CPCS A44 Concrete Pump – Trailer Mounted Course

1. Introduction

The CPCS A44 Concrete Pump – Trailer Mounted course has been designed to enable operatives to gain an understanding of the knowledge and skills required to operate a trailer-mounted concrete pump safely and productively. The Health and Safety at Work Act, other relevant regulations, and their approved and current guidance will be adhered to. This course is aimed at people who have previous experience of operating plant machinery and have been working in the construction industry for a minimum of 6 months. The CPCS A44 course is for anyone who uses or will be using trailer-mounted concrete pumps. It is ideal for those operators who have attended a novice course and have sufficient practical experience operating a pump to be ready for a theory and practical technical test. There are currently a few ways experienced workers can gain a Red CPCS Trained Operator Card. Experienced Worker Practical Assessments – For those that find a Testing and NVQ route difficult due to language or literacy skills and those who feel their current experience meets the required standard. This option is also beneficial to employers with workers that are CITB Grant eligible. This is because a full grant is available to registered employers with eligible employees. Full details can be found on the CITB website. The second option is a combined NVQ and practical assessment route. This tends to be the most cost-effective and beneficial route for both parties. The CPCS qualification forms a part of the NVQ, and the experienced worker does not have to take any further theory or practical tests. Should the worker require a Red CPCS Trained Operator Card, he will need to pass the CPCS Technical Test (Theory and Practical). This card is valid for 2 years and is not renewable. When the NVQ has been passed, the operator will be able to part exchange his Red card for a Blue Competent Operator Card, which is renewable every 5 years. This proves more cost-effective than the alternative route in the long term.

1.1. Course Overview

This course covers the skills and knowledge required to prepare and operate a mobile concrete pump. The course duration is three days for inexperienced operators and two days for experienced operators. This is a test programme, so please refer to the CPCS Scheme for details of accreditation. This course will enable candidates to be aware of the scope and nature of the occupation and the needs of the industry. This course leads to a CPCS assessment and to obtain the Red Trained Operator Card. With the endorsement that as this category is a testing programme to prepare candidates for the assessments, it is not a direct route to the blue competent operator card. This course will enable experienced operatives to relax and enjoy learning in an informal way, but with the focus on passing the CPCS tests. Theory and practical topics are discussed and reinforced in a step-by-step process. Candidates will learn so many new things and reinforce so many current practices. It is not important that operators learn by our way, but the yes answer reveals to many that operators need more education. At the end of the course, candidates will have the knowledge to tackle the CPCS categories technical test, theory test, and practical test. This course is for mobile concrete pump operators only and is not designed for static pump or piling rigs. These operators will have to wait until testing programmes are introduced for each of these categories.

1.2. Benefits of the Course

The flexibility of the CPCS scheme means that experienced workers can get their red operator card by just taking the theory testing element of the NVQ in Plant Operations. The CPCS then allows a 2-year grace period for completing the NVQ Level 2, during which time workers can operate machines on a blue competent operator card. This is great for workers and businesses who may not have the time or resources to commit to a full NVQ but still need to prove their competence. In today’s increasingly safety-conscious environment, the demand for NVQ qualified workers and competent operator cards is only likely to increase.

By sending your employees on a CPCS training course, you will make a valuable contribution to their ongoing professional development and provide them with a nationally recognised competence qualification. However, it will also bring great benefits to your business. This qualification will guarantee a high level of operator performance, whilst minimising the risk of accidents on site. It will also lead to increased productivity and less downtime since operators will have a good understanding of the machines and be able to apply this in their work. On obtaining their red operator card, your employees will have proof that they have been trained to the required national standard. This is often crucial evidence when tendering for contracts and providing an auditable health and safety record.

1.3. Target Audience

The course is aimed at the operators who have at least 6 months experience in operating a concrete pump. The course will also cater for those with limited experience, and those who are in supervisory roles of these operations. Manager and foremen of these operations would benefit from understanding the roles of their operatives, and learning the regulations their operations must adhere to. Both practical and theory training as well as assessment packages have been designed in this course. This course is aimed at experienced workers to complete their practical and theory assessments on a multiplicity of machines. This includes operators with transient experience wishing to consolidate their training efforts on one of these machines. This is a very thorough examinable course. Experienced workers are encouraged to familiarise themselves with the CPCS technical test. This will allow an on sight assessment with a CPCS Tester at any time during the RED card life span. This option will be favourable to those whose learning pattern is more spread out over time, or those who do not wish to undertake a formal training course. A theory test can be skipped if the candidate feels competent. This would require the request of a theory test paper, and a sealed envelope to return the completed test to the Training Provider for marking. Evidence of original theory test and a completed practical assessment will be sent to the National Plant Operators Registration Scheme (NPORS) who will then issue the relevant card. This course is intended to be delivered as a Foundation modern apprenticeship in collaboration with the Construction Plant-hire Association (CPA) and CITB. This apprenticeship targets new entrants to the Craft and Operative sector. It is aimed at 16-24 year olds and up-skilling the existing workforce to make the operatives and the industry employer more competent and professional. This is a standard of proficiency that is desirable for those in or about to enter into the plant hire sector. An experienced worker aged 25+ will also benefit from this structured competency learning package which targets NVQ Level 2 of the Plant Operations NVQ/SVQ.

