Cold Sintering of Calcium Carbonate for Construction Material Applications

Abstract

An alternative to traditional binder-based construction materials using "cold sintering", a hydrothermal mechanism that involves subjecting the sample to simultaneous pressure and comparatively low temperatures, was explored. Ground and precipitate calcium carbonates (GCC and PCC) were used as the primary starting materials. Ordinary portland cement (OPC) and zinc oxide were studied for comparison. Compressive strength tests showed promising results from the OPC mortars with the cement mostly replaced by GCC. Scanning electron microscopy showed sintering of calcium carbonate and zinc oxide with the selection of suitable solutions. Porosity of sintered samples measured by nitrogen adsorption−desorption improved considerably. These data support the feasibility of cold sintering as an alternative method for production of conventional precast construction materials.

Dense and strong calcite ceramics prepared by room‐temperature cold sintering based on high‐pressure‐enhanced solubility

“…The BMP and HEBMP ceramics exhibit significantly superior mechanical properties to the RP ceramics, which is attributed to the suppressed cleavage and further improved dissolution activity of calcite for the smaller particles, as discussed above. These factors should also be responsible for the higher compressive strength of the calcite ceramic cold sintered from the fine powder 31 compared to that reported 29,30 with coarse raw powders. Therefore, both the high pressure and appropriately fine raw powder are important for the cold sintering of dense and strong calcite ceramics.…”

“…29 Zahabi et al employed an aqueous solution of 1.0 M NaOH as the liquid medium, and the calcite ceramics cold sintered under 230 MPa at 150 • C show a relative density of approximately 87% and a compressive strength of 23.6 MPa. 30 It is well-known that the dissolution activity of calcite could be further improved by fining the raw powder, although coarse powders with particle sizes of tens of micrometers were used in the stud-ies mentioned above. Hashimoto et al prepared calcite ceramics from a powder with a particle size of approximately 50 nm using a water-assisted cold sintering process at 150-280 • C under the applied pressure of 240 MPa.…”

Engenharia de materiais: materializando o futuro

“…As densidades tanto das matérias primas quanto das cerâmicas podem ser obtidas envolvem diferentes técnicas. Para medir densidade de carga, densidade aparente e densidade real foram usadas técnicas como o método geométrico, método de Arquimedes e Picnometria de Hélio, respectivamente (GIRALDI, 2012;HASHMI, 2016;INDUJA, 2017;NDAYISHIMIYE, 2020;ZAHABI, 2021).…”

“…O volume de poros e área superficial são parâmetros importantes na compreensão da morfologia interna das cerâmicas e poderão ser avaliados pelos métodos de Adsorção/Dessorção de Nitrogênio e Brunauer-Emmett-Teller (BET). Outras técnicas de espectroscopia poderão ser usadas em casos específicos (GALOTTA, 2021;GIRALDI, 2012;HASHMI, 2016;INDUJA, 2017;NDAYISHIMIYE, 2020;ZAHABI, 2021). Ensaios de caracterização mecânica, térmica e elétrica são também realizados de acordo com as características dos produtos de cada trabalho.…”

“…A produção de Cimento Portland Comum (CPC) é responsável por cerca de 7\% da emissão global de CO 2 , sobretudo, devido os tipos de tratamentos térmicos envolvidos no processo de fabricação (MEHTA, 2014). Uma alternativa sustentável consiste em substituir parte do cimento comum por materiais abundantes na natureza e processados a baixas temperaturas, como por exemplo, as argilas e calcários (ZAHABI, 2021).…”