Conducrete Conductive Concrete

Earthing Services is a brand associate company of FM Sudafix, and for many of its customers Earthing Services is the access point to the FM Sudafix product range.

 

FM Sudafix: The Conductive Concrete Company

saeFMS_logoREDConducrete saves time, money and lives for customers. Being one of the most rigorously tested and trialed products in the history of the electrical safety sector it is independently proven to offer a lower electrical resistance than the historical first choice premium brand. It is also faster to install for two very good reasons, less of it is required to be used therefore less installation time is required, but in many applications it does not even require water to be added. When this is compared to the greater volume required of its main rival, along with potentially other additives as well as water results in Conducrete reducing costs even further. It is no secret that for most large consumers the per bag price may be slightly higher, but buying a cheaper product on a per bag level is an unbelievably false economy. Taking such claims on face value is unlikely in the construction industry and to verify FM Sudafix’s claims one of the largest telecommunications companies in the world tested the product endlessly and not only evidenced a 60% increase in efficiency in the earthing of the deployment, but also a saving of many millions of pounds. Rarely are products as good as people claim, but Conducrete is the exception.

IMG_1053Conducrete is a conductive concrete, which creates safe zones in areas where traditional methods are unsuitable, components stolen, or enhanced safety is required. Conducrete helps to create safe systems where before there would be threats to life. The applications of Conducrete are vast and in a wealth of Earthing Services’ projects it has demonstrated astounding theft-resistance of metallic elements. The versatility of this product makes it difficult to provide an exhaustive list of its capabilities; new applications for Conducrete are being discovered frequently.

Conducrete is provided in powder form and is available in 25kg bags. It is easy to install dry directly from the bag, or mixed with water in a slurry format and pumped into the trench or hole.

Conducrete adds substantial protection to any system where low impedance earthing is required and it has been successfully utilized to enhance and protect earthing systems across many industries including the following: Electrical Utilities, Telecommunications, Broadcasting, Wind Farms, Mining, Oil and Gas, Industrial and Manufacturing, Municipal and Institutional and Military.

Summary of Conducrete’s key features and benefitsConducrete

  1. Protects earthing/grounding systems from theft and sabotage
  2. Environmentally neutral
  3. Significantly extends the life of earthing/grounding systems
  4. Dramatically enhances the performance of earthing/grounding systems for superior electrical and lightning protection for your assets
  5. Excellent overall value

Conducrete addresses the challenges of any environment in terms of electrical safety, protection of valuable elements from theft and superior earthing performance. One of the most versatile products in the sector Conducrete is demanded by consultants who operate at the cutting edge of advancements in the industry.

Aren’t all earthing enhancement products the same?

No. That’s the simple answer. It’s true that many of the other products on the market are the same or very similar. There are a small range of notably different products, some very much worse, and in rare exceptions such as Conducrete better. Why is Conducrete better? Well we have a lot of test data that demonstrates why and how Conducrete is better, and that is provided further on this page. To give an easy summary:

  • It has a lower resistivity – this means that it is more effective at discharging electrical fault current
  • It is significantly faster to install on any horizontal conductor.
  • It requires no additives, plant or water supply.
  • Any claim about its performance is backed up with verified laboratory evidence.

Improved personnel safety: Earthing without rods

CAT scanPrior to driving earth rods into the ground it is industry best practice to undertake a survey of the area using Cable Avoidance Tools (CAT) to ensureRod through cable that there are no buried services that may be located within a proximity of the installation.

Despite this every year there are instances of earth rods being driven through underground services.

The most tragic aspect of earth rods encountering underground services is that it can result in death or significant injury of the operatives installing them. The most lamentable factor associated with that is that it is overwhelmingly likely that an alternative methodology would have negated the need for any earth rods at all.

Earthing Services prides itself on helping its customers and clients adopt methods that do not require earth rods, and can be adapted for shallow excavations and small footprints. An example of this can be seen via the following link:

 

Corrosion protection: Keep your earthing system working

Earthing systems conventionally comprise metallic components, usually being copper or copperbonded steel-cored. Copper is an excellent conductor is a non-ferrous metal corroded rodcommodity, which can make it expensive, but it is the default choice of conductor for many designers and installers. As earthing systems are installed in the ground it subjects any metallic conductors to the soil conditions. If the soil conditions are particularly acidic, alkaline or toxic it can dramatically accelerate the deterioration of those metallic components. If earthing conductors deteriorate they are no longer reliable conductors, and over time they may be completely corroded away as can be seen in this image, which would mean that the system no longer functions as intended if at all.

