Cement Production Research Articles

Preparation and characterisation of pozzolanic blended cement incorporating various ratio of volcanic basalt

ABSTRACT The construction industry relies heavily on cement and concrete as primary building materials. However, concerns regarding environmental sustainability have prompted efforts to develop more durable and sustainable alternatives to Ordinary Portland cement (OPC), the commonly used binder materials with low CO2 emission, where every ton of cement produce about 0.94 ton of carbon dioxide. The present study investigates the partial replacement of clinker with volcanic basalt powder in cement production to produce eco-friendly building materials with low emission of CO2, in addition to conserve the native raw materials from depletion. The replacement was done with various ratios up to 30%. The findings are supported by XRD and FTIR analyses as well as DTG. The results indicate that the use of basalt enhances the mineralogical and physical properties of the cement, resulting in the formation of a pozzolanic cement with sustainable characteristics. Notably, a 15% basalt ratio produces the highest extent of binding cementing phases upon hydration, leading to maximum compressive strength. Further, on increasing in basalt content lead to a decrease in strength, although the compressive strength remains above the target value of 42.5 MPa for 20% and more than 32.5 MPa for 25%.

Impact of hydrochar in stabilization/solidification of heavy metal-contaminated soil with Portland cement.

Stabilization/Solidification (S/S) using Portland cement is a common soil remediation technique for heavy metal-contaminated sites. However, due to the hindrance of cement hydration by heavy metals (HMs) and the high CO2 emissions from cement production, efforts have been made to reduce cement consumption. Supplementary cementitious materials (SCMs) present an efficient alternative for this purpose. This study investigates the impact of hydrochar and modified hydrochar as SCMs for remediating soils contaminated with Zn, Pb, and Cd. Forty treated soil samples were evaluated using unconfined compressive strength (UCS), pH, Toxicity characteristic leaching procedure (TCLP), and sequential extraction procedure (SEP) tests, and statistical analysis was conducted to assess the effects of binder content, hydrochar dosage, and hydrochar type. Results show that substituting cement with hydrochar or modified hydrochar reduces UCS by 10-40%, with hydrochar having a greater negative impact than modified hydrochar. pH values ranged from 6.98 to 12.64, facilitating HMs precipitation. In heavily contaminated samples, hydrochar or modified hydrochars significantly decreased the Zn, Pb, and Cd TCLP values by 55%, 63%, and 50%, respectively. In moderately contaminated samples, the reduction was slight for Zn and Pb, with no significant change for Cd. SEP test results indicated that hydrochar or modified hydrochar in cement improves the transformation of the acid-soluble fraction to the residual fraction of Zn and Pb, but not for Cd-contaminated soil samples. Overall, these findings suggest that incorporating hydrochar or modified hydrochar as SCMs in cement contributes to reducing cement usage and CO2 emissions while enhancing the stabilization efficiency of certain heavy metals in contaminated soils.

The Toxicity Leaching and the Cement Admixtures Properties with Incineration Fly Ash of Different Furnace Types.

Incineration of fly ash is a hazardous solid waste, and there are two types of furnaces used for production. The impact of furnace types on the properties and toxicity of incineration fly ash was studied. The resource utilization of incineration fly ash has been tested. The results showed that circulated fluidized bed (CFB) ash and grate (GF) ash were alkaline materials, dioxin content ranged between 98 and 359 ng-TEQ/kg, and heavy metals exceeded 7700 ppm. The leaching of Zn in CFB ash was 110.474 ppm, and that in the GF ash was 5.985 ppm. The chlorine content in GF ash was 27.07%, 2.7 times that of CFB ash. When the content was 5%, GF ash promoted cement grinding and improved the 3-day compressive strength of cement, which was 35.55% higher than the control sample. CFB ash generates hydrogen gas during the hydration process, causing volume cracking. When 20% GF ash was added, the hydration heat release peak appeared 10.5 h ahead of time. According to the Chinese standard GB 175-2023, the maximum dosages of CFB ash and GF ash in cement were 0.22 and 0.57%. There was no risk of excessive leaching of heavy metals. During cement production with CFB and GF ash, attention should be paid to the issues of chlorine and dioxins.

