Portland Cement Research Articles

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.

Optimization of sandstone processing waste, electric arc furnace slag, and fly ash-based ternary blended eco-friendly geopolymers.

Over the years, ordinary Portland cement (OPC) has been used to meet growing demands of land and housing facilities arising out of population overburdens. It is well documented that OPCs, besides their outstanding qualities as building materials, are also significant contributors to global greenhouse gases (GHG). Consequently, recent years have noticed an emerging interest in the search for alternatives to Portland cement-based binders. Geopolymers are well-suited to serve this purpose owing to their superior attributes and low CO2 emissions compared to conventional cement. Still, the industrialization of geopolymers has not reached a meaningful value due to the prevailing fundamental barriers involving the requirement of corrosive environments and intensive heat-curing regimes in post-fabrication processes. The current study investigates the viability of using synergistic mixtures based on stone residues, pulverized ash, and steel slags in fabricating geopolymer composites cured at ambient temperature with reduced ingestion of alkalis. A comprehensive assessment of the engineering, mineralogical, and microstructural characteristics was performed in terms of setting times, physico-mechanical, durability, non-destructive, and analytical tests. Further, a scaled-down approach was utilized to evaluate the feasibility of the designed composites as construction entities. The incorporation of SW (10-40%) prolonged the setting periods (~ 150min.) and abridged the engineering properties of the ternary pastes collectively by 127% due to silica coalescences. Besides, replacements of stone residues with FA (20-30%) and EAF (30-60%) improved the blend performance due to Ca and Al assimilations. All the developed composites satisfied the acclamations for OPC grade 33, CEM V class 32.5N, and OPC Type - I suggested by IS, EN, and ASTM standards, respectively, with matrices constituting CASH-CSH-NASH-(N,C)-A-S-H type gelation complexes identified by the X-ray, infrared, and electron imaging spectroscopic analysis. In addition, a cumulative deficit of about 60-90% was observed in energy and carbon footprints relative to OPCs, indicative of the binders' sustainability traits.

Development of composition of fine-grained concrete based on ash-and-slag wastes for additive technology of manufacturing small architectural forms

Developing a fine-grained concrete composition for additive technologies is an important scientific and practical task, since traditional building mixtures are unsuitable for 3D printers, and special solutions are practically absent in mass production. This study aims to develop a composition of fine-grained concrete for additive technologies using local resources and ash and slag waste of the Ust-Kamenogorsk thermal power plant, which contributes to the expansion of the raw material base used in this area. The work was carried out taking into account the analysis of the literature review, which made it possible to identify key aspects and directions in the development of concrete mixtures for additive technologies. This article discusses the possibility of using ash and slag waste in concrete as a filler. Ash has a grain size comparable to river sand, so it can be used as a new material to replace fine filler. To obtain the mixture, 5 experimental mixtures and one reference sample were prepared. The optimal composition is considered to include 30% of M500 Portland cement, 40% of sand, and 30% of ash and slag. The physical and mechanical characteristics of this composition are as follows: the mobility of the mixture is 5.81 cm, and the setting completion time is 4 hours 19 minutes. The results of the sample tests confirmed that the created fine-grained concrete compositions are suitable for extrusion on construction 3D printers. The possibility of creating a composition based on local ash and slag waste for additive technologies used in producing small architectural forms was experimentally confirmed.

Comparison of the efficacy of carbonation and conventional curing for remediation of copper-contaminated soils by ladle slag

