Ternary Cement Research Articles

Influence of ground slag and dune sand behavior of binary and ternary cement

This study examines the effect of slag and dune sand replacement (binary and ternary) in cement production, focusing on key mechanical properties and chemical behavior, especially on fire loss and residual an insoluble examined at different curing times ranging from 2 to 210 days. The findings show that the addition of slag and dune sand powder significantly influences the mechanical and thermal properties of mortar mixtures replaced by slag the compressive strength increases up to 30% and a slight decrease up to 40 is observed %. Ternary mixes show improved long-term compressive strength, especially after 120, 210 days, although generally young strength is lower than control When binary and ternary are combined with high flexural strength, ternary mixes exhibit good long-term performance, especially in mixtures of 20-30% slag and 10% dune sand lime (ACHOURA, D and al. 2008). From a thermal perspective, the replacement of slag with dune sand lime reduces losses during combustion, indicating excellent thermal stability. The addition of dune sand lime increases the proportion of impervious residue, indicating stability and durability of the cement. Overall, the study concludes that the proper use of slag and dune sand lime especially in ternary mixes can significantly improve the long-term mechanical and thermal performance of cement mortars Thus these findings provide valuable insights for designing building materials with higher durability and strength to suit specific construction application applications.

Enhancing the High-Temperature Fracture Toughness of Ultrahigh-Performance Concrete through Optimization of Ternary Cement Matrix and Plastic Fiber Geometric Properties

Enhancing the High-Temperature Fracture Toughness of Ultrahigh-Performance Concrete through Optimization of Ternary Cement Matrix and Plastic Fiber Geometric Properties

Effect of synthetic C-S-H seeds on hydration process, mechanical properties and microstructure of seashell powder calcined sludge cement

Seashell powder calcined sludge cement (SCSC) is a new type of green low-carbon ternary cement prepared by using waste sludge and waste seashells. It reduces carbon emissions in the cement production industry and solves environmental problems such as serious soil-water-air pollution caused by long-term stockpiling of waste sludge and waste seashells, which are difficult to be utilized in a resourceful manner. However, the reduced clinker content results in lower early strength of SCSC, which limits the application of SCSC in applications requiring high early strength such as precast concrete specimens. In this paper, the effects of different dosage of C-S-H seeds on the hydration process, mechanical properties and microstructure of SCSC slurries were investigated. The results showed that C-S-H seeds significantly increased the 12-hour compressive strength of SCSC, and the 2 % addition of C-S-H seeds increased its compressive strength by 271 %, but had less effect on its later strength. The proportion of large pores in the sample with a 1 % addition of C-S-H seeds decreased by 1 %. At 12 hours, 2 % addition of C-S-H seeds increased its total hydration exotherm by 141 %. The addition of C-S-H seeds decreased the fluidity of the slurry but did not change the flow pattern of the slurry. The relationship between the rheological parameters of the slurry and the addition of C-S-H seeds was well fitted with a primary function, and the rheological equations of SCSC slurries with different additions of C-S-H seeds were obtained. The results of this paper can further broaden the application scenarios of SCSC and lay the foundation for the large-scale application of SCSC.

Application study of seashell powder calcined sludge cement: Effects of different superplasticizer on working properties, mechanical properties and microstructure of materials

Seashell powder calcined sludge cement (SCSC) is a low carbon ternary cement prepared from waste seashells and waste sludge. However, the addition of seashell powder and calcined sludge reduces the working performance of the material and restricts the engineering application of SCSC. To enhance the adoption of SCSC in construction projects, this investigation evaluates the influence of three distinct superplasticizers—Polycarboxylate Ether (PCE), Sulfonated Naphthalene Formaldehyde (SNF), and Sulfonated Melamine Formaldehyde (SMF)—on the workability, mechanical strength, and microstructural properties of SCSC. The effects of superplasticizers on SCSC slurries were analyzed by mechanical property tests and macro-micro property characterization means such as scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FTIR), hydration thermal analysis and nuclear magnetic resonance (NMR). The results showed that the fluidity of SCSC slurries was increased by 73.3 %, 32 %, and 23.5 %, the initial setting time was extended by 29.6 %, 21.3 %, and 16.6 %, and the compressive strength was increased by 22.7 %, 19.6 %, and 5.7 % for the additions of PCE, SNF, and SMF at an amount of 0.25 %, respectively. The addition of superplasticizers prolonged the hydration induction period of SCSC, optimized the pore size distribution of the material, and reduced the structural porosity. The study shows that PCE has the best suitability for SCSC slurries, and should be preferred in the practical application of SCSC slurries. The results of the study can provide a reference for the application of SCSC slurries in engineering.

