Calcium Silicate Hydrate Research Articles

Unveiling the dissolution mechanism of calcium ions from CSH substrates in Na2SO4 solution: Effects of Ca/Si ratio

The decalcification behavior of calcium silicate hydrate (CSH) under sulfate attack poses a critical challenge to the long-term durability of cement-based infrastructure, yet understanding its underlying microscopic mechanisms remains elusive. This study employs molecular dynamics to compare the differences in calcium ion dissolution capability of CSH substrates with varying Ca/Si ratios under sulfate solution exposure. The results show that the dissolution amount and dissolution efficiency of Ca are positively correlated with Ca/Si, and the root cause depends on the basic structure of CSH. With the increase of Ca/Si, the electronegativity of CSH decreases, and the adsorption capacity and stability of cations weaken. Meanwhile, Ca ions are less limited by the silicate chain coordination, water molecules are more likely to invade the substrate interior and replace the Ca ions. This research aims to provide a molecular basis for cement production and durability applications in marine engineering.

Analysis of thixotropy of cement grout based on a virtual bond model

Thixotropy of cementitious materials is a crucial intrinsic property that determines the flowability and workability of cement-based grout. A novel virtual bond model of cement particles is developed in this paper to depict the thixotropy of cement grout. A particulate description of the reversible and erasable interparticle bonds is established based on experimental observations with a focus on the non-contact interactions mainly contributed in practice by calcium silicate hydrates (C–S–H). The structural breakdown of the cement network is realized through bonds breakage under applied motion, and the bonding network recovers with regeneration of interparticle connections that involve reversible hydrate reactions in the mixture. The balance between bond rupture and rebuilding can be tuned by assigning different strength limits for bond breakage. We have implemented this model in the open-source code Yade to carry out 3D discrete element method simulations of a rotational vane system filled with spherical particles, and the results show good agreement with experimental data. The modelling results reveal the transition from a solid-like structure to a fluid-like medium within cement suspensions caused by the evolution of broken interparticle bonds. The results also provide a distinct view of thixotropic variation upon disturbance. This model is extendable to other cohesive materials providing an explicit physical definition of the interparticle interactions. It also provides a theoretical explanation for the empirical estimations of thixotropy common in engineering industries and a potential means of measuring cementitious granular flow that may be useful in future studies.

H2 diffusion in cement nanopores and its implication for underground hydrogen storage

Understanding the transport and adsorption characteristics of hydrogen (H2) in calcium silicate hydrate (C-S-H) nanopores is critical to minimize the leakage risks from cement in the wellbore region during underground H2 storage (UHS). However, the critical physiochemical properties of H2 in C-S-H nanopores remain inadequately understood. In this work, we perform molecular dynamics simulations to comprehensively investigate the H2 distribution and diffusion properties in the C-S-H nanopores, considering the crucial parameters of temperature, pressure, and pore size. We evaluate how the density distribution, mean squared displacement (MSD) and diffusion coefficient of H2 evolve with variations in these crucial parameters by comparing H2 properties in C-S-H nanopores with those of bulk H2. We show that H2 molecules are prone to adsorb on C-S-H walls and form a high-density adsorption layer due to strong interactions between C-S-H walls and H2. We find that the confinement of C-S-H nanopores significantly limits the diffusion of H2, leading to smaller diffusion coefficients. Moreover, the diffusion of H2 demonstrates pronounced anisotropic characteristics, with H2 diffusing significantly faster in the direction parallel to C-S-H walls than in the direction perpendicular to the C-S-H walls. We demonstrate that there is a critical pressure, beyond which the diffusion coefficient of H2 parallel to C-S-H walls is close to that in the bulk phase and remains stable. We also show that the impact of nano-confinement gradually diminishes with increasing pore size. Under a given temperature/pressure condition, once the pore size exceeds a threshold, the H2 diffusion coefficient in the C-S-H nanopore is close to that of bulk H2. Our results provide valuable insights into H2 diffusion and adsorption in the C-S-H nanopores at the molecular level, which is critical to assessing and minimizing H2 leakage risks from cement in the wellbore.

