Traditional Cement Research Articles

Thermal, Mechanical, and Microstructural Properties of Novel Light Expanded Clay Aggregate (LECA)-Based Geopolymer Concretes

The construction sector’s reliance on traditional cement significantly contributes to CO2 emissions, underscoring the urgent need for sustainable alternatives. This study investigates fine (0–4 mm), rounded, uncoated, porous-surfaced lightweight expanded clay aggregate (LECA)-based geopolymers, which combine the low-carbon benefits of geopolymers with LECA’s lightweight and insulating properties. Geopolymers were synthesized using lignite-rich fly ash with varying ratios of LECA to aggregate. Mechanical testing revealed that the reference mixture without LECA (REF-GEO) achieved the highest compressive strength of 37.89 ± 0.75 MPa and flexural strength of 7.62 ± 0.11 MPa, while complete substitution of the aggregate with LECA (LECA-100%) reduced the compressive strength to 17.31 ± 0.88 MPa and flexural strength to 3.41 ± 0.11 MPa. The density of the samples decreased from 2.06 g/cm3 for REF-GEO to 1.31 g/cm3 for LECA-100%, and thermal conductivity dropped significantly from 1.15 ± 0.07 W/mK to 0.38 ± 0.01 W/mK. Microstructural analysis using XRD and SEM-EDX highlighted changes in the material’s internal structure and the increase in porosity with higher LECA content. Water vapor permeability increases over time, particularly in samples with higher LECA content. These findings suggest that LECA-based geopolymers are suitable for low-load or non-structural elements. They are ideal for sustainable, energy-efficient construction that requires lightweight, insulating, and breathable materials.

A State‐of‐the‐Art Review on Effectiveness of Geopolymer Technology Toward Dye Degradation, Heavy Metal Encapsulation and Its Future Prospects on Environmental Remediation

ABSTRACTGeopolymers are an innovative class of environmentally friendly materials gaining significant attention in construction, materials science, and sustainable technology. As alternatives to traditional cement‐based materials, geopolymers exhibit unique mechanical properties suitable for various construction applications, including use as construction materials, coating materials, and high‐temperature‐resistant materials. Notably, geopolymers can effectively adsorb heavy metals, dyes, and radioactive pollutants, offering substantial environmental benefits. This review paper explores the process and mechanism of geopolymerization, as well as the application of geopolymers in the treatment of contaminants. It details how aluminosilicate precursors contribute to the photocatalytic degradation of dyes, examining the role of different raw material sources, types of activators or additives used, and preparation methods. This paper highlights the effectiveness of geopolymers in dye degradation, providing insights into the underlying mechanisms. Additionally, the review delves into the interaction of geopolymers with heavy metals through mechanisms such as chemisorption, complexation, adsorption, ion exchange, intraparticle diffusion, and the solidification of heavy metals within the geopolymer matrix. This comprehensive analysis of existing research aids researchers in understanding the capabilities and limitations of geopolymer materials in environmental remediation. Beyond waste reduction, the review addresses the broader environmental impact of geopolymers, particularly their potential for reducing the carbon footprint compared to traditional cement. This aspect is crucial for evaluating the overall sustainability of geopolymers. Furthermore, the paper emphasizes the importance of life cycle durability assessments (LCA) to evaluate the ecological footprint of this eco‐friendly concrete throughout its lifetime, from raw material to end‐of‐life disposal. LCA provides a complete perspective on the sustainability of geopolymers, guiding future research and applications in sustainable construction. By synthesizing current research on geopolymers, this review paper serves as a valuable resource for researchers in geopolymer technology, offering insights into future research directions and potential applications.

Shelf-Stable Sporosarcina pasteurii Formulation for Scalable Laboratory and Field-Based Production of Biocement.

