Advanced Research Journals of Science and Technology
ADVANCED RESEARCH JOURNALS OF SCIENCE AND TECHNOLOGY
(ARJST)
RECYCLED AGGREGATE CONCRETE WITH GGBS AND QUARRY DUST
2349-3645
G.Gautham Kishore Reddy1, S.Uttamraj 2, 1 Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India. 2 Assistant professor , Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
Abstract The recycling of Construction and Demolition Wastes have long been accepted to have the possibility to conserve natural resources and to decrease energy used in production. In some nations it is a standard substitute for both construction and maintenance, particularly where there is a scarcity of construction aggregate. The use of recycled aggregate weakens the quality of recycled aggregate concrete which limits its application. For improving the quality of recycled coarse aggregate, various methods are adopted. In the current study, M25 concrete mixture is obtained by weight replacement of cement, fine aggregate and coarse aggregate with Ground Granulated Blast furnace Slag, Quarry Dust and Recycled Concrete Aggregates respectively in the proportions of 30% and 50% replacement. An attempt has been made to obtain a right combination of concrete for the proper usage of recycled materials economically, and the results obtained when compared with the original concrete have been satisfactory. Use of recycled materials in concrete can be described in environmental protection and in economical terms.
*Corresponding Author: G.Gautham Kishore Reddy , Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India Published: August 27, 2015 Review Type: peer reviewed Volume: II, Issue : I Citation: G.Gautham Kishore Reddy, Research Scholar (2015) RECYCLED AGGREGATE CONCRETE WITH GGBS AND QUARRY DUST
INTRODUCTION GENERAL The growing need for infrastructural development has placed a huge demand on coarse aggregates, which make up about three-quarters of concrete, the most used manmade material in construction. This demand exerts pressures on aggregate resources and creates ecological imbalance which impacts negatively on the environment; rendering the production of concrete using natural aggregates unsustainable. In addition to ecological imbalances created by over-exploitation of aggregates, the open disposal of commercial, industrial and agricultural wastes has exacerbated environmental conditions. Due to the scarcity and increasing prices of construction materials, there is the need to investigate and utilize alternative materials in construction. The increasing demand and interest in aggregates from non-traditional sources such as from industrial by-products and recycled construction and demolition wastes provides opportunities to make use of wastes which would otherwise have negative consequences on the environment. Recycling of such wastes for use in construction therefore provides a
means to address both environmental and infrastructural development challenges. A report mentioned that the use of recycled concrete aggregate provides significant benefits towards sustainable development by reducing the need of land filling while conserving the use of increasingly scarce good quality virgin aggregate; potentially leading to an annual savings of three hundred million dollars ($300,000,000.00) in operator costs by US ready-mixed concrete industry. Any construction activity requires several materials such as concrete, steel, brick, stone, glass, clay, mud, wood, and so on. However, the cement concrete remains the main construction material used in construction industries. For its suitability and adaptability with respect to the changing environment, the concrete must be such that it can conserve resources, protect the environment, economize and lead to proper utilization of energy. To achieve this, major emphasis must be laid on the use of wastes and byproducts in cement and concrete used for new constructions. The utilization of recycled aggregate is particularly very promising as 75 per cent of concrete is made of aggregates. The use of recycled aggregates from construction and demolition wastes is showing prospective application in construction as alternative to primary (natural) aggregates. Research on the usage of waste construction materials is very important since the materials waste is gradually increasing with the increase of population and increasing of urban development. The reasons that many investigations and analysis had been made on recycled aggregate are because recycled aggregate is easy to obtain and the cost is cheaper than virgin aggregate.
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Advanced Research Journals of Science and Technology
ORDINARY PORTLAND CEMENT Portland cement is the most commonly used type of cement in the world today. Portland cement can be found in both concrete and mortar, where it acts as a binding agent. On a chemical level, Portland cement is a fine powder comprised of a minimum of 66% calcium silicate, with the remainder largely being a mix of aluminum, and iron. Portland cement is a hydraulic material, which requires the addition of water in order to form exothermic bonds, and is not soluble in water.
Further characterization may be achieved using the following: grading, shape, inclusion, bulk density, water absorption, chemical composition and drying shrinkage.