2. Safety Precautions

Steel toecap safety boots, hi-vis jacket, hard hat, and safety goggles must be worn at all times. No operatives are allowed to wear shorts on site. Gloves must be worn when using the hose. Failure to use the correct PPE will result in that operative not being allowed to work the machine. All PPE must conform to the relevant British Standards and be CE marked. This will be checked on site. Any PPE considered to be substandard or damaged will not be allowed. If there is a failure to comply with this regulation, the machine will be shut down, and that operative will be removed from the site until correct PPE is obtained. If there is any incident involving injury to the operative, CPCS A44&47 (NPORS) will investigate, so it is in the operatives’ and the employers’ interest to adhere to this. If there is any machinery entering a site, it is the operatives’ and employers’ responsibility to check it complies with the Supply of Machinery (Safety) Regulations 1994. If this is the case, the inspector’s guide will be a useful tool to ensure you comply. This will involve checking the machinery has a CE mark, instructions in English, is right for the job, and at the right risk. The type of work and location will determine the general hazards that could face the site. These tasks will involve potential hazards to the surrounding public and other site operatives. It is important to locate these hazards and adequately control the risk. A hazard is anything that could cause harm. Site location and type of work may often dictate that others at risk will use the site as a thoroughfare. Precautions must be taken to cordon off areas for the public, and if this is not possible, place a signaller to use as a warning system for machinery operators. Where the public has access to the same area as a Telehandler, a physical barrier may need to be used as a control measure. The main hazard when concrete pumping is involving people working near the placing hose, usually with screed or to try and rectify any mistakes. The force of the pump can cause the hose to violently move in unpredictable directions. This could prove to be fatal if a hose comes into contact with a workman or trips someone down a flight of steps. To reduce this risk, it is best to put the people around the hose on the pump safety awareness course so they are aware of the dangerous areas and best avoidance should trouble occur.

2.1. Personal Protective Equipment (PPE)

Health and Safety at Work Act 1974 requires employers to protect the health, safety and welfare of persons at work. This includes consulting with employees, and where there is a recognised hazard, providing and maintaining a safe work environment. The review and development of this unit was detailed for the variety of tasks and conditions a trailer mounted concrete pump operator may be expected to work in. The following is a guide to reduce the risk of injury when operating a trailer mounted concrete pump. All employees were consulted for the hazards and risks associated with the tasks and conditions of operating a trailer mounted concrete pump. Input was gained from a series of discussions and site visits with large and small concrete pumping contractors and a plant hirer. A draft document was prepared and circulated to employees for review and comment. Any comments received were incorporated into the document where practicable. In practice this was an ongoing exercise throughout the review and development process. Where comments were not incorporated it was due to conflicts with other sections of CPCS (in which case the other section was deleted or modified) or where comments were conflicting or impractical. An example of this was a suggestion to wear a harness and safety line for all tasks above ground level. Feedback was also obtained from a construction health and safety consultant and where practicable, was incorporated. Suffixes were added to some clauses stating the varying levels of risk, to enable a more specific requirement without the need for a separate clause for high, medium or low risk. E.g. (L) – task, condition or site with low risk. The final document was again circulated for review and comment and was developed into an A3 format as a readily accessible reference. Well labelled hazard identification signs with designated areas for specific task hazard assessment are available in the CPCS A33/44/45 Technical Test and NVQ.

2.2. Hazard Identification

The concrete pump itself is popular put to use in moving large volumes of concrete. It’s also true to say that the entire concrete pumping industry is driven by the will to move concrete from point A to point B as quickly as possible. Because of this production-driven mentality, it is often said that the industry is hasty and this can lead to cutting corners and unsafe work practices. Analysis of accident and injury reports from job sites paints a picture of an industry where the pace of work and lack of understanding of safe work practices has led to a high rate of incidents. In identifying and evaluating potential hazards for concrete pumpers, it is best to start by looking at the factors that have led to accidents from other similar types of work.

When in the process of concrete pumping, hazards are inevitable. It is how they are dealt with that can affect the severity of the consequences. It is best to find the hazards before they become a reality and this comes from hazard recognition. No pumping job is without hazards. Pumping concrete is an extremely tough job and to be effective it requires a strong, healthy and determined workforce. People are the most valuable resource in the concrete pumping and placement industry. But their work in the industry can cause it to take a costly toll on their bodies in terms of physical and mental health if they are not aware of the potential dangers and are not making an effort to work safely.

2.3. Emergency Procedures

If the emergency services decide to evacuate or remove the casualty, the area where they were working or the plant was operating must be made safe and suitable for work to be resumed.

In a medical emergency: – Where possible, turn off the machine and make the area safe. – Dial 999 or 112 and ask for an ambulance. – Give clear directions to the site and nature of the emergency. – Continue to give first aid to the casualty. – Inform the persons in charge of the work-site.

If there is an emergency, the concrete pump operator must: – Make the area safe. – Isolate the plant to prevent further injury or damage. – Inform the person in charge of the work-site. – In case of serious injury dial 999 and make arrangements for medical assistance. – First aid boxes should be provided on site and each vehicle should carry a first aid kit. – First aid should be administered by a trained first aider. All serious injuries must be reported to the relevant enforcing authority.

3. Equipment Familiarization

3.1 The primary components of a “typical” trailer-mounted concrete pump are the (material) receiving hopper, the concrete pumping unit, the placing hoses, and the attachment and any associated equipment. The well-known Rock Valve is mainly a concrete flow control valve mounted underneath the hopper which is designed to offer a more constant and controllable flow of concrete, giving less wastage of mix. Concrete pumps up to 30 cubic metres per hour receiving a 4″ pipe will not require the Rock Valve as the flow of mix is not overly fast and is more controllable. Some Rock Valves are operated hydraulically and some are electrical. Electrical valves can only be operated when the pump is running as it is powered by the pump’s electric supply, whereas hydraulic valves can be operated at any time.

