Calcined Clay Research Articles

Lower-carbon concrete technologies

In this article, we introduce the IStructE's new concrete technology tracker, which has been compiled to inform members about the development of lower-carbon alternatives to conventional Portland cement-based concrete. We also look in more detail at four emerging technologies: Limestone Calcined Clay Cement, Seratech, Cambridge Electric Cement, and Brimstone.

Use of spent fluid catalytic cracking catalyst (FCC) in Limestone Calcined Clay Cement (LC3) systems: Studies in pastes and mortars

This study evaluates the substitution of calcined clay for a waste from the petrochemical industry, spent fluid catalytic cracking catalyst (FCC), as a source of reactive aluminosilicates in Limestone Calcined Clay Cements (LC3) systems. Three carbonate types were used to make cement-type LC3: a high-purity calcium carbonate, waste from the marble industry, and another from a dolomite soil source. LC3 blends were prepared by mixing 50 wt% OPC, 5 wt% calcium sulfate dihydrate, 30 wt% FCC and 15 wt% from each carbonate source. A mixture than substituting the carbonate source for a siliceous source was prepared to analyse the influence of carbonate phases in LC3 systems. The hydration process of the LC3 blends was studied by X-ray diffraction, thermogravimetric analyses, isothermal calorimetry and FESEM. Mechanical properties were studied by measuring compressive strength at 7, 28 and 90 days. The obtained results corroborated that the mortars prepared with LC3 cements using the FCC obtained higher compressive strength than the control mortar prepared with ordinary Portland cement (OPC) at 28 and 90 curing days. It has been demonstrated that FCC is a by-product that can substitute calcined clay, and the different sources of carbonates such as high purity, waste or contaminated with magnesium do not interfere with the performance of this type of cement.

Fluorescence microscopic investigation of PCE superplasticiser adsorption in calcined clay blended cement.

Global efforts to minimise carbon dioxide emissions are also leading to attempts to use calcined clays (CC) as a partial substitute for cement in concrete. While the hydration mechanism of such CC blended cements is now well understood, the range of effective admixtures like polycarboxylate ethers (PCE) is limited. There are PCE types that promise relatively high effectiveness, but the mechanisms of action are not yet sufficiently understood. For a detailed understanding of the adsorption of such PCEs, spatially resolved studies of the binder were performed using a combination of fluorescence and scanning electron microscopy. In a comparison of two superplasticisers, the investigations have shown different sites of preferred adsorption in a CC blended system and the results can be correlated with flow tests and setting behaviour. The investigations have shown that a certain PCE type has a higher adsorption on CC and other components of a blended system in comparison to other types.

Study on the performance of ternary blended cement with calcined clay and recycled concrete powder

Recycled concrete powder (RCP) has a large amount of calcium carbonate, which suggests that it can be used to make limestone - calcined clay (CC) cement (LC3) system by replacing limestone powder. So that it can promote the recycling of construction demolition waste and reduce the requirement of the natural resource for LC3. In this study, the fresh and hardened properties of CC-RCP cement system were comprehensively characterized by varying the CC/RCP ratio and dosage, including rheological, mechanical properties, hydration products and pore structure. The results indicate that the addition of CC prolong the setting time, but the effect could be mitigated by the recombination of RCP. By comparing with RCP, CC had a less obvious effect on increasing viscosity, but it could improve the shear thickening behavior of paste. In the case of less total content of CC and RCP, a ratio of 1:1 CC/RCP was better for the development of long-term strength. Whereas, with the increasing of substitution, the mixtures with CC alone or blending with RCP in a 2:1 ratio achieved higher strength. The incorporating of CC and RCP could make the conversion of C4AH13 into hemicarboaluminate (Hc) and monocarboaluminate (Mc), and it resulted in a denser structure with more medium capillary pores and gel pores than that mixtures with CC only.

