Limestone Calcined Clay Cement Research Articles

Performance of limestone calcined clay cement (LC3) incorporating low-grade marine clay

Clay is a globally abundant material and can potentially be used as a cement substitute after calcination. Though kaolinitic clay exhibits notable reactivity, the potential of low-grade clay with relatively low kaolinite content remains underexplored. This study comprehensively analyzed the chemical and mineralogical composition of marine clays at various locations and depths in Singapore, assessing their feasibility for preparing limestone calcined clay cement (LC3). The hydration kinetics and microstructure development of LC3 pastes, incorporating calcined marine clay, were investigated by XRD, isothermal calorimetry, SEM, and MIP. Additionally, a mini-migration test was employed to investigate chloride ion diffusion in LC3 pastes. The results revealed that Singapore marine clays contain relatively low kaolinite content (16–20% by QXRD). Despite a 25% reduction of 28 days compressive strength compared to reference OPC, LC3 samples exhibited outstanding resistance against chloride penetration regardless of kaolinite content (<40%) or replacement level (LC3-70 or LC3-50). The chloride diffusion coefficient (LC3-50) is one order of magnitude lower than the OPC system. Overall, our findings broaden the selection of raw materials for LC3 preparation and underscore the robustness of LC3 to resist chloride penetration, irrespective of variations in the clay's quality or source.

Optimizing the pore structure and permeability of calcined clay limestone cement through shell powder

Limestone calcined clay cement (LC3) as a novel low-carbon cement shows potential as an OPC replacement due to its lower clinker content and excellent performance. Nevertheless, Low degree of hydration in early age resulted in high porosity impacting properties. In this study, shell powder was employed as a carbonate filler to optimize the pore structure of LC3. The results indicated that adding shell powder improved pore structure, consequently enhancing compressive strength from 35.8MPa to 40.5 MPa at 28 day. The collaboration of shell powder with limestone led to the highest compressive strength 41.2 MPa and lowest porosity 18.4% at 28 days. The matrix had good compatibility when limestone and shell powder are combined for LC3. With the increased content of shell powder, the volume fraction of gel pores gradually increased, and the harmful pores decreased, which promoted the transformation of pores into gel pores. Pore connectivity was reduced, resulting in a denser LC3 matrix. Therefore, shell powder was a material that can effectively improve the mechanical properties and pore structure of LC3.

Anisotropic size effect of 3D printed LC3-based engineered cementitious composites (LC3-ECC)

One of the critical factors affecting the development of 3D concrete printing (3DCP) is the challenging issue of in-situ reinforcement. Engineered Cementitious Composites (ECC) are printable self-reinforced materials, and their application in 3DCP technology can facilitate de-steelisation. However, traditional ECC materials pose certain concerns for sustainable environmental development. The integration of Limestone Calcined Clay Cement (LC3) suitable for 3DCP into ECC (LC3-ECC) presents an ideal solution to the aforementioned challenges. Moreover, conducting comprehensive research into its size effects is an essential step from experimentation to engineering application. A thorough exploration of the size effects of 3D printed LC3-ECC in compression, shear, and flexural fracture aspects is conducted to derive size effect laws. The relationship between the anisotropic mechanical properties and size effects has been established. The mold-cast LC3-ECC precisely follows the Bažant size effect law (SEL). The fiber orientation effect enhances bridging efficiency, leading to the fact that the mechanical properties of certain printed LC3-ECC are hardly affected by the size effect. The mechanical performance of some printed LC3-ECC depends on interlayer strength, making its primary reason for size effect not in the Fracture Process Zone (FPZ) energy release, hence closer to the Multifractal Scaling Law (MFSL). LC3-ECC exhibits weak anisotropy in mechanical properties, showing satisfactory stability. However, under flexural fracture behavior, the anisotropic size effect is higher, necessitating careful consideration in structural design.

Evaluation of sulfuric acid effect on bending strength of steel used in concrete reinforcement in sanitation structures

