CONCRETE USING RECYCLED AGGREGATES

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1 International Journal of Civil Engineering and Technology (IJCIET) Volume 8, Issue 9, September 017, pp , Article ID: IJCIET_08_09_049 Available online at ISSN Print: and ISSN Online: IAEME Publication Scopus Indexed CONCRETE USING RECYCLED AGGREGATES Dr. K. Ramadevi Associate Professor, Department of Civil Engineering, Kumaraguru College of Technology, Coimbatore, Tamilnadu, India Dr. R. Chitra Assistant Professor, Department of Civil Engineering, Government College of Technology, Coimbatore, Tamilnadu, India ABSTRACT Worldwide, cities generate about 1.3 billion Tonnes of solid waste per year. Building materials account for about half of all materials used and about half the solid waste generated worldwide. The waste, generated in the construction, maintenance, repair and disposal phases of a building, is called Construction and Demolition (C&D) Waste. Management of C&D waste is a problem faced not only in India but by the global community and quantum of waste produced occupies a huge fraction of the total solid waste generation by mass. Furthermore, a continued environmental awareness instigates the pressure for reuse of construction materials instead of classifying them as waste materials. Using construction waste material as an aggregate for developing new concrete product is technically viable and may, in some circumstances, be environmentally beneficial. The recent government initiative to stop sand mining insists the need to recycle, reuse and substitute natural aggregates in order to ensure environmental sustainability. This research work aims at making one such experiment where recycled aggregates are produced from C&D waste thus paves a way, for the effective management of concrete debris. The concrete waste was collected from the waste yard in the college campus, segregated, crushed in jaw crusher, sieved, washed and used for concreting for a mix proportion of M5, as a replacement for natural course aggregates in proportions of 0%, 30%, 60% and 100%. On testing, the compressive strength was found to be increasing and split tensile strength and flexural strength were observed to be nearly equal to that of normal concrete mix. Therefore, use of recycled concrete aggregate showed acceptable performance with respect to mechanical properties. The recycled aggregates obtained from waste concrete are more angular and have higher absorption and specific gravity than natural coarse aggregates and it resulted in increased strength and improved load carrying capacity. However, further studies to determine the effect on durability and improvement on workability are necessary. Key words: C&D waste, Recycled aggregate, Fineness modulus, Slump test, Specific gravity editor@iaeme.com

2 Dr. K. Ramadevi and Dr. R. Chitra Cite this Article: Dr. K. Ramadevi and Dr. R. Chitra, Concrete Using Recycled Aggregates. International Journal of Civil Engineering and Technology, 8(9), 017, pp INTRODUCTION Concrete is the premier construction material across the world and the most widely used in all types of civil engineering works. Among the ingredients for concrete, aggregates, i.e. inert granular materials such as sand, crushed stone or gravel form the major part. In recent years due to continued large scale extraction, use of aggregates from natural resources has been questioned at an international level. This is mainly because of the running down of quality primary aggregates and greater awareness of environmental protection. Hence the use of recycled aggregate from construction and demolition waste (C&D waste) in concrete is gaining momentum these days. Recycled aggregate concrete may become the need of the day in the years to come.. RECYCLED AGGREGATES The main source for recycled aggregates is construction and demolition waste. Most of the waste materials produced by demolishing structures are disposed by dumping them as landfill or for reclaiming land. But with the demand for land increasing day by day, the locations, capacity and width of the land that can receive waste materials are becoming limited. Added to it, the cost of transportation makes disposal a major problem. Hence, reuse of demolition waste appears to be an effective solution and the most appropriate and large-scale use would be to use it as aggregates to produce concrete for new construction. Recycled aggregate concrete utilizes demolition material from concrete and burnt clay brick masonry construction as aggregate. 3. SOURCES OF CERAMIC WASTE Coimbatore city Municipal Corporation says that population of the city is lakhs and the quantity of garbage generated is 601 MT/day which includes concrete debris, steel, glass, plastic waste, broken bricks etc,. It was estimated that an average of 1 MT/year of concrete waste was produced from testing of various concrete specimens. Waste concrete cubes and cylinders were collected from Structural Technology Center laboratory of our Institution. The collected waste were taken to a crusher unit nearby and crushed into various sizes. After screening, the materials were separated into the size of coarse aggregate required for replacement in concrete. 4. OBJECTIVES To replace natural coarse aggregate by the recycled coarse aggregate in various percentages (0%, 30%, 60% and 100%) To study and compare the mechanical properties - compressive strength, split tensile strength, flexural strength of hardened concrete specimens with and without recycled aggregates 5. MATERIALS USED The materials used are PPC cement of grade 43, River sand of size passing through 4.75 mm IS sieve and retaining on 150 micron IS sieve, natural coarse aggregate & recycled coarse aggregates size 0mm and 1.5mm is used in the ratio 60:40 and potable water available in editor@iaeme.com

