To achieve high tensile strain capacity in cementitious composites

Experimental study on the enhancing effect of polyaspartate polyurea on cementitious composites

Arch action and beam action in reinforced engineered cementitious composite (ECC) beams subjected to shear

Calcium sulfoaluminate-belite (CSAB) cement has gained interest as an alternative low-CO2 cement to conventional portland cement (PC) for various applications, offering beneficial properties such as reduced setting time, rapid strength development, and shrinkage compensation. CSAB cement production requires less limestone, lower clinkering temperature, and lower clinker grinding energy compared to PC. The reduced limestone requirement is attributed to the chemical composition of CSAB cement—having lower CaO and higher Al2O3 contents. The surplus limestone rejected by PC plants due to low CaO content presents an opportunity for its use in CSAB clinker production, potentially offering a sustainable approach to alleviate the strain on limestone reserves for future cement manufacturing. This study investigates the suitability of limestones having clayey and siliceous impurities with less than 40% CaO content (by weight) for producing high ye’elimite CSAB cement. The chemical compatibility and scale of utilization of limestone are discussed by comparing the performance of produced cements with a commercial CSAB cement having similar composition. The amount of gehlenite phase was dependent on the free-CaO available for clinkering reactions, restricting the utilization of low-grade limestone to 15%–20%. The experimentally observed phase compositions were found to be in reasonable agreement with the phase assemblage predicted by FactSage modeling. A modified formula for the lime saturation factor was proposed for raw mix proportioning of CSAB clinkers. This study reports the development of laboratory-synthesized CSAB cements of optimal compositions exhibiting similar heat of hydration, microstructure evolution, and strength development as that of commercial CSAB cement.

Supramolecularly co-assembled composite bone cement prepared from tea polyphenol-modified tricalcium phosphate/tricalcium silicate with osteogenic, antibacterial, and immunomodulatory effects.

This study investigates a novel stay-in-place permanent formwork system employing fiber-reinforced polymer (FRP)–reinforced ultrahigh-strength engineered cementitious composites (UHS-ECCs) to enhance the durability and structural performance of concrete structures. The flexural behavior and failure mechanisms of reinforced concrete beams incorporating a 3-mm FRP bar–reinforced, 20-mm-thick UHS-ECC formwork were evaluated through experimental testing, digital image correlation, and theoretical analysis. For comparison, ultrahigh-performance concrete (UHPC) was used as an alternative formwork material. To improve interfacial bonding, the precast formwork was fabricated with rectangular grooves spaced at 50 or 120 mm. The results indicated that the UHS-ECC formwork effectively mitigated early crack localization, resulting insuperior load-carrying capacity and postyield stiffness. In contrast, the UHPC formwork was more susceptible to localized cracking, which induced interfacial deformation incompatibility and consequently reduced structural ductility and load-bearing capacity. These findings demonstrate the potential of FRP-reinforced UHS-ECC permanent formwork as a viable solution for improving the mechanical performance and durability of concrete structures.

Micromechanical design strategy for enhancing tensile ductility of strain-hardening basalt fiber reinforced cementitious composites

Experimental investigation on application of 3D-printed auxetic cementitious composites to strengthen concrete block masonry

Granite-waste as a sustainable lead-free X-ray shielding concrete: Effect of composition on the strength and ability to counter X-ray.

Microstructural evolution and mechanical behavior of carbonated high-toughness recycled cementitious composites revealed by in-situ 4D CT

Optimizing High‐Temperature Performance of UV-treated polypropylene fibre-reinforced cementitious composites using hybrid machine learning and ensemble AI techniques

Thermal degradation of polypropylene fiber-reinforced cementitious composites, tensile behavior and crack evolution assessed by digital image correlation

Experimental insights into high-performance fibre-reinforced cementitious composites (HPFRCCs) as retrofitting materials in reinforced concrete columns

Construction of three-dimensional nanoconductive network and its synergistic effect in multifunctional cement composites