Time-varying moisture characteristics and C-S-H gel properties of concrete in dry and hot environments

The construction of deeply buried tunnels has intensified concerns regarding shrinkage cracking and the long-term performance deterioration of lining concrete in dry-hot environments. These issues are related to the dynamic interconversion of internal moisture states, the changing moisture behavior over time, and the evolution of calcium silicate hydrate (C-S-H) properties. However, the mechanisms underlying these phenomena are not fully understood. This study investigates the dynamics of moisture content across different states, the source and composition of evaporated water, as well as the mechanism of change in the microscopic properties of C-S-H in concrete subjected to dry-hot conditions (40℃ and 60℃) and standard curing environments through tests on water loss rates, chemically bound water, and low-field nuclear magnetic resonance. The findings reveal that at 40℃ and 60℃, hydration products were generated rapidly before mold removal, leading to significant increases in chemically bound water, interlayer water, and gel water, while capillary water was notably consumed. After mold removal, the rate of chemically bound water increase slowed, while interlayer water, gel water, and capillary water evaporated significantly, with gel water comprising 87.27 % and 83.51 % of the evaporated water at 40℃ and 60℃, respectively. From day 1 to day 28, interlayer water, gel water, and capillary water contents decreased significantly, with reductions of up to 85.98 % at 60℃. In dry-hot environments, moisture primarily exists as chemically bound water and gel water, contrasting with standard curing conditions where capillary water is also present. The study concludes that drying of C-S-H gels leads to both positive effects, such as interlayer space compression and increased indentation modulus, and negative effects, including increased microporosity and reduced matric densification, ultimately contributing to the deterioration of long-term mechanical properties.

Influence of polypropylene fibers on the tensile mechanical properties of calcium silicate hydrate: molecular simulation.

This research assesses the influence of polypropylene (PP) fibers, both homopolymer and hydroxylated (PPOH), on the tensile properties of calcium silicate hydrate (C-S-H) composites through molecular dynamics (MD) simulations. Our models explore C-S-H matrices integrated with PP and PPOH fibers at varying polymerization degrees. The results demonstrate that both PP and PPOH fibers significantly influence the tensile strength and Young's modulus of the composites. Notably, PPOH fibers contribute to more substantial mechanical enhancements than PP, attributed to the increased polarity and enhanced intermolecular interactions from the hydroxyl groups. The study reveals a nonlinear relationship between polymer additive content and mechanical performance, with optimal properties at a polymerization degree of 20. Additionally, stress-strain analysis indicates that PPOH composites exhibit superior ductility and fracture energy, particularly at polymerization degrees of 20, showing enhanced ultimate strain and fracture energy by up to 9.6% and 13.9%, respectively, compared to PP counterparts. These results highlight the crucial role of tailored polymer additive composition and chemical modifications in maximizing the mechanical efficacy of C-S-H-based materials, enhancing their durability and structural performance. All MD simulations were conducted using LAMMPS. The models employed a combination of Clayff and Cvff force fields. During the entire tensile simulation, the system was configured under the NPT ensemble at 300K.

Insights on the mechanical properties and failure mechanisms of calcium silicate hydrates based on deep-learning potential molecular dynamics

The molecular-scale mechanical properties of calcium silicate hydrates are crucial to the macro performance of cementitious materials, while achieving coincidence between accuracy and efficiency in computational simulations still remains a challenge. This study utilizes a deep-learning potential, specifically developed for calcium silicate hydrates based on artificial neural network, to achieve molecular dynamics simulations with accuracy comparable to first-principle methods. With this potential, the elastic properties and uniaxial mechanical behaviors are explored, wherein the anisotropy and impact mechanism of calcium ratios are analyzed. The results add to evidence that the deep-learning potential possess a higher accuracy than common force fields. The anisotropy of elastic modulus is mainly attributed to different atomic interactions in various directions, while the anisotropy of strength is additionally affected by the form of failure. This study may advance the accurate molecular-scale simulation and deepen the understanding of the strength source and cohesion mechanism of cement-based materials.

