This page has only limited features, please log in for full access.
Sustainable rammed earth (RE) material was formulated using pulp mill fly ash (PFA), an industrial waste product, as an alternative low carbon cementing material. The alkali-silicate activation of PFA in RE showed substantial strength improvement. However, combinations of calcium bentonite clay and raw PFA without activation imparted significantly better frost resilience properties. The recommended RE formulation with 5% PFA, 5% Portland cement and 15% bentonite showed 3.56 MPa compressive strength at 28 days curing and retained 92% strength after 12 freeze–thaw cycles. Further, the leachate analysis revealed that the cementitious reaction products immobilized toxic elements within the stabilized RE matrix.
Amin Ajabi Naeini; Sumi Siddiqua; Chinchu Cherian. A novel stabilized rammed earth using pulp mill fly ash as alternative low carbon cementing material. Construction and Building Materials 2021, 300, 124003 .
AMA StyleAmin Ajabi Naeini, Sumi Siddiqua, Chinchu Cherian. A novel stabilized rammed earth using pulp mill fly ash as alternative low carbon cementing material. Construction and Building Materials. 2021; 300 ():124003.
Chicago/Turabian StyleAmin Ajabi Naeini; Sumi Siddiqua; Chinchu Cherian. 2021. "A novel stabilized rammed earth using pulp mill fly ash as alternative low carbon cementing material." Construction and Building Materials 300, no. : 124003.
The inorganic solid waste generated in pulp and paper industries called pulp mill fly ash (PFA) is a potentially valuable resource as supplementary cementitious material. However, large PFA volume is discarded in landfills due to stringent environmental regulations and lack of proper guidelines for safe alternative applications, thereby posing substantial environmental liability. The present study investigated the effectiveness of recycled PFA as a green binder for stabilizing weak silty sand pavement subgrades by conducting a series of laboratory experiments. The important physicochemical and ecotoxicological properties of PFA indicated its valuable potential for beneficial application as an energy-efficient and low embodied carbon construction raw material. Further, the substantial soil strength and stiffness after PFA treatment and short-term curing under ambient conditions indicated its efficiency as an effective stabilizer. The dramatic improvement was mainly due to the hydration reactions of calcium-rich PFA, leading to stable cementitious compounds. Microstructural evolution of PFA treated and cured soil revealed the formation and deposition of new products in the inter and intra-aggregate pores, thereby forming strong inter-particle bonds and a dense matrix with refined pore structure. Further, the leaching tests confirmed that the cementation process minimized the bio-availability of toxic metals present in the treated soil by encapsulating in the newly formed water-stable compounds. These results demonstrated that recycled PFA could be successfully implemented as an environmentally and economically sustainable binder in road construction and rehabilitation applications, reducing stockpiles of this waste and associated ecological footprints.
Chinchu Cherian; Sumi Siddiqua. Engineering and environmental evaluation for utilization of recycled pulp mill fly ash as binder in sustainable road construction. Journal of Cleaner Production 2021, 298, 126758 .
AMA StyleChinchu Cherian, Sumi Siddiqua. Engineering and environmental evaluation for utilization of recycled pulp mill fly ash as binder in sustainable road construction. Journal of Cleaner Production. 2021; 298 ():126758.
Chicago/Turabian StyleChinchu Cherian; Sumi Siddiqua. 2021. "Engineering and environmental evaluation for utilization of recycled pulp mill fly ash as binder in sustainable road construction." Journal of Cleaner Production 298, no. : 126758.
The continual growth of pulp and paper industry has led to the generation of tremendous volumes of fly ash as byproducts of biomass combustion processes. Commonly, a major part of it is landfilled; however, updated environmental regulations have tended to restrict the landfilling of fly ash due to rising disposal costs and the scarcity of suitable land. The pulp and paper industries are therefore urgently seeking energy-efficient mechanisms and management for the beneficial use of fly ash in an ecological and economical manner. This paper offers a comprehensive review of existing knowledge on the major physicochemical and toxicological properties of pulp and paper mill fly ash to assess its suitability for various bound and unbound applications. The current state of various methods used for the valorization of pulp and paper mill fly ash into more sustainable geomaterials is briefly discussed. This paper also presents promising and innovative applications for pulp and paper mill fly ash, with particular reference to agriculture and forestry, the construction and geotechnical industries, and the immobilization of contaminants. It was identified from a literature review that modified pulp and paper mill fly ash can be environmentally and economically advantageous over commercial coal-based fly ash in various sustainable applications.
Chinchu Cherian; Sumi Siddiqua. Pulp and Paper Mill Fly Ash: A Review. Sustainability 2019, 11, 4394 .
AMA StyleChinchu Cherian, Sumi Siddiqua. Pulp and Paper Mill Fly Ash: A Review. Sustainability. 2019; 11 (16):4394.
Chicago/Turabian StyleChinchu Cherian; Sumi Siddiqua. 2019. "Pulp and Paper Mill Fly Ash: A Review." Sustainability 11, no. 16: 4394.
The intrinsic morphology, mineralogy and gradation characteristics of geomaterials and geosynthetics play a pivotal role in determining their vital geotechnical properties. In view of this, this paper attempts to demonstrate the relevance of advanced digital image analysis for micromorphological characterisation of geomaterials and geosynthetics based on the critical appraisal of pertinent literature. Although many studies have been dedicated to enhancing the current state of practice pertaining to the potential applications of digital image analysis in diverse fields of practical and research requirements, there is a lack of well-established procedures for quality-assured sample preparation, execution of image processing and analysis. In light of inferences gathered from up-to-date literature, this study emphasises the fact that digital image analysis can be an effective complementary tool to conventional methods for physical and micromorphological characterisation of geomaterial and geosynthetics, in view of assessing their macroscale engineering behaviour.