Steel corrosion and critical chloride content in concrete with calcined kaolinite clay, fly ash, and limestone powder under natural and accelerated marine environments

This study aims to investigate steel corrosion and critical chloride content in concrete with calcined kaolinite clay, fly ash, and limestone powder. The chloride diffusion coefficient and compressive strength of concrete, and weight loss of steel were measured after the specimens were exposed to the tidal zone in a real sea environment for 1 and 2 years. The depassivation time of the embedded steel and the critical chloride content of the concrete under an accelerated marine environment were investigated in the laboratory. The test results revealed that the coefficient of chloride diffusion and critical chloride content of concrete and weight loss of steel decreased with increasing calcined kaolinite clay contents. Although utilizing calcined kaolinite clay in concrete mixtures reduced critical chloride content (0.655% by wt. of binder for OPC and 0.573 to 0.427% by wt. of binder for C15 to C45) because of the lower portlandite content, it caused a longer rebar depassivation time (46 days for OPC and 63 to 237 for C15 to C45). The ternary binder systems of cement, calcined clay, and fly ash demonstrated the best overall performances, i.e., the lowest chloride diffusion coefficient (0.29 ×10−12 m2/s) and the highest compressive strength of the concrete (38.7 MPa), and no weight loss of embedded steel at 2 years of exposure.

Investigation on chloride migration behavior of metakaolin-quartz-limestone blended cementitious materials with electrochemical impedance spectroscopy method

Calcined clay and limestone powder composites offer a viable solution for reducing carbon emissions in building materials by allowing significant cement replacement. However, there is a need for further investigation into their impact on durability, especially for low-grade clays. In this study, different ratios of metakaolin and quartz powder are utilized to simulate various grades of calcined clay, while limestone powder is incorporated as a partial cement substitute. Initially, the influence of metakaolin content on rapid chloride migration was analyzed. Subsequently, various analytical techniques such as free water content, Mercury Intrusion Porosimetry (MIP), X-ray diffraction (XRD)/Rietveld method, and electrochemical impedance spectroscopy (EIS) test were employed to investigate the effects of metakaolin contents on the pore structure, phase assemblage, and electrochemical parameters of the blended cementitious system. The relationship between chloride migration coefficient and free water content, critical pore size, and impedance parameters was established to determine the key indicators for chloride migration. The study revealed that systems with partial metakaolin content demonstrate improved chloride resistance in the blended system, which could be predicted using Rct1 from the EIS test. Furthermore, the inclusion of metakaolin and limestone powder facilitated the formation of Monocarboaluminate (Mc) and Hemicarboaluminate (Hc), leading to the refinement of the pore structure and inhibition of chloride transport within the blended material. This study indicates the potential of low-grade calcined clay to enhance the overall durability of the blended cementitious system while contributing to carbon emissions reduction.

Properties of Self-Compacting Concrete (SCC) Prepared with Binary and Ternary Blended Calcined Clay and Steel Slag

The recent emphasis on sustainable development in the construction industry has made it essential to develop construction and building materials that are not only affordable, but have minimal negative impact on the environment. This study investigates the valorisation of steel slag, which is mostly considered to be a waste material in several parts of the world, by blending with calcined impure kaolinitic clay to partially replace ordinary Portland cement (OPC) in the preparation of self-compacting concrete (SCC). OPC was substituted with steel slag at a constant level of 10%, whereas calcined clay replaced OPC at varying levels, ranging from 10 to 30% in a ternary blended mix. The hardened properties evaluated include compressive and flexural strengths. Samples containing only calcined clay showed a lower fluidity, which was significantly improved when steel slag was added to the mix. SCC containing 10% steel slag and 20% calcined clay obtained 28 days compressive strength, which was 3.6% higher than the reference cement concrete. An XRD analysis revealed a significant decrease in the peak heights of portlandite in mixtures containing steel slag and calcined clay, regardless of their replacement percentage. Generally, all the blended cement samples performed appreciably in resisting sulphate attack. The results of this study demonstrate that using steel slag and calcined clay together can significantly improve the fresh and hardened properties of SCC without compromising its mechanical properties.

Adsorption of anti-inflammatory and analgesic drugs traces in water on clay minerals