Biocement is an environmentally friendly alternative to traditional cement that is produced via microbially induced calcium carbonate precipitation (MICP) and has great potential to mitigate the environmental harms of cement and concrete use. Current production requires on-site bacterial cultivation and the application of live culture to target materials, lacking the convenience of stable formulas that enable broad adoption and application by nonscientific professionals. Here, we report the development of a dry shelf-stable formulation of Sporosarcina pasteurii, the model organism for biocement production. At laboratory scale, when inoculated at an equivalent concentration of viable cells, we show that this formulation produces biocement equal in strength to that produced using live cell cultures. We further demonstrate that this formulation forms biocement in the field within 24 h, leading to ground improvement with increased bearing capacity. These results illustrate that preserved, shelf-stable bacteria can contribute to rapid biocement production and can be adopted for scaled geotechnical and construction purposes.

Recycling of Agricultural Film Wastes for Use as a Binder in Building Composites.

Plastic film, also known as low-density polyethylene (LDPE), poses serious environmental challenges due to mass production, short life cycle, and poor waste management. The main aim of this paper was to examine the suitability of using agricultural waste film as a binder in construction composites instead of the traditional cement slurry. Molten at temperatures of around 120-150 °C wastes was mixed with fine sand and gravel aggregate as filler. Twelve samples consisting of different mixtures were produced-F20, F25, F30, F35, F40, F45, F50, F60, F70, F80, F90, and F100-where a given number indicates the weight ratio of film waste to aggregate used. The composites were subjected to various tests, including volumetric density, compressive strength, and flexural strength. The volumetric density (ρ) of the composites decreased with increasing amounts of waste. Composites containing 100% recyclate (F100) depicted density, ρ = 0.74 g/cm3, was 50.7% lower than for a composite that contained 20% recyclate (F20). The highest soakability was recorded in F20 (2.19%). Subsequently, the absorbency tested in composites decreased with increasing recyclate content. Compression strength (σcomp) was highest for F40 (σcomp = 39.46 MPa). In contrast, F20 had the lowest recorded compressive strength value (σcomp = 11.13 MPa) and was 71.8% lower than F40. F70 had the highest recorded flexural strength value (σflex = 27.77 MPa). The other composites showed lower strength for higher amounts of recyclate and the amount of sand. SEM imaging proved that the contact zone between the aggregate grains and the bonding phase of the recycled film was consistent, with no anomalies, cracks, or voids. The results prove that LDPE film waste is suitable for use as a binder in building composites. However, appropriately selecting proportions of the recyclate, sand, and gravel aggregate is crucial to obtain a composite with technical parameters similar to those of cementitious composites.

Enhancing concrete mechanical properties using nano-silica, calcined clay, and glass fibers optimized by response surface methodology

This study investigates the combined effects of nano-silica, calcined clay, and glass fibers on the mechanical properties of normal-grade concrete (M30), with a primary aim to utilize industrial waste materials and improve concrete performance while promoting environmental sustainability. Response Surface Methodology (RSM) was employed to optimize material proportions and evaluate their impact. The experimental design incorporated nano-silica (0– 10%), calcined clay (0–30%), and glass fibers (0–2%), corresponded to the minimum and maximum values in the range. A total of 120 specimens were tested to assess compressive strength, flexural strength, rebound hammer values, and ultrasonic pulse velocity (UPV). The optimized mix predicted compressive strength of 49.41 MPa, flexural strength of 9.05 MPa, rebound hammer value of 62 MPa, and UPV of 5445 m/s. Validation tests demonstrated observed compressive strength of 46.55 MPa, flexural strength of 8.05 MPa, rebound hammer value of 60 MPa, and UPV of 4890 m/s, with errors of 5.79%, 11.00%, 3.22%, and 10.19%, respectively. Analysis of variance (ANOVA), a statistical method for determining the significance of factors on observed outcomes, indicated that nano-silica had the most substantial impact on all performance metrics. The models showed high reliability, with R² values of 0.9653 for compressive strength, 0.9268 for flexural strength, 0.9266 for rebound hammer, and 0.8894 for UPV. The study demonstrates the potential of incorporating waste materials like calcined clay and nano-silica into concrete to enhance its mechanical properties and reduce environmental impact. This approach aligns with sustainable construction practices by lowering reliance on traditional cement, reducing carbon emissions, and promoting the reuse of industrial by products. The findings support the development of cost-effective, durable, and eco-friendly infrastructure, addressing the dual objectives of improved performance and environmental sustainability.

