Strain-hardening performance of low-carbon engineered supersulfated cement composites: The promoting role of Yellow River sediment

Le résumé fourni par la source

Engineered cementitious composites (ECCs) are a type of fiber-reinforced building material known for their high ductility, effective crack management, and resilience to damage. However, their broader use is limited by the significant carbon footprint of Portland cement and the expense of ultrafine quartz sand. This study develops a cost-effective, low-carbon engineered supersulfated cement composite (ESSCC) by employing a solid waste-based supersulfated cement (SSC) as the binder and completely substituting fine aggregate with locally dredged Yellow River sediment (YRS). The effects of the sand-to-binder ratio and fiber volume content on the mechanical properties and microstructure were investigated. The optimal mixture exhibited a 28-day compressive strength comparable to its optimal quartz sand counterpart, while the ultimate tensile strain reached 4.2%, representing a 55% increase. Microstructural and micromechanical analyses revealed that the YRS enhanced the fiber-matrix interface, raising the frictional bond stress ( τ 0 ) by 31% and slip-hardening coefficient ( β ) by 70.8%, while significantly reducing matrix fracture toughness ( K m ). The optimized micromechanical condition yielded a higher Pseudo strain-hardening indices ( PSH ). This synergistically improved the composite's macroscopic strain-hardening and multiple-cracking behavior. A lifecycle assessment reveals that, compared with a standard ECC, ESSCC can reduce the carbon emission of materials by about 70%, the cost can also be reduced by 22.4%. This study illustrates a feasible approach to producing sustainable ECC with enhanced mechanical performance through the synergistic use of industrial by-products and natural waste sediment.

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