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A. Bahurudeen - One of the best experts on this subject based on the ideXlab platform.
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Development of Sustainable Alkali Activated Binder for Construction Using Sugarcane Bagasse Ash and Marble Waste
Sugar Tech, 2020Co-Authors: Thanabalan Murugesan, R. Vidjeapriya, A. BahurudeenAbstract:The rapid growth in the construction sector leads to high demand for construction materials and hence global research studies focus on the use of sustainable alternative materials to meet the demand. Sugarcane bagasse ash is a by-product from sugar industry and about 44,220 tonnes/day is disposed of as waste in India. Bagasse ash consists of reactive silica and can be used as a sustainable source material in alkali Activated Binder instead of disposed as a waste. Similarly, marble waste from marble processing plants can be used as an alternative for fine aggregates. Alkali-Activated concrete has high strength and durability compared to conventional cement concrete. Bagasse ash can be blended with other industrial by-products like slag to produce high quality of alkali-Activated concrete without cement. The combined effect of bagasse ash and marble waste in alkali-Activated mortar is not yet investigated. This present study focuses on the performance of bagasse ash and marble waste as a precursor and fine aggregates respectively in alkali-Activated mortar. Influence of three different molarities (6 M, 8 M and 10 M) and two curing methods (heat and ambient curing) and three levels of replacement using bagasse ash (10%, 20% and 30%) were investigated. This experimental results showed that a considerable improvement in compressive strength for bagasse ash with marble waste blended alkali-Activated mortar specimens compared to only bagasse ash blended mortar specimens. Moreover, the strength of bagasse ash blended specimens was increased with molarity. Ambient cured bagasse ash blended specimens exhibited higher strength compared to the heat cured specimens.
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a circular framework for the valorisation of sugar industry wastes review on the industrial symbiosis between sugar construction and energy industries
Journal of Cleaner Production, 2018Co-Authors: Athira Gopinath, A. Bahurudeen, Srinivas Appari, Prakash NanthagopalanAbstract:Abstract This paper provides a comprehensive review of literature on the properties of sugar industry waste, their varied uses in energy and construction sector, performance and limitations. An efficient upcycling of sugar industry waste in energy production would help the energy sector to reduce its dependency on non-renewable fossil fuels. Literature demonstrates that in the recent years there has been an increased research interest in thermochemical conversion of sugarcane bagasse to produce cleaner energy, rather than its landfilling or combustion. On the other hand, utilisation of secondary by-products from sugar industry in the production of cement, bricks, paver blocks, Activated Binder and other construction products helps to cut down the carbon footprint of the construction industry, while improving the properties of the final products. From the perspective of the sugar industry, such an arrangement eliminates disposal problems and creates additional revenue. Although independent research studies investigating the use of sugar industry by-products exist, few studies consider these valorisation options together to minimise waste and to create an efficient material flow chain. This study identifies various material and energy recovery pathways from published literature and connects the materials and processes to form a continuous material supply chain with minimum wastage. From the findings, a symbiotic framework has been developed with primary and secondary by-products from the sugar industry serving as source materials for energy production and sustainable construction products.
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Agro-waste ash based alkali-Activated Binder: Cleaner production of zero cement concrete for construction
Journal of Cleaner Production, 1Co-Authors: Vs Athira, V Charitha, G. Athira, A. BahurudeenAbstract:Abstract Alkali-Activated Binders are sustainable alternatives to carbon-intensive conventional cements. A comprehensive review of the potential of different agro-waste ashes and their performance as precursors in alkali-Activated Binders are essential to enable their acceptance in the construction sector. Hence, the present study focusses on a systematic review of the alkali-activation of bagasse ash, rice husk ash, corn cob ash, palm oil fuel ash, wheat straw ash, and sugarcane straw ash. Moreover, their influence on the mechanical and durability characteristics of alkali-Activated concrete is also presented. Based on the review, it is found that except for rice husk ash, all the other agro-waste ashes have almost similar silica content as that of fly ash. The morphologies of the different agro-waste ashes are found to be distinct. Incorporation of agro-waste ashes in fly ash-based Binders results in better resistance to acid attack than slag-based Binders. Addition of agro-waste ashes brought down the drying shrinkage of slag-based Binders significantly. Ambient curing is beneficial for bagasse ash-based alkali-Activated mortar specimens. Water absorption is higher for agro-waste ash based alkali-Activated Binder specimens due to the porous cellular structure of agro-waste ashes. Enhanced performance at elevated temperatures is observed for agro-waste ash based alkali-Activated Binders. Rice husk ash-based Binders are remarkably stable at elevated temperatures.