FOSSIL FUEL EMISSION PREDICTION SYSTEM USING MULTIPLE KERNEL GAUSSIAN PROCESS

<p>According to the United States Environmental Protection Agency, 81% of greenhouse gas emission is due to Carbon-dioxide. When fossil fuels, solid waste, trees, and wood products are burnt, Carbon-dioxide emission occurs. The concentration of Carbon-dioxide in the atmosphere is reduced when it is absorbed by plants as a part of the biological carbon cycle. The major sources of CO2 emission are from fossil fuel such as coal, natural gas, oil, cement production, gas flares used in industrial plants and bunker fuels used in ships. Increase in CO2 emission leads to the increase in global warming. Climate change, change in seasonal events and decrease in agricultural productivity are the major impacts of global warming. Hence it is important to study and analyse CO2 emission based on the recorded data across the globe. Further the major source of emission must be detected and alert messages must be sent to the pollution control boards in various countries to take necessary remedial actions. This work focuses on predicting the CO2 emission in the near future in various countries based upon the “Fossil-Fuel CO2 Emissions by Nation” dataset recorded by Carbon Dioxide Information Analysis Center (CDIAC), Oak Ridge National Laboratory. This system comprises of data cleaning, data normalization, optimization, and model building. The model built using Multiple Kernel Gaussian Process (MKGP) will predict the concentration of CO2 that may be present in the atmosphere in upcoming years. Based on the prediction the major source of CO2 emission is identified. We have studied the effects of Radial Basis Function kernel, Rational Quadratic, Periodic kernel and combinations of the kernels on India USA and China dataset. We have proposed a Multi-Kernel Gaussian Process for predicting the fossil fuel emission (MKGP - FFE). It has been inferred that combination of kernels performed well when compared to individual kernels in most of the cases.</p>

Thermodynamic study on the phase assemblage of MPC exposed to natural and accelerated carbonation conditions

AbstractMagnesium phosphate cement (MPC), which belongs to chemically bonded phosphate ceramics, is commonly applied as a repair material and waste stabilization/solidifications. However, studies on the influence of CO2 on the phase assemblages in MPC are limited. A thermodynamic simulation approach is employed to explore the influence of CO2 on the equilibrium phase assemblage of MPC. The mechanisms of natural and enforced carbonation of MPC have been investigated in this work. The results disclose that Mg carbonates are less likely to precipitate in magnesium ammonium phosphate cement (MAPC) cured under CO2, while MgCO3·3H2O is the only carbonation product of magnesium potassium phosphate cement (MKPC). The carbonation resistance of MAPC is better than that of MKPC. The increase of activity of magnesia employed in MPC obviously enhances the formation of brucite and slightly promotes the carbonation of MPC.

Manufacturing Sub-Sector Dynamics and Economic Growth in Nigeria (1981-2022)

This study examined the impact of manufacturing sub-sectors dynamics on economic growth in Nigeria covering the period 1981-2022. Data for the study were extracted from the Central Bank of Nigeria (CBN) statistical bulletin and World Development Index (WDI) 2022. The method of data analysis used is the linear regression method with the application of the Error Correction Model (ECM). The major findings of the study reveal that Cement production (CP) contributes positively but insignificantly to economic growth in Nigeria (β = 2.622724 and p-value = 0.4414 > 0.05), Beverages and Tobacco Production (BTP) contributes positively but insignificantly to economic growth in Nigeria (β = 2.040513 and p-value = 0.0018 > 0.05), Chemical and Pharmaceuticals Production (CHP) contributes negatively but insignificantly to economic growth in Nigeria (β = -17.39120 and p-value = 0.5188 > 0.05) and Pulp paper and paper products (PPP) contribute positively but insignificantly to economic growth in Nigeria (β = 56.85029 and p-value = 0.5062 > 0.05). It is therefore the recommendation of the study that the government should create an enabling environment and adjust its taxation rate on these companies which is currently at 24% to around 18% and the federal and state governments should create a system to protect forests from illegal loggers who are indiscriminately exploiting and felling the national trees.

Study on the Factors Influencing the Adsorption Mechanism of CSH Gel for Chloride Ions

Calcium silicate hydrate (CSH) gel is an important hydration product of cement, significantly influencing the coagulation and hardening processes, as well as the mechanical properties, volume stability, and durability of cement. Moreover, it plays a crucial role in the adsorption of harmful ions. In this study, CSH gel was synthesized through the precipitation of calcium acetate and sodium silicate and was subsequently used to adsorb chloride ions. The results indicated that when the calcium-to-silicon ratio was 1.2, the CSH gel exhibited excellent adsorption performance for chloride ions introduced via CaCl2 and NaCl, with adsorption capacities of 17.45 mg·g−1 and 8.06 mg·g−1, respectively. The adsorption of chloride ions in CSH gel primarily occurs due to the physical adsorption of chloride ions on the surface and within the internal pores of the CSH gel, accompanied by a displacement reaction between hydroxide ion and chloride ions.

