Optimise the use of concrete making and placing machines

Optimise the use of concrete making and placing machines

India’s per-capita consumption of cement is roughly half the global average of 500 kg, and way behind neighbouring China’s 1,750 kg. So, there’s massive scope for growth in the cement sector and, correspondingly, in the associated concrete industry. Here, CW profiles a few users of core concre...

India’s per-capita consumption of cement is roughly half the global average of 500 kg, and way behind neighbouring China’s 1,750 kg. So, there’s massive scope for growth in the cement sector and, correspondingly, in the associated concrete industry. Here, CW profiles a few users of core concrete equipment who are committed to getting the most out of their machines. Maximising the productivity of concrete machines rented out “We recently deployed 60cum/hr and 30cum/hr batching plants and 32-m static concrete placers for the construction of a LNG tank in Dhamra, Odisha,” shares Munish Taneja, Executive Director, Indiabulls Store One, a leading rental player in the Indian market. “To ensure that the machines functioned optimally and delivered maximumproductivity, our operation team followed the preventive maintenanceschedule prescribed by the OEM, used good quality spares andconsumables, inspected the equipment every week to identify wear/tearof critical items, provided trained operators with the equipment, and opted for models with highly advanced technology,”he adds. “While a strong operations team capable of managing critical sites canhelp manage challenges, the biggest challenges we have faced in theoperations of concreting equipment are poor quality mix or high-gradeconcrete supplied by customers, which leads to choking of boom placers/concrete pumps, lack of trained operators, the hightransportation and installation cost of the concrete batching plantowing to the size of various components, maintenance and upkeep ofthe equipment during idling, and the high maintenance cost ofconcreting equipment, mainly due to many wear parts like mixing drumliners, concrete pipes and chutes.” Should you make or outsource concrete to maximise productivity? “In constructing the Mumbai Metro Rail, we usually used boom placers as these are suitable for placing concrete upto the required height and radius (unlike high-rise buildings where the boom falls short),” shares Pramod B Joshi, Additional General Manager (P&M Head, All India), Ahluwalia Contracts India. “We used a 36-m boom, although in some instances contractors used a 43-m boom. For metro construction, concrete boom placers work better than stationary concrete pumps, especially when the quantity of concrete involved is limited. Boom placers are easier to use and shift to the next job.” The operator’s skill is the most critical factor affecting the productivity of a boom, he continues. “In city areas, spaces are usually limited and traffic poses a concern. A skilled operator can help ensure the safety of the site and passers-by.” Productivity may also be hampered by traffic, adds Joshi. “The team incharge of logistics, the transport of concrete and placement of the boom, and getting the authority’s approvals for all this play a key role.” “Deploying our own batching plant is productive when the monthly need for concrete exceeds 2,000 to 2,500 cum for a 30 cum/hr plant, and 5,000 cum for a 60 cum/hr plant,” he continues. “Our preferred plant for a metro project is a 30 cum/hr or 60 cum/hr machine depending on the quantity of concrete needed, with a twin-shaft mixer and SCADA software. We set up a site quality lab when the plant is installed by own at our site.” “If the monthly need for concrete is less than 1,200 to 1,500 cum or if the site is too congested, we outsource the procurement of concrete,” adds Joshi. “Setting up a plant requires approval from the Weights & Measures Department and pollution certification. If this process is likely to be time consuming, then, again, we outsource the concrete. Quality checks on the concrete mix design are essential to ensure quality of concrete. Monitoring productivity with quality checks is the most important factor in operating a batching plant.” Layouts and teams for mega pours and maximum outputs “For the construction of 348 residential buildings and administrativeoffices for the Nagpur Improvement Trust at Lakadganj, Nagpur, wedeployed a batching plant of 60 cum/hr capacity, as the dailyneed was upwards of 100 cum,” says Sachin Aware, Maintenance Head, Harsh Construction. “To maximise the output of the plant, we ensured adedicated short (less than 20m) ramp to load the aggregate and put upa partition to ensure no mixing with sand. The logic wasthat loading aggregate is the most time-consuming of all the processesinvolved in making concrete. If loading is done correctly, theprocess can be optimised. We used a stationary concrete pump to pour the concrete.” “In constructing the raft foundation of a district court in Nasik, weneeded to pour 1,400 cum of concrete without a break,”he continues. “Arranging separate teams to continue the pour over successive shiftshelped complete the job with a mixer and boom in about 27 hours.” “In general, a batching plant will deliver 80-85 per cent of itsstated capacity onsite,” adds Aware. “We choose a plant sizedepending on the project needs; our plants vary from 20 cum per hourto 60 cum/hr but if you want to use a boom pump of 70-80 cum/hr, even the latter size can prove small. Nine of our batchingplants are from Aquarius Engineers and six concrete pumps, all chosenbecause the brand delivers good services.” Adhering to operational instructions pays “For our ongoing major construction project, the construction of Capitaland, an international tech park located on the 200 Feet Radial Road in Chennai, we are using a Schwing Stetter M1 T batching plant with 56 cum/hr capacity, stationary pumps and the S36 SX boom pump,” says Arumugasamy Subramaniam, Chairman, VRMX Concrete India, a ready-mix concrete supplier and construction company with operations in Chennai. “We use another five Schwing batching plants to supply RMC, each of 60 cum/hrcapacity.” In his view, productivity is an outcome of following the operational instructionsprovided by product experts, which include strict maintenance andservicing protocols. “Training programmes by Schwing also help technicians keep machines running optimally.” “Our only challenge in using the boom pump is the occasional need foran extended reach,” adds Arumugasamy. “As this issue has only come up on rare occasions,we decided against buying Schwing’s product with a greater reach.Instead, we resolved the issue by connecting a compatible hose withthe machine.” Buy right for the best outcome “We usually get an 18-month timeline to implement projects, the most typical of which is the construction of a factory building with mezzanine floors and adjacent buildings to house ancillaries such as administration offices and a canteen,” shares Nirav Ved, Construction Manager, Kajima India. “One such project in Sanand spanned 70,000 sq m of covered area on a plot size of about 100,000 sq m, and the surrounding approach roads, pavements and culverts. Some of the buildings are fully or partially in RCC; the batching plant is used for the foundation, beams, the hollow core, etc.” “We prefer a batching plant with a 30 cum/hr capacity because that is the most commonly available capacity in the market,” he continues. “Plants of lower capacity don’t fulfil our scheduled requirement while higher capacity plants are rarely available at short notice.We prefer an inhouse batching plant to outsourcing our RMC needs because it saves on transportation costs. This decision usually depends on the availability of space on site as a batching plant usually needs 1,000 sq m.” If it cannot install a plant onsite, the company outsourcesits RMC needs to a nearby source, addsVed.“We check the vendor’s plant calibration records, equipment calibration records, delivery records, quality control measures, aggregate stores, and so on. Irrespective of whether we make our RMC or outsource our needs, we set up a laboratory onsite to conduct multiple tests to ensure that the RMC supplied adheres to our quality standards, including air content and cube tests and temperature and slump checks.Productivity is an outcome of having a batching plant of the correct size, sufficient transit mixers to ensure delivery is on schedule, and sufficient boom placers onsite.”

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