Originally designed as a cement which would set slowly, allowing enough time for it to be properly laid, and a water resistant cement which could be used in construction applications where water would come in contact with the cement, Portland cement was first patented in 1824 by an English man, Joseph Asp din, but the mix which became truly successful, and which is still used today, was designed by his son, William Asp din in around 1843. RECYCLED CONCRETE AGGREGATE Role Of The Aggregate In Concrete Regarding concrete, which is the construction material of our era, the protection of the environment concerns three basic axes: • Use of high amounts of raw materials (aggregates for the production of cement and concrete) which result in the decrease of available natural resources which is continuously sub-graded. • Consumption of high amounts of energy for the production, transport, use of raw materials and final ones, as cement and concrete. • Creation of big volumes of old concrete from old construction works (demolition wastes). The cementing medium has two main functions. 1. To fill voids between aggregate particles providing lubrication of the fresh (plastic) concrete and water tightness and durable structure in the hardened concrete. 2. To give strength to hardened concrete.
Recycled Concrete Aggregates
Necessity For The Re-Use Of RCA Urbanization growth rate in India is very high due to industrialization. Growth rate of India is reaching 9% of GDP. Rapid infrastructure development requires a large quantity of construction materials, land requirements & the site. For large construction, concrete is preferred as it has longer life, low maintenance cost & better performance. For achieving GDP rate, smaller structures are demolished & new towers are constructed. Protection of environment is a basic factor which is directly connected with the survival of the human race. Parameters like environmental consciousness, protection of natural resources, sustainable development, play an important role in modern requirements of construction works. Recycling reduces the cost (LCC) by about 34-41% & CO2 emission (LCCO2) by about 23-28% for dumping at public / private disposal facilities.
The aggregate in concrete has three main functions. 1. To provide a relatively cheap filler for the cementing material. 2. To provide a mass of particles which are suitable for resisting the action of applied loads, abrasion the percolation of moisture and the action of the weather. 3. To reduce the volume changes resulting from the setting and hardening process and from moisture changes in the cement paste. The simplest and most common method for characterization of aggregate is on the basis of the specific gravity, i.e. (i) normal weight (ii) light weight and (iii) heavy weight.
Use of RCA
The Use of Recycled Aggregates in Concrete Regarding that the quality data of old concrete is often unknown (w/c ratio, kind and amount of admixtures, aggregates origin and gradation, etc.), as well as the differentiation of its properties during its performance time, 12
Advanced Research Journals of Science and Technology
the knowledge and tests of RCA should refer to four categories: • Historical data of RCA referring to the composition of old concrete, masonry etc. petrography characteristics, data of old structures. • Physical characteristics, especially in water absorption, specific gravity, amount of chlorides and sulphates, amount of contained foreign ingredients, possibility of creation of alkali–silica reaction. • Mechanical characteristics, testing resistance to abrasion/degradation by the use of L.A. machine, percentage of soft granules. • Environmental characteristics, especially in cases where RCA seem to create ‘‘leachates’’.
This renders the control of the free water-to-cement ratio (w/c) and the workability of fresh concrete difficult and, results in a higher shrinkage and creep of the hardened concrete when compared with the concrete prepared with natural aggregates. CO2 emissions for GGBS and cement production Typical CO2 Emissions for Portland Cement and GGBS Production
Recycled Wash Water and Aggregate Recovery Trucks returning from site to be washed out discharge into a “concrete reclaimed where the coarse aggregate and coarse sand are recovered from the “liquidfines for reuse. Coarse aggregate recovered from fresh concrete can be recycled and considered as equivalent to virgin aggregate, provided the mortar is adequately washed out. Cement
GGBS
Durability –increased resistance to acids Peaty soils –acidic environment
Typical system for recycling wash water/aggregate recovery Typical rural low volume ready mixed plants operate a recycling system that settles the solids from the fines out of suspension and then allows reuse of the clear wash water. The solids that have settled are periodically removed and allowed to dry, prior to disposal to landfill. For larger plants the amount of solid material to be disposed of is prohibitive, and a recycled wash water system (see Figure) is typically used. Quality Control The flow of quality control is from investigation of the original concrete to application of the recycled coarse aggregate concrete. Quality control is carried out according to the construction specification & manufacturing guidelines for recycled coarse aggregate concrete. Quality control covers the three respective processes for the material • Original concrete • Recycled coarse aggregate • Recycled coarse aggregate concrete. As a result of examination, any material that does not adapt the quality requirements of the construction specification and/or manufacturing guidelines at any of three processes is restricted from use. Mix Proportions
Working with Ground Granulated Blast furnace Slag (GGBS) Concrete Water Demand GGBS allows for water reduction of 3 to 5% in concrete without any loss in workability. Water should not be added to GGBS concrete after dispatch from the concrete plant as it reduces strength and durability of the concrete. Placing, Compacting and Pumping GGBS makes concrete more fluid, making it easier to place into formwork and easier to compact by vibration. GGBS concrete remains workable for longer periods allowing more time for placing and vibrating. Pumping is also easier due to the better flow characteristics. Concrete with 50% GGBS Strength development GGBS concrete has slightly slower strength development at early ages, but will have equal if not greater strength at 28 days compared to non GGBS concrete.