Soil contamination poses an increasing challenge for global sustainable development. Traditional remediation methods, such as using ordinary Portland cement (OPC) for treating contaminated soils, are limited by high CO2 emissions, significant energy consumption, and natural resource depletion. A sustainable approach utilizing steel production waste (ladle slag, LS) to efficiently remediate copper (Cu)-contaminated soils was proposed in this study. The efficacy of this remediation using carbonation and conventional curing methods was compared. Cu-contaminated soils, spiked with varying initial concentrations, were treated with 10 % LS and subjected to both conventional and carbonation curing for different durations. Leaching behavior, strength development, and chemical and mineral properties of LS-remediated Cu-contaminated soils were assessed. The results demonstrated that both CO2 and conventional curing significantly reduced Cu leaching in contaminated soils by 4–5 orders of magnitude compared to untreated soils. CO2 curing achieved these reductions in a shorter time (56–72 hours) than conventional curing (28–56 days). Additionally, CO2 curing sequestered up to 8 % CO2 in the soils. However, higher Cu concentrations hindered carbonation reactions, lowering CO2 sequestration. While CO2 curing improved soil strength, increased initial Cu concentration diminished this effect. During CO2 curing, the formation of Ca- and Mg-carbonates contributed to microstructural densification and binding, thereby improving strength. These carbonates also encapsulated Cu, preventing its leaching. In contrast, the addition of Cu enhanced hydration reactions and improved the strength development of Cu-contaminated soils subjected to conventional curing. Conventional curing produced calcium aluminum silicate hydrate, which effectively bound soil particles, filled pores, and encapsulated Cu, reducing its leaching.

Development of sustainable self-healing engineered cementitious composites incorporating maximum amounts of natural pozzolan

In light of the scarcity of the most commonly used supplementary cementitious materials in Engineered Cementitious Composites (ECC), there is a pressing need to explore alternative materials to replace them. This paper considers the influence of integrating high amounts of natural Pozzolan (NP) on the sound and self-healing characteristics of ECC, including compressive and flexural strengths, deflections, cracking behavior, ultrasonic pulse velocity, rapid chloride permeability, and microstructure both before and after pre-cracking and recovery periods. NP contents at Portland cement (PC) ratios of 1.2, 1.5, 1.8, and 2.2 were explored, along with a combination of (50 % NP + 50 % slag)-to-PC ratio of 2.2. The results obtained indicate that superior self-healing properties can be achieved with the use of NP instead of slag, particularly at higher NP/PC ratios. Furthermore, the ductility of ECC significantly increased with the inclusion of NP, reaching more than twice the deflection capacity of the control specimens at various ages. The results of this research confirm the formation of additional C-A-S-H-type healing products as the outcome of the NP incorporation on the self-healing ability of ECC. In addition, the life cycle assessment analysis (LCA) highlights the significant reductions in energy consumption, CO2 emissions, and cost of ECC mixtures prepared with increased inclusion of NP, up to a 2.2 NP/PC ratio.

Effect of cellulose degradation products on 63Ni sorption on Portland cement

Concepts of nuclear waste repositories make use of large quantities of cementitious materials, especially near surface disposal facilities in which cement, mortar, and concrete are used both as structural materials and waste immobilization matrices. The retardation of radionuclides by the cementitious barriers of these repositories is crucial for the safe long-term management of the waste. Yet both the degradation of the cementitious materials and the presence of complexing ligands originating from the waste can affect the sorption of radionuclides. Cellulosic materials present in nuclear waste degrade under irradiation and under the alkaline conditions generated by the cementitious materials and they release organic compounds. Within the cellulose degradation products, α-isosacharinic acid (α-ISA) is generally assumed to be the strongest radionuclide complexant and to have the most impact on radionuclide sorption, though the presence of other ligands in the mixture could also have an effect. In this work, the sorption of 63Ni was assessed on fresh and state III hardened cement paste (HCP). The effect of α-ISA on the 63Ni sorption at these two degradation states was investigated and compared to the effect of a complete mixture of cellulose degradation products generated by irradiation and alkaline degradation of cellulosic tissues. A higher sorption of 63Ni was observed on state III HCP (Rd = (8.6 ± 3.3) × 103 L/kg) than on fresh HCP (Rd = (1.0 ± 0.3) × 103 L/kg), and, in both cases, the sorption was higher than previously observed on pure C–S–H (calcium silicate hydrate) suggesting the involvement of other mechanisms than the sole surface complexation on C–S–H. The effect of α-ISA on the sorption of 63Ni depended on the cement degradation state, ranging from no effect on fresh cement to a maximal sorption reduction factor of 8 ± 3 on degraded cement for 10−2 M α-ISA. The effect of the mixture of degradation products from cellulosic tissues on the sorption of 63Ni was found to be considerably higher on both fresh and degraded HCP, with a sorption reduction factor of 582 ± 972 and 718 ± 327 for the fresh and degraded cement, respectively, for a corresponding α-ISA concentration of 10−2 M.