Eggshell Waste to Wonder: A Novel Approach to Sustainable Cementitious Materials

Abstract: Eggshells, a widely available byproduct of food consumption, are generated in vast quantities globally, with significant waste accumulation in domestic and industrial settings. Despite their high calcium carbonate content, eggshells are often discarded, leading to environmental concerns such as landfill congestion and methane emissions. This study explores the potential of repurposing powdered eggshells as a partial replacement for cement in concrete production, addressing both waste management challenges and the sustainability of cement manufacturing. In this experimental investigation, cement was replaced by eggshell powder in varying proportions of 2.5%, 5%, 7.5%, and 10%. Concrete mixes were prepared, and the resulting properties, including mechanical strength and durability, were evaluated. The results showed that the mix with 10% eggshell powder replacement exhibited the best performance, demonstrating optimal mechanical strength and durability. This study underscores the feasibility of utilizing eggshells as a sustainable alternative material in concrete, contributing to circular economy practices. By reducing reliance on mined limestone and decreasing carbon emissions associated with traditional cement production, the use of eggshells offers an eco-friendly solution to both waste management and industrial sustainability. The findings support the growing recognition of eggshells as a recyclable resource in various industries, including construction, and highlight their potential to reduce waste accumulation while promoting sustainable development.

Field Test on the Application of Industrial Solid Waste in the Grouting Process of Pre-Bored Grouted Planted Pile

In the installation of pre-bored grouted planted (PGP) piles and other composite pile foundations, cement is commonly used in the grouting stage. However, the cement-production process generates significant CO₂ emissions, which are not favorable for achieving low-carbon societal goals. This study explores the use of industrial solid waste (mineral powder and gypsum powder) mixed with cement as a grouting material in test pile TP1, while traditional cement grout was used in test pile TP2. Both test piles were instrumented with optical fiber sensors along their shafts. The findings indicate that the ultimate load-bearing capacity of TP1 was approximately 93% of that of TP2, signifying a 7% reduction when mineral and gypsum powder were added to cement. Additionally, TP1’s peak surface friction in various soil layers ranged from 1.29 to 2.79 times that of the bored pile, whereas TP2’s peak surface friction was about 1.42 to 3.10 times higher. The cement consumption for TP1 was roughly 65% less than for TP2, and the cost of grouting materials for TP1 was reduced by 35%. This study confirms that utilizing solid waste in the grouting stage of PGP piles is feasible, and optimizing material proportions may enhance future performance.

Exploring the potential and strength characteristics of waste sodium silicate-bonded sand for sustainable application in alkali-activated slag concrete

Alkali-activated slag concrete (AASC) with odium silicate-bonded sand (WSSS) is a potential solution to mitigate the environmental impact of traditional cement. However, its feasibility for structural applications has remained uncertain. This study examined the potential of WSSS to substitute fine aggregate in AASC compared to natural aggregates and Quartz sand. The exceeded compressive strength of AASC suggested its practical applications for structural purposes. The alkali activator concentration influenced the compressive strength of concrete. The optimal concentration of 5% to 6% increased compressive strength. In addition, the aggregate type significantly affected the strength, structural performance, and erosion rate of concrete. The erosion rate in alkali-activated slag mortar with natural aggregates in the presence of the strong alkali was remarkable compared to WSSS and Quartz sand. This study highlighted the potential of WSSS as a low-cost, durable aggregate alternative for AASC. This offers a promising solution for more environmentally friendly construction materials.

