Advantages

The patented PileMedic® system is the latest technology for encapsulation, repair and strengthening of piles and columns. 

We invite you to watch videos of some of our projects to appreciate the ease of installation of this amazing versatile product.

The system works equally well on all materials including steel, concrete, and wood or timber.  These FRP laminates are constructed with multiple layers of carbon and/or glass fabrics pressed together and passed through a specially-designed equipment that applies resin under pressure and heat to form a solid thin flexible laminate.  The laminates can be used to repair and strengthen deteriorated and/or corroded columns in railroad and highway bridges, buildings, industrial facilities and underwater piles in coastal structures and piers.

The PileMedic® system offers the following advantages compared to other conventional materials and methods for repair of columns and piles:

  • 3-4 times stronger than steel
  • Fastest repair & strengthening system with no traffic control!
  • Increase axial capacity beyond original strength of column
  • No weak seams along height offers uniform confining pressure (360°)
  • Provides structural confinement
  • No costly divers for underwater repair
  • Does not corrode
  • No metallic parts
  • Grout or resin can be pressurized to penetrate all cracks and crevices
  • Available in carbon or glass
  • Works equally well on concrete, steel and wood or timber piles and columns
  • One size fits all piles (no delays for customized jackets)

In the following, each of these advantages will be discussed in more detail.

PileMedic® laminates are considerably stronger than steel .  Typical mild steel has a tensile strength of 36000 psi; on the other hand, PileMedic® laminates have tensile strength ranging from 60,000 to over 155,000 psi!  The strength of PileMedic® is significantly higher  than ALL other pile jacket systems in the market.  Below is a comparison of some of the mechanical properties of PileMedic® with other pile jacket systems obtained from those manufacturers' published literature.  As can be seen PileMedic® is as much as 10 fold stronger than some of the jacket systems used to date!
Products Tensile Strength, psi (MPa) Modulus of Elasticity, ksi (GPa)
PileMedic® PLC150.10
156,000 (1,080)
13,800 (95.5)
PileMedic® PLC100.60
101,000 (698)
7,150 (49.3)
PileMedic® PLC60.60
62,000 (431)
3,500 (24.1)
Five Star PileForm F
20,000 (137.9)
780 (5.4)
Five Star Rock Water
16,000 (110)
780 (5.4)
Fox Industries FX-70
15,000 (103)
700 (4.8)
Denso SeaShield Series 400
15,000 (103)
Not Listed
BASF APE Translucent Jacket
10,000 (69)
Not Listed
MFG FRP Pile Repair Sleeves
20,700 (142)
940 (6.5)

Strength Comparison of Pile Jackets

Because PileMedic® laminates are manufactured in our plants, little time is needed in the field to complete the repair of columns. This allows PileMedic® to be the fastest repair and strengthening system on the market.  In many cases, deteriorated bridge piles can be repaired without any need for traffic control. Likewise, in industrial plants, corroded columns can be repaired quickly with little disruption to the operations of the facility.

It is a well-established fact that lateral confinement of concrete or grout significantly increases its compressive strength.  This increase is expressed in the following mathematical equation:
ff' cc =f' c +4.1 f l
where the terms are defined as follows:
f' c = compressive strength of grout (unconfined)
f l = lateral confinement pressure offered by the jacket
f'cc = compressive strength of the confined grout

The gain in axial load capacity of a pile as a result of this confining pressure can be best described in the following example.

Assume a square 12x12 inch square pile is constructed with 4000 psi (28 MPa) concrete.  For simplicity, the contribution of any steel rebars that may be present in the pile are ignored in this example.  The axial capacity of this pile is calculated as:
P = 0.85 x (4000 psi/1000) x (12x12) = 490 kips (2180 kN)

Alternative 1: Next, assume that the square pile is encased in an ordinary 18-inch diameter cylindrical shell/jacket and the shell is also filled with a 4000 psi (28 MPa) grout.  Because all jackets used to date are weak and have one or two seams along the height, these jackets offer virtually no confining pressure to the pile.  In other words, the bolted or glued seams in these jackets are the weakest link in the chain and will fail very early on under the smallest internal pressure as the grout dilates outwards. Thus,in this case, the axial capacity of the retrofitted pile will be:
P= 0.85 x (4000 psi/1000) x (9x9x3.14) = 865 kips (3848 kN)

Alternative 2: Assume that the above pile is encased in a 2-ply PileMedic® laminate with a tensile strength pf 155,000 psi.  Note that the thickness of this 2-ply laminate system including the epoxy that will be applied in the field will be less than 0.08 inch (2 mm).  Nevertheless, this seamless jacket offers a confining pressure of:
f l = 2 plies x 155000 psi x 0.025 inch thick/(18 inch/2) = 860 psi (5.93 MPa)
The axial capacity of the square pile encased in PileMedic® jacket will be:
f'cc = 4000 +4.1 x 860 = 7525 psi (51.88 MPa)
P = 0.85 x (7525 psi/1000) x (9x9x3.14) = 1626 kips (7233 kN)

Thus, as a result of the confining pressure offered by the PileMedic® jacket, the pile carries an additional 761 kips (3385 kN) of axial load!!