THE EFFECT OF CEMENT KILN DUST ON THE PROPERTIES OF CEMENT

Due to the nature of the technological process, the cement industry is a significant source of dust. Managing industrial waste is a global problem worldwide; cement kiln dust is an example of such waste. The dust from the cement kiln is a by-product of the cement production process obtained during the grinding and burning of the raw materials inside the cement kiln. Still, due to its high alkaline content, it cannot be returned to the kiln, but its disposal and landfill can cause many environmental problems. It is necessary to find alternative methods for its utilization. Due to its fineness and composition like that of cement, there is a growing interest in the use of this powder as a partial substitute for ordinary Portland cement. The purpose of this paper is to investigate the influence of dust obtained during the production of cement clinker on the properties of cement (specific surface area, standard consistency, setting time, and compressive strength) and its implications in the conditions of its application.

Expansion in low calcium fly ash-based geopolymer concrete: chemical factors influenced by silica fume and NaOH concentration

Geopolymer technology offers a sustainable alternative to energy-intensive cement production, potentially reducing dependence on natural resources and mitigating environmental impact. Silica fumes (SF) are mostly used to enhance the fresh, hardened, and durable performance of geopolymers. However, their influence on geopolymerization may result in the expansion of the geopolymer mortar (GPM) due to reaction with alkaline liquid. In this study, the effect of NaOH concentration, particle size and dosage of SF, alkaline liquid-to-binder ratio, Na2SiO3-to-NaOH ratio, and sand-to-binder ratio on the expansion behavior of a low calcium fly ash (FA)-based GPM was investigated. FA-based GPMs were tested using two distinct SFs with varying particle sizes (SF1 = 9.5 µm and SF2 = 16.2 µm) and two varying dosages of SF (2.5% and 5%). Physical observations of GPMs revealed that NaOH concentration, particle size and dosage of SF are crucial factors that significantly impact the expansion which is concomitant with a reduction in compressive strength. Analytical techniques such as X-ray diffraction (XRD), Rietveld analysis, Fourier transform infrared spectroscopy (FTIR), and Thermo Gravimetric Analysis (TGA) were employed to comprehensively investigate reaction product(s) that led to the expansion of such GPMs. The chemical analysis confirmed the presence of excess analcime in the mortars fabricated by blending SF1 and FA at 12 M NaOH concentration. This study is the first to report the expansion of low calcium FA-based GPMs blended with a SF of particle size 9.5 µm. These findings emphasize the significance of selecting the appropriate SF particle size to prevent expansion and ensure optimal compressive strength in geopolymer applications.

Performance of Molasses Waste as a Cement Replacement to Study Concrete Compressive Strength

To reduce the negative environmental impact of cement production and preserve natural resources, an experimental investigation was conducted to study the performance of concrete specimens at different curing ages and to determine the compressive strength of these specimens by replacing cement with molasses. Experimentation was carried out on the concrete specimens at a temperature range of 25 °C to 30 °C; six specimens were cast for each replacement ratio, except for 0.75% wt. of cement (86.55 g) and 1% wt. of cement (113.6 g), where five samples were considered for each ratio. The average 28-day compressive strength of the conventional concrete specimens came out to be 29 MPa, but increased to 40 MPa with the addition of 0.25% wt. of cement molasses (28.85 g). It was observed that as the percentage of molasses waste in the concrete mix was further increased by replacing the cement, the compressive strength of the concrete specimens increased gradually and then significantly decreased. The findings shed light on the prospect of using molasses waste instead of cement in the concrete mix. Also, it is worth mentioning that about 30% of the cost–benefit was obtained with reference to that of conventional admixtures available in the market for the production of concrete. However, it is notable that a long-term durability study needs to be conducted before making it viable. This work not only addresses a sustainable and innovative method of waste management (SDG12), but also contributes to low carbon emissions (SDG13). The novelty of this work lies in the fact that no such kind of study has been conducted in Pakistan so far, in addition to the very limited international literature available, and, in particular, no evidence on the compressive strength results at higher molasses dosages, i.e., 1% wt. of cement (113.6 g) and 2% wt. of cement (230.8 g).

Comparative Life Cycle Assessments of Laboratory and Pilot-Scale Mechanochemical Processes for Producing Carbonated Mineral Products as Cement Substitutes.

