There are two ways of making concrete:
Mixing of cement, sand and aggregate on site through a site-mixer
Mixing of cement, sand, aggregate, fly ash and chemicals in a computerised plant and then sent to site through transit mixers
We prefer the use of RMC for slabs as due to large quantities it is technically and financially feasible. RMC, if procured from a good national brand like ACC, Prism RMC etc. gives better assurance on quality of concrete.
There are vested interests which spread misinformation about RMC. Use of RMC removes the freedom that a contractor has to use less cement while making concrete on site. Also, use of RMC from a national brand helps as they have strong quality control and have computerised systems.
We are seeing more and more acceptance and awareness of RMC for slab in the builder floors and villa segment among homeowners now, as owners are becoming more aware.