Manufacturers of batching plants and ready mix cement are ecstatic. Mostly, it’s the new government’s announcement to stress on infrastructure projects that has made them happy. With the construction and infrastructure industry taking a big blow last three years, the construction equipment market has been badly hurt. “It was a chaotic situation for players,” says Vikaas Ahluwalia, MD, Ahlcon RMC.
Demand is cyclic and in the current economic situation the demand has become less predictable. “Aggregates form major component of raw material and to ensure supply of quality aggregates in the unorganised aggregate industry is another risk. The third risk is that the entry barrier in this business is too low and hence too many players are in this market. This business is not considered glamorous by many people and hence it is not able to attract people with leadership potential,” says Anil Banchorr, chief executive – concrete business at ACC Limited.
One of the key factors that have been propelling the growth of concrete batching plants has been the strict emphasis on quality control.
Simply put, water + cement + aggregate = concrete. The production process is fairly simple. This and the longevity of concrete and its many structural uses is why there are a number of concrete manufacturing plants (a.k.a. ready-mix plant, concrete batch plant, mobile batching plant, etc.). Concrete batch plants come in many varieties and brands. Some are fixed in place and some are portable. They come in a variety of sizes in terms of their hourly production rates. But it’s always the same, water + cement + aggregate = concrete. Some additives may be included for special properties such as improved surface finish, different strengths or to add colour.
Mobile batching plants are an innovative, customised concrete production solution for contractors. The plant requires no foundation and can accommodate aggregates, cement, fly ash, water, etc. "It has a foldable design and thus reduces transport cost and shifting time. Moreover, contractors don’t have to hire concrete mixers. Earlier, the construction period would stretch for four to seven years and contractors would maintain the equipment at the site and this proved to be expensive as they would hire numerous types of equipment. But now with contracts being executed faster, having a mobile batching plant serves the purpose,” says VG Sakthikumar, chief operating officer, Schwing Stetter (India).
Mobile batching plant is designed for the production of all types of concrete, mixed cements, cold regenerations and inertisations of materials mixed with resin additives. The design includes multiple containers that separately transport all the elements necessary for the production of concrete, or any other mixture, at the specific job site. In this way, the operator can produce exactly what he wants, where he wants and in the quantity he wants through the use of an on-board computer. Once production is started, the various components enter the mixer in the required doses and the finished mixed product comes out continuously ready for final use. It is also suitable for the recovery of materials destined for landfill disposal, such as cement mixtures regenerated from masonry rubble. The mobile batching plant is easy to transport. It can be fixed-mounted on a truck, mounted on a truck with tipping box or mounted on an interchangeable cradle.
“On the other hand, portable plants are used to put the concrete production right at the construction site. This is convenient and cost effective. Concrete batching plants are widely used to produce various kinds of concrete including quaking concrete and hard concrete, suitable for large or medium scale building works, road and bridge works and precast concrete plants,” says a spokesperson at Al-Shams, a Delhi-based manufacturer and supplier.
Modern concrete batch plants employ computer-aided control to assist in accurate measurement of input constituents, as well as tie together the various accessories for coordinated and safe operation. With concrete performance so dependent on accurate water measurement, systems will often use moisture probes to measure the amount of water that is part of the aggregate (sand and rock) material while it is being weighed, and then automatically compensate the mix design water target.
“Our equipment is built with high level of reliability and come with a long service plan. We are a tad expensive compared to our competition, but the long life of the machinery covers the investment within a couple of years. Our machines are also fuel efficient. This may not apply to most equipment available in the Indian market,” says Sakthikumar.
Bin level indicators are an integral part of the production and operation of cement and concrete plants. They are critical to the protection against costly spills from overfilling and against material outages. In addition, continuous level sensors are used for inventory management of materials such as cement and fly ash in the concrete production process. Rotary paddle and tilt switch point level monitors are staples in the industry. They are rugged, reliable and very cost effective. Other sensors, such as RF capacitance/admittance sensors can be considered for some applications as well. In the inventory monitoring area the weight and cable inventory monitor is one of the most common that is used by concrete batch plants to monitor fly ash, cement and aggregate inventories.
For instance, Schwing Stetter (India) has about 30 persons working in the design and research department. They are responsible for three major products classes like the batching plants, the concrete plant and the mixer. The mixer and the pumps come under the category of equipment, whereas plants are more like a project that involves structural designing. The company has formed teams to work on various aspects such as fabrication, structural, hydraulics and electronics and electrical. Apart from this, it draws technology inspirations from two design departments based out of Germany. The company constantly trains its people on new technologies that area applicable to the department they work in.