Valorization of Fine-Fraction CDW in Binary Pozzolanic CDW/Bamboo Leaf Ash Mixtures for the Elaboration of New Ternary Low-Carbon Cement

This paper presents the characterization of a binary mixture of construction and demolition waste (CDW) and bamboo leaf ash (BLAsh) calcined at 600 °C (novel mixture) and the study of its pozzolanic behavior. Different dosages in a pozzolan/Ca(OH)2 system were employed. The aim is the valorization of fine-fraction CDW that achieves a more reactive binary mixture and allows an adequate use of CDW as waste, as CDW is a material of limited use due to its low pozzolanic activity. The pozzolanic behavior of the mixture was analyzed using the conductometric method, which measures the electrical conductivity in the CDW + BLAsh/CH solution versus reaction time. With the application of a kinetic–diffusive mathematical model, the kinetic parameters of the pozzolanic reaction were quantified. This allowed a quantitative evaluation of the pozzolanic activity based on the values of these parameters. To validate these results, other experimental techniques were used: X-ray diffraction, thermogravimetry and scanning electron microscopy. Also, mechanical compressive strength assays were carried out. The results show an increase in the pozzolanic activity of binary mixes of CDW + BLAsh for all the dosages used in comparison to the pozzolanic activity of CDW alone. The quantitative assessment (kinetic parameters) shows that the binary mixture CDW50 + BLAsh50 is the most reactive (reaction rate constant of 7.88 × 10−1 h−1) and is superior to the mixtures CDW60 + BLAsh40 and CDW70 + BLAs30. Compressive strength tests show higher strength values for the ternary mixes (OPC + CDW + BLAsh) compared to the binary mixes (OPC + CDW). In view of the results, the binary blend of pozzolans CDW + BLAsh is suitable for the manufacture of future low-carbon ternary cements.

Long-term strength and resistance to chemical aggressive environments of blast furnace slag, pozzolan and limestone ternary cements

In the cement industry, the search for a less expensive binder using mineral additions from industrial by-products or natural resources has become a major concern on the one hand to compensate for the deficit in the manufacture of Portland cement and on the other hand to reduce the environmental impact linked to the massive use of Portland cement. This research aims studying the feasibility to produce ternary cement systems by replacing clinker with a binary combination of two different mineral additions. Two types of ternary cement systems were studied: type A with 65% clinker and 35% (natural pozzolan and limestone), and type B with 65% clinker and 35% (blast furnace slag and limestone), were the combination of mineral additions was 10%+25%, 17,5%+17,5%, and 25%+10%, respectively. Study of mortars (type A or B, and sand) compressive strength at the ages of 28 days, 1 year and 3 years was carried on. Resistance to chemical aggressive environments, namely sulphuric acid (H2SO4) and hydrochloric acid (HCl) solutions, was also studied after an initial 28 days curing and for six months period of immersion, by compressive strength test, weight and pH changes. The effect of aggressive environment on the internal microstructure was also studied by mercury intrusion porosimetry (MIP).

Seashell powder calcined slag cement: A novel green low-carbon ternary cement

To reduce the carbon dioxide emissions during cement production, this research utilized seashell powder and calcined slag to replace a portion of the cement clinker, creating a novel green, low-carbon, ternary cement—seashell powder calcined slag cement (SCSC). This study investigated the impacts of seashell powder and calcined slag on the mechanical properties, hydration process, and microstructure of SCSC. The findings revealed that the addition of seashell powder and calcined slag improved the material’s toughness and promoted the formation of cementitious products such as carboaluminate phases, C-A-S-H gel, and ettringite, with a 15% mixture of seashell powder and calcined slag increasing the compressive strength ratio of SCSC to ordinary Portland cement to 112%, and reducing the proportion of large pores by 3%.

