Properties Of Clay Research Articles

Effects of occurrence form of soil organic matter on the Atterberg limits and thermal conductivity of clays

Abstract Because of the interfacial interactions between mineral soil particles and soil organic matter (SOM), SOM occurs in various forms in the soil, and the mineral-associated and particulate forms are fundamental. Many recent studies have concentrated on the effects of SOM content and type on the geotechnical behavior of soil. However, the influence of SOM occurrence forms is not well understood, nor is there a scientific classification standard for SOM in geotechnical engineering. The main objectives of this study were to explore the effects of SOM occurrence forms on a few physical properties of clays to develop an engineering classification standard of SOM. First, this paper reviews the interfacial interaction mechanism, factors that influence the relation between mineral soil particles and SOM, and the classification method of SOM in soil science. Three predominant clays (montmorillonite, illite, and kaolinite) were then used as the matrix, and three groups of artificial soil samples with different SOM contents (wu ranging from 0 to 50% by weight) were prepared by adding peat. A chemical extraction method was used to determine the amount of different forms of SOM. Moreover, the Atterberg limits wL (wp) and thermal conductivity λ of artificial soil samples were tested. Based on the experimental results, the relationship between the form of SOM and these physical parameters was established. The experimental results show that the wL (wp) vs wu, and λ vs wu fitted curves were not monotonic but piecewise linear and could be divided into two straight lines with different slopes; wu corresponded to the inflection point of wL (wp) vs wu, and λ vs wu curves were closer to the threshold value wu,2. Finally, a simple engineering classification method of SOM is proposed.

Effectiveness of the adsorption properties of clay in relation to the disposal of organic waste from poultry farms

This article discusses an important problem related to the disposal of organic waste from poultry farms. Bird droppings are one of the main sources of environmental pollution and consume significant resources for disposal. The search for effective and environmentally safe methods of disposal of such waste is very relevant. The article focuses on the study of the adsorption properties of a clay accumulation site. Due to the insufficient knowledge of this technology of manure burial, full-scale modeling was performed to determine the effectiveness of protecting the components of the ecological and geological environment. It is shown that under conditions of complete water saturation, the liquid fraction from the organic waste layer will easily seep through the voids and cracks of the clay layer and poison the underlying soils and groundwater. It is concluded that a clay special site alone does not provide guaranteed environmental safety of the environment. Engineering and environmental recommendations are given on the mandatory combination of this method of burial of litter with a litter made of a layer of sealed film coating.

Clay based heterogeneous catalysts for carbon-nitrogen bond formation: a review.

Clay and modified clay-based catalysts are widely used in organic transformation. Owing to the interlayer ions and good ion exchange capacity of clay, replacement with another ion and incorporation of different nanomaterials can be done. Due to these significant properties of clay, it can be utilized in the synthesis of various organic compounds. Carbon-nitrogen bonded compounds possess diverse applications in different fields. These compounds are prepared using different solid acid heterogeneous catalysts. This review presents a detailed discussion on clay used for the carbon-nitrogen bond formation reaction, such as the Biginelli reaction and A3 and KA2 coupling reactions. Additionally, other C-N bond formation reactions using various clay-based catalysts such as bentonite, montmorillonite, hydrotalcite and halloysite clay with various metals, metal oxides, Kegging type heteropoly acid and various nanomaterial incorporated clay heterogeneous catalysts are discussed.

Characterization and Suitability Assessment of Ameskroud Clay Deposits for Ceramic Applications

The identification of natural clay deposit parameters is critical for the development of ceramics. This research underscores the essential role of understanding clay properties in producing high‐quality ceramics and represents a comprehensive characterization methodology, shedding light on the untapped potential of natural clay deposits for ceramic applications. This study investigates red clays from the Triassic, as well as yellow and gray clays from the Cretaceous period, collected from the western High Atlas of Morocco (Ameskroud). The characterization of clays from this geographic region is innovative, as they have not been previously investigated for their suitability within ceramic applications. The investigation encompasses an examination of the geological context, mineralogy, chemical composition, and physicochemical attributes of these clays. Furthermore, the thermal behavior, firing characteristics, and compressive strength of the clay samples were assessed when fired at 900°C, 1000°C, and 1100°C. Mineralogical analysis reveals that illite predominates with relatively low levels of kaolinite and chlorite. The primary chemical constituent is SiO2, followed by Al2O3 and Fe2O3. Notably, yellow clay exhibits a significant CaO content exceeding 10%. At 1100°C, the clay specimens exhibit reduced water absorption rates (ranging from 9.88% to 17.1%) and enhanced mechanical performance, with compressive strengths ranging from 22.33 MPa to 36.07 MPa, attributable to the sintering process. The findings affirm that the raw clays sourced from the Ameskroud region possess characteristics suitable for various ceramic applications, making them ideal candidates for the production of dense bricks and ceramic tiles.

