Engineered Cementitious Composites with Super-Sulfated Cement: Mechanical, Physical, and Durability Performance

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction

Background:

• Ordinary Portland cement (OPC) production has significant environmental implications.
• Engineered cementitious composites (ECCs) offer enhanced ductility but often rely on OPC.
• There is a need for sustainable binders in high-performance cementitious materials.

Purpose of the Study:

• To investigate the feasibility of using super-sulphated cement (SSC) as a sustainable binder in ECCs.
• To evaluate the performance of ECCs incorporating SSC with and without fly ash (FA).
• To compare the mechanical properties, durability, and shrinkage of SSC-based ECCs with traditional OPC-based ECCs.

Main Methods:

• Preparation of ECC mixtures using SSC with varying fly ash (FA) to SSC ratios (0 to 1.5).
• Comprehensive testing of mechanical properties: compressive strength, flexural strength, and ductility.
• Durability and physical property assessment: ultrasonic pulse velocity, rapid chloride permeability, and drying shrinkage.
• Microstructural analysis using Scanning Electron Microscopy (SEM) with Energy Dispersive X-ray (EDX) and X-ray Diffraction (XRD).

Main Results:

• ECCs with SSC demonstrated comparable compressive and flexural strengths to OPC-based ECCs.
• All SSC-based ECCs met engineering application criteria, particularly at FA/SSC ratios of 0 and 0.8.
• ECCs with FA/SSC ratios of 1.2 and 1.5 exhibited ultra-ductile performance exceeding the control.
• SSC-based ECCs, especially those with fly ash, showed reduced drying shrinkage compared to OPC-based ECCs.

Conclusions:

• Super-sulphated cement (SSC) is a viable and sustainable alternative binder for engineered cementitious composites (ECCs).
• SSC-based ECCs offer a promising balance of mechanical strength, enhanced ductility, and improved durability.
• The incorporation of fly ash further optimizes the performance of SSC-based ECCs, particularly in terms of ductility and reduced shrinkage.