As shown to the right, all pile jackets currently available on the market contain either one or two rows of bolts along the height or a tongue and groove seam that must be epoxied in the field.  These seams introduce planes of weakness in the jacket because not only water and oxygen can enter the jacket at these points, but the seams also prevent the jacket from applying any confining pressure on the pile and the grout. Pile Jackets with Two Bolts and Epoxied Seams

The newly developed PileMedic® is the only product on the market that allows construction of a seamless cylindrical shell around an existing pile or column. The absence of the seal means that the jacket has a uniform high tensile strength at all points around its 360 degree circumference.   As the pile and grout is loaded in the axial direction, the concrete and grout dilate and tend to expand outward.  However, the presence of this high strength jacket prevents that lateral expansion and applies an opposing confining pressure to the pile and grout.  As calculated above,this confining pressure results in significantly higher axial capacity for the pile. Square Pile Jacket Installation

Click above to see the PileMedic® installation process.

It is possible to start the process of wrapping the PileMedic® laminate around the pile at or above waterline.  Once the laminate is wrapped a couple turns, then the finished part of the jacket can be lowered into water while additional new parts are created.  This process allows making long jackets in the field that extend below waterline without the need for divers to assemble the shell underwater.

There may be a need for divers to seal the bottom of the annular space between the pile and the jacket.  However, this can also be achieved by attaching a deflated small inner tube (similar to a bicycle tube) to the inside face of the jacket.  Once the jacket reaches its final position, the tube can be inflated to create a seal at the bottom of the jacket.

Many of the existing jackets require steel straps or bolts to hold the jacket together. These hardware must be either constructed with stainless steel which adds to the cost or it will corrode in time, resulting in additional maintenance costs.

Piles Repaired with Jacket and Steel Straps

With conventional jackets, the grout is placed in the annular space, leaving the cracks in concrete or the voids in the wooden pile unfilled; this will result in a continuation of the deterioration of the pile.

On the other hand, the seamless jacket created by PileMedic® allows the grout or resin to be pressurized.  For example,when a cracked concrete pile or a timber or wooden pile is being repaired, it is possible to fill the annular space with a low viscosity resin.  This resin can be pumped under pressure, forcing it to penetrate all the cracks in concrete and the crevices in wood or timber.  At the end of the repair, we will be left with a solid durable pile.

For repair of wooden utility poles or timber railroad bridge piles, this procedure results in a solid pole or pile with no voids.  This will not only make the pole or pile stronger than the original pole or pile, but will also prevent any bugs to cause decay of the wood or timber in the future.

Confinement Effect on Pile with PileMedic®

PileMedic® laminates are constructed with either carbon or glass fabrics.  The laminates can be customized to include multiple layers of unidirectional or biaxial fabrics based on the project design requirements.

It is generally accepted that contact between carbon and steel must be prevented as this could result in galvanic corrosion.  In practice this is achieved by applying a layer of glass fabric as a barrier over the steel and carbon fabric.  In construction of PileMedic® laminates a thin glass veil is included on both faces of carbon laminates.  Therefore, all of our laminates can be directly applied to any pile whether made with steel or other materials.
SuperLaminate

The jackets available to date, whether cylindrical or square, have to be custom-made for each project.  Obviously this creates scheduling problems for the contractors to order the jackets well in advance of the project so that the jackets can be constructed.  Furthermore,any jacket that does not fit the piles must be returned, adding cost and delay to the project. Another problem with these jackets is that as shown here, the jackets are bulky and require significant space for storage and transportation. Transporting Bulky Pile Jacket

In contrast, PileMedic® jackets are supplied in boxes that typically contain a 4-ft wide x 300-ft long (1.2 m x 91 m) roll of laminate.  These boxes can be stored in little space and each box has enough laminate to create a large number of jackets in the field.  More importantly, since the jackets are created in the field directly on the pile, they are guaranteed to fit and there will be no concern about advance ordering to custom-build the jackets or the need to return any jackets that do not fit.  Lastly, the laminates allow the contractor to create a jacket with the smallest annular space.  This significantly reduces the labor and materials cost associated with mixing and placing of grout in the field.


Square Pile Jacket