3.1. Components of a Trailer Mounted Concrete Pump

Functional testing of the unit can be carried out to prolong battery life and prevent battery failure at a critical time on site. The control unit is the most delicate part of the pump machine and should be stored in a dry, dust-free environment to prevent electrical and mechanical failures. Regular inspection of the control unit’s electrical components and wiring should be carried out primarily to inspect for water damage.

The control unit incorporates the prime mover control, which is usually a cable or servo-operated lever on the diesel engine providing manual control of the throttle to provide a constant speed for the engine. Other functions on the control unit may include control levers for directional control of the pumping ram, control for the agitator, and an adjustable pressure control for the different hydraulically driven devices.

Adequate shelter and washing down the machine or carrying out maintenance under the cover of a waterproof canopy will prevent water damage for sensitive electrical components. The control unit on a concrete pump is a versatile device used for a number of different functions. Control units can vary from a simple direct mechanical linkage to a complex and sophisticated remote control unit. The remote control is a device separate from the main control unit, which enables the operator to control the pump at the placing site. The remote control unit is very useful when the placing site is a long distance from the pump unit.

Daily, weekly, and monthly maintenance checklists are usually provided with the machine’s operating and maintenance manual. These checklists are designed as a basic guide for the operator and can be modified to suit specific job site requirements. It’s a good idea to make copies of these checklists to use when on site.

It is important for the operator to be familiar with his machine in order to provide a safe and efficient service. An efficient operator will understand and know how to maintain his machine, he will also recognize when the machine is not working as it should and be able to identify any problems or malfunctions. Regular maintenance and inspection is the first step in the process, to prevent premature failure, machine downtime, and costly repairs. Regular maintenance is the key to prevention.

This subject area is outlined into 3 main headings which are: a. Trailer, the prime mover to the pump unit. b. The control unit, usually diesel engine drive of various hydraulic pumps. c. The pump unit, usually self-contained on the trailer and capable of minimal assembly at the job site.

3.2. Pump Maintenance and Inspection

Concrete pumps require regular maintenance for it to be an effective tool in placing concrete. If the concrete is highly abrasive, the interval will be shortened to as frequent as 200 hours. There are a number of components that some suppliers may consider to be ‘consumables’; often these are wear parts that do not need replacing every time. Pump priming times should be checked and recorded to provide indication of wear in the fluid end components. Leakage from the rams and pistons can be expected and will increase the priming time. The following is a guide. Note that CPCS is not a maintenance or repair procedure manual and the following stated is not exhaustive. After a daily operation: As with the prime-assist units, the water supply tank, valve, and hoses should be flushed through. Close the material valves and then continue to pump water until all material is flushed before stopping the engine. This should take no longer than 10 minutes. Provides air and water line with 100 psi constant pressure. Check the data plate to prove the current working pressure.

3.3. Operating Controls

The concrete pump operating panel on the electric pump is simple and is used to control the flow rate of concrete by adjusting the amps on the electric motor. The lever should always be in the forward position, indicating that the machine is operating. This can be moved to the center to put the machine into bypass. In this position, the electric motor will still be running, but the pump will not be working. The amps should be slowly turned up to the position at which concrete is being pumped effectively. Care should be taken not to over-amp the machine when pumping. If this is occurring and the machine stops pumping concrete and is making a loud noise, stop the machine and reduce the amps. Allow the machine to run for a few seconds to regain its primed state before continuing with pumping.

The electrical drive electric start engine ignition is turned on by turning the key in a clockwise motion. As the key is turned, the operator must look at the ignition indicator on the control panel. Two red lights will appear if the start sequence is out of order. This can be corrected by turning the key off and then repeating the start-up procedure. Four green lights and one red light indicate that the engine is ready to be started. Before starting the engine, make sure the truck P.T.O is disengaged and the mixer is not in operation. The engine start button is then pushed to start the engine. Under the engine start button is the emergency stop button. This acts to immediately cut the power to the engine ignition and stop the engine. To stop the engine, simply push the engine start button again.

The operating controls of the concrete pump are simple and straightforward, but it must be remembered that during operation personnel are involved in the direct flow of concrete and an understanding of how to stop the machine and/or emergency stop the machine is essential.

4. Concrete Pump Operation

Starting the concrete pump. There are two types of concrete pumps, those with and those without the necessity of a flexible hose being attached to a placing boom. A digout occurs of the ground to allow for the pump and lorry to be level whilst working. A steel plate is then placed on the floor of the digout to house the pump, for pumps with booms one end of the plate will have to be dugout by 400mm and will some have wedge-shaped pins to help keep the plate stable. If the concrete is to be pumped through the double gate on the pump unit the pipe rack will have to be removed to allow enough room to take the pipe around the back of the trailer. On arrival to site non-road tow units can be winched off the lorry and manoeuvred into a suitable working position using towing eyes situated on the pump unit, road tow units can be disconnected from the lorry (after chocking the wheels) and then manoeuvred into position using the towing eye located on the trailer drawbar. An articulated lorry can disconnect from a trailer and move out of the way to save time whilst the pump is being set up. Once in a suitable position, the pump can then be set up ready to begin. Concrete can be pumped in two ways, either directly into the hopper of the pump or into the section of pipe between the pump and boom (otherwise known as the detention hopper). Most pumps can pump mix on the lowest slump specified and some larger models can cope with high volume pours. Smaller output pumps will struggle to cope with high volume pours and high slump mixes. Pumps without a detention hopper will have a pair of metal or rubber clamps on the last section of the boom where pipes can be attached, this pipe will then be clamped to the boom and lowered into a trench to reach the footings for pushing through houses and reaching over drains. Detention hoppers can also be used with pipe for reaching over houses, this allows the pump to be set up a distance away from a building or garage and the concrete to be taken to the pump and pumped from the hopper.