Calcium nitrate as a modifier agent for metakaolin-based geopolymer mortar

Calcium nitrate, that is a calcium source, is generally used as an accelerating agent, antifreezing admixture, and corrosion inhibitor for Portland cement systems. Metakaolin, which is regularly used as a precursor in the production of geopolymers, lacks calcium. This can cause inefficiency of the geopolymerization process and alter the properties of the cementitious product. To overcome this problem, the potential benefits of adding calcium nitrate as an alternative calcium source for the metakaolin geopolymer mortar were investigated. Different ratios of calcium nitrate, ranging from 0.5 % to 10 %, were added into metakaolin geopolymer mortar. Different tests were conducted to know the effect of calcium nitrate on some properties of metakaolin geopolymer specimens, which were cured in either air or water. Advanced analysis methods were leveraged to unlock deeper meaning from the findings. The results indicated that adding calcium nitrate led to increased flowability and shortened setting time. The addition of 0.5–7 % calcium nitrate increased mechanical strength but reduced transport properties, whilst the addition of 10 % calcium nitrate led to adverse effects. The addition of 0.5–7 % calcium nitrate can mitigate the strength deterioration rate resulting from water curing and decrease drying shrinkage. The incorporation of appropriate ratios of calcium nitrate can form calcium silicate hydrate gel and densify the microstructure.

Effects of Waste Glass Bottle Nanoparticles and High Volume of Waste Ceramic Tiles on Concrete Performance When Exposed to Elevated Temperatures: Experimental and Theoretical Evaluations

This article reports the durability performance of modified concrete with silica nanoparticles and a high volume of waste ceramic tiles under varying elevated temperatures. Ordinary Portland cement (OPC) was replaced with 60% waste ceramic tiles powder (WTCPs) and supplemented with 2, 4, 6, 8, and 10% nanopowders from waste glass bottles (WGBNPs) as a rich source of silica. The natural aggregates (both coarse and fine) were fully replaced by the crushed waste ceramic tiles (WTCAs). After 28 days of curing, the modified specimens were exposed to varying elevated temperatures (200, 400, 600, and 800 °C) in a furnace followed by air cooling. Tests such as residual compressive strength, weight loss, ultrasonic plus velocity, visual appearance, and microstructural analysis were conducted. Additionally, analysis of variance (ANOVA) was used to validate the performance of the proposed predictive equations, as well as their terms, using p-values and F-values. It was discerned that OPC substitution with WTCPs and WGBNPs significantly improved the concrete’s performance under elevated temperatures. It is observed that the addition of 2, 4, 6, 8, and 10% WGBNPs lowered the concrete deterioration by increasing the residual strength and reducing both internal and external cracks. This study provides some new insights into the utilization of WTCPs and WGBNPs to produce sustainable and eco-friendly modified concrete with high spalling resistance characteristics at elevated temperatures.