The compressive strength increased with a decrease in a/c ratio and is directly proportional to strength of the blended aggregate. However, when used at a higher level of replacement, the high water absorption ability of recycled aggregate results in a higher total water demand. 13
Advanced Research Journals of Science and Technology
Admixtures
AGGRREGATES
GGBS concrete is compatible with all admixtures. However care should be taken if retarding agents are specified as GGBS can have a retarding effect on the set. If you require specific advice consult your admixture supplier or contact Eco-cement.
Aggregates are the major ingredients of concrete. They constitute 70-75% of the total volume; provide a rigid skeleton structure for concrete, and act as economical space fillers. The aggregates form the main matrix of the concrete. The aggregate particles are glued together by the cement and water paste. With cement and water the entire matrix binds together into a solid mass called concrete. Aggregates influence the properties of concrete such as water requirement, cohesiveness and workability of the concrete in plastic stage, while they influence strength, density, durability, surface finish and colour in hardened stage. It is therefore significantly important to investigate the various properties of aggregates.
Initial setting time of GGBS concrete
Aggregates are generally inert and broadly divided into two categories, i.e. fine and coarse, depending on their size. Aggregates with grain size below 4.75mm are termed fine aggregates and above 4.75mm are termed as coarse aggregates. I.S.383-1963 defines the requirement of aggregates.
QUARRY DUST
EXPERIMENTAL PROGRAM
The reduction in the sources of natural sand and the requirement for reduction in the cost of concrete production has resulted in the increased need to identify substitute material to sand as fine aggregates in the production of concretes especially in Concrete.
This experimental study includes PG research work for the workability test and hardened concrete specimens test.
TESTS ON MATERIALS CEMENT Although all materials that go into concrete mix are essential, cement is very often the most important because it is usually the delicate link in the chain. The function of cement is first of all to bind the sand and stone together and second to fill up the voids in between sand and stone particles to form a compact mass. It constitutes only about 20 percent of the total volume of concrete mix; it is the active portion of binding medium and is the only scientifically controlled ingredient of concrete. Any variation in its quantity affects the compressive strength of the concrete mix. Portland cement referred as (Ordinary Portland Cement) is the most important type of cement and is a fine powder produced by grinding Portland cement clinker. The OPC is classified into three grades, namely 33 Grade, 43 Grade, 53 Grade depending upon the strength of 28 days. It has been possible to upgrade the qualities of cement by using high quality limestone, modern equipments, maintaining better particle size distribution, finer grinding and better packing. Generally use of high grade cement offers many advantages for making stronger concrete. Although they are little costlier than low grade cement, they offer 10-20% saving in cement consumption and also they offer many hidden benefits. One of the most important benefits is the faster rate of development of strength. Ordinary Portland Cement (OPC) is the cement best suited to general concreting purposes. OPC 53 grade confirming with IS: 8112-2007 is used. The cement is kept in an airtight container and stored in the humidity controlled room to prevent cement from being exposed to moisture.