Most sanitation structures in the world are constructed using concrete which is reinforced by the steel, this type of concrete is called Reinforced Cement Concrete (RCC). The RCC structure is believed to be relatively resistant to corrosion which the sanitation structures are prone to due to the aggressive environment in which they are subjected to. This belief has been compromised since the reinforced concrete used in the sanitation structures such as the concrete sewer pipes has become susceptible to Microbiologically Induced Deterioration (MID). This MID leads to degradation and compromised strength and service life of the RCC. In the reinforced concrete structure, the backbone of this structure is the reinforcing steel which when its strength is compromised by the MID, the whole structure is compromised. The present research therefore aimed at evaluating the effects of sulfuric acid, resulting from the MID process, on the bending strength of steel metal used for reinforcing concrete in sanitation structures. Reinforced concrete specimens were developed using different types of cement and different concrete cover. The three different types of cement were, Ordinary Portland Cement (OPC), Portland Pozzolana Cement (PPC) and Limestone Calcined Clay Cement (LC3), while concrete covers of 15mm and 25mm were applied. They were then subjected to a harsh environment (a sample of sewage) suitable for corrosion just like in their actual operational environment. To determine the effects of sulfuric acid resulting from MID on the steel metal, the steel metal was tested using a Universal Testing Machine (UTM). The bending strengths before and after being subjected to an aggressive environment were determined. The testing of the specimens was done at an interval of 14 days for a period of three (3) months. According to the results, for a concrete cover of 25mm, LC3 showed a minimum percentage reduction in strength compared to PPC and OPC. It had the lowest percentage reduction in strength after 84 days which was 5.25%, OPC 7.20%, and PPC 7.24%. In conclusion, there was a strength reduction for all specimens tested. LC3 showed good resistance to the effects of MID compared to PPC and OPC. In terms of concrete cover, 25mm showed good resistance to MID compared to 15mm concrete cover.

Effects of biogenic sulfuric acid on simulated concrete septic tanks

Concrete is the major construction material for infrastructure development. Concrete sewer septic tanks are Constructed using the conventional ordinary portland cement (OPC) and the Portland pozzolana cement (PPC). However, OPC based concrete sewer systems are susceptible to biological, mechanical, and chemical degradation. Degradation of the concrete septic leads to their failure hence imposing tremendous environmental problems. The aftermath is the emergence of sanitation-related diseases. The wastewater from failing septic systems leads to contamination of the groundwater or the surface water resulting in the pollution of drinking water. Therefore, the need to explore other possibilities and potential construction materials to achieve sustainable sanitation is inevitable. The use of Limestone Calcined Clay Cement (LC3) in the construction of degradation-resistant concrete sewer septic systems has not been well explored in Kenya. LC3 concrete is resistant to the deterioration effects of aggressive media such as acids, chlorides, and sulfates. This paper presents experimental performance and findings of LC3 in aggressive media vis a vis OPC. The LC3 was formulated by mixing clinker, Calcined clay, limestone, and gypsum at percentages of 50 %, 30 %, 15 %, and 5 % respectively. Compressive strength, Sorptivity, and weight loss during the wet and dry cycles for both LC3 and OPC were evaluated. Simulated concrete septic tanks made of LC3 and OPC were made by casting cubes at water cement ratio of 0.5 and cured in fresh water at ambient temperature for 28 days. These cubes were passed through a regime of W-D cycles in the 3% concentration of Biogenic sulfuric acid. It was observed that after 28 days of curing OPC cubes had slightly higher compressive strength than LC3. However LC3 concrete cubes are expected to have higher compressive strength than the OPC. Cubes curing time increases due to increased pozzolanic activity. Biogenic sulphuric acid attacks on hydrated cement products cause a decrease in compressive strength. The water absorption profile of LC3 cubes was lower as compared to OPC cubes. In conclusion, LC3 cubes had a high potential of resisting degradation as compared to OPC cubes. LC3 show more impressive performance, hence LC3 It’s a potential binder for use in the construction of sewer system.&#x0D; Keywords: Septic tank, Sorptivity, compressive strength, wet-dry cycles, biological, mechanical, and chemical degradation, sustainable sanitation, LC3.

Sulphate resistance of low-clinker engineered cementitious composites examined by MicroXRF imaging.

Engineered cementitious composites (ECC) are a class of high-performing fibre-reinforced cementitious materials recognised for their increased ductility and durability compared to conventional cement-based materials, owing to their autogenously controlled tight crack widths, even when subjected to high strains. To reduce ECC's environmental impact, this research examines the use of a low-clinker binder - limestone-calcined clay cement (LC3) - as an alternative to portland cement (PC), along with fly ash to further reduce the clinker proportion and the embodied CO2 of the formulations. In conventional concrete, LC3 hydrates to a denser microstructure resulting from the synergistic reaction between limestone and calcined clay. At the lower water contents typical of ECC and with the presence of fly ash, the influence of the binder composition on the microstructure is difficult to anticipate. To examine the influence of these compositional variables on microstructure, permeability and durability, the sulphate resistance of LC3-based ECC is explored. Specifically, the ECC-LC3 blends are designed with high clinker replacement rate of 75% by mass of binder and contain either conventional fly ash or reclaimed fly ash at 50% by mass of binder. Expansion of ECC-LC3 samples subjected to standard sodium sulphate test conditions was measured up to 12 months and the depth of penetration of sulphates into the ECC-LC3 of varying compositions was quantified using micro-X-Ray Fluorescence (microXRF) imaging and modelling. The expansion results show that the ECC-LC3 formulations performed better than the PC samples and can provide adequate resistance to external sulphate attack, even when reclaimed fly ashes are used in place of the conventional ash. In addition, the shallow penetration of sulphate into these cementitious composites demonstrates the low diffusion coefficients values that were determined using the quantitative data from MicroXRF imaging.