Experimenting the compressive performance of low-carbon alkali-activated materials using advanced modeling techniques

Abstract Activated alkali materials (AAMs) are progressively utilized as an alternative to Portland cement concrete owing to their widespread application and reduced environmental impact. This research employed multi-expression programming (MEP) and gene expression programming (GEP) to create predictive models for the compressive strength (CS) of AAMs based on a dataset of 381 entries with eight distinct variables. To further assess the significance of the factors influencing the CS of AAMs, sensitivity analysis was employed. In comparison to GEP, MEP was better at predicting AAM’s CS. The R 2 score of the GEP model was 0.953, which is lower than the MEP model’s 0.970 level. This was further backed up by the results of the statistical study and Taylor’s diagram. The results of the sensitivity analysis showed that specific surface area, aggregate volumetric ratio, and silicate modulus were the three most important parameters influencing the models’ outcomes. In comparison to models built in Python, the produced models yield novel empirical equations for AAM strength characteristic prediction. Researchers and professionals in the field could use these equations to find the best proportions for mix designs, cutting down on the need for repeated laboratory tests.

Evaluating the mechanical properties and durability of portland cement mortars with sewage sludge ash as a partial replacement

Evaluating the mechanical properties and durability of portland cement mortars with sewage sludge ash as a partial replacement

Effect of Selective Milling on the Concentration Process of Critical Raw Materials from MSW Incinerator Bottom Ash

This research introduces selective milling as a reliable and effective initial concentration process to enable efficient separation and ensure high recovery rates of valuable and critical materials (minerals and metals) from processed incinerator bottom ash (pr.IBA), a treated mineral fraction originating from the conventional municipal solid waste (MSW) incinerator bottom ash (IBA) processing steps. Four different types of pr.IBA (each sample weighing up to three tons) were selectively milled using a demonstration-scale vertical roller mill to produce three distinct products: fine, middle, and coarse fractions. Chemical analysis demonstrated that a concentration step after selective milling could be reliably achieved regardless of the variation in the sources and qualities of the input materials. Specifically, calcium-containing compounds can be enriched in the fine fraction, potentially containing Ca2SiO4, CaSO4, and CaCO3. Complementary to its particle size equivalent to the raw mix, this calcium segregation could be valuable as an alternative material in cement clinker production. Conversely, the segregation of metal-bearing substances, particularly iron and copper, was detected in the coarse fraction. Such segregation is comparable to specific ore grades and enhances the possibility of metal recovery from pr.IBA.

Environmental Assessment of Calcium Sulfoaluminate Cement: A Monte Carlo Simulation in an Industrial Symbiosis Framework

Calcium sulfoaluminate (CSA) cement is recognized as an environmentally friendly alternative to Portland cement (PC) due to its lower carbon footprint and energy requirements. However, traditional CSA cement production faces significant obstacles, including the high cost and regionally constrained availability of bauxite, a key raw material. Utilizing alternative materials in the production process offers a viable approach to address these limitations. This study evaluated the environmental performance of three laboratory-synthesized CSA cements using alternative raw materials sourced through an industrial symbiosis framework. A comparative assessment with PC was conducted, focusing on energy consumption and CO2 emissions as key environmental performance indicators. The environmental impact of the CSA cements was analyzed using Monte Carlo simulations, a robust statistical approach based on data for the constituent raw materials. This method provides a practical alternative to a full life cycle assessment (LCA) when comprehensive data are not available. The results demonstrate that the CSA cements have significantly lower environmental impacts compared to PC, achieving energy savings of 13–16% and CO2 emission reductions of 35–48%. These results emphasize the potential of industrial symbiosis to enable more sustainable CSA cement production while addressing raw material constraints. In addition, this approach highlights the wider applicability of industrial symbiosis frameworks in the construction industry, contributing to a zero-waste future and supporting global climate goals.

Vitrified Clay for the Production of a Green Sustainable Ultra-High-Performance Fiber-Reinforced Concrete.