Study on Mechanical Properties of Clay Mixed with Construction Waste and Lime Powder

Abstract: Clay is widely distributed in Yiyang City. Due to its low strength and great influence on construction safety, clay needs to be improved and reused in actual projects, which leads to problems such as increased construction cost and delayed construction period. In this paper, construction waste, lime powder and clay are mixed according to a certain proportion, so as to improve the strength of soil and reduce construction costs. It is found that construction waste can improve the ductility of soil, but it has no obvious effect on the improvement of compressive strength of soil. When 20% construction waste and 4% lime powder are added, the compressive strength of soil is improved most obviously.

Influence of anionic polyacrylamide on the freeze–thaw resistance of silty clay

Freeze–thaw (FT) alternation can severely affect the properties of fine–grained soils, often leading to the failure of foundation backfill projects, such as open canals and roads in cold regions. To address these problems, a water–soluble anionic polyacrylamide (APAM) was used to improve the properties of fine–grained soils, particularly silty clay. This study aims to analyze the effects of the APAM polymer on the physico–mechanical and microstructural properties of silty clay under both unfrozen and FT cycles. For this purpose, different addition dosages and FT cycle numbers were determined, and then a series of zeta potential, thermal conductivity, permeability, triaxial compression, and scanning electron microscopy (SEM) tests were conducted on the soil samples. Additionally, a unidirectional freezing test was constructed to investigate the coupled thermo–hydro–mechanical processes of APAM–treated soil samples under subzero temperature conditions. The results showed that the addition of the APAM polymer significantly enhanced the macroscopic engineering properties and microstructural characteristics of silty clay. This improvement was attributed to the charge neutralization, adsorption bridging effect, and hydrophobic interaction provided by the APAM polymer. However, all the soil samples showed a significant deterioration in their engineering properties during FT cycles, especially after the third FT cycle. It was notable that APAM–treated soil samples were superior to the untreated sample in terms of FT resistance. During the unidirectional freezing process, the pore water migrated from the unfrozen zone towards the freezing front due to the temperature gradient. The treated sample's pore water migration volume was considerably lower than that of the untreated sample, resulting in a 55.25% reduction in total frost heave when the APAM dosage was 0.30%. The findings of this paper may be utilized to mitigate the risk of frost damage to foundation backfill projects in cold regions, as well as to get a better understanding of the stabilization mechanism of the eco–friendly APAM polymer.

The Categories and Application of PCE Superplasticizers in Concrete

Polycarboxylate ether superplasticizers (PCEs) are water reducers in the concrete mix that play a significant function in aspects of reducing the water-to-cement ratio, improving impermeability, increasing compressing strength, and meditating the shrinkage. This paper introduces the characteristics of PCEs, discusses the application, advantages, and disadvantages of concrete, and puts forward some measures. The mechanism of PCEs is the dispersion function of the molecular structure and the neutralization. Currently, PCEs are updated from one generation to another, conventional PCEs mainly include methacrylate ester, isoprenol ethe, and methallyl ether-PCEs. Another two major types of PECs are vinyl ether-based and calcium silicate hydrates PCEs, respectively. The application of PCEs revolutes novel types of concrete, such as ultra-high performance concrete and self-compacting concrete. When applying PCEs, retardation has to be considered. Meanwhile, another drawback of PCEs is that they can hardly work with other admixtures. A novel type that is considered clay properties can be another research field.

Influence Mechanism of Water Content and Compaction Degree on Shear Strength of Red Clay with High Liquid Limit.

