Design, dynamic performance and ecological efficiency of fiber-reinforced mortars with different binder systems: Ordinary Portland cement, limestone calcined clay cement and alkali-activated slag

The dynamic mechanical properties and ecological efficiency of cement-based composites are of vital importance to the development of green building materials and dynamic loadings resistance. In this study, the dynamic mechanical properties, ecological and economic efficiency of fiber-reinforced mortars (FRMs) made with different binder systems, including ordinary Portland cement (OPC), limestone calcined clay cement (LC³), and alkali-activated slag (AAS), were compared. In addition, different rheological parameters were designed to evaluate the dynamic mechanical properties of FRMs. The fiber pull-out testing, Barrett-Joyner-Halenda (BJH) testing, and scanning electron microscope (SEM) were used to reveal the difference in the dynamic mechanical properties of FRMs made with different binder systems. The results showed that the loss factor of FRM made with LC³ was the highest, 70% and 150% higher than that made with OPC and AAS as the plastic viscosity of mixtures was at the same range. In addition, the loss factor of FRMs made with OPC and LC³ improved by 25% and 8.6% respectively as the plastic viscosity was improved to a higher level and caused more uniform fiber distribution. The fiber pull-out and microstructure testing indicated that FRM made with LC³ showed appropriate pore size distributions and good fiber-matrix interfacial properties. The ecological evaluation and cost analysis showed that the EE, ECO₂e, and the cost of unit loss factor of FRM made with LC³ were the lowest among three kinds of mortars, showing 48369.1 MJ/m³, 6894.4 kgCO₂/m³, and 20288.0 RMB/m³ respectively. Compared with FRM made with OPC, the above parameters were reduced by 55.8%, 66.9% and 46.0% respectively. Therefore, the FRM made with LC³ shows higher potential for designing green building materials with great dynamic loadings resistance, compared with FRMs made with OPC and AAS.