Industrial and environmental significance of photonic zirconia nanoflakes: Influence of boron doping on structure and band states

S.P. Ratnayake,C. Sandaruwan,M.M.M.G.P.G. Mantilaka,N. de Silva,D. Dahanayake,U.K Wanninayake,W.R.L.N. Bandara,S. Santhoshkumar,E. Murugan,G.A.J.Amaratunga,K.M. Nalin de Silva 한국공업화학회 2021 Journal of Industrial and Engineering Chemistry Vol.95 No.-

A unique zirconia nanomorphology possessing an enhanced photocatalytic efficiency was developedutilizing a convenient single-sol synthesis process which involved in-situ doping of zirconia by boron. The boron-doped zirconia exhibited aflake morphology as opposed to the spherical pure form andsubsequent crystallographic investigations implied the phase conversion from binary to single-phasealong with the shape due to the doping. Optical characterization indicated a modified band structurewith newly generated isolated impurity states within the principle zirconia band edges. As per the X-rayspectroscopy data, boron was detected as chemically bound to oxygen while electron paramagneticresonance indicated the presence of an adsorbed oxygen lattice. During UV and simulated solarirradiation trials, respective removal capabilities of 90% and 93% of the model compound wereaccomplished, hence the effectiveness of the photocatalyst was confirmed. The enhanced photoactivityobserved in the UV region was attributed to combined effects of the boron-induced isolated impuritystates within principle band edges of zirconia, the defect-rich planer morphology, favorable interfacialinteractions and the greater availability of oxygen on the lattice. Developed nanoflakes are stable, inert,and efficient hence exhibiting compelling suitability in the remediation of harmful industrial organiccompounds.

Performance enhancement of concrete by using ceramic waste as a partial replacement for coarse aggregate

M. Harikaran,P. Kulanthaivel,A.R. Krishnaraja,P.C. Murugan 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.2

A significant quantity of the world's volume of construction and demolition waste comes from the ceramic and constructionsectors. To reduce such waste, ceramic waste is used as one of the ingredients of concrete material in this study to improvethe engineering characteristics of the concrete. In this investigation, ceramic waste aggregate is used in place of natural coarseaggregate in proportions of 0%, 20%, 40%, 60%, 80% and 100%. Laboratory studies on Compressive strength, Split Tensilestrength, Flexural strength, and Shear strength were carried. The findings of experimental tests showed that adding ceramicwaste increased the compressive strength of CRWAC40's (Ceramic Waste Aggregate Concrete) as compared with CC(Conventional Concrete) and the values of compressive strengths being 37.75 MPa and 36.25 MPa respectively. CC andCRWAC40 have split tensile strengths of 3.15 MPa and 3.58 MPa respectively. In this case, the split tensile strength ofCRWAC40 is increased by 13% when compared to conventional concrete. Flexural and shear strengths of CC and CRWAC40are 5.32 MPa, 7.48 MPa and 5.72 MPa, 7.82 MPa respectively. Based on the laboratory test results, it has been concluded thatceramic waste aggregate could be used up to 40% in replacement of conventional coarse aggregate in concrete to improve itsengineering properties.

Eco-Efficient Concrete: A sustainable reutilization of Ceramic Tile Waste Powder (CTWP) as a partial replacement for cementitious material in a recycled fine aggregate concrete

S. Janani,G.S. Rampradheep,P. Kulanthaivel,P.C. Murugan 한양대학교 청정에너지연구소 2022 Journal of Ceramic Processing Research Vol.23 No.6

The waste generated from the construction will not only leads to environmental crisis but also project overrun. Theenvironmental problems results in increase of pollution that leads society to unfit for living organisms. Many investigationshave been carried out on the area of Construction Waste (CW). At the end of 2025, the volume of CW generated will nearlydouble to 2.2 billion tons worldwide. Construction waste contributing 40% depletes earth’s environment. The researchcomprised of two phases. Phase one focuses on the reduction of material waste generated from the construction that can bereutilized as fine aggregate in concrete of different proportions 25%, 50%, 75% and 100%. Phase two aims to decrease theamount of CO2 emission from the cement and that can be achieved by utilization of CW material - Ceramic Tile Waste Powder(CTWP) as a substitute for cement in varying proportions 0%, 10%, 20%, 30% and 40%. The research showed theperformance of Eco-Efficient Concrete with different proportions of CTWP and Recycled Fine Aggregate (RCFA) throughmeasured properties. The use 30% CTWP & 100% RCFA replacement level adequate for compressive strength improvementat 28 days is 24.8 N/mm2. The simultaneous use of increased percentage of CTWP & RCFA at different replacement levelsenhances the durability Properties.

