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Item Strength characteristics of laterized mortars using processed laterite(Springer, 2019) Basavana Gowda, S.N.; C, C.; Yaragal, S.C.The rapid pace of population growth in India has enforced the construction industry to use construction materials at an accelerated rate leads to the exhaustion of natural resources. Large-scale constructions have a severe influence on the environment instigating many threats either directly or indirectly like exhaustion of the river due to unscientific sand mining being done at a frightening level, etc. To address this issue, it is required to find substitutes for river sand for producing mortars. One among the locally available marginal resource is laterite. In this study, an attempt is made to study the performance of cement mortars using laterite as fine aggregate in replacement levels of 0, 25, 50, 75 and 100% to natural fine aggregates (river sand). Studies were carried out in two stages, initially river sand is replaced with laterite quarry waste (unprocessed laterite), and then it is replaced with the processed laterite. The flowability and compressive strength characteristics of mortars are studied. Results indicate that, the decrease in compressive strength of mortars with increase in replacement levels of river sand by unprocessed laterite was more, when compared to mortars with processed laterite. However, there is only 13% reduction in strength for laterized mortar with 100% processed laterite when compared to control mortar is observed. © Springer Nature Singapore Pte Ltd. 2019.Item Studies on Uniaxial compressive strength of laterite masonry prisms(2011) Unnikrishnan, S.; Narasimhan, M.C.; Venkataramana, K.Laterite is a well known conventional building material in Asian countries. In spite of its large popularity in construction, a systematic characterization of this material, as a building block, has not been seriously attempted so far. The strength and elastic properties of laterite masonry are influenced by the individual properties of the laterite blocks and the mortar. In the present study, characterization of the laterite block and the mortar and compressive strength of laterite masonry prisms have been investigated using detailed laboratory experiments and numerical analysis. The experimental results, related to the compressive strength and stress-strain characteristics of laterite and mortar and compressive strength of laterite masonry prisms are presented. Finite element analysis of laterite masonry prism has also been carried out. The studies have shown that the modulus of elasticity of laterite blocks tested is less than that of mortar used in making the laterite masonry. Further, the laterite masonry prisms have been observed to have failed by bond failure and subsequent splitting of laterite blocks. Also, increase in thickness of mortar joint gives rise to a decrease in laterite tensile stresses in mortar joint leading to higher prism strengths, if bond remains intact. © 2011 CAFET-INNOVA technical society. All right reserved.Item A model study on accelerated consolidation of coir reinforced laterite and blended shedi soil with vertical sand drains for pavement foundations(2012) George, V.; Santosh, G.; Hegde, R.N.; Durga Prashanth, L.; Gotamey, D.; Ravi Sankar, A.U.Sub-grade soils of lateritic origin are frequently encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. Coir is a natural fiber that can be used in place of geosynthetics and geogrids, and it is biodegradable and environment friendly. This work deals with the accelerated consolidation of un-reinforced and coir-reinforced laterite and blended lithomargic soils, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50kg (0.0013 N/mm2) to 500kg (0.013N/mm2) using circular ferro-cement moulds. It was observed that at lower preloads up to 300kg, the relative increase in consolidation (Cr) for randomly reinforced soil with vertical drains was significantly higher than that of un-reinforced soil without vertical drains. Also, the Cr for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with values above 38.71%. However, in the case of higher preloads of 450kg and 500kg, the Cr for randomly reinforced soil with vertical drains was insignificant, and the Cr for un-reinforced soil with vertical drains remained slightly higher at around 9.59% for similar comparisons. The aspect-ratio of coir fibers used was 1: 275. © 2012 Cafet-Innova Technical Society. All rights reserved.Item Accelerated consolidation of coir reinforced lithomargic laterite soil blends with vertical sand drains for pavements(2012) George, V.; Hegde, R.N.; Vardhana, M.V.; Santosh, G.; Gotamey, D.It is found that sub-grade soils of lateritic origin encountered in the construction of highway embankments in various regions of India, often comprise intrusions of soft lithomargic soils that result in large settlements during constructions, and differential settlements at later stages. This necessitates the use of appropriate soil improvement techniques to improve the load-carrying capacity of pavements. This work deals with the accelerated consolidation of un-reinforced and coir-reinforced laterite and blended lithomargic soils, provided with three vertical sand drains. The load-settlement characteristics were studied for various preloads ranging from 50kg (0.0013 N/mm2) to 500kg (0.013N/mm2). Studies were performed using circular ferro-cement moulds. It was