Development and Characterization of Alkali-Activated Lithium Slag-Fly Ash Composite Cement

As the demand for environmental sustainability grows in the global construction industry, traditional cement production faces significant challenges due to high energy consumption and substantial CO2 emissions. Therefore, developing low-carbon, high-performance alternative cementitious materials has become a research focus. This paper proposes a new low-carbon cement (alkali-activated lithium slag-fly ash composite cement, ALFC) as a substitute for traditional cement. First, the alkali activation reactivity of lithium slag (LS) is enhanced through calcination and grinding, revealing the reasons behind its improved reactivity. Then, alkali-activated LS and fly ash were partially used to replace cement to prepare ALFC, and the effects of the water-to-binder ratio (W/B), LS content, and NaOH addition on the flowability and mechanical properties of ALFC were investigated. XRD, SEM/EDS, and TG/DTG analyses were conducted to examine its hydration products and microstructure, revealing the hydration mechanism. The results show that the flowability of ALFC increases with W/B but decreases with a higher LS content. When W/B is 0.325 and the LS content is 25 wt.%, flowability reaches 200 mm, meeting construction requirements. LS calcined at 700 °C for 1 h significantly enhanced ALFC’s 90-day flexural and compressive strengths by 39.73% and 58.47%, respectively. The primary hydration products of ALFC are C-S-H, N-A-S-H, and C-A-S-H gels, with their content increasing as the NaOH concentration rises. The optimal NaOH concentration and LS content for ALFC are 2 mol/L and 25 wt.%, respectively.

Reinforcing mechanisms review of the graphene oxide on cement composites

Abstract By virtue of the abundant oxygen-functional groups, ultra-high specific surface area and superior mechanical properties, graphene oxide (GO) has been proven as one of the outstanding candidates in cement composites. Compared with the traditional cement pastes, the GO-reinforced cement composites exhibit benefits in pore structure, mechanical properties, and durability. In addition, the abundant oxygen-containing functional groups on GO can promote the hydration rate of cement and combine with hydration products to fill the pores. To further improve the performance of GO-reinforced cement composites and promote the application of composites in practical engineering, it is necessary to comprehensively understand the reinforcing mechanisms of GO on cement composites. In this work, the enhancement mechanisms of GO to improve hydration, nucleation effects, mechanical strengthening mechanisms, antiseepage mechanisms and pore-filling effects of GO are systematically revealed. The optimal dosage range of GO mixing in the current study is calculated by considering the factors of mechanical property and microscopic characterization, but the economic cost also needs to be considered in future development studies. This review will promote the application of the more cost-effective and high-performance GO-reinforced cement composites in practical construction engineering.

Shrinkage behavior of alkali-activated materials using ground bottom ashes, calcined clays, volcanic ashes, and fluidized bed combustion ashes as precursors

The global decline in the availability of fly ash and slag, the most common precursors for alkali-activated materials (AAMs), necessitates the exploration of alternative materials. Alkali activation technology presents an opportunity to utilize a wide range of naturally occurring and industrial byproducts rich in aluminosilicate minerals as precursors, offering a low-carbon alternative to traditional cement. This study investigates the volumetric deformations in AAMs produced from four groups of nontraditional and natural pozzolan-based (NNP) materials: low-purity calcined clays (CC), volcanic ashes (VA), ground bottom ashes (GBA), and fluidized bed combustion ash (FBC). Volumetric deformations—including chemical, autogenous, and drying shrinkage—were characterized using ASTM standards for portland cement. Chemical and autogenous deformations were minimal across most materials, while excessive drying shrinkage was observed in all but the calcined clays. The application of shrinkage-reducing admixtures and internal curing effectively mitigated this shrinkage. Further analyses of total heat release during activation, bound water content, pore solution surface tension, and porosity provided insights into the shrinkage and expansion mechanisms. With effective drying shrinkage control measures, alkali-activated NNPs show promise as viable low-carbon binders.