Comparative study of silica-based porous materials in the purification of radioactive wastewater

A significant challenge in the treatment of low-level radioactive wastewater is the effective purification of low-concentration radionuclides. Silica-based adsorbents are advantageous for the deep-purification of low-concentration metal ions. This study investigates three primary types of silica-based adsorbents: functionalized mesoporous silica, various modified zeolites, and mesoporous calcium silicate hydrate (C-S-H). These adsorbents were synthesized and their deep-purification effects on heavy metals and radionuclides were compared. The results indicated that mesoporous silica showed relatively poor adsorption for most metal ions. Zeolites outperformed mesoporous silica, with Zn framework-modified zeolites showing enhanced adsorption for several metal ions. Notably, C-S-H displayed superior adsorption performance, achieving high adsorption capacities for various metal ions and radionuclides. Specifically, at a dose of 0.5 g/L, the adsorption efficiency of C-S-H for numerous radionuclides in nuclear power plant wastewater exceeded 92–99 %, highlighting its potential for practical applications. An in-depth analysis of the physical and chemical structure and the adsorption mechanisms of C-S-H revealed its large mesoporous structure and electrostatic attraction to cations across a wide pH range. Multivalent cations were removed through exchange with Ca2+ in C-S-H, whereas monovalent cations were removed through exchange with Na+ in C-S-H. The cyclic structure of silica-oxygen tetrahedra in C-S-H, which promotes large pore formation and provides abundant ion exchange sites, underpins its excellent adsorption properties. This study offers valuable insights for the selection and application of silica-based materials in radioactive wastewater treatment.

Characterization of sulfate-driven deterioration through the microstructural and nanomechanical characteristics of the components of cement paste

The hydration reaction products of Portland cement are primarily responsible for all the characteristics of concrete. When sulfate agents attack the reaction products, their chemical and microstructural alterations are highly complex, necessitating fundamental knowledge across various length–time scales. In this study, nanomechanical properties were incorporated into microstructural and chemical analyses at varying sulfate exposure levels to investigate the sulfate-driven deterioration of Portland cement paste. The nanomechanical characteristics were observed using a nanoindentation test following cement paste was exposed to MgSO4. Microstructural and chemical analyses of the impact of sulfate exposure on the hydration products were performed. According to the statistical deconvolution of the nanoindentation data, the elastic modulus of the calcium silicate hydrate (C-S-H) gel progressively declined with increasing exposure period to MgSO4 solution according to the statistical deconvolution of the nanoindentation data. In contrast, the volume percentage of pores gradually increased. The changes in the elastic modulus were linearly related to the Ca/Si molar ratio of the C-S-H gel. New phases and microcracks due to exposure to MgSO4 were observed. The experimental research undertaken in this study suggested that one of the primary reasons for the decrease in the macroscopic characteristics of cement concretes when they encounter MgSO4 is the decalcification of C-S-H gel, which is mechanically, morphologically, and chemically described.

Highly efficient phosphate adsorption using calcium silicate hydrate-embedded calcium crosslinked polyvinyl alcohol thin film

The removal of phosphate from water is necessary to avoid eutrophication. In this work, a novel composite film of calcium silicate hydrate (CSH) immobilized within calcium cross-linked polyvinyl alcohol (CSH–PVA) was developed for efficient phosphate removal from water using a simple and environmentally friendly preparation method. The characterization showed that flake crystal-like CSH nanoparticles were immobilized on a PVA film (86–106 μm). Amorphous calcium phosphate and hydroxyapatite were observed after phosphate adsorption. The adsorption efficiency and capability of phosphate were examined under various conditions using batch experiments. The phosphate removal data fitted well to the pseudo-second-order kinetic model (R2 = 0.9903–0.9999) and the Langmuir isotherm model (R2 = 0.9958), which estimated a maximum removal capacity (99.01 mg g−1). Phosphate adsorption was found to be endothermic with spontaneous adsorption via chemisorption with strong affinity (ΔG° = −3.96 to −8.62 kJ mol−1, ΔH° = 65.4 kJ mol−1, and ΔS° = 232.94 J mol−1 K−1). Additionally, significant amounts of fluoride and carbonate ions affected phosphate adsorption at levels exceeding 5-fold and 20-fold that of phosphate, respectively. An excellent removal efficiency was achieved in the range of 72.06%–97.87% using phosphate-containing real samples. Therefore, the proposed CSH–PVA film showed great potential for effective phosphate removal from water, with potential for further use as a fertilizer.