 

 

 

 

 

Using Conducrete protects encased metallic components from aggressive environments and to evidence this the following test method was used:

accelerated corrosion test schematic

Two identical plates were used in the test, one encased in Conducrete, and one left bare:

bare shim

 

Following the test the bare plate looked like this:

plate without Conducrete

Following the test the plate encased in Conducrete looked like this:

Plate protected by Conducrete

Here we see simple contact scarring of the metal whilst the Conducrete was still in liquid form, after which the molecular bond was formed and no further interaction was required. This demonstrates how impressively effective Conducrete is at protecting against the threats of corrosion or deterioration from aggressive ground environments.

Evidence: Independent laboratory data

Almost without exception earthing enhancement products lack any evidence as to how effective they actually are. That’s another area where Conducrete is different; the product has been exhaustively tested and on every occasion found to be demonstrably superior to the competition. If you are buying an alternative product we strongly recommend that you ask for such evidence from the supplier for comparison.

 

Resistivity:  

 

res report cover

The resistivity of Conducrete is one of its best attributes that help it safely disperse electrical current.

There are a number of other products available in the international market that claim to offer comparable performance.

As part of this test it was deemed appropriate to compare the performance of Conducrete to the most ubiquitous brand of conductive aggregate. It has been available in the market for decades and is often branded on behalf of other companies.

 

The following image demonstrates the methodology adopted for the test.

 

 

 

 

 

Res method

The tests undertaken over a number of months produced the following results:

res results

The results demonstrate that Conducrete remained the most stable method and achieved the lowest resistivity, which was confirmed in the conclusions of the report:

res conclusions

 

 

Compressive strength:  

Compressive Strength Report

As Conducrete is a conductive concrete it is logical that customers or stakeholders would want to be confident that it was strong enough as well as being a high performance earthing compound.

The compressive strength of structural concrete begins at 17MPa and can be produced commercially up to 138MPa. Residential and light commercial building projects typically use concrete strengths ranging from: 17MPa to 34MPa.

At 32.5MPa (32,500Kn/m²) a standard bag of Conducrete mixed in the appropriate ratio with water can achieve sufficient compressive strength to be used as both a structural foundation, and an earth termination network, and this has been assessed as viable for earthing substations and many other structures or infrastructure.

A further usage of Conducrete where it relies on its structural strength is in the “sub-base” methodology that has been adopted by many customers. For more information please either look lower on this page or use the following link:

 

 

 

 

 

 

 

 

 

Impact resistance:  

Impact report coverEarthing systems almost invariably incorporate some variety of copper component. Because copper is a non-ferrous metal it is an attractive commodity to steal, this being the case protecting an earthing system from the genuine threats posed by thieves is a logical and legitimate concern.

Copper theft is an endemic issue, but as an industry we repeatedly install it in ways which thieves predict and know how to overcome.

The performance of electrical safety systems may result in people living or dying. We need to create not only a system which works, but will be robust enough to still exist for years to come, and that has to include addressing theft prevention.

The Association of Chief Police Officers (ACPO) estimates that copper theft costs the UK economy in excess £770m per year. The British Transport Police consider copper theft second only to terrorism in terms of severity and priority to address.

One of the requirements of the Construction (Design and Management) Regulations 2007, identifies the need to plan, manage and act to ensure the protection of the public, including trespassers. We as designers recognise our duty of care to our clients: If there is a better way of doing something we do it.

We need to offer those segments of society who may be tempted to steal as much of a disincentive within the constraints of our remit to design, supply, install and maintain electrical safety systems: part of the answer is Conducrete. Not only is the process of stealing copper from electrical systems incredibly hazardous to the thieves perpetrating the crime, it can expose engineers or the public to dangerous fault current. In less severe outcomes it can easily result in operational downtime for a site or infrastructure, and if the site is in a remote location it could extend that operational downtime and exposure to dangerous fault current for excessive quantities of time.