As awareness of the impact of anthropogenic activities on climate change increases, the concepts of durability, resilience, and sustainability in concrete tend to be adopted more seriously in the concrete construction industry. In this sense, one of the concrete technologies that began in the 1980s and that significantly contributes to maximize the beneficial effect on all these concepts are the ultra-high-performance concretes, a very attractive technology because it presents ultra-high strength and durability performances far superior to those of conventional concretes, a performance that is leading to a permanent increased demand. However, the development of these concretes has been widely criticized due to their high ecological impact, which is mainly attributable to the high cement dosages required for their production (800-1000 kg/m3). To address this criticism in a comprehensive manner and thereby reduce the embodied carbon attributable exclusively to the material, this research was oriented to determine the effect of an industrial by-product of vitrified clay, as a partial or total substitution for cement, silica fume, and limestone aggregate, on the compressive strength, flexural toughness, and embodied CO2. For the UHPC's evaluated in this work with a dosage of 2% by volume of steel micro-fibers, the results evidence the feasibility that the following substitutions by mass: 30% of the Portland cement, 100% of the silica fume, and 30% of the limestone aggregate and powder, do not detract the fresh stage, the compressive strength, the static modulus of elasticity, and the flexural strength, leading to significant reductions of the embodied CO2.

Lightweight, high-strength, thermal- and sound-insulating reed scraps/portland cement composite using extruded resin particles

The development of a lightweight composite made from reed scraps, Portland cement, and polystyrene particles can simultaneously address issues related to reed waste, environmental pollution, and carbon emissions produced by the construction industry. However, standard polystyrene particles have low bonding strength with Portland cement and reed scraps, giving the resulting composites inferior mechanical properties and thermal and acoustic insulation characteristics. To overcome these limitations, nano-silicon expanded resin particles (NSERP), composed of polyvinyl alcohol, polystyrene, nano-silicon, and various modifiers, were introduced to replace traditional polystyrene particles in the composite. These novel particles enhanced the interfacial bonding strength and improved the mechanical properties, as well as the thermal and acoustic insulation capabilities of the composites. This study investigated the effects of the water-cement ratio, reed scraps-to-cement ratio, and NSERP dosage on the composite's properties through single-factor experiments. The optimized composite had a density of 0.66 g/cm³ and a compressive strength of 2.5 MPa, and its sound absorption coefficient in the middle and high-frequency bands was 0.7, which was approximately 4.3 times higher than that of conventional silicate composites. Its thermal insulation performance surpassed that of standard composites. This lightweight, high-strength, thermally insulating, environmentally friendly, and energy-efficient multifunctional composite has potential applications in building energy conservation, traffic noise reduction, and new energy battery insulation.

Water Resistance of Compressed Earth Blocks Stabilised with Thermoactivated Recycled Cement.

Low water resistance is the main shortcoming of unfired earth materials, requiring chemical stabilisation for some durable applications. Ordinary Portland cement (PC) is an efficient stabiliser, but it goes against the ecological and sustainable nature of earth construction. This study explores the use of low-carbon thermoactivated recycled cement (RC) obtained from old cement waste as a new eco-efficient alternative to PC in the stabilisation of compressed earth blocks (CEBs). The objective is to improve the durability of the CEB masonry even when applied in direct contact with water, without compromising its eco-efficiency. The water resistance of the CEBs with 0% (unstabilised) and 5% and 10% (wt. of earth) stabiliser and partial to total replacement of PC with RC (0, 20, 50, 100% wt.) was evaluated in terms of compressive strength under different moisture contents, immersion and capillary water absorption, low-pressure water absorption, water permeability and water erosion. Low absorption and high resistance to water erosion were achieved in stabilised CEBs, regardless of the type of cement used. The incorporation of RC increased the total porosity and water absorption of the CEBs compared to PC, but significantly improved the water resistance of the unstabilised blocks. The eco-friendlier RC proved to be a promising alternative to PC stabilisation.

