Scope and Objective of the Study
The study covers the following aspects, which are based on the following Terms of Reference:
- The relationship of fly ash bricks to construction sector, in the context of fly ash generation by coal based thermal power plants.
- The present status of fly ash brick manufacture in India, availability of fly ash, and potential of utilization of fly ash bricks.
- Status of fly ash brick technologies in India by way of research work being done by various institutions, and technologies being used for manufacture of these bricks.
- Keeping in view, the technological status for fly ash brick manufacture, assessment of the technologies for its relevance and suitability, keeping in view material inputs required, energy requirements, costs, infrastructure requirements etc.
- Evaluation of the short-term and long-term economic aspects based on the above. This analysis is relevant for technology evaluation and assessment.
- Spin-off in terms of those in the construction sector and environment.
- Based on the technology assessment, impact and spin-offs, identification of inputs to effect the implementation of recommended course of action.
- A detailed Action Plan for implementing the recommended options for India, giving the available technologies. Identification of a set of agencies identified for implementing the same.
- Examination of impact of the recommendations.
- Approach This Techno-Market Survey looks into technologies suitable to India based on aspects like requirements of inputs, costs, economic benefits and impact etc., and is an overview report for technology options available for fly ash brick manufacture. For the purpose of construction industry, fly ash bricks and precast blocks (solid and hollow) are direct substitutes of conventional bricks. Thus, this study looks at the technologies of both.
It may also be noted that various cements and mixes which can be made using fly ash, have the potential become raw materials for fly ash bricks and blocks of various specifications. Therefore, this aspect has also been discussed.
In some fly ashes and its products, radio activity has been noticed due to the presence of trace elements. This is relevant while designing applications of fly ash products. Though this aspect is at a nascent stage of research, it has been thought relevant to be discussed.
India will continue to depend heavily upon its coal reserves for power generation. Based on the thermal power generating capacity as per different Five year Plans, starting at about 51 million tonne in 1994, India will generate about 90 million tonne of fly ash by the turn of the century.
By virtue of its physical characteristics and sheer volumes generated, fly ash is a serious problem. Some of the aspects of the problem are:
- It is a very difficult material to handle in dry state because it is very fine and readily airborne even in mild wind.
- It disturbs the ecology of the region, being a source of soil air and water pollution.
- Long inhalation of fly ash causes silicosis, fibrosis of lungs, bronchitis, pneumonitis etc.
- Flying fine particles of ash create great nuisance for people living near power stations, corrode structural surfaces, and affect horticulture.
- Eventual settlement of fly ash particles over many hectares of land in the vicinity of power station brings about perceptible degeneration in soil characteristics.