planning and should be designed to handle proper drainage flow rates in case of emergencies, especially if the city is in a documented flood, hurricane, or monsoon zone.

It's essential for city water-shed systems to have adequate accommodation in allowable slope velocity and open-channel hydraulics to deal with any excess water movement.

RCP allows for heavy waterflow with minimal erosion and dependence on soil support, making it ideal for storm drainage.

Applications in Construction

Apart from moving non potable water within cities, RCP is used for transporting non potable water underground over long distances.

Because RCP can be installed in either a trench or embankment conditions, it has incredibly versatile applications in construction.

It can even be installed by jacking or micro-tunneling when open-cut is not feasible.

For instance, culverts are an important part of roadwork considerations, placed in areas where water needs to flow under man-made structures.

They have to withstand heavy pressure loads from the construction atop them, high amount of water flow inside, and the pressure from surrounding soil and other materials, therefore RCP is ideal for these installations.

Applications in Irrigation

With the ability to transport large amounts of water quickly and efficiently, RCP provides a leading solution in agricultural settings.

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The installation of buried RCP can help with irrigation efforts and environmental management applications, rather than using surface level piping that has to deal with uneven topography of textured soils.

Because of its lifespan of over 100 years, RCP buried pipe is an excellent choice for irrigated agriculture in farming and will last for endless rotations of crops and their associated runoff.

Furthermore, the buried pipe is free of environmental issues such as freezing, blockages, or roadway interference to which open channel irrigation systems or above ground piping would be subjected.

Now that the applications and usage of RCP have been discussed, let us investigate more practical aspects of concrete pipe. When it comes to RCP, the physical aspects of handling, installing, and the actual joints and diameters of the pipes themselves are crucial to the strength, efficiency, and longevity of the pipe system.

RCP Measurements: Sizes and Uses

General RCP specifications for projects are as follows:

Standard RCP

Diameters (D) = 12” to 144”

12” to 144” diameters are typical for conveyance of sewage, storm drainage, and culvert systems. Other applications are irrigation systems and treatment plant piping.

Elliptical RCP

Diameters (D) = 15” to 144”

15” to 144” round equivalent diameters of elliptical pipe are excellent choices for spatial restrictions, clearance limitations, or when a piping system requires greater flow capacity for shallow conditions. Elliptical RCP has a geometric, flattened ellipse shape that can be orientated to have either a horizontal or vertical major axis.

Arch Pipe

Diameters (D) = 15” to 84”

15” to 84” round equivalent diameters, with sizes up to 144” equivalent diameter available in some locations, arch pipe is similar to elliptical pipe in use, including for various storm water applications. Shaped into an arch form, this pipe is good for limited cover conditions and improved hydraulic capacity at low flows.

Installing RCP

When installing sections of RCP, 2 workers, 1 foreman, and a backhoe or crane operator are necessary. Workers securely manage the pipe and with the assistance of a crane or backhoe, it is lowered into place.

Two

workers

One

foreman

One

backhoe/crane operator

The spigot end of the new section is typically slotted into the bell end of the previously installed pipe. It is essential to place and join the sections of RCP correctly and securely.

A properly fitted pipe system will be able to withstand external pressures, environmental considerations, and corrosion, leading to longer lasting pipes that will serve their purpose for several decades with no issues.

RCP and Concrete Joints

Any joints for a concrete pipe system need to be able to withstand pressure, structural stressors, possible erosion and environmental concerns, and other considerations. Joints are important for limiting inflow and infiltration in a closed system. Some of the most commonly used joints in RCP systems include:

These kinds of concrete pipe joints each have unique advantages that include inherent strength, flexibility, soil-tightness, and leak resistance.

Concrete joints are designed to control the positioning and compression of the sealing materials or gaskets, allowing the rigid nature of the joint to govern the hydraulic characteristics of seals, bends, and junctions. Further, joint deflection allows the flexibility of the pipe joints to the minimum angular deflection specified, to form a long radius or to return to grade. Even with larger degrees of angular deflection within specification limits, pressure on the joints is bearable and supported by the pipe material itself.

Governing Standards

ASTM International

Joint Performance Characteristics

Concrete pipe joints are manufactured according to ASTM International standards, providing project appropriate joint designs that can include the following performance characteristics:

•   Ease of installation
•   Strength to handle shear or vertical shift
•   Pipeline continuity and smooth flow without interruptions.
•   Resistance to infiltration of groundwater or backfill materials
•   Resistance to exfiltration of sewage or storm water

Why Choose Concrete Pipe?

For decades, concrete pipe has been the first choice of contractors, city planners, engineers, and transportation departments.

Not only is RCP an incredibly versatile pipe material, but its proven long lifespan also means that any large-scale installations will remain reliably in place and save costs on unnecessary repairs or replacements.

RCP design can be applied to essentially any project, and the range of applications makes it the number one choice.

Other benefits of RCP's inherent resiliency and sustainability include locally sourced material, reinforcements and pipelines that are resistant to disruptive events. These benefits provide RCP installations that will last for more than 100 years with few problems.