4.1. Setting Up the Pump

The first job in any project is to site the machine in a suitable position. Try to ensure that level ground can be found so that the machine, when level can function correctly, it can work on uneven ground, but shimming will have to be done and this slows down the setting up procedure. Block the wheels and level up the machine with the screw jacks provided. An unevenly leveled machine will cause the hydraulic pumps and valves to cavitate (starve for oil) and this will result in sluggish operation, and loss of hydraulic power. Failed levelling here is the most common problem encountered. Ensure the machine is completely levelled up. A spirit level placed on the hopper will indicate the correct position. Now set up the delivery pipes, ideally these should be supported every metre by either a hook or a T piece fixed into scaffolding, especially when using large diameter hose. Steel wire from the pipes to the structure can be used to prevent “pipe whip” should fittings come loose. The hoses should always be as straight as possible, avoid tightly looping them around bends this increases the potential for blockages. Any sharp bend in a hose will reduce its effectiveness, and care should always be taken to avoid dragging the hoses across the ground which can cause friction damage. Damage to hoses is the most common and costly form of damage and is easily avoidable with application.

4.2. Pumping Techniques

The most effective method for placing concrete when using a concrete pump is to decide on the most appropriate delivery line layout. This will depend on the site access, the location of the concrete pour, and the volume of concrete being placed. In the event of having tight site access with the pour location being a fair distance from where the pump will be set up, it may be best to set the pump up in a central location. This will allow for the use of the same pump position to place concrete in two different locations. A prime example of this could be pumping concrete for house footings. It would be most cost-effective to set the pump up in a driveway or path at the front of the house and then simply move the delivery line from one side of the house to the other to place the concrete. This way, you can eliminate the need for extra fittings and dismantling and moving the pump to another location.

The concrete pump can be a very efficient method of placing concrete, providing that the pump is set up properly. This includes having an adequate volume of concrete, sufficient water content for the particular mix, and pipes that are large enough to allow the concrete to flow freely. Additionally, the line should be properly anchored at the end. It is recommended that a smaller line, possibly a 40-meter line, be used to allow for easier placement of the concrete and to reduce the likelihood of blockages, which can be very difficult to clear. It is also a good idea to have an assistant at the delivery end to help with the movement and placing of the hose, as well as to monitor the concrete output to ensure that the pump is not overloaded at any stage.

4.3. Troubleshooting Common Issues

If the concrete is over compacted, the pressure relief valve may activate to protect the material cylinder. Do not continue to run the pump with this problem and consult your manufacturer for advice.

Electrical problems can occur when the pump is provided with a poor power supply. To protect the motor from damage, the motor protection cutoff will automatically stop the motor starting. If power is suddenly lost, stop the pump to prevent concrete setting inside the pump line. If you are unable to find or rectify the fault, call an electrician. Always consult your manufacturer for electrical troubleshooting.

Sudden loss of concrete could be caused by air having entered the pump line. If so, concrete discharge will be accompanied by a spluttering noise. Stop the pump, release the pressure, and the ball catcher will automatically remove the blockage. After this, ensure all the couplings are tight, start from the pump and work your way back to the concrete. If this does not remove the problem, consult the pump tools section above for the maximum size of aggregate the unit can handle and the recommended minimum delivery hose diameter. Any deviation from these factors can cause blockages and pressure buildups. If you are still experiencing problems, narrow down the potential cause by working at the pipe, for example, reducing the delivery length or removing any sharp bends. If removing a section of pipe, plug the open ends to prevent another blockage. Successfully locating the problem can save time and unnecessary part replacement. The fault could be a simple fix involved with the delivery end of the concrete. If it does not compact well, it can allow air contact around the surface, allowing a buildup of air pressure and the pipe may become violently dislodged.

5. Pumping Applications

An understanding of how concrete behaves during pumping is important for a pumping contractor. He must be able to determine whether the concrete mix is suitable for pumping. He must know its target slump (a matter discussed thoroughly in section 4.1). Concrete behaves differently at various slumps and temperatures. Concrete pumping is a highly effective method of placement, but effective does not always mean easy. The various types of work mentioned require judgment calls on the part of the contractor in order to determine the correct type of pump to use, how to set it up, and how to do the actual job. Pumps come in various sizes and different types of work may more readily accommodate one type of pump than another. Step one in decision making is determining whether the pump needs to be a trailer on wheels, a truck, or a stationary pump. After that, it needs to be determined which type of pump within those categories will be best. Pumps range from high pressure/low volume models that are very effective for line pumping to a low pressure/high volume model. Then there are also the various types of boom pumps used for large construction sites and other better left inaccessible missions.

Concrete pumping is the most widely used method of concrete placement. A44 accredited pumping contractors place concrete into areas inaccessible by concrete trucks. Often a concrete truck is too large or too heavy for the site or cannot access the area that needs work due to its weight or the site’s ground conditions. Other times there is simply not enough work to merit ordering a concrete truck with its large minimum requirement. An A44 pumping contractor can perform all of these jobs. His pump can be set up virtually anywhere, whether it is inside a building, on a scaffold in order to do repairs to a wall or slab, or in the backyards of a residential home. Pumps are also used to place concrete on top of, around, or underneath existing structures. This is often done for the purpose of repairs. A44 pumping contractors are trained to use the different types of pump systems to do such work in the safest, most efficient, and clean manner.

The successful placement of concrete is dependent upon careful planning and suitable equipment. A wide range of concrete placement systems are available to suit the varied needs of the residential homebuilder, the general contractor, the state Department of Transportation, and the do-it-yourselfer. Despite the claims of all equipment manufacturers, there are no all-purpose placement methods. The equipment needed to place concrete will vary with the scope of work, site access, and available materials.