To investigate the influencing factors and mechanisms of shear strength of red clay with a high liquid limit, which was selected at different milepost locations based on the Nanning Bobai Nabu Section Project of the Nanning Zhanjiang Expressway, the basic physical properties of red clay were determined using a liquid plastic limit test, compaction test, inductively coupled plasma optical emission spectrometer (ICP-OES), and X-ray fully automatic diffractometer (XRD). Red clay with a high liquid limit was selected. Furthermore, the direct shear test was used to study the effect of different water contents and compaction degrees on the shear strength. The experimental results demonstrate that under the same compaction degree, the shear stress of the soil sample increases significantly with an increase in normal stress, and the greater the water content, the smaller the shear stress of the soil sample. At 200 kPa, the shear strength of soil samples with 24% water content is 57%, 46%, and 35% of the shear strength of soil samples with 15% water content under different compaction degrees(K) of 86%, 90%, and 93%, respectively. Under the same moisture content, the shear stress of the soil sample shows an increasing trend with an increase in the degree of compaction, and the greater the compaction degrees, the greater the shear stress of the soil sample. The cohesion c and internal friction angle φ of soil samples increase with an increase in the compaction degree, but the increase in cohesion c is also affected by the water content. Under the condition of low water content, the cohesion c of soil samples can be increased by 1.06 times when the water content is 15% and by 0.47 times when the water content is 18%. Under the condition of high water content, the cohesion c of soil samples with 21% water content only increases by 0.3 times, and that with 24% water content only increases by 0.35 times.

Investigation of the microscopic properties of natural structured clay

Conducting quantitative research on the microstructure of soft clay can reveal the essence of its soil mechanical behavior, which is of important practical significance for geological disaster risk assessment and prevention. To quantitatively investigate the microscopic properties of natural structured clay, soft clay soils from various sedimentary environments in the Hangzhou Estuarine Bay area were chosen as the research subject in this study. Subsequently, a comprehensive investigation into the microstructure of clay was conducted, involving X-ray phase analysis and SEM imaging analysis. The results revealed the following: (1) In comparison to the deep clay deposited in fluvial-lacustrine environments, the shallow mucky clay in marine sediments had a higher clay mineral content, accounting for 48%. Illite makes up the majority of it, with minor levels of kaolinite and montmorillonite being present. (2) The shallow mucky clay in the Hangzhou Estuarine Bay area had a typical agglomerate-flocculated structure. In contrast, the deeper clay showed a flocculated structure with less uniform particle sizes, strong stacking randomness, poor directional alignment of soil pores, and tends to form arrangements where edges are adjacent to faces or edges are adjacent to other edges. (3) Compared to the deep clay deposited in fluvial-lacustrine environments, the marine-deposited shallow mucky clay displayed orderly pore arrangements, strong directional alignment, significant pore shape variability, and minimal pore size changes between adjacent pores. The microstructure of soil plays a crucial role in determining the physical, mechanical, and other engineering properties of the soil. This study provides insightful information about the relationship between clay microstructure and geotechnical characteristics in Hangzhou and the surrounding areas.

Investigation of the mechanical properties of magnesium chloride on magnesium oxide improved kaolin clay

In our study, samples were prepared by mixing 2%, 4%, and 6% MgO doses with the dry weight of kaolin-type low-plastic clay. In each MgO dose, 1% and 2% of the soil weight, respectively, MgCl2 chemicals were added, and all samples were mixed at the optimum water content ratio (16.2%). All components were mixed with a planetary mixer for 10 minutes until homogeneous, and then the mixture was poured to have 25 blows for 5 layers. All samples were cured under room conditions for 3–10 days to be tested on the Unconfined Compression Test. From the results, it was observed that the undrained shear strength of the sample increased as the percentages of MgCl2 and MgO rose. It can be said that the interaction between MgO and MgCl2 contributes to the cementation of the clay, and sorel cement plays a role in the mechanical strengthening of kaolin clay based on its effect on strength development. Extending the curing time also developed the mechanical properties of kaolin clay and improved the hardness of the samples by increasing the elastic modulus. In this way, early failures were attained at early strains, and the ductility of the samples increased. We finally saw that the mixture of MgO and MgCl2 worked well as a building material for kaolin clay. The study also tried to get rid of some of the problems that come up with filling materials used in geotechnical engineering and shoring projects, like swelling, shrinkage, and low mechanical properties.