Carbonation Resistance of Ternary Portland Cements Made with Silica Fume and Limestone.

Ternary blended cements, made with silica fume and limestone, provide significant benefits such as improved compressive strength, chloride penetration resistance, sulfates attack, etc. Furthermore, they could be considered low-carbon cements, and they contribute to reducing the depletion of natural resources in reference to water usage, fossil fuel consumption, and mining. Limestone (10%, 15%, and 20%) with different fineness and coarse silica fume (3%, 5%, and 7%) was used to produce ternary cements. The average size of coarse silica fume used was 238 μm. For the first time, the carbonation resistance of ternary Portland cements made with silica fume and limestone has been assessed. The carbonation resistance was assessed by natural carbonation testing. The presence of coarse silica fume and limestone in the blended cement led to pore refinement of the cement-based materials by the filling effect and the C-S-H gel formation. Accordingly, the carbonation resistance of these new ternary cements was less poor than expected for blended cements.

Utilization of carbonated alkaline solid wastes in ordinary Portland cement-metakaolin-limestone ternary mixture: Underlying the role of low grade-sustainable calcium carbonate sources

Alkaline solid wastes are widely generated as by-products annually from construction demolition, steel making, and metal refining industries. Consequently, there is high pressure on their disposal and environmental protection. Carbonation treatment of alkaline solid wastes provides a potential way to valorize CO2 and produce low-grade artificial limestone particles. This study investigates the utilization of carbonated alkaline wastes, including recycled cement fines, steel slag, iron recycled steel slag, and magnesium slag in green ternary cement (limestone-metakaolin-cement system) production. The detailed characterization of carbonated alkaline solid wastes and the performance of metakaolin-cement based ternary systems were evaluated. The reaction mechanism of carbonated alkaline wastes in metakaokin-cement based binder is proposed. The results indicated carbonated alkaline solid waste powder containing relatively low calcite (14.4%–50.38%) and negative surface charges. In addition, the amount of reactive Si at Q3 and Q4 were observed. The precipitated calcite on the surface of particles resulted in the deterioration of the workability of ternary mixtures compared to natural limestone. However, the equivalent amount of CO3-AFm phases produced by precipitated calcium carbonate and additional hydrates from the reaction of amorphous silica in carbonated alkaline solid wastes contributed to a comparable mechanical performance (49.5 MPa–50.82 MPa) and compact microstructure of ternary binders. Carbonated alkaline solid wastes can be a sustainable component to replace natural limestone in green ternary cement production.

Utilization of Waste Brick Powder as a Partial Replacement of Portland Cement in Mortars

Partially substituting Portland cement (PC) with waste brick powder (WBP) is an effective method to reduce environmental pollution. In this paper, the effects of a WBP with low pozzolanic activity on the fresh and hardened properties of blended cement with 0–40% WBP or 50% of WBP+GGBFS (by mass) were studied. Sodium sulphate (SS) (1.5 and 2.5%, related to powder mass) was used to activate the blended cement with 40% WBP or 50% WBP+GGBFS at 20 °C. Results show that the performance of blended cement is decreased with the increase in WBP content since the WBP with low pozzolanic activity mainly contributes to the dilution effect. Binary cement with 10% WBP shows a similar carbonation depth and chloride migration coefficient to PC. Ternary cement with 10% WBP and 40% GGBFS exhibits a slightly lower strength at 90 days and a lower chloride migration coefficient than PC. The SS solution increases the compressive strength at 2 days and decreases the compressive strength at 28 and 90 days. Moreover, the SS solution results in a lower carbonation depth and chloride migration coefficient, except for ternary cement with 10% WBP and 40% GGBFS, which shows a higher carbonation depth at 42 and 68 days. This paper provides a reference for the application of WBP to produce green mortars.