5.1. Residential Construction

On work sites where basements, driveways, walkways, and other concrete slabs are being poured, a concrete pump can be the best alternative to using a wheelbarrow or bucket. In the case of basement construction, which is our most common residential application, sometimes there is simply no other alternative to concrete pumping, due to the deep and narrow nature of basement excavations. Oilfield companies and/or other construction contractors working at remote locations can benefit from a mobile unit designed for road and rail access. On a larger scale, track-mounted equipment and other specialized machinery designed to more effectively navigate difficult terrain can be used on energy and utility construction projects. Concrete pumping can offer an economically sound solution to concrete access and placement on any type of worksite.

In the residential sector, concrete pumping can be the best way to place concrete, particularly if the project is too small to warrant hiring a concrete delivery truck. Concrete delivery trucks can cause damage to driveways and sidewalks when parked directly on them to deliver concrete. Additionally, large concrete delivery trucks are often unable to access new ‘in-fill’ construction projects done down narrow side streets, because of the trucks’ size and the close proximity of homes on both sides of the street. Adding to the difficulty, dirt and damage done by large concrete delivery trucks often costs more than the cost of the concrete. For these types of hard to reach projects, concrete pumping is a ‘no-brainer’.

5.2. Commercial Construction

Commercial construction offers the greatest opportunity for concrete pumpers because of the large scale of the projects. These types of construction projects require flexibility and the ability to meet an ever-changing set of conditions. A44 pump operators are often called on to pump a variety of concrete mixes into difficult places. In a single day, they may be asked to pump a slab on grade, piling encasement, or a column footing. Each of these applications provides its own set of challenges. With high-rise construction, concrete must be placed up the side of the building. Concrete booms provide a cost-effective method of getting concrete into high-rise cores and can later be used for window washers and scaffold anchoring. Precast plants are frequent places for A44 pump work. Panel and plank erection is a fast and effective construction method but it demands a machine that can easily move from one form to another and still deliver quality concrete. Concrete pressure is the key to achieving a high-quality surface finish. Concrete placement in the 5-7 MPa (700-1000 psi) range, ultra-low pressure, provides a solution that is often faster and less labor-intensive than mechanical placement with a similar surface quality. This is because form vibrators can be eliminated and the wetter mixes allow for easy finishing. Until recently, there has been no good ultra-low pressure solution for the pump industry. Now there is a newly developed tool for A30 pump operators working on flatwork and A44 operators pumping into forms.

5.3. Industrial Projects

The specific rate at which concrete can be placed using a pump will depend on many factors. Access to the site for the concrete pump and the concrete delivery truck is crucial, so too the configuration of the area. The rate of concrete placement must allow the concrete to be placed correctly and efficiently finished, so timing of the pump to the placing crew is also important. However, in nearly all situations, the overall placing rate using a concrete pump is more efficient than using other means of placement.

5.3. Industrial Projects Concrete pumping can reduce the downtime on mixers and other equipment and also reduce the need for other types of equipment to move the material to where it is needed. Concrete pumping can also decrease the amount of manpower required to place concrete and can result in a more efficient and quality placement. Because of the efficiency of concrete pumping, it is sometimes the only method of concreting some complex and awkward areas. Due to the technical and effective means of placing concrete using a concrete pump, the concrete is often being placed in a way which achieves the specified design and performance of the concrete. This is often not achieved when using other methods of placing concrete.

Pumping Applications A44 Concrete Pumping Pumping is an efficient means of placing concrete and sometimes the only way of getting concrete to some locations because the material is specifically designed to be pumped. The method is used successfully in both residential and commercial concreting projects and results in placing concrete in a way which cannot be achieved by any other method of transportation.

6. Pumping Efficiency

The defining factor to downtime is very often the blockage of the line. Knowing that a blockage has occurred is usually straightforward with indications being a loss of delivery from the line and a sudden increase in system pressure. On this happening, the mix should be emptied from the hopper and the delivery stopped. The blockage should then be located and cleared. The method in which a blockage is cleared depends on its location and the type of pipeline being used. Possible removal methods will be the use of the reverse pump, air or water pressure. The clearing of a blockage should never be attempted with the delivery of more mix. On most occasions, it is likely that the blockage has caused damage to pipeline accessories, and so it is recommended that relevant parts are kept as spares to avoid downtime at a later date.

To achieve the most efficient pumping time, the following points should be followed. Find out the maximum output of the pump. Each pump has an optimum output which can be measured by pumping into a measuring box. Once the output has been ascertained, the system pressure should be adjusted in accordance with the pump manufacturer’s recommendations. This is usually stated as a maximum delivery line pressure. When this has been completed, the pipe size and length should be considered. The correct diameter of the pipe has its own maximum delivery capability, a rate which should not be exceeded. Details can be found in the pipeline equipment manual provided by the pipe manufacturer. If the pipeline is a considerable distance away from the pump, it may be theoretically possible to increase the output by one more size of pump. This will help to increase the delivery line pressure and maintain the required rate mentioned above.