Support Patterns of Roadways Under Fractured Surrounding Rocks Based on the Quality Level of Rock Mass

The roadway project of broken rock mass in the Shilu Iron Deposit was taken as the research object to discuss the stability control of the surrounding rocks using support patterns with broken rock mass. The grade evaluation of rock mass quality was conducted based on the geomechanical classification of rock mass. The roadway support effect in broken rock mass was calculated. Then, the section convergence characteristics of roadway surrounding rocks were analyzed under the current support scheme using displacement monitoring technology. The conclusions were described as follows: (1) The surrounding rock integrity of the No. 6 and No. 7 transportation roadways in the middle section of the Baoxiu mining area (Level 120) is poor. Based on geological survey data and rock mass classification, the rock mass quality in this region has been rated as Class IV. The joint support pattern of the anchor net and shotcrete was used according to the support guidelines. (2) The parameters for the support structure within Shilu Iron Deposit were designed, according to the requirements, as follows: the use of Portland cement; a shotcrete thickness of 55 mm; resin bolts with a minimum outer diameter of φ 20 mm and a length of 2200 mm; and row and column spacings of 1100 mm each. Meanwhile, a rectangular metal mesh of 80 × 80 mm was used as the anchor mesh. (3) The cross-section displacement reached 20 mm within a week using the support pattern according to displacement monitoring results of the on-site roadway section. Moreover, the convergence deformation rate significantly changed. However, the rate rapidly decreased after the first week, and the cross-section showed no further deformation after one month. The support pattern could control the displacement of surrounding rocks, which was verified by the monitoring results.

Application of novel deep neural network on prediction of compressive strength of fly ash based concrete

ABSTRACT Fly ash (FA)-based high-strength concrete (HSC) has attracted significant interest due to its potential to substitute Portland cement, offering both environmental benefits and improved performance. However, the design of FA-HSC is challenging, as key factors such as fly ash percentage, water content, and superplasticizer dosage have a complex influence on compressive strength. This study aims to develop an efficient predictive tool for FA-HSC mix design, using artificial intelligence (AI) models to address the inherent variability and uncertainty in these parameters. Six AI models, including a Deep Neural Network (DNN), were employed to analyse the relationships between mix design variables and compressive strength. The DNN model, in particular, demonstrated superior performance compared to the other models, with a high coefficient of determination (R2 = 0.89), variance accounted for (VAF = 88.3%), root mean square error (RMSE = 0.06), and residual standard error (RSR = 0.31). These results indicate that the DNN model can provide reliable predictions of compressive strength, offering a more efficient alternative to traditional trial-and-error methods. The AI-based approach can save both time and material costs while optimising performance. Overall, this AI-driven model contributes to the advancement of sustainable concrete technology by enabling more precise and resource-efficient mix designs for FA-based high-strength concrete.

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%.

Examining the global warming potential of hempcrete in the United States: A cradle-to-gate life cycle assessment

In the United States reducing greenhouse gas emissions associated with building construction by 90% by 2050 necessitates significant measures to be undertaken within the construction industry. Such measures include advanced construction techniques and bio-based material solutions such as hempcrete. This paper explores the mix design development and environmental impact assessment of hempcrete with an aim of reducing embodied impacts and achieving carbon negativity. Hempcrete being increasingly incorporated into both conventional and cutting-edge construction methods such as large-scale 3D printing is recognized as a carbon-negative material due to sequestered carbon in its constituent materials. Particularly, with the high carbon footprint associated with traditional Portland cement concrete, hempcrete presents a viable and low-carbon or even carbon-negative option for emerging construction techniques. The degree to which hempcrete achieves carbon negativity is contingent upon the proportion of hemp and lime within the mix design. Consequently, a comprehensive Life Cycle Assessment (LCA) is essential for evaluating the carbon-reduction potential of hempcrete. This study conducts a cradle-to-gate LCA of various hempcrete mix designs including a hybrid LCA of the environmental impact of domestically cultivated hemp. The results show that the global warming potential (GWP) of industrial hemp is −1.72 kgCO2e/kg. The LCA of different mix designs reveals that carbon negativity is reached when the hempcrete composition includes no less than 20% hemp by weight. Moreover, findings underscore the importance of including lime's carbon absorption in calculations to attain carbon negativity as incorporation of hemp alone may not be adequate. The study concludes that optimizing the constituents of hempcrete to achieve carbon negativity is vital for effective climate mitigation and adaptation strategies.

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.