observed that at lower preloads of up to 250kg, the relative increase in consolidation (Rct) for randomly reinforced soil with vertical drains was significantly higher than that of un-reinforced soil without vertical drains. Also, the Rct for un-reinforced soil with vertical drains was quite higher than that of un-reinforced soil without vertical drains, with an average value of 20.84%. In the case of higher preloads the Rct values for randomly reinforced soil with vertical drains were moderate with an average value of 22.67%. An additional increase of up to 27% at lower pre-loads and 11.83% at higher pre-loads was observed due to the effect of random reinforcement when compared to use of vertical drains alone. © 2012 ejge.Item Use of Laterite as a sustainable building material in developing countries(CAFET INNOVA Technical Society cafetinnova@gmail.com 1-2-18/103, Mohini Mansion, Gagan Mahal Road, Domalguda, Hyderabad 500029, 2014) Kasthurba, A.K.; Reddy, K.R.; Venkat Reddy, D.V.Utilisation of local materials is an important step to sustainable construction to reduce transportation cost, save embodied energy, and protect the environment. This paper advocates the use of local laterite-a soil type rich in iron and alumina formed under hot and wet tropical conditions-due to its cost effectiveness and energy efficiency than that of conventional modern materials in tropical developing countries. This paper summarizes the occurrence and characteristics of laterite and then highlights the need for developing universal database of properties and standard testing protocols to facilitate evaluation and extensive use laterite in building applications. Understanding of properties and potential challenges of using this material will benefit for the development of suitable strategies/techniques for sustainable construction. Overall, this study identifies various factors that should be considered for efficient utilization and managements of laterite in construction to meet the growing demand of new housing and infrastructural in different regions of developing tropical world. © 2014 CAFET-INNOVA TECHNICAL SOCIETY. All rights reserved.Item Synthesis of Green Iron Nanoparticles using Laterite and their application as a Fenton-like catalyst for the degradation of herbicide Ametryn in water(Elsevier B.V., 2017) Sangami, S.; Manu, B.The Fe nanoparticles were synthesized using eucalyptus leaf extracts. The low cost and locally available laterite was used as a source of iron rather than using iron salts (Ferrous sulfate, Ferric chloride etc.). The raw laterite particles (RLPs) and synthesized green iron nanoparticles (LGFeNPs) were characterized using FESEM-EDX, XRD, FTIR and BET techniques. The obtained results confirm that 20–70 nm of spherical iron particles were formed with surface area of 36.62m2?g. Later, the LGFeNPs were applied as a Fenton-like catalyst for the degradation ametryn in aqueous medium. The effect of variables (H2O2?COD (1–3.25), H2O2?Fe (2–10), pH (2–5) and reaction time (30–240)) involved in the treatment process was studied on two responses (COD and ametryn removal efficiency) using the response surface methodology. The optimum values were found to be 2.125, 6, 3.5 and 135 min for H2O2?COD, H2O2?Fe, pH and reaction time respectively with H2O2 dosage of 17 mg/L and 2.83 mg/L of LGFeNPs. The analysis of variance (ANOVA) results proved that, the obtained results were satisfactory with predicted values. Compared with chemical (NaBH4 reduction) and green synthesis using iron salts as a precursor, the laterite based green synthesis proved to be more effective in degradation of ametryn with faster reaction kinetics. © 2017 Elsevier B.V.Item Nano-scale Iron Oxide as Heterogeneous Fenton Catalyst for Organic Pollution Degradation and Heavy Metal Remediation in Water Sample of Byramangala Lake, Karnataka(IOS Press Nieuwe Hemweg 6B Amsterdam 1013 BG, 2019) Nagappa, D.; Manu, B.A nano-scale iron oxide (Fe2O3/Fe3O4) heterogeneous Fenton catalyst was synthesized for aqueous heavy metals remediation and was utilized to degrade organochlorine pesticides (OCPs), namely, alpha-, and delta-hexachlorocyclohexane (?-HCH and ?-HCH) as well as heptachlor epoxide (HE), in Byramangala lake water sample. Nano-scale Fe2O3/Fe3O4 was synthesized via Solution Combustion Synthesis (SCS), with glycine as fuel and iron oxide separated from raw laterite soil sample (RL) as oxidizer for the reaction. Based on detailed characterization, it was found that iron oxide constituted 34.31% of the RL sample. Later, detection of hematite (Fe2O3), hypersthenes (MgSiO4) and lepidocrocite (FeOOH) in the separated fraction confirmed extraction of Fe2O3 fraction. Next, collection of Byramangala lake water samples and analyses of physico-chemical parameters revealed nil dissolved oxygen (DO) and high chemical oxygen demand (COD) levels. Oxidation of detected pesticides and susceptible heavy metals using the nano-scale Fe2O3/Fe3O4 was investigated under various experimental conditions: pH (3 and 7), dosages of H2O2 (1-9 mM L-1) and nano catalyst (0.05-0.4 g L-1), as well as contact time (5-120 min) in batch experiments. Optimum values were found to be contact time of 50 mins at near-neutral pH at 5 mM L-1 H2O2 and 0.25g L-1 Fe2O3/Fe3O4 dosages, respectively. Under optimized conditions, 100% removal of both ?-HCH and ?