Ready Mixed Concrete (RMC)

Ready Mixed Concrete(RMC) Ready-mix concrete (RMC) is a ready-to-use material, with predetermined mixture of Cement, sand, aggregates and water.

AIJAZ AHMADSEC BNIT SRINAGAR

RMC&SMC

Merits and DemeritsContentsScope of RMCTests on aggregatesHistoryMaterials UsedConclusionBatching Plant

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SCOPE OF READY MIX CONCRETEMajor concerting projects like dams, roads, bridges, tunnels, canals etc.2. For concreting in congested areas where storage of materials is not possible.3. Sites where intensity of traffic makes problems.4. When supervisor and labour staff is less.5. To reduce the time required for construction etc.6. Huge industrial and residential projects.

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History

Concrete Batching Plant equipment that combines various ingredients to form concrete. Some of these inputs include water, air, admixtures, sand, aggregate (rocks, gravel, etc.), fly ash, silica fume, slag, and cement.Two types of plantsDry mix plants/Transit Mix Plant Wet mix plantsA concrete plant can have a variety of parts ,including: mixers, cement batchers, aggregate batchers, conveyors, radial stackers, aggregate bins, cement bins, heaters, chillers, cement silos, batch plant controls, and dust collectors.

Types Dry Mix Concrete Plants : After weighing all ingredents are discharged into a chute which discharges into a truck. Meanwhile water is weighted and discharged through the same charging chute into the mixer truck. These ingredients are mixed during the transportation to the jobsite.Wet Mix Concrete Plant: combines some or all the ingredients (including water) at a central location into a concrete mixer, I,e concrete is mixed at the same point and the simply agitated on the way to the jobsite to prevent setting.

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Materials used in RMC

8Ready Mix Concrete (R.M.C)

Equipment requiredInline BinsSilosScrew Conveyer BeltTransit MixersConcrete PumpsVibrators

Inline Bins

Inert raw materials like course and fine aggregates are stored in bins called inline bins where the trucks carrying the aggregates can dump easily

SilosAirtight container used to store cement and flash.

Screw Conveyer Belt

Cement and fly ash are fed to holding hopper with the help of screw conveyer fixed in inclined position.

Transit Mixers

o transport and used tmix the concrete upto the construction site

Concrete Pumps

Machine used for transferring liquid concrete by pumping.

VibratorsMechanical devices used to generate vibrations to remove airvoids in concrete and for proper copaction of concrete

16Animated Photo of Process of RMC

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BatchingMixingTestingTransportingPlacingCompactingCuring

PROCESS OF RMC :

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Test on Concrete

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MERITS OF R.M.C.1. Better quality concrete is produced. 2. Elimination of storage space for basic materials at site.3. Elimination of Hiring plant and machinery4. Wastage of basic materials is avoided.5. Labour associated with production of concrete is eliminated.6. Time required is greatly reduced7. Noise and dust pollution at site is reduced.8 .No wastage at site9. Environment friendly

DEMERITS OF R.M.C.1. Need huge initial investment.2. Not affordable for small projects (small quantity of concrete)3. Needs effective transportation system from R.M.C to site.4. Traffic jam or failure of vehicle creates problem if proper dose of admixture is not given.5. Labours should be ready on site to cast the concrete in position to vibrate it and compact it.6. Concrete's limited time span between mixing and going-off means that ready-mix should be placed within 90 minutes of batching at the plant.

Conclusion

Ready Mix Concrete is a modern technique of production of concrete in massive quantities away from the actual site of placing. It is very useful where demand of concrete is very high and construction sites are in congested areas, where mixing on site is not possible due to lake of storage place. RMC is ready to use material. It is widely adopted throughout the world. The Supervisory and labour costs associated with the production of RMC is less, and the quality of concrete is high. It gives higher strength to the structure and it also provides higher Durability to the structure. It reduces noise pollution as well as air pollution. It is suitable for huge industrial and residential projects where time plays a vital role. So ultimately it provides economy in the construction and better finish to the structure. Hence now a days the advantages of RMC are realized by engineers and contractors in the construction industry.

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