Investigations on stone dust and ceramic scrap as aggregate replacement in concrete Veera Reddy.M Professor, Civil Engineering Department, Kakatiya Institute of Technology and Science Warangal 506 015, Andhra Pradesh. muralavreddy@gmail.com ABSTRACT Conservation of natural resources and preservation of environment is the essence of any development. The problem arising from continuous technological and industrial development is the disposal of waste material. If some of the waste materials are found suitable in concrete making, not only cost of construction can be cut down, but also safe disposal of waste materials can be achieved. So in the present paper, an attempt has been made to assess the suitability of stone dust and ceramic scrap in concrete making. In the laboratory stone dust has been tried as fine aggregate in place of sand and ceramic scrap has been used as partial/full substitute to conventional coarse aggregate in concrete making. Cubes, cylinders and prisms were cast and tested for compressive strength, split tensile strength and modulus of rupture after a curing period of 28 days. The results indicated effectiveness of stone dust as fine aggregate and partial replacement of conventional coarse aggregate by ceramic scrap upto 20 percent, without affecting the design strength. Keywords: Stone dust, ceramic scrap, economical, waste products, disposal. 1. Introduction In the last decade, construction industry has been conducted research on the utilization of waste products in concrete. Some of waste products are fly ash, rice husk, saw dust, discarded tires, plastic, glass rock, steel slugs, stone dust and ceramic. Each waste product has its specific effect on properties of fresh and hard concrete. The use of waste products in concrete not only makes it economical but also solves some of the disposal problems. The crushed rock flour can be used to replace the natural sand in concrete (Nagaraj and Banu, 1996). The use of crushed ceramic aggregate can be used to produce lightweight concrete, without affecting strength (Kanaka sabai et. al, 1992). The stone dust can be used as alternative material in place of sand in concrete based on grain size data (Babu shanker et al,1992). Sand can replaced by rock flour upto 40% without affecting strength and workability (Sahu et al,2003). The sand can be replaced fully with rock flour (Rao. S. P et,2002). However a slight loss in workability has been noticed with increase in replacement of san by rock flour. Sand can be replaced fully by rock flour without much loss of workability (Rao. G.T et. al,2002). Nearly 20% of rock is converted into rock flour while crushing rock into aggregate at stone crushing plants. In ceramic insulator industry, there is a mass failure of about 30 to 50% of the total production due to improper mixing of raw materials, excess water, 661
improper drying and too much of heating. No work has been reported using stone dust and ceramic scrap together in concrete so far. Hence the present work has been planned to evaluate suitability of these waste materials in concrete production. 2. Experimental Program 2.1 Materials 2.1.1 Cement The cement for the whole work was procured in a single consignment and properly stored. The properties of cement (IS: 12269, 1987) used in the investigation are presented in Table 1. 2.1.2 Fine Aggregate a) Sand: River sand was used as fine aggregate. The specific gravity of sand was 2.65 and fineness modulus of fineness was 2.54 b) Stone dust: Stone dust used in the laboratory investigations was procured from a local crushing plant. The specific gravity of stone dust was 2.63 and fineness modulus was 2.67 2.1.3 Coarse Aggregate a) Conventional Coarse Aggregate: Machine crushed granite obtained from a local Quarry was used as coarse aggregate. c) Ceramic Scrap: The ceramic scrap was obtained from a local ceramic insulator industry. The ceramic insulators are initially broken into pieces with hammer into required size. The properties of Conventional aggregate and crushed insulator ceramic scrap are shown in Table 2. and the sieve analysis data of fine and coarse aggregate data is presented in Table 3 2.2 Preparation of Specimens The quantities of the constituents of the concrete were obtained from the Indian Standard Mix Design method (IS: 10262,1982). The variation of strength of hardened concrete using stone dust as fine aggregate and ceramic scrap as partial / full replacement is studied by casting cubes, cylinders and prisms. The concrete was prepared in the laboratory using mixer. The cement, fine aggregate and coarse aggregate were first mixed in dry state to obtain uniform colour and calculated amount of water obtained from workability test was added and the whole concrete was mixed for five minutes in wet 662