Enhancing concrete pavement performance using refuse derived fuel fly ash as a sustainable cementitious material

ABSTRACT The utilization of waste materials in concrete is becoming increasingly important for sustainability in construction. This research investigated the mechanical performance and environmental safety of concretes containing Refuse Derived Fuel fly ash (RDF FA), a waste product from waste incineration plants. The innovative mix design strategically used RDF FA as both cement replacement and cementitious addition in concrete. Compressive and flexural strength test results showed that RDF FA addition increased both compressive and flexural strengths, while RDF FA replacement decreased strengths (< 28 days cured) compared to those of traditional cement concrete. Microstructural and mineralogical analyses revealed dense C–S-H formation in RDF FA added samples, indicating improved hydration. In contrast, RDF FA replacement reduced cementitious products and hindered hydration. RDF FA’s high SiO2 content and favourable SiO2/CaO ratio enhanced pozzolanic reaction in RDF FA added samples, further improving strength development. Leaching test results demonstrated that heavy metal concentrations in RDF FA-modified concretes remained within environmental protection limits. Thus, with proper mix design, RDF FA has the potential to be a sustainable supplement for concrete, reducing industrial waste and natural resource use. This work provides an approach to balance enhanced concrete performance with environmental safety when using RDF FA.

A comprehensive review of the formation, properties, and applications of limestone calcined clay cement (LC3)

Limestone Calcined Clay Cement (LC3) has emerged as a promising alternative to conventional Portland cement due to its reduced carbon footprint and improved performance characteristics. This comprehensive review explores the formation, properties, and applications of LC3, aiming to provide a detailed understanding of its potential in sustainable construction practices. The review begins with an overview of the raw materials involved in LC3 production, highlighting the synergistic effects of limestone and calcined clay in enhancing cementitious properties and reducing clinker content. Structural and chemical transformations during the calcination and hydration processes are discussed, emphasizing the role of supplementary cementitious materials in optimizing cement performance. The mechanical, durability, and environmental attributes of LC3 are critically examined, showcasing its superior strength development, resistance to chloride ingress, and lower energy consumption compared to traditional cements. Applications of LC3 in various construction sectors, including residential, commercial, and infrastructure projects, are elucidated, demonstrating its versatility and potential for global adoption. Furthermore, challenges such as standardization, scalability, and economic feasibility are addressed alongside future research directions aimed at advancing LC3 technology. This review consolidates recent advancements and establishes LC3 as a viable solution for sustainable cement production, offering insights into its transformative impact on the construction industry and environmental sustainability.

Effect of liquid-solid ratio on metakaolin-based geopolymer binder properties

AbstractThis article aims to achieve the hardening of geopolymer binder-based metakaolin under the same setting time and hardening temperature as traditional cement. It studied the hardening of the geopolymer binder-based metakaolin at two temperatures of 60 °C and room temperature using different liquid-to-solid ratios of 0.8, 0.95, and 1.1. The bulk density, compressive strength, sitting times, thermal conductivity, and microstructure were measured for geopolymer binders. Based on the specified range for cement characteristics, the geopolymer binder was solidified at room temperature, utilizing a liquid-to-solid ratio of 0.8 to achieve optimal results stratified according to the cement's ideal characteristics. It had a bulk density of 1.264 g cm−3, compressive strength of 19.12 MPa, initial setting time of 288 min, final setting time of 358 min, and thermal conductivity of 0.49 W m−1 K.

Enhancing crack self-healing properties of low-carbon LC3 cement using microbial induced calcite precipitation technique

Limestone Calcined Clay Cement (LC3) is a promising low-carbon alternative to traditional cement, but its reduced clinker content limits its self-healing ability for microcracks, affecting durability. This study explores the application of Microbial Induced Calcite Precipitation (MICP) technique to enhance the crack self-healing capacity of LC3-based materials. Bacillus pasteurii was utilized to induce calcium carbonate precipitation to improve the crack self-healing capacity of LC3, thereby addressing its limited durability due to reduced clinker content. Experimental tests focused on optimizing the growth conditions for B. pasteurii, evaluating the compressive strength, capillary water absorption, and crack self-healing rates of the modified LC3 material. Results showed that under optimal conditions (pH of 9, inoculation volume of 10%, incubation temperature of 30°C, and shaking speed of 150 rpm), the bacterial strain exhibited maximum metabolic activity. The Microbe-LC3 mortar demonstrated a self-healing rate of up to 97% for cracks narrower than 100 μm, significantly higher than unmodified LC3. Additionally, the compressive strength of Microbe-LC3 was enhanced by approximately 15% compared to standard LC3 mortar after 28 days. The capillary water absorption was reduced, indicating improved durability due to the microbial-induced calcium carbonate filling the pores. This study confirms that MICP technology is a viable approach to significantly enhance the performance of LC3, contributing to the development of more durable and sustainable cementitious materials for construction applications.

