Here are the key concrete equipment technologies that meet user demands
The line-up of key concrete equipment available today spans pumps, vibrators, batching plants and mixers. Do these machines adequately meet user demands or are some features missing? Should this line-up include other equipment? CW provides some answers.
Concrete pumpsWhile all the equipment needed is available in the current market, Concrete Consultant Riyaaz Patel points out that from the perspective of the progression of the industry, concrete equipment across the board must be made more efficient. “Most of all, we need incremental improvement in concrete pumping technology,” says Patel.
Why’s that?Concrete pumps available today have been designed to pump existing concrete, explains Patel.
The line-up of key concrete equipment available today spans pumps, vibrators, batching plants and mixers. Do these machines adequately meet user demands or are some features missing? Should this line-up include other equipment? CW provides some answers. Concrete pumps While all the equipment needed is available in the current market, Concrete Consultant Riyaaz Patel points out that from the perspective of the progression of the industry, concrete equipment across the board must be made more efficient. “Most of all, we need incremental improvement in concrete pumping technology,” says Patel. Why’s that? Concrete pumps available today have been designed to pump existing concrete, explains Patel. Whereas, in the near future, he sees a need for the opposite approach, for pumps to be designed and, thereafter, for the material to be re-engineered by concrete consultants capable of performing complex analysis to suit the pump action. This alternate approach would help pressure raw material suppliers to manufacture technically correct material. “Shotcrete is an excellent example wherein materials have to be specifically sourced to suit the machine requirements,” says Patel. The construction industry already has concrete pumps that can pump from 30 cum/hr to 150 cum/hr, horizontally, to more than 500 m and, vertically, more than 150 m, protected by new safety features, observes Chaitanya Bhagde, Manager Plant and Machinery, Shapoorji Pallonji and a Chartered Mechanical Engineer. “But with buildings touching new heights, concrete pumps must perform better.” Bhagde elucidates the need for higher pressure capacity pumps and pumps that can efficiently push various grades of concrete, which are also in the process of upgradation. Also, wireless remote-control technology is a useful solution when a pump is used at a height and distance where the operator can’t see the actual picture. “We need better safety features in the concrete pump such as a limit switch for the hopper to stop the agitator immediately,” says Pramod B Joshi, Additional General Manager (P&M Head, All India), Ahluwalia Contracts India. Concrete pumps choke when we use them for concreting 10m below the ground, adds Joshi. “Some special arrangement should be made so that this doesn’t happen.” Ideally, the concrete pump should calculate the quantity of concrete needed so that the productivity and the concrete received from the ready-mix concrete (RMC) vendor or batching plant can be calculated, Joshi continues. “At present, we calculate the quantity of concrete manually. Also, concrete pumps and boom placers should display the quantity of concrete pumped. Without this, we cannot figure out the quantity of concrete wasted or received from the RMC vendor. An energy meter with the RMC plants would help calculate the electricity consumed to identify the cost of production.” Pump productivity To maximise the productivity of concrete equipment, Patel proposes a shift from intermittent pumping to continuous pumping and innovation in the material used to prepare concrete pipes so as to reduce their drag and friction. How does continuous concreting work? Bhagde shares his experience: “We placed the concrete pump directly below a concrete batching plant with the arrangement of a revolving chute. After some trials and errors, we started continuous concrete. This approach helped maximise the productivity of the plant and pump, and save on time and concrete transportation costs. As some concrete pumps don’t have a cable remote, we developed and used a remote control to operate the pump from a distance where the operator could monitor the placement and pump. This helped avoid communication errors.” Concrete vibrators Compaction directly impacts the strength and performance of concrete. “While we are using advanced high-frequency vibrators for compaction, which deliver speedily, further development would make vibrators lighter in weight and easier to handle without compromising the output desired,” notes Bhagde. “Ideally, the electronic components should be easily replaceable to avoid downtime and repair lead time.” Concrete vibrators that are currently available don’t show how much compaction has been done; this is handled by the workers, adds Joshi. “This can be improved.” The use of needle vibrators is questionable because they cause the aggregate to settle, which, in turn, brings about internal changes in the concrete matrix and affects its structural behaviour, opines