The whole test program is as follows The experimental study was divided into four major segments viz. 1) Mix Design 2) Checking the fresh properties of the mix M25 • Slump test 3) Casting Cubes 4) Curing 5) Tests on Hardened concrete specimens • Compression Test • Flexural Strength Test • Split Tensile Test MIX DESIGN Design of M25 as per IS: 10262:2009. a) Maximum size of aggregate = 20 mm b) Degree of workability = 0.90 c) Degree of workability = Good d) Type of exposure = Mild Design of concrete (M25) 1) Determine the target mean strength
fck' = fck+1.65(S)
= 25+1.65*4 = 31.6 N/mm²
2) Selection of water –cement ratio (W/C) Max water content = 186 kg (Nominal max size of aggregates 20mm) 3) Cement content from W/C Cement
= 0.44
= 186/.44 = 422.73 kg
4) Valve of all in aggregates a)Percent of CA as total aggregates = 0.62 b) Change of W/C = 0.44-0.5=0.06n c) CA in all aggregates = (0.06/0.05)*0.01=0.012 d) Total all in aggregates (e') = 0.62+.012=0.632 14
Advanced Research Journals of Science and Technology
5) Value of all fine aggregates
(e‘) = 1-0.632=0.368
6) The mix of calculation as per unit volume e) Volume of cement = (mass of cement / specific gravity)*(1/1000) = (422.73/3.15)*(1/1000) = 0.1342 m³ f) Volume of water ity)*(1/1000)
= (mass of water / specific grav-
= (186/1)*(1/1000) = 0.186 g) Volume of admixture nil h) Volume of all in aggregates = (1-0.1342-0.186) = 0.6798 i) Mass of coarse aggregates = (e'*volume of CA*sp.gravity*1000) = (0.632*0.6798*2.75*1000) = 1181.49 kg j) Mass of fine aggregates = (e‘*volume of FA*sp.gravity*1000) = (0.368*.6798*2.49*1000) = 622.91 kg Procedure • Initially, a known volume of cement concrete is prepared with a required proportion of ingredients and water - cement ratio. • The slump mould is cleaned for any remaining cement particles or impurities and is properly oiled at the inner surface. • Then the prepared concrete sample is put into the mould which is placed on a non-porous plate, in 3 layers with a tapping of 25 times for each layer by a standard tamping rod. The extra heap of concrete present on the top of the mould is cut off or leveled off. • Then the mould is lifted up vertically by taking care not to disturb the cast cement in the mould. • The nature of slump is analyzed to get the workability of the given cement concrete sample.
Concrete Moulds
Details Of Tests And Test Specimens Sr.no.
Tests
Test Age
No. of Specimens
Specimens
1
Compressive Strength (150mm x 150mm x 150mm)
3, 7, 28 days
18
cube
Curing After 24 hours the specimens were removed from the moulds and immediately submerged in clean fresh water and kept there until taken out just prior to testing.
Slump Values M25 with 30% replacement-103 mm M25 with 50% replacement- 99 mm Placing of concrete mix in Moulds The concrete is casted in to cube moulds of size 100mm×100mm,beam moulds of size100×100×500mm and cylindrical moulds of 200 mm height ×150 mm dia. The moulds used for the purpose are fabricated with steel seat. It is easy for assembling and removal of the mould specimen without damage. Moulds are provided with base plates, having smooth to support. The mould is filled without leakage .In assembling the moulds for use joints between the section of the mould are applied with a thin coat mould oil and similar coating of mould oil is applied between the contact faces of mould and the base plate to ensure that no water escape during filling .The interior surfaces of the assembled mould shall be thinly coated with mould oil to prevent adhesion of concrete. After mixing the proportions in the mixing machine, it is taken out into the bucket. The concrete is placed in to the moulds (cubes, beams & cylinders), which are already oiled simply by means of hands only without using any compacting devices.
Curing Of Concrete Moulds
TESTS ON SPECIMENS Compressive strength of concrete Compressive strength of concrete is defined as the load, which causes the failure of a standard specimen.(Ex 100 mm cube according to ISI)divided by the area of cross section in uni-axial compression under a given rate of loading. The test of compressive strength should be made on150mm size cubes. place the cube in the compression-testing machine. The green button is pressed to start the electric motor. When the load is applied gradually, the piston is lifted up along with the lower plate and thus the specimen application of the load should be 300 KN per minute and can be controlled by load rate control knob. Ultimate load is noted for each specimen. The release valve is operated and the piston is allowed to go down. The values are tabulated and calculations are done.
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Advanced Research Journals of Science and Technology
PROCEDURE
Compression Test
I. Remove the specimen from water after specified curing time and wipe out excess water from the surface. II. Take the dimension of the specimen to the nearest 0.2m III. Clean the bearing surface of the testing machine IV. Place the specimen in the machine in such a manner that the load shall be applied to the opposite sides of the cube cast. V. Align the specimen centrally on the base plate of the machine. VI. Rotate the movable portion gently by hand so that it touches the top surface of the specimen. VII. Apply the load gradually without shock and continuously at the rate of 140kg/cm2/minute till the specimen fails. VIII. Record the maximum load and note any unusual features in the type of failure. The results are recorded for further analysis. Specimens are tested at each age to compute Compressive Strength = P/A Where, P: Ultimate compressive load of concrete (KN) A: Surface area in contact with the platens (mm²) RESULTS AND DISCUSSION
Compressive Strength of M25-30% Replacement
Compressive Strength of M25-50% Replacement
CONCLUSION • The experimental results suggest that the RAC with GGBS & QD in 30% replacement, have the similar compressive strength values as of the traditional concrete.