The use of carbonated mineral products in cement production reduces carbon emissions and enhances durability. This study evaluated the environmental sustainability of using mineral carbonated biomass fly ash (BFA) as a partial cement replacement in European cement production. Laboratory-scale and simulated large-scale scenarios were analysed. Incorporating 20% mineral carbonated BFA showed potential for a 33% reduction in the annual Global Warming Potential (GWP) of cement products. Energy consumption factors, such as ball milling and mineral carbonation processes, were evaluated using a machine learning model and comminution flow sheet model simulations. The machine learning model predicted CO2 absorption and energy requirements for mineral carbonation, showing greater efficiency in large-scale scenarios. Life cycle assessments consistently revealed GWP reductions for OPC-BFA mixtures, with additional emissions reductions when incorporating flow sheet modelling and machine learning data. However, the study's limitations include simplified CO2 flue gas treatment, use of the mean EU electricity mix, exclusion of transportation impacts, and reliance on simulation data. Additionally, the cement mix exhibited reduced compressive strength. This study highlights the potential of mineral carbonated BFA to reduce cement production's environmental impact while emphasising the need for balanced optimisation between sustainability and material performance.

Preliminary investigation of the effects of high-temperature thermal activation on the activity of graphite tailings and the mechanical properties of graphite tailings mortar

The disposal of graphite tailings, a byproduct of graphite mining, poses significant recycling challenges. This study explores eco-friendly cement mortar by partially replacing sand with activated graphite tailings, focusing on waste utilization. Activating the pozzolanic properties of graphite tailings at various thermal activation temperatures converts them into high-quality binder materials. Quantitative assessments of graphite tailings' activity, conducted through ion leaching tests and raw material diffraction analysis, produce an activity index Ka, evaluating their performance under different thermal activation temperatures. Variable testing of substitution rates and activation temperatures examines changes in mechanical properties, microstructure, and pore distribution of the graphite tailings mortar. Optimum results reveal a 30 % substitution rate and a 750°C activation temperature. Graphite tailings, as pozzolanic binder materials, enhance mortar strength by improving particle size distribution, reducing "micro-area bleeding" and "boundary effects". After thermal activation, reactive minerals on the tailings' surface undergo secondary hydration reactions with cementitious products, modifying chemical structures and micro-morphology at the interface. Semi-quantitative XRD analysis and FT-IR spectroscopy characterize the ensuing chemical reactions, unveiling molecular bond and functional group changes. The superior performance of thermally activated graphite tailings primarily stems from increased active SiO2 and Al2O3 post-activation. The active SiO2 and Al2O3 reacts with cementitious products to form C-(A)-S-H gels, filling micro-pores at the tailings-mortar interface, which is the key characteristic that enables graphite tailings to serve as high-quality pozzolanic binder aggregates. A predictive model for compressive strength, utilizing reference models from solid waste mortar concrete, quantifies the positive impact of chemical activation. The theoretical results obtained from this predictive model closely align with the experimental findings.

Physicochemical principles of creating alumina cements based on nickel and cobalt spinel

The article discusses the physicochemical principles for the production of alumina cements based on nickel and cobalt spinel. The results of tetrahedration of the CaO–Al2O3–CoO–NiO system, which undergoes changes due to solid-state exchange reactions in the high-temperature region of the CaO–Al2O3–CoO subsystem at a calculated temperature of 1439 K, as well as the decomposition of the Ca3CoAl4O10 ternary compound near 1530 K, are presented. Thermodynamic analysis establishes the stability of the conodes of the above system, allowing for its triangulation. Modifications of the subsolidus structure are combined and given for the temperature of 1530 K. All binary, ternary, and quaternary combinations thermodynamically stable in the subsolidus region of the system under study are presented. Topological graphs depicting the interconnection of elementary tetrahedrons, which allow the prediction of solid-state processes in multi-component systems, have been constructed. Based on the study of the structure of the CaO–Al2O3–CoO–NiO system, the possibility of technological forecasting of heterophase materials with high-performance characteristics is substantiated.

