Vibrating Pokers & Concrete Pokers
Solid concrete compaction requires reliable equipment you can trust. Once the concrete has been poured into the form, there’s no going back. You need quality, consistent concrete vibration to get the job done.
At Key Services, we specialise in concrete compaction and surface preparation equipment for the construction industry. Our clients and partners include:
- Construction Contractors
- Plant Hire Companies
- Civil Engineers
- Tool Hire Companies
We only supply the highest quality components, for dependable results on every job. Our partnership with Vibtec - the leading UK manufacturer of high frequency electric pokers, ensures premium quality at commercially competitive prices.
We have created this guide to share our concrete vibration expertise and to help you choose the right type and size of poker for every project.
All concrete must be vibrated immediately after placement, to ensure even distribution within the form and to remove air bubbles. Concrete does not naturally flow as a continuous solution, so requires vibration to consolidate the concrete, and to remove holes and voids. Trapped air can total up to 20% of the volume of wet concrete. Without the right type of vibration, the concrete develops a honeycombed structure as it hardens. These air pockets weaken the overall structure and prevent the concrete from adhering to reinforcement bars; compromising the integrity of the concrete.
Proper vibration of the wet concrete using correct techniques will ensure a compact, dense, strong and even finish.
Benefits of concrete vibration include:
- Increased density
- Increased strength
- Improved bonding with reinforcement structures and construction joints
- Smooth finish
The three most common methods of vibration used within the construction industry are:
- Surface vibration
- External vibration
- Internal vibration
Pan or screed board vibrators are clamped onto the surface of the concrete during screeding, either directly, or on metal bars. This method is only suitable for shallow concrete. Surface vibration is used for industrial flooring, pavements and paving slab concrete compaction.
External vibrators transmit vibrations to the concrete through the formwork. They are attached to the form at horizontal and vertical regular intervals and moved progressively. This method is only suited to delicate or thinner areas of concrete, such as archways or tunnel linings. The form absorbs much of the vibration, as this is not directly applied to the concrete, so a higher output of energy is required when using this technique.
This is the most widely used concrete compaction method, used on many construction tasks. Commonly known as pokers, worm drives, pencils, needles, immersion vibrators and high frequency internal pokers, within this guide we will refer to these as pokers.
The poker is plunged into wet concrete and slowly withdrawn at a rate of around 1 inch per second. This vibrates the concrete causing trapped air bubbles to rise to the surface. The distance between immersion intervals is determined by the type and depth of concrete and the diameter of the poker. Each layer of concrete is compacted prior to laying the next, to create dense, smooth results.
Vibrating pokers consist of three primary components:
This is used to convert electric or hydraulic power into mechanical rotary motion. Depending on the amenities and services available at the site, you may have connection to mains electricity, or use an electric motor, an air compressor, or an engine.
This is a durable, steel reinforced protective hose which houses a flexible shaft, and fixes to the drive unit with drive couplings. Shafts are typically available in 5 metre lengths with additional bespoke lengths made to order.
The shaft rotates an eccentric weight supported on bearings inside a sealed reinforced head. This provides highly focused vibration at an optimum frequency of approximately 12,000 vibrations per minute. The head impacts the concrete at high frequency and amplitude, so needs to be capable of withstanding regular use in tough conditions. It is a good idea to keep more than one head diameter available onsite to account for differing job conditions, slump types and form sizes.
These three parts can either be sourced as separate components; providing the flexibility to change poker heads for different tasks, or as a complete unit, ready for action.
Features which indicate quality for industrial use include:
- A detachable nose at the end of the head that can be changed without debris entering the poker.
- Steel reinforcements in the hose to prevent breakage and damage to the shaft.
- An integrated protection system to prevent electrical overload across the entire length of the unit from the moment the power is connected. As concrete pokers are used outside in all weather conditions, user safety is paramount.
Internal pokers are ideal for the following concrete based projects:
Poker heads are available in a range of diameters from 25mm to 75mm, providing effective vibration suited to a host of jobs. Different equipment is required depending on the consistency of the concrete and the size and shape of the form.
The following section provides guidance on choosing the right sized poker head for the task in hand.
For high volume pours - Required for footings and foundations. We recommend a minimum dimension of 75mm. This should provide a vibration capacity starting at around 20 cubic metres per hour.
