Conference Papers
Permanent URI for this collectionhttps://idr.nitk.ac.in/handle/123456789/28506
Browse
3 results
Search Results
Item High Strength Flowable Alkali Activated Slag Concrete Mixes produced using industrial wastes(Institute of Physics Publishing helen.craven@iop.org, 2019) Manjunath, R.; Narasimhan, M.C.A new class of High-Strength Flow ableAlkali activated Slag Concrete(HSFASC)mixes is developed using steel slag sand and EAF (Electric Arc Furnace) slag aggregates, respectively, as the fine and coarse aggregates. These mixes use the ground granulated blast furnace slag as the source material. Thus it is to be recognized that all the three materials used - GGBFS, slag sand and EAF slag aggregates are by-products of the Iron and Steel Industry, and are available in very large quantities demanding safe disposal. Different amounts of Sodium silicate solutions, with specified amounts of Sodium Hydroxide flakes dissolved in them, are used as alkaline solutions. Test specimens were cast using a total of nine HSFASC mixes, (based on Taguchi's Method), each of which satisfied the relevant EFNARC guidelines with respect to their rheological properties. The test results indicate higher compressive strengths values for all the mixes tested herein. Microstructure studies are conducted on samples from the fractured surfaces of test specimens of different mixes, using advanced SEM, EDX and XRD analyses and the results are discussed. © 2019 IOP Publishing Ltd. All rights reserved.Item Effect of addition of OPC on Performance characteristics of Self-compacting Alkali activated slag concrete mixes(Institute of Physics Publishing helen.craven@iop.org, 2019) Manjunath, R.; Narasimhan, M.C.An attempt has been made in the present research to develop construction friendly, self-compacting, alkali-activated slag concrete mixes with ground granulated blast furnace slag (GGBFS) as the major source of binder material. In an effort to make the concrete mixes more eco-friendly and sustainable, by-products from Iron and Steel Industry such as steel slag sand and Electric Arc Furnace (EAF) slag aggregates, were used as the fine and coarse aggregates respectively. While the total binder content has been varied in the range of 700 - 800 kg/m3 (in increments of 50 kg/m3), all the trial mixes had a constant w/b ratio of 0.40. Different amounts of sodium silicate solutions, with specified amounts of sodium hydroxide flakes dissolved in them, are used as alkaline solutions, with the combined Na2O percentage in them varying between 6% - 8%. Test specimens were cast with mixes which showed enhanced flow-properties as per relevant EFNARC guidelines and were tested for their mechanical strength and durability characteristics. Effect of admixing of ordinary Portland cement (OPC) in smaller percentages (2.5% - 10 %, in increments of 2.5%), on the performance characteristics of this novel class of AAC mixes is evaluated. Increased cement contents are found to lead to better flow ability properties and higher strengths values with lower sorptivity values in all the Cement-Admixed, Self-compacting, Alkali-Activated Slag Concrete mixes (CASAASC mixes) tested herein. Studies with a scanning electron microscope have shown more densified morphologies developed, accounting for better performances of these mixes. © 2019 IOP Publishing Ltd. All rights reserved.Item Experimental studies on shear strength characteristics of alkali activated slag concrete mixes(Elsevier Ltd, 2020) Manjunath, R.; Narasimhan, M.C.; Shashanka, M.; Vijayanand, S.D.; Vinayaka, J.In the present study an attempt has made to study the shear strength characteristics of alkali activated slag concrete mixes developed using steel slag sand and Electric Arc Furnace (EAF) slag aggregates, respectively, as the fine and coarse aggregates. These mixes use the ground granulated blast furnace slag (GGBFS) as the primary source material. Thus it is to be recognized that all the three materials used-GGBFS, slag sand and EAF slag aggregates are by-products of the Iron and Steel Industry, and are available in very large quantities demanding safe disposal. Different amounts of Sodium silicate solutions, with specified amounts of Sodium hydroxide flakes dissolved in them, are used as alkaline solutions. The test results indicate higher compressive strengths values for all the mixes in the range of 50-70 MPa with their shear strength values ranging between 7.5 and 12.0 MPa. Further the relationship between shear strength and compressive strength of the AASC mixes was also developed. © 2019 Elsevier Ltd. All rights reserved.