The aim of this study was to assess the adsorption of four non-steroidal anti-inflammatory drugs (NSAIDs), namely Paracetamol (PRC), Diclofenac (DIC), Ibuprofen (IBU), and Ketoprofen (KET), using both batch and continuous experiments with clay. Various analytical techniques, including XRD, FTIR, SEM coupled to EDX, and Zeta potential, were employed to characterize both raw and calcined clay. XRD and FTIR analyses confirmed the kaolinite nature of the clay. SEM data revealed a lamellar structure formed in the clay after calcination at 550 °C. Adsorption tests were conducted to determine the optimal adsorption conditions. Batch kinetics of adsorption demonstrated rapid adsorption of all four NSAIDs, with the highest adsorption occurring at pH 4 (DIC, IBU, and KET) and pH 6 for PRC, using a concentration of 20 mg L−1 of calcined clay. Additionally, the pseudo-second-order model provided the best fit for all NSAIDs adsorption processes. Maximum adsorption capacities, as determined by the Langmuir model, were 80 mg g−1 for PRC, 238 mg −1g for DIC, 138 mg g−1 for IBU, and 245 mg g−1 for KET. In fixed bed column studies, three dynamic models (Thomas, Adams-Bohart, and Yoon-Nelson) were utilized to describe the breakthrough curves, with linear regression used to identify key characteristics for process design. The fixed bed column adsorption study revealed that DIC exhibited the highest removal efficiency at 98%, while KET, IBU, and PRC were more persistent, with removal efficiencies of 77.1%, 76.7%, and 67.1%, respectively. The Thomas model was deemed appropriate for describing the breakthrough curve. These findings offer valuable insights into the interactions between clay and pharmaceuticals with varying physicochemical properties. They also provide information on the adsorption models, saturation, and adsorption capacities of various pharmaceuticals on natural clays, which can be crucial for further research and environmental remediation efforts.

Synergistic effect of recycling waste coconut shell ash, metakaolin, and calcined clay as supplementary cementitious material on hardened properties and embodied carbon of high strength concrete

Researchers are investigating eco-friendly binders like coconut shell ash (CSA), metakaolin (MK), and calcined clay (CC) as supplementary cementitious materials (SCM) in high-strength concrete (HSC). Abundantly available as industrial or agricultural waste, these materials, when combined with Portland cement (PC), offer synergistic benefits. This not only improves concrete performance but also addresses waste disposal issues, presenting a sustainable and environmentally friendly solution for long-term use in HSC production. However, this study performed on fresh and mechanical characteristics of HSC blended with CSA, MK, and CCA alone and together as SCM after 28 days of curing. A total of 504 samples of standard concrete were cast and the cubical samples were tested to achieve the targeted compressive strength about 80 MPa after 28 days. The experimental results indicated that the rise in tensile, flexural and compressive strengths of 9.62%, 8.27%, and 10.71% at 9% of CSA, MK, and CC as SCM after 28 days of curing. As SCM content increases, the density, porosity and water absorption of concrete decrease. Moreover, the workability of fresh concrete is getting reduced when the concentration of SCMs increases in HSC. In addition, the concrete's sustainability assessment revealed that employing 18% MK, CC, and CSA as SCM reduced carbon emissions by approximately 11.78%. It is suggested that using 9% CC, MK and CSA together in HSC yields the best results for practical applications in civil engineering.

Durability-Related Transport Properties of Limestone Calcined Clay Cement Mortars

This study investigates the effect of utilizing a combination of limestone and calcined clay as cement re-placement on the transport properties that indirectly define the behavior of the matrix throughout its service life, such as total porosity, water absorption due to capillary action, water permeability penetration, chlorine diffusion, and car-bonation depth. Mortars were made of blends with different levels of cement replacement (%15, %30, %45) by a substi-tution ratio of 2:1 (calcined clay: limestone), with adjusted gypsum content in each system composition. Furthermore, the influence of kaolinite content in clays on transport prop-erties was also investigated. Based on the results, all LC3 blends exhibited a significant improvement in terms of total porosity, capillary water absorption, water penetration re-sistance, and chloride diffusion compared to OPC mortars. Moreover, the higher the replacement level of cement, the higher the resistance to movement or transport of ion spe-cies through the mortars. The improvement in the transport properties for LC3 blends can be attributed to its enhanced porosity refinement as well as the enhanced chloride bind-ing capacity. In contrast, a slight improvement in the transport properties was observed with increasing the kao-linite content of the calcined clays. This result indicates that utilizing low-grade calcined clay has no significant effect on the transport properties. The carbonation resistance of the LC3 blends was lower as compared to OPC. Furthermore, increasing the cement substitution rate resulted in a pro-gressive decrease in carbonation resistance. Overall, an in-crease in cover depth would be required to achieve a similar service life in terms of carbonation as that of the OPC.