For civil engineering jobs requiring mass concrete pours - Including bridges, structural supports, floor slabs, foundations and retaining walls. A head dimension of 45mm to 75mm will provide between 10 and 35 cubic metres of quality compaction per hour.
Low volume pours for floor slabs and beams - A head dimension of around 35mm should achieve approximately 6 cubic metres per hour.
Low volume pours for columns, thin beams or thin wall sections - Choose a head dimension between 25mm to 35mm, for in upwards of 1.5 cubic metres per hour.
It is important to remember that efficiency cannot be increased by removing the poker too quickly as this will not allow enough vibration time to remove all the air. Likewise, leaving the poker immersed for too long could result in the concrete mix starting to separate. Use the right size to achieve the right result and don’t be tempted to use a larger vibration head than necessary. This will not increase efficiency but could compromise the quality of the job.
As well as providing you with high performance concrete consolidation, internal vibrators are also portable, for use across multiple locations and jobs. You need longstanding reliability in a tough and heavy-duty environment, so it is important to choose the highest quality available within your budget.
Choosing a supplier who can also provide maintenance will ensure ongoing consistent performance, reducing breakages which lead to delays and extra costs. Great results need constant high levels of vibration on every job. Choosing quality products supported by a maintenance service will give you a better return on your investment in the long term – saving time and money.
Robust reliability in equipment is vital to completing jobs on time to high standards. A guaranteed supply is also crucial – work can grind to a halt if equipment fails. Waiting for parts costs time and money, and causes frustration.
Key Services have over 40 years’ experience supplying construction and civil engineering equipment. To ensure a ready supply of high quality concrete compaction components, we stock a range of British made pokers from Vibtec, alongside a choice of high strength heads.
German brand Wacker Neuson is a well-known brand for concrete compaction equipment in the industry. However, their monopoly in the market means higher prices for end users. Vibtec products are manufactured to the same high quality and specifications, providing an equal level of choice and reliability, without paying a premium just for the brand name.
Here are some of the benefits of supplying British made products from the leading UK manufacturer:
- Guaranteed high quality
- Increased value for money – you could save hundreds of pounds
- Full control over the supply chain, which is shorter and more transparent
- Stock availability without manufacturing delays
- Fast delivery
These benefits mean we can offer quality, on demand, on time.
Electric pokers provide high performance, low noise and no fumes. In addition, the units contain built in frequency convertors, so you can simply plug in and get to work, with no lengthy set up time. It is also cheaper and easier to extend the power cable than a flexible shaft and the light weight, portable hand-held unit can be carried to all areas of the site.
For fast results, with fewer dips, our range of high speed flexible drive pokers and power units provide high power stability and high centrifugal force, for a wider radius of vibration.
- High efficiency
- Low consumption - no refuelling downtime or fuel costs
- High stability
- High performance compaction
- Lightweight and portable
- Low noise
- Fume free
Vibtec’s 160 AX Electric Internal Poker provides safety, strength, power and the versatility to match the requirements of every task at hand. This unit provides a fully integrated combined poker, shaft and drive unit that is durable and resistant to water and dust. A quick release screw assembly enables you to change poker heads easily, with a choice of four head diameters and lengths available.
Features and benefits:
- Poker and drive light weight electric poker system
- Choice of four head sizes 25, 32, 40, 48, 58mm
- Drive length 1,2,3,4,5 metres
- Special high speed quality flexible shaft
- Drive unit hand carried Power Unit
- Double insulated
- IP44 Electro Magnetic compliant
- High impact Plastic Housing
- Quick release screw assembly
- Quick release hexagonal shaft tag
Premium quality at an affordable price. This unit incorporates an aluminium invertor / switch box with a residual current circuit breaker for phase failure and overload protection. Heads and noses are interchangeable, for reduced downtime and ease of maintenance.
Features and benefits:
- Oil resistant, steel reinforced 5 metre shaft with 10 metre cable
- Pokers sizes 31, 39, 50, 58mm
- Polyurethane noses available 110/1/50 and 230/1/50 pokers available
- Robust, heavy duty, heat dissipating aluminium switch box with Marquant Switch
At Key Services we are constantly on the lookout for improved technology to increase on-site performance for our clients. We have recently introduced a premium head to our range, which includes a squirrel cage rotor with copper inserts instead of aluminium. This provides increased strength, higher efficiency and greater corrosion resistance. The heads also feature a detachable nose, which can be changed without debris entering the poker. The head is fitted with temperature sensors and high quality roller bearings. The stator is sealed for 100% water resistance, for full motor protection.