Recycling some byproducts for fabrication of green cement with good mechanical strength and high efficiency for wastewater treatment

This research aims to produce green cement, as an alternative to traditional cement, with outstanding performance. Five alkali-activated cement pastes were fabricated based on NaOH-activation of slag (GGBFS), bypass (B), and/or silica fume (S). Codes of five pastes are C, C-20B, C-30B, C-10B10S, and C-20B10S, as C is the control paste containing 100% slag. The compressive strength of the fabricated pastes was measured at different curing regimes: Conventional curing for 3 months and autoclave curing at 4 bar/153◦C, 7 bar/178◦C, and 10 bar/198◦C for 4 h. XRD, TGA/DTG, SEM/EDX, and BET/BJH techniques were utilized to clarify the phase development, morphological and texture features of the formed alkali-activated composite pastes. Besides, the removal capacity of some pastes for methylene blue and indigo-carmine dyes from aqueous media was evaluated. The results confirmed that C and C10B10S (80%GGBFS + 10%B + 10%S) pastes have significant mechanical properties and distinctive meso-porosity that can remove both anionic and cationic dyes.

An investigation on workability and strength on compression of GPC with addition of different aspect ratio glass fibers

The heating of limestone and other materials to high temperatures to produce Ordinary Portland cement (OPC), a key component in concrete releases of carbon dioxide CO2 which makes the construction industry a notable contributor to greenhouse gas emissions. The search for more sustainable alternatives has led to the exploration of alkali-activated materials as a replacement for OPC. Alkali-activated materials are a class of binders that can be used in concrete production without the need for traditional cement. These materials often include industrial by-products such as fly ash, GGBFS (sometimes also called GGBS) (Ground Granulated Blast Furnace Slag), and other waste materials. The development and adoption of alkali-activated materials represent a promising avenue for reducing the environmental impact of the construction industry. On-going research and collaboration are crucial to addressing technical challenges and promoting the widespread use of these alternative binders. The exploration and utilization of alternative materials such as GGBFS, fly ash, and geopolymer concrete play a crucial role in mitigating the environmental impact of the construction industry, particularly in terms of reducing CO2 emissions and utilizing industrial by-products effectively. A good concrete mix is obtained from combination of different size of aggregates. Addition of fibers plays a crucial role in enhancing the tensile strength of concrete. Similar synergy of addition of different aspect ratio of optimum dosages fibers as of different size of aggregates may improve strength and ductility of concrete. Short fibres can stop the propagation of micro-cracks with enhancement of toughness, and long fibres can stop the propagation of macro-cracks. From the aforementioned perspective, it is preferable to add the same volume of fibre with a different aspect ratio to improve the pre- and post-cracking performance of concrete. It also aids in boosting maximal strength.This study aims in preparing geopolymer concrete with graded glass fibres in order to investigate improvement the strength in compression and workability.