To demonstrate that Conducrete is highly efficient at protecting encased copper components a study was commissioned to ascertain how difficult it would be to extract encased metallic components.

SledgehammerA sample of cast Conducrete was repeatedly subjected to mechanical impacts from pick axes and sledgehammers, both from above and the side and in a range pickaxeof different temperatures.

It is pertinent to note that in no practical application would Conducrete be unsupported, and exposed on all four sides, so such destructive tests are only achievable in a laboratory.

In a real life scenario the conductor is overwhelmingly unlikely to be exposed in air on all surfaces simultaneously.

 

Impact evidenceAs such even the superficial damage identified on the product is unlikely to occur in a theft attempt on a live site.

It is pertinent to note that in no practical application would Conducrete be unsupported, and exposed on all four sides, so such destructive tests are only achievable in a laboratory.

As the conclusions of the report state Conducrete offers effective protection against the threats presented by thieves.

 

Impact conclusions

 

Thermal Shock:  

shock coverThermal shock is a concern when determining suitable conductors for an earthing system. In much the same way as friction generates heat when two physical shock rigobjects are rubbed against each other, when electrical current is passing through a media it will increase temperature.

Conductors must be appropriately determined to be able to withstand the prospective rise in temperature, which will be determined by assessing the fault current it will likely experience, and for the length of time it is required to hold it.

It is all too common to hear of companies installing an earthing enhancement product on the presumption that it will appropriately manage the thermal shock risk posed by a site’s risk profile without evidence to confirm this.

Conducrete has been independently tested to verify its suitability for withstanding high current thermal shock and the following extract from the report demonstrates its effectiveness.

 

 

 

shock conclusions

 

 

 

 

 

High Current Density Shock:  

Kinectrics logo

 

Current density is the electrical current per unit area of cross section. High current densities have undesirable consequences. Most electrical conductors have a finite, positive resistance, making them dissipate power in the form of heat. The current density must be kept sufficiently low to prevent the conductor from failure.

Clause 9.8 of BS 7430:2011+A1:2015 Note 1 states “…Failure of an electrode to meet its purpose is fundamentally due to excessive temperature rise at the surface of the electrode…” Note 2 continues this point “…as soil moisture is driven away from the soil-electrode interface, the resistance increases and will ultimately become infinite if the temperature rise is sufficient. For short-duration loading this occurs in the region of 100°C and results in complete failure of the electrode.”

In the event that conductors cannot sufficiently manage high current density they can become dangerously unstable, and other earth enhancement materials of lower compressive strength have High current density shock testexploded under these test conditions. On a live site that would render the protection system useless and potentially significantly dangerous.

Independent testing was undertaken at Kinectrics Laboratories in which a 1682V/688A charge was passed through a cast block of Conducrete.

Under these test conditions Conducrete achieved a current density of 1,074 A/m² on the above test block (the dimensions of which were 150mm x 150mm x 1400mm, a
13.25mm diameter copper conductor was placed lengthwise down the middle of the sample).

A similar study on copper at Newcastle University determined that a 1m length of 40 x 4mm² solid copper conductor achieved a current density of 438 A/m².

The Conducrete in this example has a significantly greater current density carrying capacity than 40 x 4mm² solid copper conductor. During the curing process Conducrete forms a molecular bond/mesh with adjacent material, which enables it to more efficiently disperse fault current. On a live site where the product is able to interface with the surrounding ground mass (not exposed in air) it would enhance experienced performance.

 

 

Environmental attributes:  

On any variety of construction project consideration should always be given to the impact of the site on the environment, and this must also consider the products, methods, and resources used, future resource consumption and maintenance work.

To ensure that Conducrete is sensitive to environmental impacts it was tested by Accuracy Environmental Laboratories Ltd. in Canada to NSF/ANSI Standard 60, Section 8 for backfill applications with a maximum diameter of 12 inches and a maximum aquifer contact depth of 20 feet with an assumption of a minimum ½ acre aquifer (293,760 gallons) of 25% porosity.

leachate image

Leachate Data (TCPL Procedure) based on Regulation 558 performed by Accuracy Environmental Laboratories Ltd. Demonstrates that Conducrete is environmentally neutral.

