Developing mortar using limestone flash-calcined dredged sediment/millstone-clay cement binder (LFC)

Abstract

This study aims to develop a sustainable cement binder that resembles limestone calcined clay cement by examining the effects of flash calcination on the physical and mineralogical properties of materials, and their potential as pozzolanic material. The study will evaluate whether flash-calcined material, made from marine sediments or excavated clayey soils at 750 °C, can be a substitute for metakaolin (MK), commonly used to enhance cementitious formulations. The researchers aim to determine whether the flash-calcined material can achieve similar properties to MK when developing mortar made of limestone flash-calcined sediment/millstone-clay cement (LFC). The study shows that flash calcination improves pozzolanic reactivity by enhancing BET surface area and density without altering chemical characteristics. The Chapelle test confirms pozzolanic reactivity in the flash-calcined sediment (FCS) and flash-calcined millstone clay (FCMC), and physical, mechanical, and microstructural tests are conducted to analyze their impact on various formulations of mortar and paste samples. The results suggest that LFC with MK, FCS, and FCMC can achieve better strength than the reference mix C0. Microstructural tests demonstrate that mortar designed with FCS and FCMC have similar compositions to that with MK.