Getting the job completed in a timely manner ultimately comes down to the productivity of your team. Poor quality or heavy vibrating equipment is hard to handle and tiring – meaning more rest breaks or even strains and injuries.
Pokers supplied by Key Services are designed to keep vibrations in the concrete, rather than in the user’s arms and hands. The AX poker includes a specially designed handle to improve grip while reducing hand vibration. The units are lightweight and include built in thermal protection against heat and overload, to keep your team working at peak productivity.
Pokers supplied by Key Services are compliant with the following directives and standards:
- 89/336/EEC Electromagnetic Directive
- 91/368/EEC & 89/392/EEC Machinery Directive
- 2000/14/EC Noise Directive
- BS EN 292-1, BS EN 292-2, BS EN 294 Machinery Safety Regulations
For great results and to ensure the safety of your team, we’ve put together some health and safety guidance, split into two sections:
- General Good Practice
- Safe Operation
- Use the correct size and length of poker head for the concrete form, slump consistency and depth.
- Immerse the head vertically for effective compaction.
- Never allow the head to come into contact with the form surface or reinforcement bars. This will damage both your equipment and the quality of the concrete.
- Compact one course at a time, allowing the head to partially enter the previous course to ensure a solid bond.
- Immerse the head at the correct intervals along the form. This will be approximately four times the head diameter.
- Do not over vibrate – This will cause the aggregate to settle and the water and paste to rise.
- Do not under vibrate – This leaves voids and air pockets which weaken the concrete and damage the appearance.
- Never leave the poker running when not in use as internal bearings may incur heat damage. The poker is designed for operation only whilst immersed in concrete.
- Keep spare vibrator equipment on site to prevent downtime in the event of a mechanical failure.
- Clean all components correctly after use.
- Store equipment in a safe, dry environment when not in use.
- Read all safety manuals and instructions provided with the equipment prior to use.
- Only allow trained personnel to use the equipment.
- Some vibration will be transferred to the user – Learn how to recognise the difference between normal sensations and potential problems.
- Do not attempt to use the poker under the influence of alcohol, drugs, or tiredness.
- Check the condition prior to use – Do not attempt to use if parts are damaged or missing.
- Check all the components have been properly fitted together.
- Wear the correct protective clothing, i.e. gloves, safety goggles, steel capped footwear.
- Never remove seals or protective covers – These are in place to protect the equipment and your safety.
- Never touch the vibrating head while in operation - Hold the hose at least one metre away from the head of the vibrator.
- Never engage shaft to the drive while the power is switched on - This could damage the shaft’s core or cause an accident.
We recommend regular maintenance of all poker components to ensure longevity and high performance on every job. Maintenance should be carried out at least every six months, or for every 500 hours of operation. Maintenance may be required as often as every three months if equipment is in regular or continual use; as is the case for hired equipment, or on lengthy construction projects.
At Key Services, our team of highly skilled engineers are fully equipped to deal with poker maintenance and repair and hold stock of all vital components. Our maintenance service keeps your equipment running for longer, so you can keep your costs down.
Key Services are a family run business with over 40 years of experience supplying and maintaining construction equipment to the industry. Our established services and key partnerships with leading manufacturers enable us to offer you quality equipment and spare parts at competitive prices.
We also purchase from a wide range of suppliers, which means we can always source a product to match your needs. We hold high levels of stock across a range of products, to ensure fast, reliable service and delivery for any concrete compaction job. We also collect from and deliver to any location within the UK.
With our extensive construction industry experience and highly trained teams of engineers, we provide an invaluable maintenance and repair service. Our superior back up service saves you delays, man hours and money over the life time of your equipment.
No job is too big or too small. Orders can be placed over the telephone, by fax, by email or through our website.
Our experienced advisors are always happy to offer help and advice on the right products for the job, prior to advising on options, availability and price.
Call us on: 02476 559770
Fax us on: 02476 559558
Email us: email@example.com
Visit our website: www.keyservicesuk.co.uk
Unit 5 Challenge Close
Challenge Business Park