Executive Summary : | Kota stone industry causes serious environmental problems, loss of green pasture, choking of drains in the rainy season, dust nuisance, pollution of water from contamination and spoiling the aesthetics of the entire region. Kota stone is low-grade limestone (Sedimentary nature) located in Kota, Jhalawar, Ramaganjmandi. Production is more than 20 MT/ year. Main constitutes of kota stone are Calcium Carbonate (Low), MgO, SiO, (Rich), Al2O, etc. The processing of Kota stone by chain saw, diamond wire saws from quarries to smaller size results in more than 50% solid waste generation. Every year about 50 million tonnes of stone waste is generated from stone industries which may increase to a level of 350 million tonnes in the coming decades.
The CSIR-CBRI has developed a technology wherein 50-70% of waste is being utilized as cementitious binder. Products developed include Paver blocks complying IS:1565; Tiles: complying IS: 1237-2012; Lightweight blocks meeting IS: 2185 (IV)-2008; Excellent thermal insulation & good acoustic properties of CFC blocks. The capacity of the plant is 5000 units/day and its Profitability: 30-35 %. Stakeholders are Rajasthan State Pollution Control Board, Jaipur and Kota Stone Small Scale Industry Association (approx. 250 industries). Start-up capacity: Two plants has been set up in Kota by Govt. with a production Capacity of 8,000 for flooring tiles, 3,500 rough pavers and 5,000 blocks/day and utilizing approx. 100 tonnes Kota stone waste per day. However, the amount of wastes generated from flaggy limestone industries are up to 10-12 MT per year and also generated by mining & processing of Kota stone which is accumulated over 50 years are estimated to be about 150 MT.
The use of Kota stone waste would add additional value by addressing environmental issues such as global warming; solid waste disposal; energy exploitation; and also address strength issues at the same density as foamed concrete. The proposal relates to sustainable buildings in terms of Waste utilization, building energy saving policy Lightweight, high strength, low thermal conductivity heat insulation, less energy intensive. Lightweight foamed concrete has gained interest in buildings-energy efficiency in terms of thermal insulation and reduced energy consumption in buildings in terms of building insulation & heat preservation.
Lightweight concrete is a type of concrete, which includes an expanding foaming agent which increases the volume of the mixture while giving additional qualities and lessening the dead weight. High-Performance LAC (HPLAC) has a lower density, usually in 1100-1950 kg/m³, which can reduce over 20-50% bulk density of concrete and the consumption of materials such as steel, resulting in cost savings and economic benefit. The utilization of mineral admixtures such as silica fume, fly ash and slag promoted the development of high-strength and high-performance LAC. HPLAC with compressive strength of 55-60 Mpa and density of 1800-1900 kg/m³ can be prepared with excellent impermeability and resistance to chloride ion penetration by the addition of 10-15 wt% fly ash and silica fume. By introducing 10 wt% of fly ash, silica fume and slag high-performance LAC with a density of 1624 kg/m³ and compressive strength of 60.5 MPa was successfully produced. Advantages of Light Weight Composites are High strength, durability, a very high strength-to-density ratio, Resistance to freezing and thawing, reduce or no drying shrinkage, excellent thermal and acoustical properties, easy transportation, less reinforcement and Reduction in dimensions of foundation. Lightweight reinforced concrete can be used in making structural elements and save money, especially, in High-rise buildings built on low-strength soil, where there are not sufficient coarse aggregate mines. Objective: i. Development of lightweight composites using Stone waste and waste pozzolanic materials.
ii. Development of Light Weight Composites with at least 50%-60% of fly ash content should be produced in tile making.
iii. National Thermal Power Corporation Limited, (NTPC) Central Road Research Institute (CRRI), New Delhi. Energy Conservation Building Code (ECBC) guideline shall also be consulted.
iv. Performance improvement by using natural/synthetic fibres.
v. The tiles should be assessed for cost-effectiveness, weight, strength, durability and fire resistance. The thermocol and other lightweight materials will be used in place of wood in tiles may be flammable, hence, all such products proposed under the project should be tested for fire resistance and flammability, especially if they are to be used as wall panels in building construction and meet fire resistance standards.
vi. Optimization of thermal performance for the composite climate.
vii. Scale up of the developed process up to pilot level |