In this work, the mechanical properties of hybrid fiber-reinforced cementitious composites (CP-ECCs) composed of polypropylene fibers (PPs) with varying volume fractions and 1% volume fraction chopped carbon fibers (CFs), as well as the influence of different fly ash (FA) contents on material performance under both room temperature (20°C) and high-temperature conditions, are systematically studied. Through experiments conducted at five target temperatures (20, 200, 400, 600, and 800°C), the residual mechanical properties, fundamental mechanical properties, and microstructural evolution patterns of the CP-ECC were analyzed. The results indicated that the mechanical properties of the material generally tended to increase with increasing temperature, reaching peak strength at 600°C, followed by a significant decrease at 800°C. Scanning electron microscopy (SEM) analysis revealed that the incorporation of PP fibers effectively suppressed cracking and spalling in concrete at 600°C. Moreover, the carbon fiber-like reinforcement structure formed by the CF fibers and molten PP fibers further enhanced the mechanical properties of the ECCs at elevated temperatures. This study innovatively designed a novel high-temperature resistant hybrid fiber ECC material. This material provides a new theoretical foundation for the application of ECCs in high-temperature environments, with significant theoretical value and practical significance.

Concrete is inherently heterogeneous but is often modelled as homogeneous at the macroscale for simplicity. Accurately representing this heterogeneity using mesoscopic modelling minimises reliance on extensive laboratory testing, enables efficient parametric studies, and thereby reduces both experimental effort and overall costs in developing sustainable cementitious composites. Mesoscale modelling, which treats concrete as a heterogeneous three-phase system comprising mortar, aggregate, and the interfacial transition zone (ITZ), offers a practical balance between accuracy and computational demand. It can simulate both the mechanical properties and the nonlinear behaviour of concrete, while capturing size effects that significantly influence these properties. It simplifies parametric investigations, deepens understanding of crack initiation and propagation, and facilitates the efficient generation of comprehensive datasets. Despite these advantages, mesoscale models can be computationally intensive due to numerous contact regions and thin ITZ layers. To address this challenge, the present study develops a random-aggregate Representative Volume Element (RVE) framework for simulating uniaxial compressive and tensile strength, as well as biaxial strength, of conventional ordinary Portland cement (OPC) concrete. Parametric studies are conducted to evaluate the effects of RVE size, aggregate shape, and ITZ thickness on the simulation of uniaxial compressive and tensile strength of OPC concrete. The optimal configuration, a 5cm RVE with circular aggregates and ITZ thickness of 0.1 times the aggregate diameter, reproduced uniaxial compressive and tensile strengths while reducing the number of finite elements by approximately 90% relative to full-scale (15cm) modelling, which significantly reduces computational time. The framework is validated under biaxial loading, demonstrating its capability to capture complex multiaxial behaviour. It is further extended to simulate the uniaxial compressive response of recycled aggregate geopolymer concrete (RAGPC), advancing low-carbon, circular-economy materials. The results demonstrate that the proposed mesoscopic RVE framework offers an effective, extensible, and computationally efficient approach for simulating the mechanical response of different types of concrete, highlighting its potential as a robust tool for sustainable cementitious composites.

Valorization of coal gasification slag via Fischer-Tropsch tail gas driven calcination: hydration mechanisms, life cycle sustainability and heavy metal leaching assessment of composite cement.