state. Meanwhile the moulds are screwed tightly to avoid leakage; oil was applied on inner surface of the moulds. The concrete after mixing was poured into moulds in three layers by poking with a tamping rod. The cast specimens were removed from moulds after 24 hours and the specimens were immersed in a clean water tank. After curing the specimens for a period of 28 days, the specimens were removed from the water tank and allowed to dry under shade. Table 1: Properties of cement Sl. No 1 2 3 4 5 6 Property Specific gravity Fineness Initial Final setting Standard Compressive setting time time consistency strength Value 3.00 97.80 68min 9 hours 28 min 30.00% 54.28 N/mm 2 Table 2: Properties of coarse aggregate Sl. No 1 2 3 4 Property Sp. gravity Fineness modulus Impact value Crushing value Conventional Coarse 2.70 6.90 16.50 20.20 aggregate Ceramic scrap 2.40 7.06 18.20 24.70 Table 3: Details of Sieve analysis of fine and coarse aggregate. Sl.no Sieve Designation Percentage passing Fine aggregates Coarse aggregates Natural sand Rock flour Natural aggregates Ceramic scrap 1 40mm 100 100 2 20mm 93.20 87.20 3 10mm 100 100 11.20 5.20 4 4.75mm 100 100 5.20 1.20 5 2.36mm 98.40 98.20 6 1.18mm 77.20 75.60 7 600microns 45.50 46.60 8 300microns 12.60 8.40 9 150microns 8.8 4.20 Conforming IS 383 1970 663
3. Tests For each batch of concrete, three cubes of 150mmX150mmX150mm size were tested to determine compressive strength (IS: 516, 1959). Three prisms of 100mmX100mmX500mm size were tested in flexure (IS: 9399, 1979) under three point loading to determine modulus of rupture. And three cylinders of 150mmdia.X300mm height size were tested for split tensile strength (IS: 5816,1999). 3.1 Mix Selection The grade of concrete adopted for investigation was M 25. The mix proportion of concrete for laboratory investigations was arrived by designing as per Indian standard method. The final mix used was 1: 1.62: 3.24 with water cement ratio of 0.48. The details of mix designations and specimens used in experimental programme are given in Table 4. Table 4: Details of Mix designations and specimens Sl. Mix Fine Coarse aggregate Number of specimens No Designation aggregate Conventional Ceramic scrap CubesCylindersPrisms 1. MC Sand 100% 3 3 3 2. M0 Stone dust 100% 3 3 3 3. M1 Stone dust 90% 10% 3 3 3 4. M2 Stone dust 80% 20% 3 3 3 5. M3 Stone dust 70% 30% 3 3 3 6. M4 Stone dust 60% 40% 3 3 3 7. M5 Stone dust 50% 50% 3 3 3 8. M6 Stone dust 100% 3 3 3 4. Results and Discussions After comparison properties presented in Table 3, it is observed that the stone dust can be used as conventional fine aggregate. By comparing the properties of ceramic scrap and conventional coarse aggregate presented in Table 2, it can be concluded that the ceramic scrap can be used in place of conventional coarse aggregate. The experimental test results are presented in Table 5. It can be observed from the Table 5 that the strength of concrete is increased due to usage of stone dust as fine aggregate. But strength is reducing due to usage of ceramic scrap as coarse aggregate. And It is clear 664
from the fig. 1 that replacement of coarse aggregate by ceramic scrap in excess of 20 percent, leads to reduction of strength below conventional mix (MC). Hence in concrete with stone dust as fine aggregate, conventional coarse aggregate can be replaced partially by ceramic scrap upto 20 percent. Table 5: The experimental test results Sl. No 1 2 3 4 5 6 7 8 Mix Designation MC M0 M1 M2 M3 M4 M5 M6 Compressive strength (N/mm 2 ) 33.93 35.85 34.52 33.93 33.78 33.34 33.19 32.59 Split tensile strength (N/mm 2 ) 3.25 3.35 3.28 3.26 2.97 2.93 2.88 2.83 Modulus of rupture (N/mm 2 ) 4.98 5.16 5.06 4.98 4.80 4.74 4.56 4.40 5. Conclusions Figure 1: Image showing the variation of strength vs % ceramic scrap The following conclusions are drawn from the present investigations carried out: Stone dust can be effectively used as fine aggregate in place of conventional river sand, in concrete. 665
Ceramic scrap can be partially used to replace conventional coarse aggregates (10 to 20%), without affecting its structural significance. 6. References 1. Babu Shankar, N. and Md.Ali,1992., Engineering Properties of Rock Flour. National Conference on Cement and Building Materials from Industrial Waste., pp 167 172. 2. Nagaraj, T. S. and Zahida Banu.1996, Efficient utilization of rock dust and pebbles as aggregate in Portland cement concrete. The Indian Concrete Journal, Vol70, No 1, pp 1 4. 3. Sahu. A. K., Sunil Kumar and Sachin. A. K, 2003, Crushed stone waste as fine aggregate for Concrete. The Indian concrete journal. 4. Kanaka Sabai, V. and Raja Shekaran A.,1992, Ceramic insulator scrap as Light Weight Concrete. National Conference on Cement and Building Materials from Industrial Wastes. pp 8 15. 5. Rao. S. P., Seshagiri Rao. M.V and Sravana, 2002, Effect of crusher stone dust on some properties of concrete. National conference on advances in construction materials, ACIM, Harmipur, H.P, Pp 196 201. 6. Rao G.T and Andal T.,2002, A study of behaviour of concrete with stone sand replacing river sand. National conference on advances in construction materials, ACIM, Harmipur, H.P, Pp 196 201. 7. IS: 12269 1987, Specification for 53 Grade ordinary Portland cement. BIS New Delhi 8. IS: 383 1970, Specification for Coarse and Fine Aggregates from natural sources for concrete (Second revision). 9. IS: 9399 1979, Specification for apparatus for flexural testing of concrete. BIS New Delhi 10. IS: 516 1959, method of test for strength of concrete Bureau of Indian standards. New Delhi, India 11. IS: 10262 1982 recommended guidelines for concrete mix Design, BIS. New Delhi, India, 1982. 12. IS: 5816 1999 method of test for splitting tensile strength of concrete BIS New Delhi. 666