The effects of grinding on the properties of Portland-limestone cement

This paper presents a study of seven Tunisian cements with varying limestone filler content, manufactured on an industrial scale. The purpose of the study is to promote Portland-limestone cement in countries where these cements are not usually used. Materials characterization showed that the grinding quality of the seven cements was very different. This parameter was defined by the ratio of specific surface (Blaine) and residue at 40 μm. Generally limestone fillers behave in a similar way to crushed clinker although they do accelerate the setting because they are finer. Monocarboaluminate appeared from a young age when filler content was high. At a young age (2 days), mechanical strengths are equivalent, at least if grinding quality is satisfactory. At a medium age (28 days), grinding quality influences performance. At a later age (1 year), only those cements with high limestone content underperform. Limestone fillers increase sorptivity and modify porosity but have little influence on dimensional stability.