Table of Contents: 6. Pumping Efficiency 6.1. Maximizing Pump Output 6.2. Minimizing Pump Downtime 6.3. Proper Cleaning and Maintenance

6.1. Maximizing Pump Output

It should be noted that the maximum theoretical output rate of a pump is of no significance in itself, but it is a starting point in the determination of the best method to employ in any particular project. Output can be increased by employing a larger pump or by applying acceleration on concrete with high slump to the extent that segregation will result in lower strength at the cost of durability. It is logical and desirable in the case of pumped concrete to aim for the leanest mix that is still workable from the point of view of the ease, pressure, and speed of pumping. The lower friction losses with such a mix will result in higher output and power saving. Segregation must be guarded against in altering the mix; a small increase in slump can usually achieve the desired result. Any chemical accelerators that are added to aid penetration should be carefully assessed; they can lead to high student rate and difficulty in placing the concrete due to shortened lifespan. Pump output can deteriorate with time on the same mix; the cause may be a drop in aggregate quality, worn pump equipment, or blockage in the line. Periodical assessment can ensure that the working mix is still best suited to the project and the cause of any loss of output can be identified and rectified. Periods of downtime between the placing of different phases of the work or between different projects can be expensive. If pump equipment is hired, it may be more economic to move to the new phase or project with the pump still loaded with some concrete.

6.2. Minimizing Pump Downtime

Before outlining how to minimize pump downtime, we should identify what causes downtime. Downtime can be caused by either blockages in the pipeline or a build up of concrete in the pumping cylinders – often happening when the mix is too stiff for the system. The first common pump blockage is caused by the line pump process being too slow for the delivery of concrete. This allows air to enter the system and then pockets of air can become lodged in the line. Material in the line will not clear easily and the best way to avoid this situation is to make certain that the delivery rate is appropriate to the type of concrete being used. Too much concrete in the hopper at this point is often the start of the problem. The second common pump blockage can be caused at the end of the line where the material free drops into a form or on to the ground. If the slope in the trench, form or slab is not correct and too steep, you receive the situation where the material is falling and the line is not able to push it out. This type of blockage is common in using the boom pump and can cause a build up of air in the line. A third and less common cause of blockages resulting in downtime is an operator error when changing the direction of flow at the valve. This cause and the previously mentioned air pockets can be cleared by slowly increasing the pump pressure till the material breaks free.

6.3. Proper Cleaning and Maintenance

The next step is to inspect the condition of the concrete cylinders. If the piston cups are worn, there will be excessive concrete spilling out the front of the cylinders. Measure the diameter of the inside of the cylinder barrel to determine if the cylinder is worn to the point where the piston cup needs to be replaced. A worn cylinder will reduce overall pumping efficiency, so it is important to replace piston cups at the right time. Always consult with the pump dealer or manufacturer for advice when replacing piston cups, as there are many different types and qualities of cups available on the market.

An effective way to remove dirt from the system is to run the machine with the inlet and return hoses in a barrel of oil cleaning solvent. This will circulate the solvent and dissolve and suspend varnish and gum deposits caused by the oil inside the pump. After doing this for a few hours, drain the oil from the hydraulic reservoir and the pump, and fill it with new oil.

After cleaning all the attachments, the next stage is to inspect the pump and the machine. First, inspect the condition of the priming system. Run the pump with water going through it and ensure that there are no leaks in the system and that the flow is the same as when the machine was new. Inspect and replace any small parts in the system, such as the check valve, as needed. This will ensure a fast and effective priming process in the future, saving a lot of time. Now is a good time to change the hydraulic oil. This is very important, as if the oil is not replaced at regular intervals, it will contain foreign material from the hydraulic system, which can cause damage to the various pumps and motors in the machine.

Concrete pumping is the most efficient way to deliver concrete to the desired location, and proper cleaning and maintenance of the machine will ensure that the equipment operates efficiently for a long period of time. Start the process by taking the hopper off the pump and washing it with water. Do not use recycled concrete for this, as any dry concrete chemicals left in the hopper or hoses could block the valves and ruin the pump. After washing the hopper, let the machine pump out the remaining concrete from the system, making sure that the concrete is pumped out of the delivery hose as well. Once all the concrete has been removed from the system, the next step is to clean the hoses and other attachments. Attach a sponge or “pig” (a type of foam device) to a hose and push it through the delivery hose system using water from a water pump. This will force the leftover concrete out of the hose. The sponge can be removed from the other end and cleaned if it will be used again in the future. Now is a good time to inspect the hoses and other attachments for excessive wear and damage. Repairs can be made at an earlier stage to prevent hoses from bursting during jobs.

7. Safety Inspections and Maintenance

Always ensure that the machine is in a safe condition before starting any work. This may generally mean removing hydraulic or electrical energy sources. If faulty equipment is in an unsafe condition, the immediate remedy may be the disconnection or removal of relevant components to render the condition safe until proper repairs can be carried out. Replacement components must be of at least the same standard as the removed ones.

7.1.1 General Safety Remember that all functional testing should be carried out safely and where possible in accordance with the manufacturer’s recommendations and without being detrimental to the proper functioning of the machine. It may sometimes be necessary to jam switches or bypass safety cut-outs under controlled circumstances to isolate an electrical or hydraulic fault.

Maintain the pump unit in a clean condition both inside and out. This will assist in identifying any leaks. Start the pump up and check over all functions. This assists with the identification of any electrical or hydraulic faults.

7.1. Daily Pre-Start Checks

Daily pre-start checks are an essential first safety step. They are also necessary for the efficient operation of the concrete pump because an unscheduled breakdown can cause considerable delay and added cost. Pre-start checks involve surveying the machine for any wear and tear and ensuring that it is in safe working order. Before commencing the daily checks, visually inspect to make sure the machine is parked on a level surface and that the brakes have been applied. This inspection should involve checking the hydraulic oil level, coolant level, and fuel water separator. All of which are important daily checks. Next, start the engine and check the warning lights and gauges to make sure they are in working order. Then carry out a series of checks specifically to ensure that the concrete pumping equipment is in a safe and operational condition. This will involve checking the hopper cover and grate, oil cooler, and radiator for any signs of blockage and foreign material. Also, make sure all the safety decals are being used and are in good condition. Any specific checks should relate to items requiring maintenance as indicated in the operator’s manual. This will generally include safety checks of various hydraulic components and systems and can be an ongoing education for the operator.