Cost and Value

Because RCP continues to be the strongest, most durable, efficient, and environmentally friendly pipe available, these attributes yield a higher value over the course of its lifetime.

Dependability

Longevity of RCP is a proven fact, and no pipe material on the market is currently better understood and more frequently relied on than concrete piping.

Plus, the continuous research and development of RCP within the industry continues to enhance its uses and instill confidence in installing concrete pipes.

Construction/Design Flexibility

Because RCP provides reliable pipeline solutions for a variety of projects, including deep burials, open-cut trenches, shallow burials, trench-less, tunnels, or complex alignment changes, concrete piping is the solution for all drainage needs.

Concrete pipe provides versatility in many project applications since it is available in a variety of shapes and sizes and is more forgiving during the installation process.

When it comes to design, RCP is manufactured in a variety of sizes, shapes, seal options, and joint designs.

Lining and coating options also allow concrete pipes to handle even the most aggressive environments.

Durability

RCP is made to last for decades. Project owners can expect concrete piping to last 100 years, and in some cases, RCP has proven to last even longer.

This is due in part to the durability of concrete as a material, and its resistance to environmental issues.

RCP's design compressive strengths of

4,000-6,000 psi
met within 24 hours of curing time

RCP's design compressive strengths of 4,000 – 6,000 psi are generally met within 24 hours of curing time and the concrete's strength and durability only continue to increase once installed.

Ease and Value of Installation

RCP's mass and rigidity make for a relatively easy and very secure placement in the ground.

Concrete joints are easy to assemble and attach, making instillation of the entire system efficient and minimizes the time and effort needed by paid workers.

Environmental Considerations

With a long lifespan, use of relatively natural products, and local availability, RCP is very environmentally friendly.

It is well documented that the cement used in concrete pipe will absorb up to 50% of the CO2 emissions associated with production over its lifespan in a process called 'carbonation'.

Concrete is the world's most commonly used building material, so precast concrete pipes can be quickly integrated into ecosystems and are generally benign to the surrounding environment.

Hydraulic Performance

RCP has several built-in features that benefit installation and performance.

The pipe's mass makes it more durable to install and resistant to flotation. RCP's rigidity allows it to greatly outperform other flexible piping systems in terms of hydraulics and liquid mass conveyance.

Joint Performance

The variety of joints applicable to RCP are a beneficial aspect of using concrete piping—from soil-tight to pressure gaskets, RCP joint integrity is monitored by certification boards and ASTM and AASHTO standards. Joint integrity lessens the likelihood of substance infiltration or embedment intrusion.

American Society for Testing and Material

American Association of State Highway and Transportation Officials

Lifespan

Many sources document the incredible lifespan of concrete piping, from the U.S. Army Corps of Engineers to transportation inspection agencies.

RCP lifespan and durability has been widely accepted to be over 100 years, and construction companies around the world attest to the use of RCP as a long-term pipeline product.

RCP's Lifespan
100 years

Mass Considerations

This is an important consideration when it comes to laying pipelines through marshy, boggy, or low-laying environs, where buoyancy can become an issue.

Buoyancy of buried pipelines depends on pipe mass and the weight of water it displaces. The performance of RCP is excellent, given that the mass of concrete pipe typically counteracts buoyant force, and the mass of liquid carried by RCP is enough to securely anchor it.

Non-Flammable

It might seem obvious, but concrete piping is immune to damage from exposure to flame and heat, unlike its thermoplastic counterparts.

This makes RCP a great option for safety considerations in all sectors, including public, private, and government.

The non-flammable nature of RCP means that fire and toxic fume hazards, and water contamination, are removed from the equation.

Quality Control

The production of RCP is a highly regulated and standardized industry.

Standard setting bodies such as ASTM and AASHTO are able to exert quality control standards over RCP products and each step of their production.

Regulated RCP production includes computer-controlled proportioning and mixing systems, absorption testing, and automated recording systems.

In fact, the American Concrete Pipe Association (ACPA) implements an on-going quality assurance program called the “Quality Cast” Plant Certification Program, or Qcast for short. Additionally, precast RCP is manufactured in a controlled environment where each piece receives a quality check prior to shipping.

Resilience

RCP is ideal for today's economic environment, being designed for long-term and sustainable project performance.

RCP resilience is a major factor in its excellence, even during exceptional weather events RCP will not buckle, burn, deflect, tear, or rust, and is immune to most environmental elements.

Strength

RCP is the strongest pipe available, and is factory tested to resist any specified design load.

The compressive strength of RCP typically ranges anywhere between 4,000 and 8,000 psi, allowing it to meet various project requirements while still meeting all relevant ASTM and AASHTO standards.

RCP strength

4,000-8,000 psi
still meeting all relevant ASTM and
AASHTO standards.

Structure and Conduit

Unlike flexible piping alternatives, RCP does not depend on the surrounding soil to support its structural performance.

This means rigid RCP immediately provides structure and conduit when it arrives onsite, with minimal need for buttressing.

Sustainability

Because RCP can last for over 100 years after installed, concrete pipes are a very sustainable material for construction projects and infrastructure.