Efficient separation and recovery of cobalt from grinding waste of cemented carbide using a sulfuric acid-sodium persulfate mixed solution

The mechanical processing of cemented carbide often generates a considerable amount of grinding waste from cemented carbide (GWCC), which serves as an important secondary resource for recovering Co and W. However, efficient separation of tungsten carbide (WC) and Co from GWCC remains challenging. This study tested an efficient process for separating Co from GWCC using a mixed solution of H2SO4-Na2S2O8. Under optimum conditions of 20 g/L H2SO4, 30 g/L Na2S2O8, 60 °C, and 1 h, the leaching efficiency of Co reached 97.0 %, compared to only 58.6 % when using H2SO4 alone. The kinetics of Co leaching in H2SO4 and H2SO4-Na2S2O8 solutions were determined to be a combination of chemical reaction control and diffusion control, suggesting that Co leaching rate in H2SO4 solution is significantly enhanced by introducing Na2S2O8. Finally, complete recovery of Co was achieved, and pure Co powder with a flower-cluster morphology was prepared from the leaching solution through oxalic acid precipitation followed by vacuum pyrolysis. The regenerative WC and Co powder can be recycled for cemented carbide production.

Preparation of magnesium potassium phosphate cement from magnesite tailings under lower calcination temperature

The identification of a more economical source of magnesium, coupled with reduced preparation costs, is essential for enhancing the competitiveness of magnesium potassium phosphate cement (MKPC) production. This study explores the utilization of magnesite tailings, waste materials produced during the mining and ore dressing process of magnesite, as raw materials for the preparation of low-cost dead-burnt magnesium oxide (MgO-T) at comparatively low calcination temperatures. The research demonstrated that impurities, specifically silicon and calcium, formed compounds with MgO during calcination, leading to the encapsulation of certain MgO particles. This encapsulation reduced both the specific surface area and hydration activity of the MgO. Despite the calcination temperature of 1100 °C being significantly lower than that of commercial dead-burnt MgO (MgO-C) at 1700 °C, MgO-T exhibited lower activity compared to MgO-C, which rendered it more suitable for the production of MKPC. Under optimal conditions, characterized by a molar ratio of magnesium to phosphorus (M/P) of 3, a borax retarder content of 15%, and a water-cement ratio of 0.15, the MKPC prepared using MgO-T demonstrated an initial setting time exceeding 60min and achieved a compressive strength of up to 79.6MPa. XRD and microstructural analyses revealed that struvite-K was the primary strength phase; however, the porosity of the specimens had a more pronounced effect on strength. By producing lower activity MgO at reduced calcination temperatures, this method obviates the need for complex purification processes when utilizing magnesite tailings, thereby decreasing the costs associated with MKPC preparation and presenting promising applications for the future.

Preliminary investigation on spent garnet as a novel supplementary cementitious material

The escalating global demand for cement, a fundamental material in infrastructure development, has exacerbated environmental challenges, particularly through significant carbon dioxide (CO₂) emissions, which account for approximately 8.3 % of global anthropogenic CO₂ output. This research explores the potential of spent garnet powder, a byproduct of abrasive water jet machining, as a sustainable supplementary cementitious material (SCM) to mitigate these impacts. The spent garnet powder, characterized by a high concentration of silicon dioxide (SiO₂), aluminum oxide (Al₂O₃), and iron oxide (Fe₂O₃), was subjected to rigorous analysis. X-ray Fluorescence (XRF) confirmed its chemical suitability for pozzolanic applications, while laser particle size analysis revealed a finer granulometry relative to Ordinary Portland Cement (OPC), which is advantageous for enhancing pozzolanic reactivity. Scanning Electron Microscopy (SEM) demonstrated the angular and irregular morphology of the garnet particles, which is conducive to improved interfacial bonding within the cement matrix. X-ray Diffraction (XRD) identified active mineral phases that are critical for promoting pozzolanic reactions, and Thermogravimetric Analysis (TGA) demonstrated the material’s superior thermal stability, with minimal decomposition at elevated temperatures. Fourier Transform Infrared Spectroscopy (FTIR) identified strong silicon-oxygen (Si-O) and aluminum-oxygen (Al-O) bond structures, indicative of robust pozzolanic potential. The Strength Activity Index (SAI) and Frattini tests further substantiated the pozzolanic activity, revealing that a 10 % replacement of OPC with SGP not only enhances compressive strength but also meets the stringent requirements of ASTM C618. Additionally, the economic analysis underscores the cost-effectiveness of utilizing spent garnet powder, presenting a viable strategy for reducing both production costs and CO₂ emissions in the cement industry. This study conclusively positions spent garnet powder as a highly promising supplementary cementitious material, with significant implications for advancing sustainable construction practices and reducing the environmental footprint of cement production.