Is Cr(III) re-oxidation occurring in Cr-contaminated soils after remediation: Meta-analysis and machine learning prediction

Whether Cr(III) in Cr(III)-containing sites formed after Cr(VI) reduction and stabilization remediation are re-oxidized and pose toxicity risks again has been a growing concern. In this study, 1030 data were collected to perform a meta-analysis to clarify the effects of various factors (oxidant type, soil and Cr(III) solid compound properties, aging conditions, and testing methods) on Cr(III) oxidation. We observed that the soil properties of clay, pH ≥ 8, the lower CEC capacity, easily reducible Mn content, and Cr(III) content, and the higher Eh value and Fe content can promote the re-oxidation of Cr(III). Publication bias and sensitivity analyses confirmed the stability and reliability of the meta-analysis. Subsequently, we used five machine learning algorithms to construct and optimize the models. The prediction results of the RF model (RMSE <1.36, R2 >0.71) with good algorithm performance showed that after ten years of remediation, the extractable Cr(VI) concentration in the soil was 0.0087 mg/L, indicating a negligible secondary pollution risk of Cr(III) re-oxidation. This study provides theoretical support for subsequent risk management and control after Cr(VI) soil remediation and provides a solution for the quantitative prediction of Cr(III) re-oxidation.

Effects of microplastic contamination on the hydraulic, water retention, and desiccation crack properties of a natural clay exposed to leachate

Microplastic (MP) can significantly affect soil behaviour and the ecosystem. This paper presents an experimental study to investigate the effects of MP contamination and leachate exposure on the desiccation cracks, hydraulic conductivity, and water retention properties of the natural black clay. The leachate was from a landfill in Australia. The black clay was incorporated with up to 2.0% MPs by weight (w/w) with diverse dimensions and mixed with water/leachate. The measured properties include saturated hydraulic conductivity (ksat), soil-water characteristic curves, moisture evaporation rates, and crack intensity factors. The results suggest that the inclusion of MPs significantly increases ksat, and this increase is more obvious for soils with larger dimensions and contents of MPs, e.g., ksat of the black clay with 2.0% of 500 μm MP increases significantly by 206% (p < 0.05). The black clay exposed to leachate exhibits a slight increase in ksat due to the low viscosity of leachate. The existence of MPs decreases the residual moisture contents and air-entry pressures, and so does the water retention capacity (v/v %) of the black clay. The exposure to leachate increases the air-entry pressures by 6.0%–15.8% of the clay. The evaporation rates increase with the dimensions and concentrations of MPs. The highest evaporation rate (0.96 g/h) can be observed in samples exposed to 2.0% 500 μm MP with water addition. For all samples, the crack intensity factors increase when MP content is between 0.2% and 1.0% and decreases slightly after that. After being exposed to leachate, the evaporation rates and crack intensity factors of the black clay are decreased by 2.4%–12.6% and 3.6%–13.7%, respectively.

Study on the Cyclic Shear Performance of Waste Steel Slag Mixed Soil

Clay soil has poor engineering properties such as poor permeability and low shear strength. Waste steel slag is an industrial by-product formed in the furnace during the steelmaking process which has high quality, durability, anti-slip properties, gelling, high permeability and good particle interlocking properties. Therefore, in order to improve the engineering properties of clay and increase the utilization rate of waste steel slag, the steel slag was mixed into the clay. Steel slag clay mix was used for the straight shear test, cyclic shear test and post-cyclic straight shear test. To investigate the strength characteristics, damping ratio, shear stiffness variation and mixed soil displacement at the reinforcement-soil interface under different steel slag dosing, vertical stress, moisture content and shear amplitude conditions. The test results show that steel slag can significantly improve the shear strength of the clay tendon-soil interface, and the improvement effect is better than the conventional material sand improved clay. The steel slag mix has a large damping ratio and shear stiffness, suggesting that it has good damping and energy dissipation properties. In this case, the shear strength, damping ratio and shear stiffness of the soil mix at 40% steel slag admixture are better. The shear strength of the steel slag mix is increased after cyclic loading compared to straight shear before cyclic loading. In addition, the water content has a greater effect on the shear strength parameters, shear stiffness and damping ratio of the steel slag clay mix compared to the vertical stress and shear amplitude. The test results can provide a theoretical basis for the replacement of sand by steel slag in improving clay soils.