By maintaining structural integrity for decades, RCP reduces the costs of replacement and any environmental harm due to unearthing the pipelines and additional construction.

One of the main considerations of any construction material or product is how long it will last before replacement is needed.

This applies to discussions of cost efficiency, maintenance expense, and the hassle of entire replacement. But many sources do attest to the sturdiness and life-cycle cost benefits of reinforced concrete piping, leading to longevity of 100 years or more. So, what are some specific factors in the durability and lifespan of RCP?

How Long Will RCP Last?

As previously mentioned, RCP has many factors that make it a long-lasting product. But what specific lifespan estimate can you expect from RCP once it has been installed?

The United States Army Corps of Engineers has attested to a usage lifespan of up to 100 years for a reinforced concrete pipe, and has documented numerous instances of installations that have lasted even longer than these parameters. According to the US Environmental Protection Agency, concrete pipes will last at least 100 years, and very large pipes can be expected to last for several centuries.

100 years

usage lifespan attested by
US Army Corps of Engineers

So, between its resilience and resistance to environmental factors, the Estimated Material Service Life of RCP exceeds alternative materials.

Material Service Life of Piping

When it comes to measuring pipeline lifespan, regardless of the material, “serviceability” is the key consideration—defined as the period of time for which a product can function at its intended role.

For example, the serviceability of sewers or culverts running underneath roadways would have to be considered as a conduit to transmit water and as a structure to support roadwork above.

The Canadian Ministry of Transportation's Gravity Pipe Design Guideline (GPDG) lists the following as factors in material degradation product wear:

•   Abrasion
•   pH Level
•   Slow Crack Growth
•   Soil and Water Resistivity
•   Electro-Chemical Corrosion of Steel
•   Acid, Chloride, or Sulphate Corrosion

Ultimately, these factors are the determinants for a pipe's life cycle analysis, or LCA, which refers to the number of years that a structure, system, or material will provide adequate service before needing replacement.

Understanding the factors that affect the estimated life span of pipelines is important to determining the longevity of RCP, and because of its natural strength and resistance to many environmental stressors and corrosion, concrete piping has one of the best serviceable lifespans, with serviceability of at least 100 years.

Abrasion

Effluent velocity does not create problems for RCP within the normal flow ranges, so abrasion damage to concrete piping is generally not a concern.

Acid Damage

Though acid is a factor in piping durability, any acid attack of RCP is usually benign.

The acid typically only attacks the surface of the pipes and be neutralized there by the concrete's alkalinity. So, without further acid replenishment, the reaction halts and the pipes are safe.

Freeze-Thaw/Weathering

Because this type of damage is caused by water penetrating the concrete and freezing, a well-made reinforced concrete pipe will not have an issue with this due to the high density and quality of the concrete.

Additionally, RCP is typically buried with the earth providing insulation from the elements and from rapid temperature changes. Thaw damage is a concern for more porous types of concrete that are exposed, such as asphalt or segmental retaining wall blocks.

Sulphate & Chloride Damage

With both of these corrosives, in order to actually damage RCP, the solutions must permeate the concrete in high concentrations, and have a supply of oxygen.

This is unlikely to occur with concrete piping, and no evidence has been reported that documents chloride-induced corrosion issues in RCP. Because of the additives and liners that can be incorporated in production, RCP in sanitary applications successfully resists corrosion attacks and H2S degradation, meeting or exceeding the100 year design life.

Because pipelines and the construction industry are always innovating and pursuing the newest in manufacturing technology, you can always expect enhancements to RCP. Let's take a look at some of the latest developments in RCP production.

Innovations in RCP Structures

In terms of future RCP trends, there have been experiments with synthetic fibers imbedded into the concrete itself in order to minimize the need for steel reinforcement, lessening any potential issues with steel corrosion that could occur in rare circumstances.

Luckily, you can keep abreast of the latest news and innovations in concrete piping with websites like the American Concrete Pipe Association's “Latest News” section.

Concrete pipe

• Significant structural strength Concrete pipe is rigid, with a significant structural strength.
• Double load barring capacity after installation The load carrying capacity of RCP can more than double after it is installed, because of the benefit gained by the bedding supporting the pipe.
• Adjustable structural strength of RCP The structural strength of RCP can be adjusted in several ways, by varying the wall thickness, concrete strength, and the amount and shape of the steel material reinforcement.

Because RCP does not have vulnerability to such damages, and has such a high structural integrity when installed, RCP is a more versatile, reliable, and long-term choice for various installations and infrastructure projects, with service lasting at least 100 years.

RCP is a standard pipe material utilized in countless industrial projects and construction applications. Used for sanitation systems, storm sewers, irrigation, culverts, water management, and treatment plant channeling, reinforced concrete piping is a mainstay in modern city planning and industrial work. RCP has undeniable, proven benefits, including its inherent strength, durability, resistance, cost-effectiveness, and ease of installation.

One major consideration of RCP is its incredible lifespan of over 100 years.

Choosing RCP for construction and industrial applications is the best option for expense, environment, and longevity.

For more High Strength Concrete Pipe Pileinformation, please contact us. We will provide professional answers.

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