Magnesium Potassium Phosphate Cement-Based Derivatives for Construction Use: Experimental Assessment

Area of Science:

• Materials Science
• Civil Engineering
• Sustainable Construction

Background:

• Magnesium potassium phosphate cement (MKPC) is a low-carbon binder with potential applications in construction.
• Optimizing MKPC properties requires understanding the influence of additives like borax and aggregate types.
• Developing sustainable building materials is crucial for reducing environmental impact.

Purpose of the Study:

• To investigate the effect of borax content on the fresh and hardened properties of MKPC pastes.
• To develop and characterize MKPC-based mortars using lightweight aggregates (expanded glass, recycled rubber).
• To evaluate the performance of these novel composite materials as sustainable alternatives to Portland cement.

Main Methods:

• Characterization of MgO powder (chemical composition, particle size distribution).
• Testing fresh paste properties: viscosity, Young's modulus, temperature, and setting time.
• Evaluation of hardened composite properties: structural, hygric, strength, and thermal parameters.

Main Results:

• 5 wt.% borax optimized MKPC paste properties, including setting time, integrity, and strength.
• Replacing silica sand with lightweight aggregates (expanded glass, rubber) reduced thermal conductivity and water permeability.
• MKPC composites with lightweight aggregates maintained sufficient strength while offering improved insulation and reduced environmental impact.

Conclusions:

• MKPC-based materials with optimized borax content and lightweight aggregates demonstrate promising performance.
• These composites offer a sustainable, thermally efficient, and environmentally friendly alternative to traditional Portland cement.
• The study highlights the potential of utilizing recycled materials in low-carbon cementitious composites.