Revisiting Ancient Roman Cement: The Environmental-Friendly Cementitious Material Using Calcium Hydroxide-Sodium Sulfate-Calcined Clay

Abstract

This study proposes an environmental-friendly cementitious material using calcium hydroxide-sodium sulfatecalcined clay based on the idea of ancient Roman cement. The pozzolanic reaction characteristics of calcined clay are studied by adjusting the ratio of calcined clay and calcium hydroxide in both experimental and thermodynamic modeling methods, which demonstrate that 70% calcined clay and 30% calcium hydroxide are the optimal ratio for the pozzolanic reaction of calcined clay to promote the formation of hydration products. Furthermore, the effect of sodium sulfate on the microstructure and mechanical properties of the cementitious materials are also investigated. Results indicate that 5% sodium sulfate (relative to the total mass of the binder) can accelerate the pozzolanic reaction of calcined clay and optimize its mechanical properties. Overall, this study provides a non-clinker cementitious material with high utilization of calcined clay to reduce energy consumption and CO 2 emissions.

From Nanoparticles to Gels: A Breakthrough in Art Conservation Science

“…Inspiration in designing novel sustainable materials with enhanced properties can also come from ancient civilizations and cultures, where nanomaterials and interfacial phenomena were exploited based on empirical knowledge. Examples include archeological or paleontological materials that survived to recent times, or the enhanced properties of Maya plasters (that mixed biomacromolecules in calcium carbonate biominerals) and Roman cement . With today’s awareness and scientific understanding of colloidal and interfacial processes, the time thus is ripe for a new, sustainable breakthrough in the preservation of works of art.…”

“…Examples include archeological or paleontological materials that survived to recent times, 136 or the enhanced properties of Maya plasters (that mixed biomacromolecules in calcium carbonate biominerals) 137 and Roman cement. 138 With today’s awareness and scientific understanding of colloidal and interfacial processes, the time thus is ripe for a new, sustainable breakthrough in the preservation of works of art.…”

New Insight into Energy-Saving Calcination of Limestone: Preparation, Characterization, and Application of Partially Calcined Limestone

“…Nowadays, the replacement of cement clinker by activator combined supplementary cementitious materials (Slag, fly ash, calcined clay, etc.) has become a significant direction for low-carbon cement. − Limestone and CaO are widely used and accepted as integral components for their various sources. ,,,,− However, the lack of an alkaline environment and early mechanical property development limit its large-scale application. The frequently used NaOH and NaSiO 3 combined with slag, fly ash, and other solid wastes have good strength development, but their high alkalinity and cost have yet to be effectively solved. , Many studies have shown that Ca­(OH) 2 and CaO are potential alternatives, ,, for the bulk cost of NaOH is approximately 5–6 times higher than that of CaO .…”