A Review: Construction and Demolition Waste as a Novel Source for CO2 Reduction in Portland Cement Production for Concrete

There is an increasing global recognition of the need for environmental sustainability in mitigating the adverse impacts of cement production. Despite the implementation of various carbon dioxide (CO2) mitigation strategies in the cement industry, such as waste heat recovery, the use of alternative raw materials and alternative fuels, energy efficiency improvements, and carbon capture and storage, overall emissions have still increased due to the higher production levels. The resolution of this matter can be efficiently achieved by the substitution of traditional materials with an alternative material, such as calcined clay (CC), construction and demolition waste (CDW), which have a significant impact on various areas of sustainable development, including environmental, economic, and social considerations. The primary objectives of employing CDW in the Portland cement production are twofold: firstly, to mitigate the release of CO2 into the atmosphere, as it is a significant contributor to environmental pollution and climate change; and secondly, to optimize the utilization of waste materials, thereby addressing the challenges associated with their disposal. The purpose of this work is to present a thorough examination of the existing body of literature pertaining to the partial replacement of traditional raw materials by CDW and the partial replacement of Portland cement by CDW and to analyze the resulting impact on CO2 emissions.

EFFECTIVENESS OF CALCINED CLAY IN SAUDI ARABIA AS SUPPLEMENTARY CEMENTITIOUS MATERIAL

Portland cement concrete is the most consumed material in buildings and infrastructure. The use of portland cement is not limited to building constructions, it is also used as a repairing material. The production of portland cement has a noticeable economic and environmental effects. The paper addresses the economic and environmental benefits of using calcined clay as supplementary cementitious material with high partial replacement of portland cement. The economic benefits include the initial costs and the maintenance cost, which is achieved by enhancing the concrete durability. The cost of calcined clay is strongly affected by the transportation expenses and the availability of local sources. The environmental benefits include the reduction of the CO2 footprint caused by portland cement production.

Low CO2 emission cement from alkali-activated gravel wash mud and quartzite dust

High CO2 emissions and rising energy costs result in an increasing demand for innovative, environmentally friendly and energy-efficient construction materials. Gravel wash mud (GWM) is a widely available industrial by-product from gravel mining which may be used as an aluminosilicate source in the production of cementitious materials. In this study, GWM from Eifel in the SW Germany was used for the synthesis of alkali-activated cement. A high NaOH leachable Si and Al content and fine grain-size makes this material particularly applicable for synthesis of alkali-activated cements and geopolymers. Silicate dust from quartzite mining in Saarland is other industrial by-product used to improve the physical properties of the cement. Both materials were thermally and mechanically processed prior to chemical activation. A single-compound activator of NaOH solution was used, leading to no addition of soluble silicates. The main advantages of the new cement are zero CO₂ emissions from raw materials during calcination, comparatively low energy demand due to short grinding time, low temperature of calcination and low demand of alkali activator/no need for soluble silicates and valorisation of GWM and quartzite dust from aggregate mining. Experiments show that calcined kaolinite clay acts as a very effective binder in the cement formulation with quartzite dust. Consequently, a very small quantity of metakaolinite in the cement mixture is necessary, which allows for a reduced quantity of alkali-activator and related production costs of the cement. Consequently, the alkali-activated cement can provide an environmentally-friendly and cost-effective material for special applications with a high heat resistance or resistance to aggressive environments.

Performance of a Single Source of Low-Grade Clay in a Limestone Calcined Clay Cement Mortar

The high kaolinite content of metakaolin makes it valuable to other industries, thereby affecting its availability and affordability for the production of limestone calcined clay cement (LC3). This work presents a study on the potential utilization of low-grade clay in place of pure metakaolin in the preparation of LC3 for mortar formulations. CEM I was partially substituted with calcined clay and limestone by 20, 30, 40, and 50 wt.%. The weight ratio of calcined clay and limestone was maintained at 2:1 for all mixes and the water-to-binder ratio was 0.48. X-ray diffraction (XRD), thermogravimetric analysis (TGA), and isothermal conduction calorimetry were used to study the hydration process and products after 28 days. Mechanical and durability assessments of the LC3 mortar specimens were conducted. LC3 specimens (marked LC20%, LC30%, LC40%, and LC50%) trailed the control sample by 1.2%, 4%, 9.8%, and 18%, respectively, at 28 days and 1.6%, 2.3%, 3.6%, and 5.5%, respectively, at 91 days. The optimum replacement of OPC clinker, calcined clay, and limestone was 20% (LC20%).