Development of an eco-friendly geopolymer mortar using slag and fly ash with high bentonite content for thermal and environmental applications

The construction industry is exploring the use of low-cost waste materials to create eco-friendly geopolymer mortar binders. Our study aims to develop various environmentally friendly geopolymer mortar mixes for thermal and adsorption applications using natural materials like bentonite and industrial by-products such as ground-granulated blast furnace slag and fly ash. Ternary geopolymer mortar pastes are prepared using equimolar amounts of slag (GBFS) and fly ash (FA), with 6%, 8%, 10%, and 12% weight of bentonite (BC) from the total geopolymer weight to study the bentonite replacement effect. The prepared mortar are tested for their physico-chemical, mechanical, adsorption, and thermal stability properties (300 °C to 900 °C). The adsorption behavior of eco-friendly geopolymer mortar mixes against crystal violet dye in aqueous solutions is also identified. The study found that adding 6% bentonite to the slag/fly ash-based geopolymer mortar mix yielded the highest mechanical characteristics. Moreover, all the ternary geopolymer mortar mixes exhibited excellent thermal stability up to 900 °C. In adsorption study, the results indicated that the mortar mixes had excellent capacities and adhered well to the Freundlich isotherm model, suggesting potential applications in treating wastewater. Using bentonite in slag/fly ash geopolymer mortar offers a sustainable, cost-effective, and heat-resistant alternative to traditional cement binders.

Microstructural analysis of geopolymer pastes contaminated with crude oil: Impact on efflorescence, physical properties, and mechanical performance

Geopolymer concrete represents a more sustainable alternative to traditional cement in particular production processes, reducing carbon emissions, recycling industrial by-products, and promoting energy efficiency. However, a notable challenge is the potential for efflorescence, which can impair material performance due to microstructural changes from alkali leaching and carbonation. Various additives have been explored to mitigate efflorescence. Using oil-contaminated sand in geopolymer and concrete cement production is emerging as a cost-effective rehabilitation strategy that also addresses environmental concerns. This study investigates the impact of crude oil contamination on geopolymer pastes, focusing on efflorescence susceptibility. Under normal ambient conditions, the geopolymer pastes did not show signs of efflorescence. However, exposure to water led to the formation of efflorescence-type products. Notably, crude oil contamination significantly influenced this outcome. Crude oil significantly decreased the occurrence of efflorescence, mainly when contamination levels ranged from 2 % to 10 %. This reduction is attributed to the oil’s effects on the paste’s pore structure, fluid migration dynamics, and viscosity, which affected water adhesion and movement through the paste. Additionally, crude oil contamination altered the chemical properties of the geopolymer pastes, causing fluctuations in the pH of leaching solutions, which affected chemical equilibrium and electrical conductivity. Compressive strength improved with 1 % crude oil contamination but decreased with higher contamination levels. Geopolymer paste with 1 % crude oil content generally increases material density and reduces porosity, enhancing mechanical properties and reducing efflorescence. However, excessive contamination undermined these benefits and negatively impacted material performance. Therefore, moderate oil contamination can be effectively used as an additive to reduce efflorescence and enhance geopolymer concrete's physical and mechanical properties. The findings provide valuable insights into the potential applications and limitations of using fly ash-based geopolymers in environments prone to oil contamination.

An Overview of Fly-ash Geopolymer Composites in Sustainable Advance Construction Materials

Fly-ash geopolymer composites are an exciting advancement in eco-friendly construction materials. Fly-ash has become a sustainable alternative to regular cement because the approach addresses critical concerns in construction, such as high energy use, excessive carbon emissions and the challenge of managing industrial waste. In this review, a brief discussion on how fly-ash geopolymer composites could transform construction practices and reduce their impact on the environment. The construction industry is a major contributor to climate change, whereas industrial byproducts like fly-ash can also be an environmental challenge. Thus, the fly-ash geopolymer composites offer an innovative solution by reusing this waste to create environmentally friendly binding materials. Fly-ash can effectively replace traditional cement in construction, improving the durability and sustainability of buildings. By reducing our reliance on regular cement, these composites could revolutionise construction practices across various industries. Developing and widely adopting fly-ash geopolymer composites could bring substantial benefits. It could significantly reduce the construction industry's carbon footprint and contribute to global efforts to combat climate change. Additionally, ongoing research aims to enhance these composites' strength, heat resistance, and chemical durability, further promoting sustainable construction and supporting a circular economy by turning industrial waste into valuable construction materials.