-HCH, and 99% removal of HE were observed. Furthermore, appreciable reduction in arsenic (As) and manganese (Mn) concentrations (95% and 76.6%) was also observed. Post-treatment, Fe2O3/Fe3O4 could be efficiently separated by an external magnetic field because of its ferromagnetic behaviour. © 2019 - IOS Press and the authors. All rights reserved.Item Characterization and performance of processed lateritic fine aggregates in cement mortars and concretes(Elsevier Ltd, 2019) Yaragal, S.C.; Basavana Gowda, S.N.; C, C.Availability of river sand is becoming scarce, due to rapid increase in infrastructure projects in India. Acute shortage of river sand, has led to indiscriminate sand mining. Adverse effect of sand mining includes river bank erosion, river bed degradation, loss of biodiversity and deterioration of river water quality and ground water availability. To address the above issues, research efforts are on, to find substitutes for river sand to be used as fine aggregate in mortars and concretes. One among the locally available resources is laterite. Laterite is a product of tropical or sub-tropical weathering, which is an abundant soil material in many parts of India. An attempt has been made to characterize the processing technique to obtain good quality lateritic fine aggregates (lateritic FA). Experiments were designed and conducted to study the performance of lateritic FA as replacement to river sand, in cement mortars and concretes. Processed lateritic FA in replacement levels of 0, 25, 50, 75 and 100 wt% to river sand at all fineness levels (Zone I to Zone IV as per Indian standards) is considered. Microstructure studies were conducted to understand the arrangement of river sand and lateritic FA with cement matrix and their Interfacial Transition Zones (ITZ) using Scanning Electron Microscope (SEM). The workability and compressive strength characteristics of cement mortars and concretes are evaluated. Laterized mortars with Zone III and Zone IV fine aggregates, at all replacement levels, result in the same compressive strengths as those of control mortars. Suitable strength enhancement technique has been attempted to achieve strengths of Zone I and Zone II lateritic fine aggregates based mortars at 100 wt% replacement, to achieve strength at least equal to or more than those of control mortars. Laterized concretes have achieved nearly the same strengths as those of control concretes, at all replacement levels and for all fineness levels (Zone I to Zone IV). © 2018 Elsevier LtdItem Extraction of iron from laterite soil and green synthesis of laterite nano iron catalyst (GLaNICs) for its application as Fenton's catalyst in the degradation of triclosan(IWA Publishing, 2022) Rashmishree, K.N.; Bhaskar, S.; Shrihari, S.; Thalla, A.K.Laterite based nano iron particles were synthesized using natural laterite extract as a precursor and Psidium guajava plant extract for its application as Fenton's catalyst in the degradation of triclosan. Chemical digestion method was used for the extraction of iron from laterite soil. Synthesized nano iron catalyst was characterized using SEM-EDS, XRD and FTIR and evaluated for its catalytic application in the Fenton's oxidation of triclosan. Maximum triclosan degradation of 69.5% was observed with nano iron catalyst dosage of 0.1 g/L and hydrogen peroxide dosage of 200 mg/L at acidic pH of 3. Hydrogen peroxide influence on the process was observed with Fenton's oxidation. Role of iron in the process has been accessed by control experiment with no nano catalyst addition in which degradation is considerably low. Fenton's oxidation was compared with conventional Fenton's oxidation driven by a green nano iron catalyst. Study claims the usage of natural laterite iron as a replacement for commercial iron in Fenton's degradation of triclosan. Regeneration and reusability studies on catalyst were studied and synthesized catalyst was observed to be reusable in three consecutive cycles. Degradation of triclosan in Fenton's oxidation follows pseudo-second order reaction with linear fit. © 2022 The Authors.Item Green synthesis of laterite iron-based nanocatalysts using Psidium guajava and Macaranga peltata plant extract for its catalytic application in Fenton’s oxidation of triclosan(Springer Science and Business Media Deutschland GmbH, 2024) Rashmishree, K.N.; Bhaskar, B.; Hari, S.S.; Thalla, A.K.Phytosynthesis of nanoiron catalysts was carried out using natural laterite extract as a precursor and Psidium guajava and Macaranga peltata leaf extract. Morphological, mineralogical and chemical characterization was done using SEM, XRD, EDS and FTIR. GL(Fe3O4)NCs were confirmed for their catalytic role in the degradation of triclosan via Fenton’s oxidation. Maximum triclosan degradation of 96.5% and 99.1% for GPsL(Fe3O4)NCs and GMpL(Fe3O4)NCs was observed at a catalyst dosage of 1.0 g/L and hydrogen peroxide dosage of 300 mg/L. A notable increase of 14.5% in the efficiency of contaminant removal was observed on increase in hydrogen peroxide with a rate constant doubled. Reusability studies for both catalysts were carried out for five consecutive cycles, and catalysts were shown to have efficient removal of triclosan in each case. The present study claims cost-effective treatment of triclosan with Fenton’s oxidation using green synthesized natural laterite iron catalyst for the degradation of triclosan in water. The degradation of triclosan in Fenton’s oxidation follows a pseudo-first-order reaction with a linear fit. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2023, corrected publication 2023.