Potential application of sludge pond ash as a novel additive for clay stabilization

Clays often have unfavorable geotechnical properties that limit construction applications on them. There is a need for sustainable soil improvement techniques to enhance the strength and stiffness of clays. While previous studies have explored clay stabilization with common supplements like cement, lime and fly ash, the utilization of sludge pond ash (SPA) as a sustainable additive has been limited and there is a lack of understanding of the interactive effects of SPA proportion, moisture content, and curing time on the mechanical behavior of clay. The objective of this study is to examine the mechanical properties of clay enhanced with SPA under different curing conditions. To achieve this, different proportions of SPA were mixed with the clay to obtain accurate findings on the efficacy of SPA addition on compaction and unconfined compressive strength (UCS) of the clay to determine mechanical properties. Scanning electron microscopy (SEM) provided imaging of clay improved with SPA to evaluate the microstructural changes in soil texture. Firstly, the sludge from a pond burned at 1000 °C (the optimal temperature determined by microstructural X-ray diffraction (XRD) analysis) was added to the mixture as 0, 2, 4, 6, 8 and 10% of the soil's dry weight, respectively. The studied samples were prepared with the same energy (equivalent to the standard Proctor test) at different moisture contents and were tested in a uniaxial device at 7, 28 and 56 days of curing. It was found that adding SPA to the base soil decreased the maximum dry unit weight (MDUW). On the other hand, it increased the optimum moisture content (OMC) of the compacted mixture. The study examined the combined effects of moisture content and curing time on the compounds, revealing that these factors induced a decrease and an increase in the UCS, respectively. The addition of SPA as an additive material to the clay mixture was found to exert a significant effect on the strength properties of the clay, with an optimal percentage of around 10%. Empirical correlations were also developed to predict the UCS of the SPA-improved clay with high precision. Furthermore, SEM analyses show that SPA acts as a glue gel between aggregate in the mixture and coat clay particles that changes the blend texture and alters weak bonding to aggregate-like particles. The results of both macro- and micro-scale analyses collectively confirm the superior efficacy of the optimal SPA replacement in enhancing various strength and stiffness properties of the clay.

Comparative Experimental Study on Strength Properties of Red Clay Modified by Cement and Industrial Solid Waste Powder

Because of the existence of clay minerals such as montmorillonite in red clay, the strength of red clay decreases significantly as water content increases. This study aims to improve the strength of red clay by using three different kinds of industrial solid waste powder, i.e., steel slag (SS) powder, fly ash (FA), and ground-granulated blast furnace slag (GGBS). At the same time, the ordinary Portland cement (OPC) was selected as a comparison of the improvement effect on the strength of red clay modified by the aforementioned industrial solid waste powder. The properties of the red clay and the industrial solid waste powder were documented comprehensively. The unconfined compressive strength (UCS) tests were conducted on the specimens of the red clay and the red clay modified by the OPC, SS, FA, and GGBS, which had been cured for 3, 7, and 21 days at a temperature of 25°C, respectively. The results showed that the strength of red clay can be significantly improved by the three kinds of industrial solid waste powder. After a 21-day curing period, the experimental results showed that the UCS of the red clay modified by 7% SS, 5% FA, and 5% GGBS increased by 252%, 131%, and 140% compared to that of the red clay without modification. However, the modification effects of the SS, FA, and GGBS on the red clay were generally inferior to that of the OPC. By observing the microstructures of the modified clay, the mechanism of industrial solid waste powder and cement improving the strength of the red clay was analyzed. The findings in this study can provide a reference for improving subgrade strength by a soil-modification method in road constructions.