Patel. The efficiency of vibration depends more on the operator than the machine itself, he continues. “However, code limitations for working conditions for laying and spreading concrete are never followed and, frequently, non-technical people are involved in the process, which is counterproductive.” Batching plants So far, we have mainly seen only stationary batching plants but this is slowly changing, according to Patel. Soon, he expects more efficient mobile batching plants to become increasingly popular to improve the quality of fresh concrete and reduce the multiple costs associated with keeping fresh concrete usable until it is fully consumed. Almost all manufacturers now offer automated versions of batching plants that yield more precise results than the typical old configuration of analogue-controlled machines, notes Bhagde. While the production cycle time can’t be modified much, as IS standards must be adhered to, he believes the lead time and other contributory factors can be taken care to increase the productivity and dependability of the plant. Compact design installations could be introduced for congested locations. When concrete is pumped directly from a batching plant, a special chute should be provided by the plant manufacturer to allow pumping operations to continue even while a transit mixer is simultaneously being loaded, adds Joshi. Missing technologies Rupesh Kumar, Corporate Quality Head, JMC Projects India, a Kalpataru Group Enterprise, lists the missing concrete equipment as follows: “An ampere metre, which checks current indicating resistance/workability of the mix, scanners to measure the temperature of concrete, camera/sensor to checkthe mix quantity and condition in the mixing drum and similarly in the transit mixer drum, robotic pipeline cleaners, placers fixable at the end of a pipeline to place concrete in a wider area, surface vibrators and finishers for large surface area like slabs, laser grids to maintain the level of large surface areas like slabs, screeds, and curtain systems to cover placed concrete to reduce the evaporation of water.” While existing mixer technology is useful, Patel is hopeful of advancement in the efficient and frictionless mixing of concrete. Digitalisation indemand Incorporating digital technology in machines underlies data collection and analysis that can help introduce more efficient operations, increase productivity per person and make quicker decisions about the design of equipment and operations, notes Patel. “Digital technology in equipment augurs more accurate measurements and precision in quantifying loads and generating online records,” adds Bhagde. “This, in turn, can help improve the quality of the outcomes and safety; reduce the cost and time taken to do a job; increase profit; and predict the need for machine maintenance.” Coming to examples of digitisation in concrete equipment, he points to automation in the controller system of batching plants, programmable logic controller (PLC) units in pumps and mixer motors and automated greasing system in pumps. While examples of digitalised equipment exist, “the concrete equipment models currently available do not incorporate digital technology sufficiently,” says Kumar. He believes digital is now well understood by everyone onsite including the workmen and, so, it must be promoted. Digitalisation clearly shows if things are going right or wrong. At present, this is left to the understanding of the workmen. Further, digitalisation makes it easier to work with machines and handle complex tasks and thus reduces the need for in-depth training while increasing productivity and accuracy. Training gaps Most operators cannot afford training and construction companies don’t send their operators for training; so, yes, we are seeing a training deficit, acknowledges Joshi. He advocates a training centre in each major city where leading manufacturers can promote their product and train Indian operators. “India seriously lacks the training infrastructure required to make people industry-ready”, adds Patel. He believes the construction industry is in a nascent stage as far as training is concerned. The construction industry needs to learn from the IT industry and adopt its continuous in-house training models and induction programmes. Training by OEMs should include quarterly or half-yearly refresher sessions to upgrade operator skills and knowledge, proposes Bhagde. Operators are inadequately trained today, affirms Kumar. “Most operators engaged with making, transporting, pumping and placing concrete don’t know concrete well and only focus on machine care. This leads to concrete being mishandled at critical times.” Manufacturers should offer training in the use of machines as well as interaction with concrete, believes Kumar. “Operators must be provided an understanding of concrete, control measures and procedures for handling adverse situations, including variations in concrete.” Service gaps In Joshi’s view, after-sales services by the major companies are poor and delayed because they don’t have sufficient staff. “The availability of spares is also of concern; some imported parts can take a month to get delivered. Involving Indian manufacturers would help fill this shortfall.”