Strength and load-bearing behaviors of cement-industrial by-products solidified crust layer over soft subsoil

Industrial by-products have a broad application prospect in sustainable soft soil treatment. The applicability and characteristics of a cement-slag-phosphogypsum based ternary cement (TC) are investigated for solidifying soft clay to create a crust layer. The strength and load-bearing behaviors of the solidified crust are characterized using unconfined compressive strength (UCS), triaxial compression, and small-scale loading tests. The ascending trends in UCS with increasing binder content (Cb) differ between TC solidified clay and cement solidified clay, and the UCS ratio between them increases with Cb. Besides, the failure strain and secant modulus of TC solidified clay have functional relationships with UCS, and the same functions work for cement solidified clay as well. In triaxial compression tests, the relationship curves of the deviatoric stress and excess pore water pressure with axial strain change to present more significant shear dilation characteristics as Cb rises from 6% to 8%, along with a sharp rise in the friction angle, suggesting the solidification performance improved to a higher level. The results of small-scale loading tests show that the ultimate bearing capacity (pu) increases with Cb and crust thickness (h), along with the potential crust failure mode transiting from punching to bending failure; the pu gets a sharp rise as Cb and h are just raised high enough to ensure the crust integrity. In more details, it is suggested to prioritize the effective solidification critical for stress spreading before enlarging h in order to achieve higher pu. Finally, TC has been applied and proven effective in engineering practice.

Particle packing optimization and pore structure assessment of ternary cementitious system based on X-ray computed tomography and mercury intrusion porosimetry

The introduction of high-volume steel slag into ordinary Portland cement (OPC) has a negative effect on the pore structure due to its poor hydraulic reactivity. Synergistic effects between steel slag and ground granulated blast furnace slag (GGBFS) in cementitious system have drawn increasing attention. In this study, the modified Andreasen and Andersen (MAA) model was adopted for the mixture design of ternary cementitious system incorporating high-volume ultrafine steel slag (USS) and GGBFS without a compromise in strength. X-ray computed tomography (X-CT) and mercury intrusion porosimetry (MIP) were applied to characterize the pore structure of various cementitious mortars in terms of porosity, pore size, pore number, pore morphology and homogeneity. Results manifested that the adverse impact of USS addition on the pore structure of binary cement was effectively mitigated in the ternary cement USS-GGBFS-OPC after mixture optimization, whereby the pore size was shifted toward a finer distribution and simultaneously with a higher uniformity and consequently promoting the compressive strength development. An increase of cumulative pore volume as captured by X-CT was associated with an exponential decrease of the number of pores while together with larger pore sizes. The increase in the number of small pores led to an increase in the pore tortuosity and degree of sphericity. The fractal dimension of pores was negatively correlated with pore inhomogeneity and compressive strength. These findings provide new insights into homogeneity-oriented mixture design of composite cementitious binders based on gap-graded particle packing, together with their synergistic effects on hydration progress.

Assessment of the potential use of construction and demolition waste (CDW) fines as eco-pozzolan in binary and ternary cements

Construction and demolition waste (CDW) represents a significant portion of the total volume of solid waste generated worldwide, an alternative is to use the fine fraction as eco-pozzolan. The study aims to evaluate the use CDW fines (< 63 µm) as supplementary cementitious material (SCM) in binary (cement and CDW) and ternary (cement, CDW and metakaolin) matrices. Binary mixtures were prepared with 5–20% CDW and ternary mixtures with up to 50% substitution (5–40%CDW, 45–10%MK). Experimental techniques of X-ray fluorescence (XRF), particle size distribution, X-ray diffraction (XRD), SEM-EDS microscopy, thermogravimetry (TG) and mercury intrusion porosimetry (MIP) were used. The physical, mechanical and microstructural properties of the pastes were evaluated. The results show that CDW fines can be used in large quantities in ternary blends to refine the pore structure, reduce water absorption and maintain mechanical strength in the 40 MPa class.