Unleashing the resilience of Reinforced Concrete Member retrofitted with composite laminates

K.S. Navaneethan,S. Anandakumar,S. Manoj,P.C. Murugan 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.5

This work presents experimental results on the performance of Aramid Fiber Reinforced Polymer (AFRP) laminates used inthe flexural retrofitting of full-scale reinforced concrete beams. The effects of variables including reinforcement placement,retrofitting orientation, and AFRP lifespan are examined. The experimental findings provide compelling evidence thatstructurally damaged beams can be retrofitted with AFRP composite material to restore their strength and stiffness. In mostcases, the retrofitted beams perform as well as, if not better than, the control beams. The efficiency of the AFRP strengtheningmethod in flexure, however, was found to vary with beam length. The examinations revealed that plate debonding was theleading cause of the failures observed. In order to overcome this difficulty, it is crucial to enhance the bonding processesbetween the AFRP laminates and the concrete substrate.

Influence of ceramic waste powder (CWP) in strength and durability performance of coir fiber reinforced concrete

S. Anandaraj,A.R. Krishnaraja,P. Kulanthaivel,P.C. Murugan 한양대학교 청정에너지연구소 2024 Journal of Ceramic Processing Research Vol.25 No.1

Concrete is stable in compression but frail in tension. For eliminating the problem, we introduce fibers in the concrete. Ceramic waste powder, when finely ground, can exhibit pozzolanic properties and the coir fiber acts as a natural fiber. Utilizing ceramic waste powder as an additional cementitious ingredient can be advantageous for the environment and theeconomy. A budgetary and sizable plain concrete can be advanced via the unreal of normal Portland cement with ceramicwaste powder. Coir fibers in concrete influences a lesser amount of compressive strength and higher amount of tensilestrength. An investigation is accomplished to test the opportunity of the inclusion of ceramic waste powder as partial cementreplacement and coir fibers were introduced to improve the tensile properties in the concrete. In this study, cement issubstituted with ceramic waste powder in amounts of 0%, 20%, 40%, 60% and 80%. A preliminary investigation revealedthat using 20% ceramic waste powder in place of cement improved the properties of concrete's strength. Further researchreveals that concrete with 0, 0.5%, 1% and 2% coir fiber addition in the concrete with constant 20% ceramic waste powder. Results shows 1% coir fiber addition and 20% ceramic waste powder as cement replacement achieved the strongest qualitiescompared to control concrete. In comparison to the other specimens, the combination of coir fibers with ceramic waste powderimproves the strength properties.

Experimental analysis of treated waste foundry and waste ceramics sand by replacement of fine aggregate in concrete

K.V. Boobala Krishnan,K. Nirmalkumar,V. Sampathkumar,P.C. Murugan 한양대학교 청정에너지연구소 2023 Journal of Ceramic Processing Research Vol.24 No.4

Due to rapid urbanization and industrialization, excessive exploitation of natural resources like river sand and gravels is amajor concern. This study investigated the use of waste foundry sand and waste ceramics as partial replacements for M-sandin concrete. M25 grade concrete with a 1:1.1:2.2 ratio and a water-to-cement ratio of 0.45 was used. Waste foundry sandunderwent pre-treatment with sodium silicate to improve its applicability. Treated waste foundry sand (TWFCS) and 10%powdered waste ceramics were combined to partially replace M-sand in different proportions (0%, 10%, 15%, and 20%). Mechanical tests, including compressive, tensile, and flexural strength assessments, were conducted after 7, 14, and 28 daysof curing. The concrete samples were exposed to a marine and acidic environment for 60 days. TWFCS 3 exhibited the lowestcompressive strength (26.39 N/mm2) after exposure to an alkaline environment, while TWFCS 1 showed the highestcompressive strength (28.63 N/mm2). Treated foundry sand showed superior mechanical properties, surpassing M-sand by15% in terms of compressive, split tensile, and flexural strength. SEM and XRD analysis were used to evaluate the concretecontaining treated waste foundry and ceramics sand.