Anasua Guharay - One of the best experts on this subject based on the ideXlab platform.
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Subgrade Stabilization Using Alkali Activated Binder Treated Jute Geotextile
Lecture Notes in Civil Engineering, 2020Co-Authors: V. P. Komaravolu, Anasua Guharay, S. K. TulluriAbstract:Many past research works proved the successful usage of synthetic geotextiles and geogrids as road subgrade reinforcement. However, reinforcing subgrades with natural geotextiles is found to be more economic and eco-friendly. The usage of this is limited by its short degradation time period in soil, and to overcome this, researchers started using treated geotextiles. In this study, a systematic lab investigation has been made to understand the behavior of subgrade strength of roads reinforced with alkali Activated Binder (AAB) treated jute geotextile. Unreinforced soils, untreated and treated jute reinforced soils are tested for CBR, bearing capacity, and the results showed a considerable increase of CBR, bearing values in treated jute geotextiles. Durability tests such as soil burial tests and tensile strengths of degraded JGT are also carried to study the increase in life expectancy of AAB treated jute geotextile. Alkali Activated Binder improves life expectancy and mechanical properties of jute, and therefore, treated jute geotextile may be used as alternative material for subgrade soil reinforcement applications.
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Effect of Freeze–Thaw Cycles on Black Cotton Soil Reinforced with Coir and Hemp Fibres in Alkali-Activated Binder
International Journal of Geosynthetics and Ground Engineering, 2020Co-Authors: Mazhar Syed, Anasua Guharay, Divyam Goel, Kunal Asati, Lin PengAbstract:Expansive black cotton soil (BCS) is predominantly impervious and undergoes swelling and shrinkage when exposed to moisture fluctuation. This results in heaving of soil, causing it to lose its mechanical strength. Use of traditional cementitious Binders like lime and cement has a significant impact on the environment and contributes almost 7% of the global CO2 emissions. In the present study, an attempt was made to improve the geomechanical properties of BCS using envirosafe alkali-Activated Binder (AAB) with naturally available coir (CF) and hemp fibres (HF). The coir and hemp fibres were chemically treated to improve their durability. AAB was prepared by blending an alkali activator solution of sodium silicate and sodium hydroxide with class F fly ash at 0.4 water to solid ratio. This study also investigated the effectiveness of coir and hemp fibre reinforced AAB–BCS at different freeze–thaw cycles. The influence of varying dosages of fibres and freeze–thaw cycles in AAB-treated BCS showed a significant improvement in soil tensile strength and durability. The microstructural and geomechanical results of treated fibres showed higher serviceability and tensile resistance compared to the untreated ones. Furthermore, nonlinear regression equations were also proposed to relate experimental test results with model-predicted results in terms of unconfined compressive strength and indirect tensile strength.
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Effect of natural fiber reinforcement on strength response of alkali Activated Binder treated expansive soil: Experimental investigation and reliability analysis
Construction and Building Materials, 2020Co-Authors: Mazhar Syed, Anasua GuharayAbstract:Abstract Expansive soil possesses high swelling-shrinkage potential owing to moisture instability, resulting in loss of geomechanical strength. In this study, an effort is made to improve the shear strength properties of expansive soil by combined effects of alkali Activated Binder (AAB) with chemically treated hemp (THF) and coir fiber (TCF). AAB is produced by the reaction between alkaline Binder of sodium silicate and sodium hydroxide in aluminosilicate precursors of Class-F fly ash and slag at various proportions. The effect of varying dosages of THF, TCF, and slag/fly ash ratio in the AAB soil mixture on compressive shear, tensile, and flexural strength is evaluated through a series of geotechnical characterization tests. It is observed that THF-AAB-soil shows higher interfacial bonding with strong interlocking density and tensile cracking resistance compared to TCF. Furthermore, in order to effectively consider the uncertainties associated with the design of subgrade for foundations, reliability indices against unconfined compressive strength and split tensile strength are predicted using Monte Carlo simulation through a non-linear regression model developed from experimental results. The study shows that the optimum dosages of fly ash-slag and fiber reinforcement are essential factors for controlling the swelling of expansive soil as well as improving its tensile strength.
