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Portland Pozzolana Cement and Fly Ash
Portland Pozzolana Cement and Fly Ash
1. Use of fly ash (Through out the world) as supplementary cementation material with Portland Pozzolona cement improves the pore structure of the mortar matrix. This leads to more durable concrete when exposed to aggressive environment. Use of Supre Plastliser advance the hydration processes and decreases the permeability.
2. Experiment studies in the behavior of two series of concrete ——One with OPC and the other with slag and fly ash exposed in to concrete in to Suphuric acid. SNF (Sulphonate Nephthalene Formaldehyde, Fly ash.)
- Result in concrete of both series shows s slight increase in weight at early age, when exposed to 0.1 % to 1.0% acid solution.
- The aggressiveness of the acid increased with the concentration of the acid. Concrete made of slag and fly ash showed less loss of weight as compared to concrete made with OPC. This once again reiterate the fact that minerals admixture reduces the permeability of concrete and prolonged the life of structures.
- Research Significance: - Slag and fly ash are being produced huge quantities in the world. Disposal of these which are the By-product of power plant, Iron and Steel industry is a major problem. Use of it in construction industry has two significance—Disposal as well as enhancement of concrete properties where in a more durable concrete is produced. Besides this is limiting the emission of “Green House” gases, main CO in Cement production. It is advantageous from the stand of cost economy, efficiency, durability and overall Ecological profile of concrete.
Hence we can say, that the pozzolonic materials such as Surkhi and fly ash which increase the workability of concrete and also reduce the evolution of heat due to hydration of Cement and gives resistance to Chemical attacks. These materials (Pozzolanic) have no cementing prosperities of their own.
Experiment carried out at Basin Bridge Construction works have shown that the recommended design strength for M-15, M-20 grade of concrete can achieved when 20% of cement is replaced by 27.5% of fly ash by weight. This requires modification of in the proportion of fine aggregate and coarse aggregate. And in the Water Cement Ratio. It’s suggested Fine aggregate reduced by 7.5% of weight of cement and coarse aggregate is increased by this amount.
Development of strength of fly ash concrete at early age is relatively slow but its strength at 28 days is shown the same as that of Mix without fly ash. As such early removal of shuttering may cause problem. In India few big Dams & massive structure PPC Cement is used.
In Hydraulic structure where water tightness is the first consideration, PPC Cement mixed concrete may help as this concrete shows more plastic, bleeds less and segregate less as compared to OPC cement.
Considering above all experimental as a true citizen of the country, we should encourage the strategy of utilization of fly ash a industrial by product for the beneficiaries Industries like Cement Factories.
a) Adsorption of Phenolic Compound (A environment Pollutant) can be done By Utilizing Cola Fly Ash.
b) There is a great impact of coal fly ash in microbial function in red literate agriculture Soil. It increases the soil pH and accordingly reduces the Fertility.
c) Recently scientists have developed Bricks for construction works with the help of fly ash.