Characteristics of the açai seed (Euterpe precatoria Martius) after thermal processing and its potential in soil-cement brick

The management of the açai palm, a species of the Euterpe genus, has grown in recent years mainly for the extraction of palm heart and the pulp of the fruit called açai. After the extraction of the’ pulp, there is a significant generation of residues, as the discarded seeds account for approximately 85% of the fruit. Therefore, this research aims to characterize the açai seed after fruit processing, as well as to evaluate the potential of thermally processed seed for use in soil-cement bricks. The seed morpho-anatomy tests were performed, including moisture content, loss of ignition, ash content, thermogravimetry, fluorescence, and X-ray diffraction of the ground seeds. Tests on thermally processed seeds included readings by X-ray diffraction and laser granulometry. After evaluating the properties of the ash, it was incorporated into soil-cement mixtures in proportions of 5%, 10%, 15%, and 20%, replacing the clinker content of LC3 (Limestone Calcined Clay Cement). Based on the results obtained, soil-cement bricks were produced with a composition of 90% soil and 10% LC3, with the LC3 cement clinker being replaced by 20% açai seed ash. The results indicate the potential for the application of açai seed ash in soil-cement bricks on a practical scale, demonstrating that the ash enhances soil stabilization and increases the compressive strength of the soil-cement matrix due to its smaller particle size compared to that of the soil grains. This not only reduces the amount of cement required for the matrix but also offers environmental sustainability through the utilization of seed waste. The study underscores the potential of applying açai seed ash in the context of environmentally significant alternative technologies and sustainable practices, emphasizing the promise of the properties found in discarded açai seeds.

Impact of Admixtures on Environmental Footprint, Rheological and Mechanical Properties of LC3 Cemented Paste Backfill Systems

This study investigates the time-dependent rheological behavior of cemented paste backfill (CPB) that contains calcined clay as a binder, particularly with LC3 (Limestone Calcined Clay Cement) compositions, using two different PCEs (Polycarboxylate Ether) superplasticizers. Rheological measurements have been conducted on four different mix designs using the Bingham model to describe the CPB mixtures. Both yield stress and plastic viscosity have been reported, and the impact of the admixture on these parameters has been investigated. Unconfined compressive strength (UCS) was measured over 182 days for all mix designs. Both admixtures showed better workability in all cases, with significantly improved yield stress and plastic viscosity compared to the reference, while showing little to no negative impact on strength over time. This study highlights that both from a binder and an admixture point of view, relevant to the industry, these calcined clay systems are ready to be used in a CPB and could make a significant impact on the sustainability of a mining operation in the near future.

Mechanical and durability performance of ternary blended calcined clay and pulverized granite mortar composites

ABSTRACT Partially replacing cement with pozzolans, apart from the enormous technical benefits, has been reported as an effective approach to reducing greenhouse gases emanating from cement production. Calcined clay and pulverised granite, in recent years, have been experimented individually for their use as filler or pozzolan in concrete to improve workability and compressive strength. This research includes study of the synergistic characteristics of these two mineral admixtures and their influence on the mechanical and durability properties of mortar. Cement was partially substituted with 5–20% by weight of the composite material to form a ternary blended cement composite. The compressive strengths of the ternary blended cements were evaluated at 3, 7, 28 and 90 days. Durability properties such as alkali silica reactivity (ASR), rapid chloride permeability test (RCPT) and performance of the blended cements in aggressive media have been discussed. Test results indicated that, blended cements containing 5% and 10% of the pozzolan recorded similar compressive strengths at 28 days and outperformed it by 2.4% and 0.6% respectively at 90 days. Beyond 10% replacement, compressive strengths declined. The ternary blended cements were found to be highly reactive, potentially causing ASR in concrete than the reference cement.