Using ceramic demolition wastes for CO2-reduced cement production

This study focuses on assessing the pozzolanic potential of two types of ceramic demolition waste, namely terracotta roof tiles and sanitary porcelain, as substitutes for traditional calcined clays in blended and limestone calcined clay (LC3) cement production. Experimental methods employed include the modified Chapelle test and XRD for pozzolanic activity evaluation, flexural and compressive strength tests, capillary absorption measurements, and SEM for microstructure analysis. Mortars containing 10%, 20%, and 30% ceramic powders and 5%, 10%, or 15% limestone filler were tested. The findings showed that porcelain powders exhibited lower pozzolanic activity due to their lower surface area and higher firing temperature of the material. Up to 20% substitution of OPC with terracotta had minimal strength impact, with a 103% strength activity index (SAI) at 90 days. Ultrafine terracotta powder showed promise in LC3 production with up to 30% OPC substitution, achieving a 97% SAI after 90 days. The poor mechanical properties of porcelain-containing mortars were explained by surfactants present in sanitary porcelain. This research informs the cement and processing industries on the potential use of specific ceramic demolition waste materials in eco-cement production, offering insights into blended pozzolanic cements and LC3 formulations, with the goal of reducing the carbon footprint of cement manufacturing.

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.

Passivation behaviour of aluminium alloys in limestone calcined clay cement (LC3)

Limestone calcined clay cement (LC3) has emerged as a promising alternative to traditional Portland cement (PC), offering reduced carbon dioxide emissions and improved mechanical and durability-related properties. However, concerns persist regarding the durability of reinforced LC3 concrete, particularly its lower critical chloride threshold and carbonation resistance. To address this issue, aluminium alloys were suggested to be used as an alternative reinforcement. This study investigates the passivation behaviour of aluminium alloys in LC3 and compares it with that in PC. Electrochemical measurements indicate that LC3 paste exhibits higher resistance and forms a more compact film compared to PC paste, suggesting its more protective property. XRD, Raman spectroscopy, and SEM analysis provide insights into the chemical composition and thickness of the films formed on the surfaces of aluminium alloys. This study enhances our understanding of the passivation mechanisms of aluminium alloys in LC3, facilitating their potential application in LC3-based structures.

Carbon-negative heat-stored limestone calcined clay cement mortar containing form-stable phase change materials

Heat-stored cement-based materials (HSCMs) with form-stable phase change materials (PCMs) have exhibited tremendous opportunities for energy conservation and emission reduction in buildings. In this study, a novel HSCM system was designed by incorporating form-stable PCMs into limestone calcined clay cement (LC3) mortar, in which a highly compatible form-stable PCM was constructed by the three-step method including the synthesis of red mud-based geopolymer hollow microsphere (RMHM), the impregnation of n-Octadecane (ODE) into RMHM and the surface precipitation of CaCO3. The microstructures, phase transition properties, chemical compatibility and thermal stability of the two resulting form-stable PCMs (namely ODE/RMHM and ODE/RMHM@CaCO3) were evaluated. A comparative analysis was conducted to reveal the influence mechanism of ODE/RMHM and ODE/RMHM@CaCO3 on the microstructural evolution, hydration reaction, mechanical and thermal properties of LC3 mortar. Moreover, the numerical model method confirmed the significant role of the prepared LC3-based in temperature control and energy conservation in building. In addition, the obtained LC3-based HSCM could achieve a short dynamic payback period and sequestered huge of carbon emissions for service life. In overall, this work opened up a novel path of economically feasible carbon-negative building materials with form-stable PCM.

