The sudden change in the cement scenario in India has made the life of construction industry very difficult. The availability of cement has gone down drastically over past few months. But that’s not all. It seems that even the choice of which cement to use does not lie any more with the customers! DIRK plays an important role in advising the construction fraternity what to do.(see visitor group picture at the Info Center)
What is the big concern about using PPC? The first and foremost is that the workability gets hit hard on the face. Surprised? Well, the fly ash present in PPC is supposed to make our concrete workable, isn’t it? Go out and give it a try. You will be shocked to see that the water demand of the resultant concrete actually goes up. The concrete becomes difficult to pump, the slump loss is sudden and the super-plasticiser dosage needs to be increased to produce meaningful concrete. It is suspected that the main cause behind these issues is the extensive grinding of the coarser ash along with clinkers while PPC is being produced. The fly ash particles loose their spherical shape when they are ground - resulting in the higher water demand of concrete.
The RMC industry is slowly coming to the terms with this issue by using classified fine fly ash as an admixture. By adding such a quality assured fly ash up to 12%, the concrete properties improve substantially not only in the fresh state but also in the hardened state.
It seems that finally construction industry can take a sigh of relief.
The next course held by the Information Centre on "Fly Ash Technology" scheduled on 3rd and 4th May 2007, we will pay special attention to this latest trend being followed in the construction industry.