7.2. Regular Servicing and Maintenance

This refers to the standard of maintenance applied by the concrete pump operator. Regular servicing is essential; otherwise, the safety provided by the system adopted, e.g. double block and bleed, could be compromised. Maintenance should follow the manufacturer’s recommendations, and hoses and ancillary equipment should be stored and maintained in a clean and contamination-free condition. Any hoses and ancillary equipment used for construction purposes should be specially cleaned and/or maintained to ensure they remain contamination-free in a safe, dry, and contaminant-free storage area. If transported back to the precast plant afterwards, the hoses and ancillary equipment should be transported in a safe manner to prevent any damage or contamination. Hoses transported on hose racks and accessories should be returned to storage boxes. Any contamination or damage could compromise the safety and quality of the product to be delivered.

7.3. Storage and Transportation Considerations

Water is the basic cause of rust and corrosion problems, so additional pest heaters or an electric heater such as a light bulb inside the control panel up to 40W can be used to keep the pump dry. Great care must be taken with the heater to avoid an electrical fire or a fire in bedding which may also be laid in the pump. An electric heater is easy to install in a control panel by using a purpose-made electric heater with a built-in thermostat. This is often more trouble than it’s worth, and using a 60W bulb inside the control panel will have the same effect. This may also be used to heat the engine oil of a diesel pump if the pump is stored in a particularly cold environment to make cold starting easier. Under no circumstances should a blowtorch or open flame be used to heat the pump for obvious reasons. Any heating elements must be disconnected before the pump is used if attached to the mains.

Whenever possible, the pump should be stored inside. If it is stored outside, it should be covered by a purpose-made cover which does not allow condensation to get to the pump. Often when the cover is removed, the daytime heating of the pump and cool nights can create condensation on the underside of the cover which will then drip onto the pump. This is a common cause of electrical problems in the control panel, and if water gets in the hydraulic oil, it can be catastrophic. Before the pump is used again, the cover should be removed and the pump left for a day without the cover to evaporate any condensation. Covers must also be secured tightly as wind could dislodge the cover and cause the pump to corrode or rust due to the cover flapping in the wind.

A trailer pump is likely to have minimal maintenance problems if it is used and looked after correctly. Problems arise if it is stored outside and the electrical components get damp or water gets into the hydraulic oil tank as the pump will be outside of its warranty and significant costs could be incurred.

8. Regulations and Compliance

By raising the standard of service and expectations for the end product, it is essential that the workforce is adequately skilled to comply with these standards. Consequently, this reduces the level of trial and error and the educational process required to rectify work that has not met the required specification. For the workforce, skilled work entails a more interesting and mentally stimulating job, as the focus of problem-solving and method improvement becomes paramount. This often leads to a much safer working environment as expected standards are legislated and any alternative methods will be tried and tested before being implemented on site.

This is perhaps a rather simplistic interpretation. The standards implemented within the pumping industry have a much wider implication, and an understanding of this can evolve a contractor’s understanding of what essential service their concrete pump is providing. In other words, standards are a method of identifying and enforcing the minimum level of requirement to complete a specific task – which for the concrete pumping industry is, of course, placing the correct quality and quantity of concrete in the right location.

One assumes “Industry standards and best practices” would be a classification system geared to separate the good from the not so good and thus prevent the bad from occurring.

8.3 Industry standards and best practices

8.1. Health and Safety Legislation

Health and safety legislation is an important part of a company’s or individual’s responsibility. Failure to meet these standards can result in fines, imprisonment or being sued for negligence. The Health and Safety at Work Act (HSWA) sets out the general duties which employers have towards employees and members of the public, and employees have to themselves and to each other. This is further defined in the Management of Health and Safety at Work Regulations 1999, which identifies that a risk assessment must be carried out to prevent accidents and ill-health to anyone involved in a work activity. The Construction (Design and Management) Regulations 2007 are there to ensure that health and safety are integrated into the design and management of construction projects from the start to finish, and to protect people from harm. The regulations apply to all construction projects and will include domestic projects. The Manual Handling Operations Regulations 1992 set out guidelines as to how to deal with loads and has a hierarchy of measures to make sure that manual handling is safe; this includes avoiding hazardous manual handling involving a risk of injury. The Personal Protective Equipment at Work Regulations 1992 require that PPE equipment is assessed to make sure it is suitable to provide effective protection taking into account the working conditions; these regulations also require employers to provide employees with sufficient information and suitable training. Any breaches of these regulations will be considered a criminal offence and the company, employer or whoever may be liable will be prosecuted in a criminal court. Any individual convicted may receive a custodial sentence or a fine dictated by the courts. Compensation claims may also go through a civil court.

8.2. Environmental Regulations

Land contamination legislation is an area of environmental regulation which could be of particular relevance to the use of concrete pumps in that they are frequently used to move large quantities of concrete to locations which are being redeveloped, often from brownfield sites. The legal requirements are that the polluter pays and that the developer is liable for cleaning up the site. In practice, this means that anyone who causes or knowingly permits the polluting of land or contamination of water resources could be liable. As concrete will be classed as a pollutant in the majority of cases involving damage to water resources or land contamination, it is necessary to be certain that the method of work employed allows delivery of the concrete to the point of placement in a manner which does not result in damage to the water resources or the environment and that the landowner has given permission for this to be done. On-site concrete pumping could be affected by regulation made under the Clean Air Acts to control air pollution. The local authority is the enforcing authority and it is illegal to carry out an operation of any description which emits dark smoke. Other regulations made under the Environmental Protection Act 1990 may also impact the use of concrete pumps, with noise emission Control of Pollution Act 1974 and waste management issues being of particular relevance.