Chinchu Cherian; Dali Naidu Arnepalli. Material characterisation by digital image analysis: a review. Environmental Geotechnics 2018, 5, 249 -262.
AMA StyleChinchu Cherian, Dali Naidu Arnepalli. Material characterisation by digital image analysis: a review. Environmental Geotechnics. 2018; 5 (5):249-262.
Chicago/Turabian StyleChinchu Cherian; Dali Naidu Arnepalli. 2018. "Material characterisation by digital image analysis: a review." Environmental Geotechnics 5, no. 5: 249-262.
Chinchu Cherian; Nikhil John Kollannur; Sandeep Bandipally; Dali Naidu Arnepalli. Calcium adsorption on clays: Effects of mineralogy, pore fluid chemistry and temperature. Applied Clay Science 2018, 160, 282 -289.
AMA StyleChinchu Cherian, Nikhil John Kollannur, Sandeep Bandipally, Dali Naidu Arnepalli. Calcium adsorption on clays: Effects of mineralogy, pore fluid chemistry and temperature. Applied Clay Science. 2018; 160 ():282-289.
Chicago/Turabian StyleChinchu Cherian; Nikhil John Kollannur; Sandeep Bandipally; Dali Naidu Arnepalli. 2018. "Calcium adsorption on clays: Effects of mineralogy, pore fluid chemistry and temperature." Applied Clay Science 160, no. : 282-289.
The recent research infers that the detailed characterization of lime-treated soils using analytical techniques enables better understanding of the complex soil–lime interaction mechanisms as well as the pivotal factors influencing the efficacy of lime treatment. In view of this, the present study focuses on evaluating the effects of lime treatment on the strength properties of sodium bentonite clay in terms of the variations in thermal characteristics derived by employing analytical thermogravimetric analysis. This technique is effectively used to monitor the consumption of free lime and evolution of new cementitious hydration products (viz., calcium silicate hydrate and calcium aluminate hydrate), as well as detrimental lime carbonation phenomenon occurring in the sodium bentonite-lime composite during short-term curing. Based on the comparative evaluation of untreated and lime-treated sodium bentonite, variations in the weight loss corresponding to thermal decomposition of different chemical phases are estimated. The additional inferences from X-ray diffraction and Fourier transform infrared spectroscopy analyses substantiated the interpretations of thermogravimetric results regarding the lime stabilization mechanisms and consequent strength evolution in sodium bentonite-lime composites. Thus, the present study demonstrates that the comprehensive analysis of thermogravimetric results enables reliable interpretation of the soil–lime interaction mechanisms and the evolution of strength during curing.
Sandeep Bandipally; Chinchu Cherian; Dali Naidu Arnepalli. Characterization of Lime-Treated Bentonite Using Thermogravimetric Analysis for Assessing its Short-Term Strength Behaviour. Indian Geotechnical Journal 2018, 48, 393 -404.
AMA StyleSandeep Bandipally, Chinchu Cherian, Dali Naidu Arnepalli. Characterization of Lime-Treated Bentonite Using Thermogravimetric Analysis for Assessing its Short-Term Strength Behaviour. Indian Geotechnical Journal. 2018; 48 (3):393-404.
Chicago/Turabian StyleSandeep Bandipally; Chinchu Cherian; Dali Naidu Arnepalli. 2018. "Characterization of Lime-Treated Bentonite Using Thermogravimetric Analysis for Assessing its Short-Term Strength Behaviour." Indian Geotechnical Journal 48, no. 3: 393-404.
The stabilization of problematic fine-grained soils using lime as an admixture is a widely accepted practice, owing to its simplicity and cost-effectiveness. The optimal quantity of lime required for soil stabilization primarily depends upon the reactive nature of soil as well as the degree of improvement desired. The term ‘optimum lime content’ (OLC) defines the amount of lime required for satisfying the immediate/short-term soil–lime interaction, and still providing sufficient amount of free calcium and high residual pH necessary to initiate long-term pozzolanic reaction. Previous researchers proposed various empirical correlations and experimental methodologies for determining OLC, in terms of clay-size fraction and plasticity characteristics of virgin soil. However, the limiting lime content obtained using various conventional methods does not account for the most influencing inherent clay mineralogy of the soil; and hence, the results of these methodologies are observed to be quite disagreeing with each other. In view of these discrepancies, the present study attempts to validate the existing conventional methodologies for OLC determination at an elementary level, by comprehending the fundamental chemistry following soil–lime interactions. Based on the theoretical and experimental observations, it is quite evident that the accuracy of conventional tests is limited by combined influence of chemical and mineralogical properties of soils. Hence, it is proposed to develop a precise methodology to ascertain the required optimal lime dosage based on scientific criteria, by incorporating the influence of soil properties such as clay mineralogy, specific surface area, soil pH, cation exchange capacity, soil acidity, base saturation capacity, and buffer capacity.
Chinchu Cherian; D. N. Arnepalli. A Critical Appraisal of the Role of Clay Mineralogy in Lime Stabilization. International Journal of Geosynthetics and Ground Engineering 2015, 1, 1 -20.
AMA StyleChinchu Cherian, D. N. Arnepalli. A Critical Appraisal of the Role of Clay Mineralogy in Lime Stabilization. International Journal of Geosynthetics and Ground Engineering. 2015; 1 (1):1-20.
Chicago/Turabian StyleChinchu Cherian; D. N. Arnepalli. 2015. "A Critical Appraisal of the Role of Clay Mineralogy in Lime Stabilization." International Journal of Geosynthetics and Ground Engineering 1, no. 1: 1-20.