Fly Ash Utilisation in The Manufacture of Green Paver Blocks and Tiles

Abstract

Coal-based thermal power plants meet the energy requirements for the developing countries in particular. The disposal of the growing amount of waste generated from coal-fired thermal power plants is becoming a serious problem to the environment. Although fly ash is the most commonly used pozzolanic material today, still it does not solve the health, environment and disposal problem related to this. Almost 120 million tons of fly ash is generated per annum at present in India and is largely responsible for environmental pollution. Also the production of huge quantities of cement requires large amount of energy, cause emission of CO2 and carry forward the allied problems. Fly ash is used for paving roads, in embankment and mine fills, making fly ash bricks etc. It can also be used as a replacement material of cement and fine aggregate in green paver blocks and tiles as a means of sustainable construction.
Today, concrete paver blocks and tiles play an integral part in paving roads, footways, parking places, etc. At the same time, depletion of mineral resources, increasing cost of construction and pollution related problems regarding the production of huge amounts of cement should be given proper consideration. So proper sustainable construction methods, such as use of fly ash based paver blocks and tiles, are indeed necessary to counteract the above problems.
This paper discusses the effect of cement and sand replacement with fly ash in high grade concrete paver blocks and tiles. Mix design was done for high grade concrete paver block by considering medium traffic. For the medium traffic the grade of concrete considered is M40. The shapes of the paver block considered in this project are Zig Zag (80 mm), Dumbbell (60 mm), I (60 mm). Sand replaced by fly ash source of steel plant Sambalpur up to 40 % and the corresponding 7 and 28 days compressive and flexural strength, water absorption, abrasion resistance characteristics were studied and compared with conventional control mix concrete. Similarly cement replaced by fly ash source of steel plant Sambalpur up to 40 % and the corresponding 7 and 28 days compressive and flexural strength, water absorption characteristics were studied and compared with conventional control mix concrete.
Cement replaced by fly ash source of steel plant Sambalpur up to 30 % and the corresponding 7 and 28 days’ flexural strength, water absorption characteristics and natural frequencies were studied of concrete tiles.
The experimental results indicate there is significant improve in strength characteristics over control concrete when sand and cement are replaced with fly ash up to 30 %. Since the fly ash is used for sand replacement it reduces the depletion of mineral resources and used for cement replacement it reduces the pollution.