Harnessing iron tailings as supplementary cementitious materials in Limestone Calcined Clay Cement (LC3): An innovative approach towards sustainable construction

The increasing demand for sustainable construction materials has led to the exploration of iron tailings (ITs) as supplementary cementitious materials (SCMs) in Limestone Calcined Clay Cement (LC3). This study investigates the effects of varying ITs content in LC3 on compressive strength, microstructure, and environmental impact. Replacing 28 % of LC3 with ITs resulted in a 42 MPa compressive strength after 28 days, comparable to ordinary Portland cement (OPC), while reducing OPC content by 50 %. Microstructural analysis revealed that ITs contributed to the formation of additional C-(A)-S-H gel, enhancing the mechanical properties of the cement matrix. The findings also showed that concentrations of Zn (0.003–0.094 mg/L), Pb (0.002–0.090 mg/L), Cu (0.005–0.018 mg/L), Mn (0.115–0.712 mg/L), Ni (0.011–0.021 mg/L) in the leachates of LC3 containing ITs were below the critical limits for surface water and groundwater. Moreover, the life cycle assessment (LCA) demonstrated significant reductions in global warming potential (43.6 %), energy consumption (37.2 %), and cost (35.5 %). This study provides an innovative solution for waste utilization and environmentally friendly cement production.

Enhancing the mechanical and environmental performance of solidified soil using construction waste and glass micro-powder

The rapid accumulation of construction waste and waste glass, coupled with their environmental hazards, has highlighted the need for sustainable waste management strategies. This study explores the potential of using construction waste (CW) and glass micro-powder (GMP) as innovative additives in soil stabilization, providing both mechanical and environmental benefits. This research focuses on enhancing the compressive strength, tensile strength, and heavy metal stabilization of solidified soils while reducing carbon emissions. Experimental methodologies involved the systematic preparation of soil samples stabilized with various proportions of CW and GMP. Microstructural analyses were conducted using Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) to understand the formation of cementitious products, including calcium silicate hydrate (C-S-H) and calcium aluminate hydrate (C-A-H), which play a pivotal role in the strength improvement of stabilized soils. This study found that the optimal formulation of 30 % CW and 15 % GMP improved compressive strength by 56.8 %, from 7.25 MPa to 11.38 MPa, while reducing porosity by 57 % and increasing tensile strength by 85 %. In terms of environmental performance, the combination of CW and GMP enhanced the soil's ability to immobilize heavy metals, with 80 % sequestration efficiency, significantly contributing to soil remediation. These findings underscore the practical engineering significance of utilizing CW and GMP for sustainable soil stabilization, providing a greener alternative to traditional binders and promoting resource efficiency in the construction industry.

Alkaline activation via in-situ caustification of one-part binders of composite precursors of waste glass and limestone

Mixtures of powders of waste glass (WG), limestone (LS), Na2CO3 and CaO were used to formulate novel one-part in situ alkali-activated cement (WG-AAC). The in-situ interaction Na2CO3-CaO-H2O promoted the formation of CaCO3 and NaOH, which promoted the WG and LS dissolution and influenced the micro- and molecular features of the resulting cementitious products. Pastes and mortars developed 1-year strengths of up to 29 MPa and were stable underwater. Characterization by XRD, SEM, EDS, and 29Si-NMR indicated that a Na2CO3:CaO ratio close to 1:1 resulted in polymerized C-S-H, CaCO3, silica gel, and Ca-modified silica gel, which were intimately intermixed and possibly crosslinked through Q3 bonds. Such phases interacted synergistically improving the underwater stability of the WG-AAC, indicating that in-situ caustification is a suitable and practical alkaline activation for SiO2-rich precursors.

Assessing the Usage of Barytes Powder and Cuddapah Stone Dust as Supplementary Cementitious Materials in Concrete of Grade M30 and M35

This research studied the effects of using Barytes powder and Cuddapah stone waste as substitutes for cement in M30 and M35 grade concrete using OPC. Cement production is known to harm the environment and consume a lot of energy, making the search for alternative materials to replace cement in concrete important.In this study, different amounts of Barytes powder and Cuddapah stone waste were added to concrete mixes as partial replacements for cement. The resulting concrete was tested for compressive strength and compared to normal concrete. The experiment involved making concrete samples with varying percentages of cement replacement, ranging from 0% to 50%, using Barytes powder, Cuddapah stone waste and Combination. The samples underwent standard curing and testing according to Indian standards.The research analysed the results to find the optimum percentage of cement replacement that provided satisfactory mechanical properties. This study determined the feasibility and effectiveness of using Barytes powder and Cuddapah stone waste as partial replacements for cement in concrete production.