This study aimed to bridge a research gap by exploring the utilization of super-sulphated cement (SSC) in engineered cementitious composites (ECCs) as a sustainable alternative to ordinary Portland cement (OPC)-based mixtures. The SSC was designed with slag, gypsum, and a small amount of OPC. The primary objective was to investigate the effects of incorporating SSC, both with and without fly ash (FA), at various FA/SSC ratios between 0 and 1.5. A comprehensive evaluation was conducted to assess the performance of the ECC-SSC mixtures, including the compressive and flexural strengths, ductility, ultrasonic pulse velocity, rapid chloride permeability, and drying shrinkage. Additionally, advanced microstructural evaluation techniques such as scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis as well as X-ray diffraction (XRD) analysis were employed to analyze the reaction products in selected mixtures. The results showed that the ECC mixture produced with SSC exhibited comparable strength to the ECC-OPC. In general, all the SSC-based ECCs fulfilled the criteria for various engineering applications, especially when the fly ash to SSC ratios were 0 and 0.8. In addition, ECCs with FA/SSC ratios of 1.2 and 1.5 showed ultra-ductile performance higher than the control ECC. Interestingly, all the FA-based ECC-SSC presented lower shrinkage characteristics than the control OPC-based ECC.

Carbon sequestration in modern cementitious materials has emerged as a critical study domain in the attempt to reduce global carbon emissions. This review analyzes the capacity of diverse and innovative concrete types, such as engineered cementitious composites (ECC), ultra-high-performance concrete (UHPC), limestone calcined clay cement (LC ³ )-based concrete, geopolymer concrete, 3D-printed concrete (3DCP), and recycled aggregate concrete, to sequester and store carbon during the curing stage. With a focused effort on understanding carbon sequestration during curing, this study offers a comprehensive overview and examines the challenges associated with optimizing curing processes, highlighting their impact on the mechanical performance and durability of carbon-sequestered matrices. The effects of different curing methods and materials are examined concerning their influence on concrete performance and the optimization for carbon storage. The study emphasizes perpetual issues and outlines critical research gaps that must be addressed to enhance the efficacy of carbon sequestration in modern concrete systems. Recommendations for future research areas are offered to facilitate the advancement of more sustainable and carbon-efficient cementitious materials.

Engineered cementitious composites (ECCs), known for their superior ductility and strain-hardening behavior compared to conventional concrete, have been predominantly studied with polyvinyl alcohol (PVA) fibers. However, the potential economic and technical advantages of incorporating steel fibers into ECCs have been largely overlooked in the literature. This study investigates the mechanical performance of ECC reinforced with different types of steel fibers, including straight, twisted, hooked, and hybrid fibers of different lengths, as compared to PVA. The inclusion of various supplementary cementitious materials (SCMs) such as slag and fly ash with each type of steel fiber was also considered at a constant fiber volume fraction of 2%. The mechanical properties were assessed through compressive strength, splitting tensile strength, and four-point flexural tests along with calculations of toughness, ductility, and energy absorption capacity indices. This study compares the mechanical properties of different ECC compositions, revealing that ECCs with hybrid steel fibers (short and long) achieved more than twice the tensile strength, 12.7% higher toughness, and 36.4% greater energy absorption capacity compared to ECCs with PVA fibers, while exhibiting similar multiple micro-cracking behavior at failure. The findings highlight the importance of fiber type and distribution in enhancing an ECC’s mechanical properties, providing valuable insights for developing more cost-effective and resilient construction.

Three-dimensional concrete printing (3DCP) has emerged as a promising technology for developing stay-in-place cementitious and geopolymer permanent formwork systems. This review critically synthesizes current knowledge on printable materials, printability requirements, structural performance, interfacial bonding, durability, sustainability, and microstructural characteristics. Existing studies demonstrate that 3D-printed permanent formworks can contribute structurally by enhancing the axial, eccentric, and flexural performance of composite members through confinement, composite action, and effective load transfer between the printed shell and cast concrete core. Interfacial bonding is identified as a key factor governing structural performance, with layer height, interface geometry, surface roughness, and casting interval significantly affecting tensile and shear bond strengths. Microstructural studies further highlight the roles of pore characteristics, hydration development, and mechanical interlocking in interface formation. Although cementitious systems dominate current research, geopolymer permanent formworks remain comparatively underexplored despite their sustainability potential. Moreover, durability studies, life-cycle assessments, and direct comparisons between cementitious and geopolymer systems remain scarce. This review identifies key research gaps and outlines future directions toward performance-based design methodologies and the broader structural implementation of 3D-printed permanent formwork systems.