To investigate the effects of tannic acid (TA) doping on the physicochemical properties, biocompatibility, in vitro osteogenic performance, and antibacterial activity of Brushite bone cement, and to evaluate its feasibility for bone defect repair. TA was incorporated into Brushite bone cement at concentrations of 0, 1.0, 3.0, 5.0, and 10.0 mg/g of solid powder, designated as Brushite, Brushite/TA-1, Brushite/TA-2, Brushite/TA-3, and Brushite/TA-4, respectively. The compressive strength and microstructure of each group were evaluated. The extracts of the bone cements were prepared and co-cultured with MC3T3-E1 cells. Cell proliferation was assessed using the cell counting kit 8 (CCK-8) assay. The cytotoxicity was observed by Calcein/propidium iodide live/dead cell staining. Cell adhesion was observed via scanning electron microscopy. After osteogenic induction, alkaline phosphatase (ALP) activity was measured and ALP staining was performed. The expression levels of osteogenic-related genes, including runt-related transcription factor 2 (Runx2), osteocalcin (OCN), osteopontin (OPN), collagen type Ⅰ (Col-Ⅰ), and integrin-binding sialoprotein (IBSP), were detected by real-time fluorescent quantitative PCR (qRT-PCR). The antibacterial activity of the bone cement against Escherichia coli was assessed using the inhibition zone method. Compared with the Brushite group, the Brushite/TA-3 and Brushite/TA-4 groups exhibited significantly increased compressive strength ( P<0.05). TA doping resulted in a higher crystal content and a more regular and dense crystal arrangement. Regarding cytocompatibility, the Brushite/TA-3 group demonstrated the most pronounced enhancement of cell proliferation ( P<0.05), whereas the Brushite/TA-4 group showed relatively lower cell proliferative activity ( P<0.05). All groups exhibited low cytotoxicity with good cell viability. Cell adhesion density and pseudopodia extension were superior in all TA-doped groups compared with the Brushite group. Regarding osteogenic activity, after 14 days of osteogenic induction, ALP activity was higher in all TA-doped groups than in the Brushite group ( P<0.05) in a dose-dependent manner. The relative expression of Runx2, OCN, OPN, Col-Ⅰ, and IBSP mRNA also increased to varying degrees in a dose-dependent manner compared with the Brushite group. Regarding antibacterial performance, only the Brushite/TA-4 group exhibited inhibitory effects against Escherichia coli, with an inhibition zone diameter of approximately 7 mm. Doping with an appropriate concentration of TA (3.0-5.0 mg/g) improves the mechanical properties, cytocompatibility, and osteogenic activity of Brushite bone cement. A higher concentration (10.0 mg/g) confers antibacterial properties but may partially inhibit cell proliferation. TA-doped Brushite bone cement demonstrates good application potential in the field of bone defect repair.

Orthopedic infections, including osteomyelitis and prosthetic joint infection (PJI), are complicated clinical problems that urgently need to be paid attention to and solved. Clinically, antibacterial drug-loaded bone cement (ALBC) has been frequently used to treat localized orthopedic infections because of its strong local antimicrobial activity. While, ALBC faces the problem of poor therapeutic effect in clinical applications due to the development of bacterial resistance to antimicrobial drugs, as well as the limitations in the bone cement's mechanical properties and drug release properties. Numerous research efforts are currently underway to create new composite bone cement by combining the use of a wide range of antimicrobial drugs, optimizing the preparation process of bone cement, introducing new antimicrobial agents and innovative materials to overcome the shortcomings of the conventional ALBC, expanding its potential for clinical use. However, the majority of related studies are performed on the in vitro level, and additional in vivo experimental data are required to confirm their efficacy and safety. This review summarizes the development of ALBC, with a focus on the research progress and innovative breakthroughs in drug selections, drug release mechanisms, and clinical applications, which is expected to provide a reference for the in-depth investigation of multifunctional bone cement and multidisciplinary cross-collaboration, as well as to expand the potential of bone cement for clinical applications.

This research evaluated graphene as a functional additive to improve the performance of cementitious composites. It aimed to assess the effect of graphene powder on concrete's mechanical behavior and optimize the mix design. Graphene powder was incorporated into concrete mixtures at dosages ranging from 0.1% to 0.5% by mass of cement. A series of standardized laboratory tests was performed, including compressive strength and flexural measurements in accordance with ASTM C39 and C78 accordingly. Microstructural and chemical characterization of both the graphene and the graphene-modified concrete was conducted using X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). Water absorption tests were performed to assess permeability-related properties, and Scanning Electron Microscopy (SEM) was employed to investigate the distribution and dispersion of graphene within the cementitious matrix. At the optimal graphene dosage with 0.4% by cement weight, the compressive strength reached 25.16N/mm² at 7 days and 37.75N/mm² at 28 days, while the corresponding flexural strengths were 2.985N/mm² and 4.47N/mm², respectively. XRD analysis confirmed the successful incorporation of graphene, as indicated by a characteristic diffraction peak at approximately 26.5°. Water absorption results showed a reduction in permeability, implying improved resistance to fluid ingress and enhanced durability. It shows that graphene can reduce cement, supporting more sustainable construction.