Viability of using limestone concrete waste from CDW to produce ternary cements type LC3

This paper analyzes manufacture of a new eco-cement (reduced CO2 footprint and LC3 clinker content) by replacing natural limestone with fine limestone concrete demolition waste (CDWH). The ternary cement’s content was partially replaced by a binary pozzolanic admixture (10%, 20%, and 30% proportions; 1:1 by weight) composed of CDWH and commercial metakaolin (MK). Results show the ternary eco-cement meets current standards’ chemical and physical requirements. The pozzolanic synergy of the additives —CDWH and MK— is comparable to silica fume, as reflected in the new mortars’ intrinsic properties (capillary water absorption and electrical resistivity), microporosity, and physical and mechanical characteristics, achieving maximum performance at 20% replacement. Kinetically, in ternary eco-cements, the formation of monocarboaluminate and hemicarboaluminate phases, the non-conversion of ettringite to monosulfoaluminate, and the reduction of the Ca/Si ratio in CSH gels all benefit kinetically as the replacement content increases. Use of limestone concrete demolition waste in manufacture of LC3 eco-cements is a viable option.

Durability of concretes with ternary cements

AbstractThe production of cements with calcined clay is becoming increasingly important for the cement industry for ecological and economic reasons. Especially the combination of the cement constituents granulated blast furnace slag (S) and calcined clay (Q) next to Portland cement clinker (K) is very promising in terms of cement properties, durability and CO2 saving potential. Due to a lack of knowledge and experience, such KSQ cements have not yet been produced in Europe.With the help of design of experiments and statistical evaluation, both the influence of the cement composition and the reactivity of the clinker and calcined clays used on the cement and concrete properties were determined. For this purpose, a total of 64 different cement compositions consisting of at least 20 wt.% clinker (two different qualities), a maximum of 59 wt.% granulated blast furnace slag and a maximum of 49 wt.% calcined clay (two different qualities) were investigated.It could be shown that in a wide range of compositions, the production of KSQ cements of strength class 42,5 acc. EN 197‐1 is possible, whereby the water demand of the cements was mainly determined by the amount of calcined clay. Most of the corresponding concretes exhibited a high resistance to carbonation, chloride and freeze thaw attack.

Evaluation of Kunkur Fines for Utilization in the Production of Ternary Blended Cements

Ternary blended cements, such as limestone calcined clay cement (LC3), represent a type of strategic binder for the mitigation of environmental impacts associated with cement production. These are estimated to reduce CO2 emissions by about 40% compared to ordinary Portland cement (OPC). In this paper, we explore the possibility of producing such ternary blends by utilizing secondary raw materials that may be locally available. Specifically, the primary limestone that is commonly used in LC3 is herein substituted with quarry dust obtained by sourcing “kunkur”, a carbonate-rich sedimentary rock (also known as caliche) that can be locally utilized for the production of ordinary OPC clinker. To optimize the blending proportions of ternary cement consisting of OPC, calcined clay, and kunkur fines, a “design of experiment” (DoE) approach was implemented with the goal of exploring the possibility of reducing the amount of the OPC fraction to values lower than 50%. The properties of the formulated blends were assessed by a combination of techniques that comprise mechanical strength testing, XRD time-dependent quantitative phase analysis, and SEM–EDS microstructural and microchemical analyses. The results suggest that ternary blended cement based on kunkur fines forms hydration products, such as hemicarboaluminates, which are also observed in LC3. This shows that such waste materials can potentially be used in sustainable cement blends; however, the presence of kaolinite in the kunkur fines seems to affect their strength development when compared to both OPC and conventional LC3.

Study of fresh properties of cemented paste backfill material with ternary cement blends