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Stabilization of Expansive Soil Reinforced with Polypropylene and Glass Fiber in Cement and Alkali Activated Binder
Advancements in Unsaturated Soil Mechanics, 2019Co-Authors: Mazhar Syed, Anasua GuharayAbstract:Expansive black cotton soil (BCS) exhibits dual nature (swelling/shrinkage) predominantly when it is exposed to moisture fluctuation. This behavior renders the BCS unsuitable for use in geoengineering applications. The present study emphasizes the polypropylene and glass fiber based soil reinforcement with a traditional cement Binder and envirosafe alkali-Activated Binders (AAB). Cement stabilization is one of the most popular methods for reducing swelling properties of BCS. However, the production of cement leads to the emission of greenhouse gases, which is a threat to modern society. Hence the present study aims to compare the geomechanical strength between AAB and cement Binder with inclusions of various discrete fibers. AAB is generated by the reaction between an aluminosilicate precursor (Fly ash and/or GGBS) and an alkali activator solution of sodium hydroxide and sodium silicate. The water to solids ratio is maintained at 0.4 in the present study. Mineralogical and microstructural characterization are performed for both cement and AAB treated BCS as well as untreated BCS through stereomicroscope, X-ray diffraction (XRD), Fourier-transform infrared (FTIR) spectroscopy, scanning electron microscope (SEM), and energy dispersive x-ray spectroscopy (EDS). The unconfined compressive strength (UCS), indirect tensile strength (ITS), California Bearing Ratio (CBR) and consolidation characteristics of both untreated and Binder treated BCS are carried out at different combinations of cement-fiber and AAB-fiber in the clay. It is observed that the proposed treatment method shows a significant improvement in geoengineering properties and aids in enhancing the shear strength and ductility properties. An addition of 5% AAB with 0.3% of polypropylene fiber reduces the plasticity and swelling pressure by 17–25%, while CBR and ITS values are increased by 28–33%. Recommendations on the practical implementation of this technique for stabilization of expansive soils are proposed based on findings of the present study.
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Effect of Strain Rate on Interface Friction Angle Between Sand and Alkali Activated Binder Treated Jute
Springer Series in Geomechanics and Geoengineering, 2018Co-Authors: Shashank Gupta, Anasua Guharay, Arkamitra Kar, V. P. KomaravoluAbstract:The interface friction angle between reinforcement and soil is a significant property that defines the suitability of geotextile for several applications such as reinforced retaining wall and slope stability. However, it is not an intrinsic property and varies with several experimental factors such as relative density of sand and shearing strain at which shear tests are conducted. Recent literature shows the wide application of jute geotextile in geotechnical constructions such as slope stability, river bank protection, and subgrade stabilization. However, its application is limited due to low durability under the soil. Therefore, to improve the resistance of jute geotextile against the biological degradation, it has been treated with the fly ash-based treatment solution. This study makes an attempt to investigate the effect of strain rate on the interface friction angle between sand and alkali Activated Binder treated jute geotextile. The tests are conducted in large shear box apparatus specifically assembled to determine interface shear properties. The jute geotextile is treated with alkali Activated Binder of four different water to solid ratios, each of them is cured at the temperature of 40 °C. The results obtained are then collated with those obtained from untreated jute geotextile. This study further delineates the effect of the degree of compaction on the interface friction between the reinforcement and sand. Hence, the interface shear properties apropos to the relative density of sand, shear strain, and treatment composition are compared and the obtained trends along with the optimum values are presented.
Jinhong Zhang - One of the best experts on this subject based on the ideXlab platform.