3 Concrete Using Recycled Aggregates the campus. The collected waste specimens are shown in Figure 1 and the recycled aggregates are shown in Figure. Figure 1 Tested concrete waste Figure Recycled aggregates 6. PHYSICAL PROPERTIES OF MATERIALS The physical properties like specific gravity and fineness modulus are done on fine aggregates, coarse aggregates and recycled aggregates as per Indian standards. The test results are shown in Table 1. Table 1 Physical properties of Aggregates S.No Properties Specimen Test result Fine aggregate.31 1 Fineness modulus Coarse aggregate.88 Recycled aggregate.84 Cement 3.15 Specific gravity River sand.1 Coarse aggregate.60 Recycled aggregate CONCRETE MIX DESIGN Concrete mix design for M5 grade is done as per IS: The results of concrete mix design are tabulated in Table. Table Mix proportions Weight W/C Cement Fine aggregate Coarse aggregate Kg/m Ratio INVESTIGATIONS ON HARDENED CONCRETE To determine the mechanical properties of concrete specimens with and without recycled aggregates, cubes of size 150 mm, cylinders of size 150 mm diameter and 300 mm length and prisms of size 500 x 100 x 100 mm were cast, cured and tested at 7 and 8 days after curing. The batching details of the concrete mix are presented in Table editor@iaeme.com

4 Percentage replacement of recycled aggregates (%) Dr. K. Ramadevi and Dr. R. Chitra Cubes (150x150x150mm) Table 3 Batching details Cylinders (150x300mm) Prisms (500x100x100mm) 7 days 8 days 7 days 8 days 7 days 8 days 0% % % % COMPRESSIVE STRENGTH TEST The compressive strength of concrete cube specimens was determined by conducting compression test on Compression Testing Machine of capacity 1000 kn. The specimens were tested at 7 th and 8 th days after curing until failure. The load at failure was observed and the compressive strength (f ck )was calculated by the following formula: Load at failure in N Cube compressive strength, f ck = Area of cube in mm The result of compressive strength test is shown in Figure 3. Figure 3 Compressive strength test results 10. SPLIT TENSILE STRENGTH TEST The cylindrical specimens with various percentages of recycled aggregates at 7 th and 8 th days after curing were placed horizontally on Compression Testing Machine of capacity 1000 kn. The load is applied gradually and tested until failure. The split tensile strength (f s ) was calculated by the formula: Split tensile strength, f s = P L D Where, P = compressive load on cylinder in N editor@iaeme.com

5 Concrete Using Recycled Aggregates L = length of the cylinder = 300 mm d = diameter of the cylinder = 150 mm The result of split tensile strength test is shown in Figure 4. Figure 4 Split tensile strength test results 11. FLEXURAL STRENGTH TEST The prism specimens were cast with various percentages of recycled aggregates, cured and tested after 7 and 8 days curing. The specimens were subjected to two point loading, the load is gradually increased until failure. The flexural strength (f b ) was calculated by the following formula: If a > 13.3 cm, If a < 13.3 cm, f b P l b d 3 P a f b b d Where, b = Breath of beam (mm), d = Height of beam (mm) a = Distance of crack from shorter length of beam (mm) l = Length of the prism (mm) The result of flexural strength test is shown in Figure editor@iaeme.com

6 Flexural Strength N/mm Dr. K. Ramadevi and Dr. R. Chitra % of Recycled Aggregates 7 days 8 days Figure 5 Flexural strength test results 1. CONCLUSIONS In this study it is found that there is not much variation in strength between ordinary concrete and 30% replaced aggregate concrete, which proves the previous works. But when the percentage of aggregate replaced increases there is a constant increase in strengths, which is a controversy to the previous works. Because it has been found that recycled aggregates obtained from recycling concrete are more angular and have higher absorption and specific gravity than natural coarse aggregates it may result on increase of strength and improved load carrying capacity. However, further studies to determine the effect on durability and improvement on workability are necessary. REFERENCES [1] Tomas U. Ganiron Jr, (015), Recycling Concrete Debris from Construction and Demolition Waste, International Journal of Advanced Science and Technology Vol.77, pp.7-4. [] Roz-Ud-Din Nassar and Parviz Soroushian, (01), Strength and durability of recycled aggregate concrete containing milled glass as partial replacement for cement, Construction and Building Materials, Vol. 9. pp [3] Markandeya Raju Ponnada1 and Kameswari P, (015), Construction and Demolition Waste Management A Review, International Journal of Advanced Science and Technology, Vol. 84, pp [4] Jitender Sharma and Sandeep Singla, (014), Study of Recycled Concrete Aggregates `, International Journal of Engineering Trends and Technology (IJETT), Vol. 13, No. 3, pp [5] Dr.K.Ramadevi and Mrs. Abinayaa.A, (017), Alternate Materials in Building Construction, International Journal of Engineering Technology, Management and Applied Sciences, Vol. 5, No. 5, pp [6] Hardik Gandhi et al, (011), Study on Use of Recycled Coarse Aggregate In Concrete, National Conference on Recent Trends in Engineering & Technology, May, pp editor@iaeme.com

7 Concrete Using Recycled Aggregates [7] IS , Recommended Guidelines for Concrete Mix Design (Bureau of Indian Standards, 009). [8] IS 386 (Part III) 1963, Methods of test for aggregates for concrete, Part 3: Specific gravity, density, voids, absorption and bulking (Bureau of Indian Standards, 1963). [9] Himanshu Kumar and G. Premkumar, Behaviour of High Performance Concrete By Using Recycled Aggregate on Beam Under Static and Cyclic Loading. International Journal of Civil Engineering and Technology, 8(3), 017, pp [10] Ing John K. Makunza, Sustainable Concrete Made From Recycled Aggregates, International Journal of Civil Engineering and Technology, 7(3), 016, pp [11] Santosh Kumar, Sonu Pal, Prof. N. Kisku, Prof. V. Pandey, Experimental Investigation of Recycled Aggregate Concrete Using Pre-Soaked Slurry Two Stage Mixing Approach. International Journal of Civil Engineering and Technology, 8(1), 017, pp