Designing general use cement with calcined illite and limestone filler

BONAVETTI, VIVIANA L.; CASTELLANO, CRISTINA C.; IRASSAR, EDGARDO F.

APPLIED CLAY SCIENCE

ELSEVIER SCIENCE BV

Año: 2022 vol. 230

0169-1317

Common raw clays are widely available and develop pozzolanic properties after suitable thermal treatment, and combined with limestone filler, contribute to developing a sustainable general use cement (GUC). A Calcined illite Clay (CC) is introduced as a new SCM in the design of GUC. The GUC formulated with the combination of CC (< 35% by mass), and Limestone Filler (LF) (< 20% by mass) as a partial replacement of Ordinary Portland Cement (OPC) was studied using an experimental design based on surface response. The select properties for the GUC design were the paste flow, flow-loss, and compressive strength at 2, 7, 28, and 90 days. The performance of properties is based on the progress of cement hydration measures as the non-evaporable bound water that cause the reduction of the volume of permeable pores. At an early age, LF stimulates the hydration of OPC, compensating partially the dilution effect. The large proportion of CC acts as a diluent of cement at an early age reducing the strength. However, an increase of strength occurs for composite cements with high CC-content and a low LF-content when the pozzolanicity of cement is confirmed. Finally, using the embodied CO2 for a given property´s goals, the best eco-efficiency GUC is obtained for LF ≤ 10% and CC-content from 17.5 to 30% as a complement of LF content.