Mechanical strength and Life Cycle Assessment (LCA) of soil-cement: comparison between mixtures of soil with ASTM type III cement, LC3, and the incorporation of by products and agroindustrial residues

Soil stabilization with binders is based on the binder action on soil particles, in turn causing an improvement in the mechanical behavior of the soil. Thus, this study aims to analyze the mechanical and environmental properties of soil-cement mixtures using Portland ASTM type III cement as binders and comparing to LC3 (Limestone Calcined Clay Cement), as well as incorporating extra raw materials such as silica fume, fly ash, sugarcane bagasse ash (Saccharum officinarum L) and açai seed ash (Euterpe precatoria Martius). The mixtures of soil, binder, extra raw materials were performed manually, and the cylindrical specimens (100 mm internal ø) were molded based on the AASHTO Normal Test. The results showed that the highest values of compressive strength ranged between 10 and 11 MPa, which were recorded for reference, soil-LC³ and soil-LC-açai seed ash mixtures. Life Cycle Assessment (LCA) was performed using the CML 2001 method with the aid of the OpenLCA software. Additionally, it was observed that the main emissions and consequences for the environment were from mixtures containing higher clinker contents.

Limestone calcined clay cement (LC3): A sustainable solution for mitigating environmental impact in the construction sector

The impact of global warming on the construction sector is a serious issue in today's world; this might be attributed to the emission of greenhouse gas (GHG) during the production process of Portland cement. Due to its advantages, cement plays a major role in the construction of civil infrastructures. Cement production is not only responsible for global warming and also creates a risk of raw material deficiency. To reduce the over exploitation of virgin materials, Limestone Calcined Clay Cement (LC3), with a proportion of Clinker 50 %, Limestone 30 %, Calcined Clay 15 % and gypsum 5 %, is found to be a suitable and sustainable alternative to preserve the ecosystem. As a result, attempts were undertaken in this work to create a mixture design approach for LC3 with the primary objective of developing higher compressive strength (CS) in a cost-effective manner. The relationship between the water to binder ratios and 28-d CS has been examined to suggest a conceptual mixture design strategy for LC3 rationally. The 28-day CS of 46.2 MPa has been observed. The suggested design technique has been presented step by step and validated using an example based on the guidelines illustrated by IS 10,262. The design technique aims to produce a concrete mix that meets specific strength, workability, and durability requirements while considering the environmental conditions and properties of materials available. The study emphasizes a systematic approach to concrete mix design, considering various factors like water-cement ratio, aggregate proportions, and workability requirements to ensure the resulting concrete meets the desired performance standards. Compliance with IS 10,262:2019 ensures that concrete used in construction is designed systematically and according to established guidelines, leading to higher quality and more predictable performance in structural applications. Further, to access the sustainability of the developed LC3 mix Life-Cycle Assessment (LCA) of LC3 was reported starting from raw material procurement to the production of concrete as the final product. In this LCA analysis, the monetary cost involved in the production of concrete, energy demand and GHG emission of the LC3 was compared with the conventional concrete. The result from the analysis revealed that LC3 possess superior performance in terms of energy requirement and GHG emission than the OPC concrete.

Characterisation of calcined waste clays from kaolinite extraction in alkali-activated GGBFS blends

Metakaolin is a well-studied supplementary cementitious material (SCM) and precursor in alkali-activation. The utilisation of limited kaolinite content clays generated from large-scale industrial activity, denoted as waste clays, in alkali-activation is still largely unexplored. This paper investigates the use of five samples of calcined waste clays from different locations in a kaolinite extraction site as precursors in alkali-activated cements (AACs). Calcined waste clay precursors are blended with ground granulated blast furnace slag (GGBFS) and activated with sodium silicate. The physical and chemical properties of the calcined waste clays are characterised. Both Chapelle and R3 tests for pozzolanic reactivity are examined based on calcined waste clay properties. The R3 test data obtained for sieved particle fractions < 63 µm show marked improvement in the case of C4, elucidating potential calcined waste clay behaviour with prior processing in alkali activated systems. Clay particle size distribution and morphology are identified as key factors to be considered for initial calcination and in mix designs, strongly affecting both the fresh properties and workability of blended pastes. Good workability is highlighted as being crucial for achieving well-behaving calcined waste clay blended binders with resulting dense microstructures and high strength values, comparable with other reported GGBFS systems. Quartz, muscovite, and alkali-feldspar present in the calcined waste clays remain stable throughout alkali-activation. Reaction of the amorphous phase fraction present in the calcined waste clays results in the formation of additional cross-linked gel. A replacement level of up to 20 wt% calcined waste clay is found to exhibit similar compressive strengths to pure GGBFS binders, whilst achieving lower porosity within the bulk. This study provides a methodology for characterising the behaviour of calcined waste clays in alkali-activated systems and a proof of concept in the formulation of novel binders that incorporate waste clays.