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Effects of activator type/concentration and curing temperature on alkali-Activated Binder based on copper mine tailings
Journal of Materials Science, 2012Co-Authors: Saeed Ahmari, Lianyang Zhang, Jinhong ZhangAbstract:This article investigates the effects of activator type/concentration and curing temperature on alkali-Activated Binder based on copper mine tailings (MT). Different alkaline activators including sodium hydroxide (NaOH), sodium silicate (SS), and sodium aluminate (SA) at different compositions and concentrations were used and four different curing temperatures, 60, 75, 90, and 120 °C, were considered. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray diffraction (XRD) were conducted to investigate the effect of these factors on the unconfined compressive strength (UCS), microstructure, and phase composition of the Binder. The results indicate that NaOH concentration and curing temperature are two important factors that affect the UCS and micro-structural properties of the alkali-Activated MT Binder. The optimum curing temperature, i.e., the curing temperature at the maximum UCS, depends on the NaOH concentration, lower optimum curing temperature at smaller NaOH concentration. Addition of aqueous SS to the NaOH solution can lead to strength improvement, with the highest UCS obtained at a SiO_2/Na_2O ratio of 1.0–1.26. Addition of powder SA to the NaOH solution profoundly delays the setting at 60 °C but improves the UCS at 90 °C. The SEM/EDX results show highly heterogeneous microstructure for the alkali-Activated MT Binder as evidenced by the variable Si/Al ratios in different phases. The XRD patterns indicate a newly formed crystalline phase, zeolite, in the 90 °C-cured specimens. The results of this study provide useful information for recycling and utilization of copper MT as construction material through the geopolymerization technology.
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effects of activator type concentration and curing temperature on alkali Activated Binder based on copper mine tailings
Journal of Materials Science, 2012Co-Authors: Saeed Ahmari, Lianyang Zhang, Jinhong ZhangAbstract:This article investigates the effects of activator type/concentration and curing temperature on alkali-Activated Binder based on copper mine tailings (MT). Different alkaline activators including sodium hydroxide (NaOH), sodium silicate (SS), and sodium aluminate (SA) at different compositions and concentrations were used and four different curing temperatures, 60, 75, 90, and 120 °C, were considered. Scanning electron microscopy/energy-dispersive X-ray spectroscopy (SEM/EDX), and X-ray diffraction (XRD) were conducted to investigate the effect of these factors on the unconfined compressive strength (UCS), microstructure, and phase composition of the Binder. The results indicate that NaOH concentration and curing temperature are two important factors that affect the UCS and micro-structural properties of the alkali-Activated MT Binder. The optimum curing temperature, i.e., the curing temperature at the maximum UCS, depends on the NaOH concentration, lower optimum curing temperature at smaller NaOH concentration. Addition of aqueous SS to the NaOH solution can lead to strength improvement, with the highest UCS obtained at a SiO2/Na2O ratio of 1.0–1.26. Addition of powder SA to the NaOH solution profoundly delays the setting at 60 °C but improves the UCS at 90 °C. The SEM/EDX results show highly heterogeneous microstructure for the alkali-Activated MT Binder as evidenced by the variable Si/Al ratios in different phases. The XRD patterns indicate a newly formed crystalline phase, zeolite, in the 90 °C-cured specimens. The results of this study provide useful information for recycling and utilization of copper MT as construction material through the geopolymerization technology.
Marios Soutsos - One of the best experts on this subject based on the ideXlab platform.
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production of sodium silicate powder from waste glass cullet for alkali activation of alternative Binders
Cement and Concrete Research, 2019Co-Authors: Raffaele Vinai, Marios SoutsosAbstract:Abstract A simple process to produce sodium silicate powder from glass cullet has been developed. A mixture of glass powder, sodium hydroxide powder, and water was heated at temperatures of 150 to 330 °C. The effects of glass to NaOH ratio, temperature and duration, inclusion of water and fineness of NaOH were investigated. Fly ash and fly ash/GGBS blends were the precursors for alkali Activated Binder (AAB) mortars produced with this sodium silicate. Compressive strengths were similar to or better than those obtained with commercially available sodium silicate and sodium hydroxide solutions. FT-IR tests suggested that the reactivity of the glass derived sodium silicate powder was related to the number of non-bridging oxygen atoms in the silicate structure. Cost comparison between AAB and Portland cement concretes gave similar results for normal strength concretes (35 MPa). AAB concretes with higher strengths (50 and 70 MPa) can be cheaper than equivalent traditional concrete.