Aloe Vera-Based Concrete Superplasticizer for Enhanced Consolidation with Limestone Calcined Clay Cement

Self-consolidating concrete (SCC) is renowned for its outstanding workability and ability to seamlessly flow into intricate structures with minimal vibrations, achieved through the incorporation of chemical admixtures. This study pioneers an innovative approach by exploring the use of the cost-effective and readily available plant extract aloe vera mucilage (AVM) as a bio-admixture for SCC. The primary objective is to assess the impact of AVM on SCC formulations, including those comprising ordinary Portland cement (OPC) and blended cement LC3 (clinker 50%, calcined waste clay 30%, limestone 15%, gypsum 5%). AVM is applied at varying dosages at up to 10%. Findings reveal that LC3 exhibits lower consistency, reduced slump values, and extended initial and final setting times compared to OPC. With increasing plasticizer dosage, V-funnel and L-box values decrease. Notably, OPC samples with both plasticizers outperform LC3 in compressive strength at 7, 14, and 28 days. Significantly, a 2.5% AVM dosage demonstrates enhanced compressive strength in both OPC and LC3 samples. In summary, this research positions AVM as an innovative and comparable alternative to commercial plasticizers, contributing to reduced yield stress and increased slump flow in SCC.

Hydration and phase assemblage of limestone calcined clay cements (LC3) with clinker content below 50 %

Limestone calcined clay cement (LC3) is a promising material for producing cement with low CO2 emissions and properties similar to, or superior to, those of Portland cement (PC), but at 50 % clinker content (LC3-50). In many applications, lower strengths than PC are acceptable, opening new opportunities to develop suitable LC3 formulations with clinker contents below 50 %. In this study, we investigate the microstructural development of low-clinker LC3 and the effect of portlandite (CH) addition on the reaction of metakaolin (MK). In low-clinker systems, the MK reaction is limited by the availability of CH. The addition of CH to the blends effectively enhanced the reaction of metakaolin and promoted the formation of carboaluminates, which significantly improved the compressive strength from 7 to 90 d. Environmental performance indicators showed that all investigated low-clinker LC3 systems had lower embodied CO2 compared to PC while achieving adequate mechanical properties.

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.

Effects of colloidal nanoSiO2 on the hydration and hardening properties of limestone calcined clay cement (LC3)

This research investigates the influence of colloidal nanosilica (CNS) on the hydration and hardening properties of Limestone Calcined Clay Cement (LC3). The sulfation degree for LC3 was first optimized based on the hydration heat, and the results suggested that gypsum increases the cumulative heat release during the hydration process of LC3, with a dosage of 2% by weight gypsum leading to the highest heat release. The effects of CNS on hydration reaction, fluidity, mechanical properties and microstructure of LC3 were then investigated. According to the results obtained from isothermal calorimetry and thermogravimetric analysis, CNS can considerably accelerate the reaction rate of the LC3 system. 3% and 5% by weight CNS can significantly improve the compressive strength of LC3 blends, especially at early ages of 3 and 7 days. The findings from this study lead to a better understanding of the modification effects of CNS on LC3 which subsequently provides an insight into regulation mechanism of CNS on LC3.

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.

RETRACTED: Investigating the potential of the limestone calcined clay cement with cement content below 50 wt%: Hydration properties and environmental impact analysis

Limestone calcined clay cement (LC3) is a promising strategy and technology to mitigate the climate change in the field of cement-based materials. The purpose of this work was to systematically investigate the properties of the LC3 system with cement content below 50 wt%, in which two clays with kaolinite content of 33.2% (MK30) and 50% (MK50) were used for comparison. Cement pastes and mortars were prepared with four coupled replacement levels of 50 wt%, 65 wt%, 75 wt% and 85 wt% by calcined clay and limestone. The compressive strength of the mortars was tested for up to 90 days. The hydration process was monitored in detail by isothermal calorimetry, phase assemblages calculated by quantitative XRD-Rietveld refinement and the reaction of metakaolin in calcined clay calculated by mass balance approach. Finally, an environmental performance indicator with consideration of CO2 emission and compressive strength was also introduced to evaluate the application feasibility of these different low-cement LC3 systems. From the observation of the experiment, cement hydration dominated the compressive strength of LC3 system before 3 days, while the pozzolanic reaction between metakaolin and CH as well as the synergistic reaction between metakaolin and limestone supported the late-strength development regardless of the calcined clay types. Compared to MK30, MK50 was more conducive to hydrates precipitation and microstructure densification, resulting in a higher compressive strength. The environmental performance indicator showed that LC3-50 and LC3-35 prepared by MK30, and LC3-50, LC3-35 and LC3-25 prepared by MK50 can be treated as ideal systems, as they presented much lower environmental impact and also maintained the desired compressive strength. The results of this work present a promising contribution to realizing the environmental sustainability of cement production.