Effect of nano-Al2O3 on the mechanical and microstructural properties of cement-based grouting material

The mechanical properties and microstructure of cement-based grouting materials are important parameters affecting the quality of geotechnical engineering, which are limited by the properties of added materials. At present, the exploration of nanomaterials has become the development trend of cement-based grouting materials. The results showed that NA can significantly improve the strength of NCBS. The most pronounced effect was observed when the dosage of NA was 1 %; compared with the control group, the strength increased by up to 45.2 %. NA particles accelerate the hydration reaction rate between cement and fly ash, generating a large amount of hydration products to fill the internal voids of NCBS. When the content of NA was 2–4 %, the strength gradually decreased with an increase in the amount of NA addition. The catalytic and microaggregate effect of the NA particles were the primary contributors to the improved NCBS mechanical properties. Aggregated NA particles were the main cause of the decrease in strength. Acicular ettringite, fibrous calcium silicate hydrate, and NA particles are the dominant components that effect the strength and microstructure of NCBSs. By comparing the relationship between NA and the strength of NCBS and the relationship between the curing age and the strength of NCBS, it was found that NA can better reflect the compressive strength of NCBS, and the correlation degree of NA to the strength of NCBS is 76 % higher than that of the curing age.

Crystal growth of hydrated calcium silicate synthesized from fly ash and lime milk at 100 °C

To maximize the high-value application of fly ash, this study investigates the incorporation of amorphous silica derived from fly ash as a silicon source and lime milk as a calcium source into microporous calcium silicate powders through dynamic hydrothermal synthesis at 100 °C for a duration of 2 h or less. The products were collected at various synthesis intervals and analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and thermogravimetric differential scanning calorimetry (TG-DSC). Results indicate that microporous calcium silicate forms through a dynamic reaction that disrupts Si-O bonds, enhancing the mobility of silica-oxygen tetrahedra and generating H2SiO42−groups. Ca2+ ions also interact with these bonds, resulting in Q1 and Q2 forms of silica-oxygen tetrahedra. Phase transformation of calcium silicate at various intervals was noted, beginning with 3CaO·2SiO2·3H2O, shifting to 2CaO·3SiO2·2.5H2O, and finally to CaO·2SiO2·2H2O at 90 min. Thus, microporous calcium silicate evolves from an amorphous C-S-H gel into a crystalline form, featuring diverse calcium silicate minerals with calcium-silicon ratios and particle sizes between 10 and 20 μm, with sizes increasing until the 80-min.

Study on Synthesis of CSH Gel and Its Immobilization of Heavy Metals

Calcium silicate hydrate (CSH) gel is the most important hydration product of cement. It influences the mechanical properties of resulting materials and plays an important role in the adsorption and immobilization of heavy metal ions. Research in the structure of CSH gel and its ability for heavy metal immobilization enables the development of tailored cement-based materials, a feature that holds significant future potential. In this study, CSH gel was synthesized under different pH and Ca/Si conditions. Structural and morphological changes in CSH gel were investigated using modern technologies. The results revealed that both pH and Ca/Si ratios were important factors influencing the structure of CSH gel. During the formation of CSH, both Cr3+ and Pb2+ can be incorporated into CSH gel, and promoting the formation of calcium hydroxide Cr3+ can also replace Si4+ in the Si-O bond.

Effect of the coconut fibers and cement on the physico-mechanical and thermal properties of adobe blocks

This work aimed to investigate the effect of cement and coconut fibers on the thermal and physico-mechanical characteristics of adobe blocks. Thus, a clayey raw material consisting of kaolinite (62 wt%), quartz (31 wt%), goethite (2 wt%) with a plasticity index of 21.5 % was used to manufacture adobe blocks amended with cement and coconut fibers. First the adobe blocks were formulated with an optimal cement content of 4 wt% before adding coconut fibers up to 1 wt%. The physico-mechanical and thermal characteristics of manufactured composites were then studied. According to the results obtained, the incorporation of coconut fibers into the clay-cement matrix decreases the apparent density and volume shrinkage and increases the porosity of the adobe blocks. The presence of coconut fibers in adobe blocks promotes the phenomenon of water absorption. The combined effect of the formation of calcium silicate hydrate (CSH) and hydrogen bonds between fibers molecules and those of clayey minerals leads to an improvement in the mechanical properties of adobe blocks. The thermal conductivity of adobe blocks decreases with the fiber content due to the presence of pores and cellulose molecules in the fibers which have an insulating nature. Taking into account their physico-mechanical and thermal properties, adobe blocks containing 0.6 wt% coconut fibers and 4 wt% cement are suitable for building sustainable habitats and thermally comfortable.