This study is aimed at evaluating the effects of ternary blended Portland cement type I (PCI) with slag and limestone (LS) powder on key engineering fresh properties of CPB: (i) rheological properties and (ii) setting time. CPB samples with PCI/Slag ratios of 50/50 (Group A) and 80/20 (Group B) were considered in this study. The effect of LS in the ternary mix was investigated by replacing the slag with increasing doses of LS (5, 10, and 20 wt%). The specimens were cast and cured over periods of 0, 0.25, 1, 2 and 4 h and tested for rheological properties (yield stress, viscosity). In addition, tests were performed to identify the initial and final setting time of the samples. In addition, microstructural tests, zeta potential and pH measurements, and monitoring experiments (temperature, electrical conductivity) were carried out to better comprehend the underlying mechanisms behind the observed changes in rheological behavior and setting time. The findings have shown that the replacement of slag by a higher dosage of LS in the ternary binder significantly affects the rheological properties of the studied CPB. It reduces the yield stress and increases the viscosity of CPB. The effect of LS on the rheological properties of CPB is mainly attributed to the physical (e.g., filler effect, lubrication, particle size) and chemical (nucleation and changes in repulsive forces between CPB particles) effects of LS in the ternary system. The findings also revealed that increasing the proportion of limestone in the CPB ternary binder system prolonged the setting time (initial and final) of the CPB mixture due to the nucleation and dilution effects of LS. Overall, the synergy between slag and LS was observed; the optimal use of LS and slag in the ternary system can serve as a sustainable alternative to the predominantly used ordinary Portland cement (OPC) or OPC/Slag binary binder, thereby reducing the energy consumption and carbon footprint associated with cement and CPB technology. The results of this research will be valuable for a better comprehension of the impacts of ternary binder with an increasing percentage of LS on the rheology and setting time of the CPB mix, ultimately, the efficient design of the mixing plant, especially the backfill transportation system.

Feasibility study on the preparation of ternary cement with calcined slag powder and seashell powder as supplementary cementitious materials

Producing limestone calcined clay cement (LC3) can reduce cement use and CO2 emissions, but the availability and quality of clay and limestone pose challenges. This paper explores substituting these materials with seashell powder and engineering spoils for their high CaCO3 content and cohesive clay. This study introduces the concept of shell powder-calcined slag cement (SCSC) and compares its properties with traditional limestone powder-calcined slag cement (LCSC). Results indicated that the 3d compressive strength of seashell powder calcined slag cement reached 29.19 MPa at 15% supplementary cementitious materials (SCM) dosage, which was 4.7% higher than that of limestone powder calcined slag cement at 27.87 MPa, and the 7d strength was 12.1% higher, which was attributed to the fact that calcium carbonate in seashell powder existed in a more active form. The addition of shell powder enhances the formation of calcium-rich compounds, leading to an optimized mineral phase composition in the ternary cement. Importantly, shell powder's impact on the heat of hydration, pore structure, and mechanical properties matches or surpasses that of limestone powder. Therefore, shell powder proves to be a viable substitute for limestone in ternary cement preparation.

Towards white box modeling of compressive strength of sustainable ternary cement concrete using explainable artificial intelligence (XAI)

Since the production of sustainable ternary cement concrete (TCC) involves a large range of constituents which can affect the compressive strength (CS) of TCC in different ways, the evaluation of CS in a unified manner is necessary. Unlike the black box machine learning (ML) models, the predictions of CS of TCC using local explanations to global understanding with explainable artificial intelligence (XAI) models have been investigated in a systematic approach by means of SHapley Additive exPlanations (SHAP). For this, two conventional ML and three ensemble ML models were used. Hyper-parameter tuning was also carried out. The ensemble ML models had a higher accuracy than the conventional ML models. Taylor diagram, model evaluation parameters and the SHAP values were used to interpret machine learning model predictivity. From insights obtained through local explanations, it can be concluded that predictions made by black box models should be used carefully.

Performance and hydration of ternary cements based on Portland clinker, carbonated recycled concrete paste (cRCP) and calcined clay

This study explored composite cements consisting of Portland clinker, two pozzolans (alumina-silica gel in carbonated Recycled Concrete Paste (cRCP) and metakaolin), and calcium carbonate. The rapid reactivity of alumina-silica gel resulted in full reaction within 28 days, while metakaolin exhibited slower reactivity. cRCP played a significant role in strength development between 1 and 7 days, with metakaolin becoming prominent thereafter. The combination of materials preserved their distinct characteristics. Early hydration was mainly influenced by clinker and cRCP, leading to high early compressive strength. After alumina-silica gel dissolved, metakaolin forms a microstructure, reducing porosity and allowing for continued strength improvement over time. The pozzolans did not hinder their respective reactions, and calcium carbonate from cRCP stabilized ettringite content, similar to limestone-calcined clay systems. This study’s findings offer insights for developing multi-component cement with cRCP and calcined clays, resulting in higher strength and reduced CO2 footprint compared to calcined clay-limestone cements.