João Castro-gomes - One of the best experts on this subject based on the ideXlab platform.
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Alkali-Activated Binders Based on Tungsten Mining Waste and Electric-Arc-Furnace Slag: Compressive Strength and Microstructure Properties
CivilEng, 2020Co-Authors: Naim Sedira, João Castro-gomesAbstract:The valorization and reusing of mining waste has been widely studied in recent years. Research has demonstrated that there is great potential for reusing mining waste for construction applications. This work experimentally investigated the strength development, pore structure, and microstructure of a binary alkali-Activated Binder. This is based on tungsten mining waste mud (TMWM) and electric-arc-furnace slag (EAF-Slag) using different proportions of TMWM (10, 20, 30, 40, and 50 vt.%). The precursors were Activated using sodium silicate (Na2SiO3) and potassium hydroxide (KOH 8M) as alkaline activator solution with solid:liquid weight ratio = 3. Pastes were used to assess the compressive strength of the blended Binder and their microstructure. The reaction products were characterized by X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), and Fourier transform infra-red (FT-IR) spectroscopy, while the porosity and the pores size properties were examined by mercury intrusion porosimetry (MIP). The results show that the partial replacement of TMWM with EAF-Slag exhibited better mechanical properties than the 100TM-AAB. A maximum strength value of 20.1 MPa was obtained in the binary-AAB sample prepared with 50 vt.% TMWM and EAF-Slag. The pastes that contained a higher dosage of EAF-Slag became more compact with lower porosity and finer pore-size distribution. In addition, the results obtained by SEM-EDS confirmed the formation of different types of reaction products in the 100TM-AAB, 100FS-AAB, and the binary-AABs mixtures such as N-A-S-H, C-A-S-H and (N, C)-A-S-H gels frameworks in the system as the major elements detected are Si, Al, Ca, and Na.
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Use of Iron Ore Overburden As a Precursor for the Synthesis of an Alkali-Activated Binder
KnE Engineering, 2020Co-Authors: Marina Filizzola Oliveira, Naim Sedira, Ana Cláudia Pinto Dabés Guimarães, Fernando Soares Lameiras, João Castro-gomesAbstract:The iron ore beneficiation process produces a large quantity of waste. Mining companies are looking for technologies that make it possible to dispose of their waste and transform it into raw material for the manufacture of products that can be applied in other areas, for example in the production of concrete, mortar, ceramics, blocks, and bricks. This study aimed at the feasibility of using a calcined iron ore overburden as a precursor of alkali-Activated Binders. For alkaline activation of the precursors, sodium hydroxide solution and sodium silicate were used in the atomic proportions Al / Na = 2 and Si / Al> 0,7. Mineralogical and microstructural characterization was carried out by X-ray diffraction (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM/EDX). Tests of compressive strength were performed for the Binders with 7, 14, 21 and 28 of curing days. The results of the analyses demonstrated that the properties of the alkali-Activated Binders produced with the overburden were similar to the Binders obtained by precursors used traditionally. It was found, therefore, that the calcined iron ore overburden, can be considered a precursor for obtaining alkaline Activated Binders
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Strength Development and Pore Structure Characterisation of Binary Alkali-Activated Binder Based on Tungsten Mining Waste
KnE Engineering, 2020Co-Authors: Naim Sedira, João Castro-gomesAbstract:The mineralogical properties of tungsten mining waste mud (TMWM) make its valorisation and re-usage as an alumino-silicate source material to produce an alkali-Activated Binder without calcination is a challenge. Moreover, the dissolution of silicate and alumina species from TMWM is very slow. Despite the crystallinity of TMWM, this study demonstrates that its combination with other sources of the alumino-silicate source was the materials–such as red clay brick waste(RCBW),ground granulated blast furnace slag (GGBFS) and electric arc furnace slag (EAFS) – improved the compressive strength and the pore structure of the alkali-Activated matrix.Thecombinedprecursors (90 vt.