Impact of Nano-SiO2 on the Compressive Strength of Geopolymer-Solidified Expansive Soil

Expansive soil is widely distributed and often needs to be improved for engineering and construction needs. Using blast furnace slag and fly ash as precursors and NaOH as an alkali activator, a geopolymer was prepared to solidify expansive soil, and the effect of nano-SiO2 on the compressive strength and water stability of the geopolymer-solidified expansive soil was further studied. The effects of alkali addition ratio, nano-SiO2 addition ratio, and curing agent addition ratio on the unconfined compressive strength and water stability of the cured soil were studied through unconfined compressive strength tests, and the curing mechanism was analyzed by electron microscopy scanning. The experimental results showed that the unconfined compressive strength and water stability of geopolymer-stabilized soil first increased and then decreased with an increase in alkali activator dosage. The optimal dosage of alkali activator was found to be 12.5%. Furthermore, it was found that adding nano-SiO2 can further enhance the strength and water stability of solidified soil. When the content of nano-SiO2 was 3%, the unconfined compressive strength was increased by 15%. With an increase in the content of nano-SiO2 doped polymer (GFNS), the unconfined compressive strength and water stability of the solidified soil showed a trend of first increasing and then decreasing, reaching a peak at a content of 20%. The cementitious materials, such as hydrated calcium silicate and hydrated calcium silicate aluminate, generated by the reaction between nano-SiO2 and geopolymer played a role in bonding and filling in the solidified soil. Under the joint action of the two, the structural arrangement between the solidified soil particles became more compact, which improved the strength of the solidified soil.

International Simple Glass (ISG) dissolution rate in a (Si, Ca)-rich environment at 90 °C and alkaline conditions

The dissolution of International Simple Glass (ISG) was investigated at 90 °C and alkaline conditions with various concentrations of dissolved Si and Ca to unravel the combined effects of those elements on ISG reactivity. Experiments were conducted over durations ranging from 20 days to 3 months. Through morphological, structural, and chemical characterizations, the glass dissolution rate was proven to be strongly correlated with the activity of dissolved silica in the solution. While dissolved calcium did not significantly impact the dissolution rate, precipitation of calcium silicate hydrates (CSH) during the experiments enhanced ISG dissolution rate, though to a modest extent. The 3-months experiments highlighted the strong correlation between the dissolution mechanism and the evolution of the nature of secondary phases in saturated solution. During the first 20 days and at high Si and Ca concentrations, CSH precipitated and aggregated, without preventing the passivating impact of the gel layer at the surface of the glass: the dissolution was controlled by diffusion. Then, a resumption of dissolution occurred between 19 days and 76 days, corresponding to the CSH growth, and a possible mechanistic switch to a hydrolysis-controlled reaction rate. Finally, in some experiments, a drop in pH due to carbonate precipitation was observed along with a decrease in the dissolution rate, falling back in a diffusion-limited regime. Overall, this study shows that at 90 °C, pH = 10 and concentrations of SiO2(aq) exceeding 50 % of saturation with respect to amorphous silica, irrespective of Ca concentration but in presence of CO2(aq), ISG exhibits a very good chemical durability.

The Coordination of Aluminum Sulfate with a Water-Soluble Block Copolymer Containing Carboxyl, Amide, Sulfonic and Anhydride Groups Providing Both Accelerating and Hardening Effects in Cement Setting

Two water-soluble block copolymers composed of acrylic acid (AA), 2-acrylamido-2-methylpropane sulfonic acid (AMPS), and optionally maleic anhydride (MAH) were synthesized through ammonium persulfate-catalyzed free radical polymerization in water. The introduction of aluminum sulfate (AS) into the resulting mixtures significantly reduced the setting times of the paste and enhanced the mechanical strength of the mortar compared to both the additive-free control and experiments facilitated solely by pure AS. This improvement was primarily attributed to the inhibition of rapid Al3+ hydrolysis, which was achieved through coordination of the synthesized block copolymers, along with the formation of newly identified hydrolytic intermediates. Notably, the ternary copolymer (AA–AMPS–MAH) exhibited superior performance compared to that of the binary copolymer (AA–AMPS). In the early stages of cement setting, clusters of ettringite (AFt) were found to be immobilized over newly detected linkage phases, including unusual calcium silicate hydrate and epistilbite. In contrast to the well-documented role of polymers in retarding cement hydration, this study presents a novel approach by providing both accelerating and hardening agents for cement setting, which has significant implications for the future design of cement additives.