Stabilization of Kuttanad clay using marble dust and sisal fiber

Construction of engineering structures on clayey soil is highly risky because such soil is susceptible to differential settlements, poor shear strength and high compressibility. So, it needs proper stabilization. Kuttanad clay are soft deposits of fine-grained soil found in the Kuttanad region of Alappuzha district, Kerala. Here construction is very difficult as the soil is poor in drainage and strength properties. The main aim of this work is to identify the various properties of lower Kuttanad clay and stabilizing the soil using marble dust powder. Marble dust is a waste product collected from marble industry. The major constituent of marble dust is Calcium Carbonate and its powder has high percentage of lime content so it can be used as an effective material for the stabilization of clayey soil. Varying percentages of marble dust are added to soil. Optimum moisture content, Maximum dry density and Unconfined compressive strength (UCS) were determined by laboratory testing and Optimum marble dust content for stabilizing the soil is determined. Sisal fiber of length 1cm in varying percentages (0.25%,0.5%,0.75%,1%) is added to clay with optimum marble dust content. Standard proctor compaction test and unconfined compressive strength test were carried out. UCS value increased with increment in fiber from 0.25 to 0.75%. The maximum strength is obtained at optimum 9% MD and 0.75% SF content.

Performance evaluation of Alccofine stabilised Marine clay as subgrade

Soil stabilization is a remedial measure that reduces permeability and compressibility, increases bearing capacity and shear strength of soil mass, which helps in reducing the settlement of structures. Marine clay is one of the major regional soil deposits in India, widely found in offshore and coastal areas. This is a type of low strength soft clay which majorly causes failure in pavements and foundation structures due to high settlements and low strength characteristics. The scope of this project is to improve the strength of marine clay by stabilizing it with alccofine. The work includes determination of index properties of marine clay by Hydrometer method, Atterberg’s test, Specific Gravity test, Free Swell test. The engineering properties of both virgin soil and soil stabilized with 3%, 6%, and 9% of alccofine are determined by various tests such as Standard Proctor test, California Bearing Ratio test. On the basis of CBR test, the optimum percentage of alccofine in marine clay is found out to be 6%.

Effect of curing strength in lime – coffee husk ash mixture on clay

Coffee husk is a fibrous material obtained from coffee beans. It is a waste from coffee industries. In order to reduce the disposal problem, utilization of waste in civil engineering works is very important. This study has been carried out to explore the utilization of coffee husk ash for improving properties of Kumarakom clay. Kumarakom clay is known to be very problematic in construction field. It is considered neither suitable for building houses nor for construction of roads. Coffee husk is a by-product of coffee roasting process. After removal of coffee beans, a huge amount of coffee husk is generated later, the ash obtained after burning of coffee husk i.e; Coffee Husk Ash (CHA) is used in this study. The Kumarakom clay can be stabilized with different percentages (5, 10, 15, 20, 25) of coffee husk ash and variation in strength can be determined by Unconfined Compression Strength (UCS) test and proctor compaction test. The optimum percentage is obtained at 20% of CHA addition. Finally, the curing strength test is conducted for varying percentages of CHA – clay mix and optimum percentage of CHA – lime mix for about 7, 14, and 28 days.

Strength improvement of clay using waste soda lime glass powder and sodium alginate

Clayey soil is generally weak in nature. When constructions are carried out on clayey soil, especially highways, railways, buildings and embankment face many difficulties. Therefore, the improvement of such type of soil is crucial. Soil stabilization can be done by different methods, which includes stabilization using lime, cement and waste materials from various industries etc. Soda lime glass powder is a waste material from glass industries. Clay is a type of soil that can be categorized as problematic due to its weak properties like volumetric expansion, low strength etc. In this soil, the shear strength of the soil is less due to its very high initial moisture content and plasticity. Construction is difficult in such type of weak clay. The main aim is to identify the properties of clay. And, to study the effect of waste soda lime glass powder (WSLGP) and sodium alginate (SA) on clay. Standard proctor compaction test and Unconfined strength test is carried out using varying (3%, 6%, 9%, 12%, 15%) percentages of WSLGP and optimum WSLGP content is determined. The sodium alginate in varying (0.25%, 0.5%, 0.75%, 1%, 1.25%) percentages is added to clay with optimum soda lime glass powder. Standard proctor compaction test and Unconfined compressive strength test were carried out. The maximum strength is obtained at optimum 12% WSLGP and 1% SA content.

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.