%TMWM+10 vt.%RCBW, 90 vt.%TMWM+10 vt.%GGBFS, and 90 vt.%TMWM+10 vt.%EAFS) were Activated using a combination of alkaline activator solutions (sodium silicate and sodium hydroxide) with the ratio of 1:3(66.6wt.%sodiumsilicatecombined with 33.33 wt.% of NaOH 10M). The results show that the compressive strength increased from11.23MPa at 28 days to reach 24.98MPawhentheTMWMwaspartially replacedby10vt.%RCBW. In addition,this study shows that the interconnected porosity decreased where the critical pore size was reduced from 21.28 µm to 0.55 µm for the tungsten mining waste-based alkali-Activated Binder and the binary alkali-Activated Binder based on TMWM and RCBW. Keywords: Mining Waste, Alkali-Activated, Microstructure, MIP, Metakaolin
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Microstructure Features of Ternary Alkali-Activated Binder Based on Tungsten Mining Waste, Slag and Metakaolin
KnE Engineering, 2020Co-Authors: Naim Sedira, João Castro-gomesAbstract:This study determines the effect of ground granulated blast furnace slag (GGBFS) and metakaolin (MK) on the microstructural properties of the tungsten mining waste-based alkali-Activated Binder (TMWM). During this investigation, TMWM was partially replaced with 10 wt.% GGBFS and 10 wt.% MK to improve the microstructure of the Binder. In order to understand the effect of the substitutions on the microstructure, two pastes were produced to make a comparative study between the sample contain 100% TMWM and the ternary precursors. Both precursors were Activated using a combination of alkaline activator solutions (sodium silicate and sodium hydroxide) with the ratio of 1:3 (66.6 wt.% sodium silicate combined with 33.33 wt.% of NaOH 8M). The alkali-Activated mixes were cured in oven at temperature of 60 °C in the first day and at room temperature for the next 27 days. The reaction products N-A-S-H gel and (N,M)-A-S-H gel resulted from the alkaline activation reaction process. In addition, a formation of natrite (Na2CO3) with needles shape occurred as a reaction product of the fluorescence phenomena. However, a dense matrix resulted from the alkline activation of the ternary precursors containg different gels such as N-A-S-H, C-A-S-H and (N,M)-C-A-S-H gel, these results were obtained through SEM-EDS analyses, as well FTIR tests. Keywords: Mining Waste, Alkali-Activated, Microstructure, Slag, Metakaolin
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Red clay brick and tungsten mining waste-based alkali-Activated Binder: Microstructural and mechanical properties
Construction and Building Materials, 2018Co-Authors: Naim Sedira, João Castro-gomes, Manuel MagrinhoAbstract:Abstract This paper illustrates the study on the synthesis of alkali-Activated Binders based on the combination of tungsten mining waste mud (TMWM) with red clay brick waste (RCBW) with the use of sodium hydroxide (SH) and sodium silicate (SS) solution as alkaline activators; with a solid/liquid weight ratio = 3, and the SS:SH weight ratio = 2:1. The synthesis of TMWM-RCBW alkali-Activated Binders was conducted at 60 ± 2 °C curing temperature for 24 h, by using different TMWM and RCBW volume proportions, namely (90:10, 80:20, 70:30, 60:40 and 50:50 vt.%). Mineralogical and microstructural characterisation was carried out by X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM/EDX), simultaneous thermogravimetry and differential scanning calorimetry (TG-DSC), mercury intrusion porosimetry (MIP) and Fourier transform infrared spectroscopy (FT-IR). The FT-IR spectra and EDX analysis demonstrated that the higher dosage of RCBW content in the samples, the higher the formation of N–A–S–H and/or C–A–S–H and/or K–A–S–H and the combination (N,C)–A–S–H and/or (N,K) –A–S–H gels during the alkaline activation process. By SEM image analysis it was also verified that more gels are formed for more denser structure of the alkali-Activated materials. The increase in the dosages of RCBW in the mixtures was also followed by an increase in compressive strength for all the tested ages. It developed from 25 to 59 MPa for samples with RCBW volume content dosage of 10% and 50% respectively. Also, the Binder matrix becomes denser and compact by gradually increasing the RCBW dosage.