8.3. Industry Standards and Best Practices

BS6049: Repair of concrete (withdrawn) was replaced by the current BS EN1504 standard. This British standard covered a number of different areas in concrete repair and protection. In general, when preparing specifications for contracts it is not uncommon both in Europe and the UK, for architects, engineers and clients to specify that they require work to be carried out to ‘BS6049’ regardless of the fact that it no longer exists. Therefore it is important to educate the industry as to the current British or European standard that should be referred to. BS6049 has been replaced by various parts of BS EN1504 as aforementioned.

BS EN1504: The ‘European standard for products and systems for protecting and repairing concrete structures’ is an umbrella standard and consists of a number of parts (which includes methods of repair). Published in 2009, parts 2-7 became British standards in 2010 therefore the older DD and BS standards were withdrawn from then. Any reference to a European standard in contract documents should be to BS EN1504 and its various parts and NOT the erstwhile BS, DD or prEN standards. For example repair mortars for concrete are covered in part 3 of the standard, so the correct reference would be to BS EN1504-3:2009. Unfortunately the system of older national standards being cross referenced from within the new European standard has led to much confusion in the industry, with the result that many clients are still requiring work to be carried out in compliance with the withdrawn standards. BS EN1504 goes some way to establishing a framework for an industry whose image problem exists in large due to a lack of understanding and education in the specialist nature of concrete repair.

Installers must ensure that their work is carried out in compliance with one or more of the various standards and good practices available to the concrete repair industry. There are currently a number of standards which refer to either materials or workmanship in concrete repair, the most important and relevant to membership being:

9. Practical Assessment

Assessments, whether formative or summative, are conducted to assess the learner’s knowledge and competency against the learning outcomes (2). During the course, the instructor will assess each candidate’s competency using the required methods to conclude whether he has met the required standard. The candidate can have any areas of his training recorded in his Logbook (A59), which he will use to progress to NVQ level 2. This logbook is issued to all competent operatives who use plant and equipment and is a vital step to obtaining NVQ (CITB approved). Areas covered in the logbook are: – Plant operations theory oral questions undertaken during practical tasks. – A59 Supervised Operatives recorded supervised activity. – Practical tests. On successful completion, candidates can achieve a Red Trained Operator Card. Valid for 2 years, this is not a CPCS qualification, but will enable the operator to work on site. The operative must then progress towards an NVQ in plant operations to achieve the nationally recognized CPCS blue Competence Card. (Stephensen, K., 2014)

9.1. Written Examination

Persons who fail this assessment will not be permitted to re-sit the assessment but may attend the operation assessment without certification as set below. The marking of this paper will be conducted before and possibly run into the first operation assessment. It is expected that persons in this category will proceed immediately to the practical assessment following a failed written assessment.

Supervisors & Safety Officer Written Assessment: – At least 3 years of experience in the planning or supervision of work in the highways or roads sector – 2 attempts to complete a 50 multiple-choice question paper – 70% pass mark

Operatives who are unsuccessful in achieving a 70% pass rate will be permitted to re-sit a different paper if still within the 10 working days provided earlier re-sits have not prompted an extension to the 10-day maximum period.

Operatives Written Assessment: – 10 attempts to complete a 20 multiple-choice question paper – 70% pass mark

The practical and written assessments will be conducted at NRSS, Blackwater and 8point8 Training, Chesterfield within 10 working days of completion of the training course. The practical will be assessed against the National Highway Sector Scheme 12 (NHSS12) training and assessment for static temporary traffic management (STTM). Staff to be carried out under the auspices of Lantra Awards. The written assessment will be split for STTM Operatives and TTM Safety Supervisors & Safety Officers. The static traffic management training will be assessed as follows:

9.2. Hands-on Skills Assessment

During the course, candidates will be provided with essential information covering all portions of the syllabus. Each module will consist of tutorials and handouts to give the students a supporting aid of knowledge to assist in the prospective examination to be taken at the end of every module or at the end of the CPCS A44 course. During the work-based module, we will begin the practical lesson in carrying a pre-shift inspection UEP to find faults, etc. with the unit. This lesson will have a written UEP to which the candidate has to fill in and then will be assessed on. Such inspection will be carried out on units both with faults and without to ascertain the cause and how to rectify the problem. Following on will be various different types of modules on how to correct basic faults with a unit. We will provide the candidates with dummy units with specific faults, requesting that the candidate correct the fault. This will be at a competency level provided by the candidate’s skill, i.e. if the candidate is failing to correct any faults, the module will run until the candidate can prove full understanding and competency to correct said faults. At this point, we will refer the candidates to their handouts or tutorials. With a good idea of expectancy regarding the examination process, we will provide the candidates with UEP fault diagnoses and repair.

9.3. Certification Process

Results for all candidates from the written examinations and the conclusion of the practical assessments are forwarded to the CPCS Test Centre. The test centre processes the results and if successful, the appropriate certification cards will be sent to the employer. If unsuccessful, a letter will be sent to the candidate detailing the fail mark in each section of the theory paper and the fail mark for each part of the practical test. For theory papers, candidates will be able to sit a re-test for the paper or the specific section(s) failed at a time and date to be confirmed by the test centre. Re-tests for theory sections can be requested at any time after the initial test; there is no limit to the number of theory re-tests a candidate can sit. The same applies for practical test section re-sits. Simulation Tests can also be arranged at the choice of the test centre. (Simulation tests essentially mirror the real tests in terms of format and questioning; however, the CPCS matched to these tests will not count as a failed or passed test)