Leachate table 2

 

Leachate table 1

The following conclusions were reached:

  • Conducrete is environmentally neutral.
  • It sets up in situ to from a solid that does not leach, dissolve or migrate into the soil or water.
  • Conducrete may be installed dry or mixed with water to form a slurry for horizontal or vertical applications.
  • Conducrete® meets NSF/ANSI – Drinking Water Treatment Chemicals – Health Effects (http://info.nsf.org/Certified/PwsChemicals/Listings.asp?Company=C0169859&)

 

The Conducrete “sub-base” approach

DSLAM2

Using Conducrete beneath foundation slabs is a highly effective, cost-efficient and practical way to achieve a reliable resistance within a shallow excavation and within a restricted footprint. This “sub-base” approach has been enormously popular with every client that has adopted it.

This approach is useful for all manner of varieties of infrastructure and because it doesn’t require any additional plant, equipment or specialist training. It removes unnecessary additional costs, time-consuming methods, or standing time on site.

This common Conducrete earthing methodology can be seen on a real project in the following images:

 

 

 

 

 

 

“Sub-base” installation overview

In applications where a foundation is required for telecoms, signalling or other infrastructure element dig an extra 50mm.

1. In applications where a foundation is required dig an extra 50mm in the excavation.

Place the required number of bags of Conducrete in the excavation.

2. Place the appropriate quantity of bags of Conducrete in the excavation.

3. Carefully empty the bags of Conducrete into the excavation. As the product is a fine powder appropriate PPE should be worn. We recommend using a craft knife along an edge and then carefully dispersing the product to an equal depth.

3. Carefully empty the bags of Conducrete within the excavation. Appropriate PPE should be worn because the product is a fine powder. We recommend running a craft knife along an edge and then carefully distributing the product.

4. Ensure that the Conducrete is evenly dispersed.

4. Ensure that the Conducrete is evenly distributed.

5. Place injection current cable into the Conducrete. This is usually a 16mm² copper wire loop with a tail to be placed in a duct to the infrastructure earth point, and tails for any adjacent earthing configuration (see image 8).

5. Place a suitable injection current conductor into the Conducrete. This is usually a 16mm² copper wire loop with a tail to be placed in a duct to the infrastructure earth point, and tails for any adjacent earthing configuration (see image 8).

6. Ensure that the injection cable is fully submerged within the Conducrete (with the exception of any to be located in ducts). This will protect the cable against corrosion and theft.

6. Ensure that the injection conductor is compeltely submerged within the Conducrete (with the exception of any to be located in ducts). This will protect the cable against corrosion and theft.

7. Redistribute any displaced Conducrete to ensure that it remains evenly distributed.

7. Redistribute any displaced Conducrete to ensure that it remains evenly distributed.

8. Place Conducrete in any interfacing trench; these are commonly excavations for interconnecting ducts.

8. Place Conducrete in any interfacing trench; these are commonly excavations for interconnecting ducts. If the foundation is for a piece of standalone infrastructure please skip to photograph 11.

9. Carefully distribute Conducrete in the interfacing trench.

9. Carefully distribute Conducrete in the interfacing trench.

10. Ensure that the Conducrete in the interfacing trench is evenly distributed.

10. Ensure that the Conducrete in the interfacing trench is evenly distributed.

12. Carefully reinstate a layer of native soil. The Conducrete will start to harden as it comes into contact with the native soil, but care should be taken to avoid mixing the layers (a way of thinking of this approach is like forming layers in a trifle). Once a complete layer of native soil covers the Conducrete the area should be manually tamped/compressed.

11. Carefully reinstate a layer of native soil over all of the installed Conducrete. The Conducrete will start to harden as it comes into contact with the native soil, but care should be taken to avoid mixing the layers (a way of thinking of this approach is like forming layers in a trifle). Once a complete layer of native soil covers the Conducrete the area to a depth of 25mm it should be manually tamped/compressed.

The advantages of this methodology over conventional methods are:

  • Incredibly fast
  • Incredibly easy
  • Incredibly effective
  • Avoids the use of rods
  • Unlike other earthing enhancement backfills it does not require any additive or even water for this methodology; this means no need for mixers or any other specialised plant equipment.

If you would like to learn more about Conducrete or how it may be used on your project please get in touch with our Nottingham office, or complete the online contact form of this website.