Slump Values S.NO
Mix type
Slump (mm)
1
M25 with 30% replacement
103
2
M25 with 50% replacement
99
• Workability of the RAC with GGBS & QD is a bit on lower side when compared to traditional concrete, but still is within the range. • However the 50% replacement of materials in concrete shows the reduction in strength with further low workability. • M25 RAC with GGBS & QD in 30% replacement is a good mix that can be used as a substitution for the traditional M25 mix, which have the added advantages of economical and eco friendly. SCOPE FOR FURTHER STUDY • There is a scope for the study in the areas of increasing the workability in the RAC with GGBS & QD by the addition of admixtures and studying its effect on other properties. • The same partial replacement can be tried for greater strength concretes up to M40, and check the suitability.
Slump Values
• Various other recycled materials and bi products can be used as replacements in concrete for environmental protection. 16
Advanced Research Journals of Science and Technology
REFERENCES 1. Tavakoli (1996), “Strength of recycled aggregate concrete made using field demolished concrete as aggregate” ACI journal March-April 1996; p-182-190. 2. Tom Wilmot and George Vorobieff (1997), “Is road recycling a good community policy?” 9th National Local Government Engineering Conference–29 August 1997. 3. Limbachiya M. C., Leelawat T. and Dhir R. K (2000), “Use of recycled concrete aggregate in high-strength concrete, Materials and Structures”, November 2000, pp. 574- 580. 4. Bodin F. and Hadijieva-Zaharieva R (2002), “Influence of industrially produced recycled aggregates on flow properties of concrete”, September-October 2002, pp. 504509. 5. Poon (2002), “Hong Kong experience of using recycled aggregates from construction and demolition materials in ready mix concrete” 2002. 6. I.R.Mithanthaya, Jayaprakash Narayan, Replacement of Sand by Quarry Dust for Plastering and in the Pavement Design, Proceedings of national Symposium at Karunya Institute of Technology on 20-21,December 2002, pp 9-15. 7. Nobuaki Otsuki, M.ASCE, Shinichi Miyazato and Wanchai Yodsudjai (2003), “Influence of Recycled Aggregate on Interfacial Transition Zone, Strength, Chloride Penetration and Carbonation of Concrete.” Journal of materials in civil engineering September - October 2003. 8. Amnon Katz (2004), “Treatments for the Improvement of Recycled Aggregate” Journal of materials in civil engineering November - December 2004.
MacLean, M.ASCE (2009), “Energy and Greenhouse Gas Emissions Trade-Offs Of Recycled Concrete Aggregate Use in Non structural Concrete: A North American Case Study” journal of infrastructure systems December 2009. 13. Aveline Darquennes, Stephanie Staquet, and Bernard Espion. (2011). “Behaviour of Slag Cement Concrete under Restraint Conditions”. European Journal of Environmental and Civil Engineering, 15 (5), 787-798. 14. Sonali K. Gadpalliwar1, R. S. Deotale2, Abhijeet R. Narde3, (2014) “To Study the Partial Replacement of Cement by GGBS & RHA and Natural Sand by Quarry Sand In Concrete” IOSR Journal of Mechanical and Civil Engineering (IOSR-JMCE) Volume 11, Issue 2 Ver. II (MarApr. 2014), PP 69-77. 15. Maneesh kumar C, Manimaran, Prasanth, (2015) An Experimental Investigation on GGBS and Fly ash Based Geo polymer Concrete with Replacement of Sand by Quarry Dust, Int. Journal of Engineering Research and Applications Vol. 5, Issue 5, ( Part -1) May 2015, pp.91-95. AUTHOR
G.Gautham Kishore Reddy Research Scholar, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
9. Md.Safiuddin, S.N.Raman and M.F.M. Zain, Utilization of Quarry waste fine Aggregate inconcrete mixures, (2007) Journal of Applied sciences research 3(3) : 202-208. 10. Shariq, M., Prasad J, and Ahuja A.K. (2008). “Strength Development of Cement Mortar and Concrete Incorporating GGBFS”. Asian Journal of Civil Engineering (Building and Housing), 9 (1), 61-74. 11. G.Fathifazl; and A.Abbas (2009), “New Mixture Proportioning Method for Concrete Made with Coarse Recycled Concrete Aggregate” Journal of materials in civil engineering October 2009. 12. Jamie McIntyre1; Sabrina Spatari ; and Heather L.
S.Uttamraj Assistant Professor, Department of Civil Engineering, Aurora's Scientific Technological and Research Academy, Hyderabad, India.
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