Limestone particle sizes and sulfate impact on the early hydration of limestone calcined clay cement

This study explores the underlying mechanisms behind the varying grain size distribution of limestone and sulfate requirement in Limestone Calcined Clay Cements (LC3) on the effects of early hydration and rheological properties. In this paper, the experimental study involving a 45 % replacement of cement demonstrates that the filler effect increases with the fineness of limestone. This is evidenced by the observed acceleration and enhancement of silicate reaction, as monitored through isothermal calorimetry (ICC). The precipitation rate of calcium-silicate-hydrate (C-S-H) increases, and the sulfate adsorption by C-S-H is also augmented correspondingly, leading to accelerated depletion of gypsum during the hydration process. The effect of limestone on the particle size of rheology was also shown that the finer the limestone, the greater the yield stress, while the sulfate has the opposite effect. The results of the Krstulovic-Dabic kinetic model indicated that the exponent and rate constant values decreased with the finer limestone and increased with the addition of gypsum. These results aid in understanding the role of limestone and sulfate requirements on LC3 systems.

Detailed Analytical EPMA Study of the OPC Pastes Prepared with the Addition of Raw and Milled Fly Ashes

Concrete and cement pastes belong to the most used building materials in human history and represent a solidified mixture of ordinary Portland cement (OPC), water, course and fine-grained aggregates. Fly ash is used as a pozzolanic additive to improve concrete properties. The fly ash property can also be modified by various treatments such as milling or size reduction with sieving. It was suggested that a beneficial pozzolanic reaction with fly ash gives high mechanical properties. Such pozzolanic reaction results in calcium silicate hydrate (C-S-H) phase formation. In this research comparative analytical EPMA study of the paste samples prepared with the addition of the milled and non-milled fly ashes has been performed to elucidate the pozzolanic reaction of the OPC with the milled and non-milled fly ashes. A higher pozzolanic reaction with CSH phase formation was observed in milled fly ash added paste.

Rapid synthesis of solid polycarboxylate superplasticizers via photoinitiated radical polymerization

The synthesis and performance optimization of solid polycarboxylate superplasticizers (PCEs) present significant challenges. In our study, a rapid synthesis of a solid polycarboxylate superplasticizer (IPCE10) was achieved using photoinitiated free radical polymerization. IPCE10 exhibited good dispersibility and improved compressive strength in concrete. Dynamic light scattering tests and molecular dynamics simulations demonstrated that the adsorption conformation of IPCE10 on the calcium silicate hydrate surface was relatively dispersed, with a thicker adsorption layer. This indicates that IPCE10 has stronger steric hindrance, resulting in superior dispersibility. Additionally, density functional theory calculations of the reaction energy barriers for radical generation by photoinitiated and azo-initiated monomers revealed that the energy barrier in the photoinitiated system was significantly lower than that in the azo-initiated system, indicating that photoinitiated polymerization is more feasible. This study proposes a simple and rapid method for the preparation of solid polycarboxylate superplasticizers, providing valuable insights for the development of high-value-added construction materials.

Preparation of slag-based alkali-activated high-temperature-resistant (600–800 °C) metal interface bonding materials by modulating CaCO3 particles

In this study, an alkali-activated binders (AABs) with excellent high-temperature performance on the surface of iron plate was prepared by using alkali-activated slag as the main material, modulating the addition of filler CaCO3 particles (CC), and using iron plate (Q235) as the coated substrate. Through characterization and analytical tests such as compressive/flexural/bond strength, XRD, TG/DSC, SEM/EDS and OM, the results showed that the bonding effect between AABs and Q235 was mainly influenced by both the internal stress of AABs and the diffusion effect of the interfacial atoms. Under the condition of not adding CC, the internal stress of AABs was much larger than the interfacial bonding force, thus causing warping and spalling at room temperature. Microscopic characterization revealed that the addition of CC reduced internal stresses and microcracks, resulting in improved interfacial bonding. Excellent bonding properties were obtained by adding 10 g of CC, with a compressive/flexural/bond strength of 6.98/0.68/0.10 MPa, and a linear shrinkage of 2.22 % after calcination at 700 °C. The crystalline transition from CaCO3 and calcium silicate hydrate to akermanite-gehlenite, merwinite and lime does not begin to take place until the calcination temperature reaches 800 °C. The failure mechanism of AABs at room temperature and high temperature was studied to provide a basis for the optimization of existing AABs and the development of high-performance AABs.