Hybrid Cements with ZnO Additions: Hydration, Compressive Strength and Microstructure

Area of Science:

• Materials Science
• Civil Engineering
• Nanotechnology

Background:

• While zinc oxide (ZnO) effects on Portland cement are known, its impact on hybrid pastes remains understudied.
• Hybrid pastes offer unique properties, making them relevant for advanced construction materials.

Purpose of the Study:

• To investigate the influence of ZnO addition on the hydration, compressive strength, microstructure, and structure of hybrid pastes.
• To determine optimal ZnO content for improved hybrid paste performance.

Main Methods:

• Setting time tests, compressive strength measurements.
• Advanced material characterization: X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Thermogravimetric Analysis (TGA) with Differential Scanning Calorimetry (DSC).
• Microstructural analysis using Scanning Electron Microscopy (SEM) coupled with Energy-Dispersive X-ray Spectroscopy (EDS).

Main Results:

• ZnO addition, up to 3 wt%, significantly delayed cement setting times by up to 39 minutes.
• Optimal compressive strength was achieved with 0.5 wt% ZnO addition across all curing periods.
• Microstructure remained largely unaffected by ZnO additions after 28 days of curing.

Conclusions:

• Zinc oxide is a promising additive for hybrid pastes, effectively delaying setting time.
• ZnO enhances compressive strength without detrimental effects on the hybrid paste microstructure.
• This research supports the potential of ZnO in developing improved hybrid cementitious materials.