A brief history of the nature, use and technology of binders in ancient constructions and buildings is outlined, including the apparent chronological discontinuities related to technological developments. The skilled and clever use of mineral resources is at the base of the technical achievements related to architectural activities, from simple adobe to high-performance modern concrete. It is argued that among pre-industrial binders the Roman pozzolanic mortars were highly optimized materials, skillfully prepared and very durable. Their innovative use in architecture is one of the keys of the successful expansion of the Roman Empire. The role of mineralogy and mineral reactions is emphasized in terms of: (1) the preparation and manufacturing of the binding materials; (2) the hardening process and the development of the physical properties of the binder; and (3) the archaeometric reconstruction of the ancient materials.

ABSTRACT Limestone provides many lessons about Earth’s systems (geosphere, hydrosphere, atmosphere, cryosphere, and biosphere) through the geochemical, hydrologic, ­tectonic, and rock cycles. Limestone is ideal for teaching cross-disciplinary STEM (science, technology, engineering, and math) subjects of biology, chemistry, and physics, along with history and culture through its uses in society as a valuable economic resource. Carbon and calcium chemistry is part of the everyday environment, and limestone deposits around the world are important archives of biotic and abiotic Earth history. Limestones provide data for reconstructing global climate change and provide important “documents” for recreating Earth’s changing biodiversity throughout geologic time, including human history. Limestone precipitation is Earth’s antidote to global warming. Limestone is volumetrically one of our most valuable natural resources with a variety of uses, as well as frequently involved with natural and human-induced environmental hazards. Limestone is a common commodity readily available to all teachers and students, thus it is the ideal material for ­budget-strapped STEM educators to use to address Next Generation Science Standards. Some uses include: using fossils to develop concepts of paleoecology and evolution; using limestones to reconstruct ancient geography (including plate tectonics); and addressing the relevance of limestone to our society as a building stone, for its medical uses, and as a potential hazard associated with karst (caves and sinkholes). Five cross-disciplinary content concepts are addressed to aid teachers in preparing limestone-centric instruction: (1) enhancement of the understanding of chemical reactions and geochemical cycles, (2) biological evolution, (3) physics applications, (4) economic and environmental impacts, and (5) historical and fine arts’ use of limestone.

Abstract This study gives an example of the steps that a repair work must include to be successful. It deals with a specific building, repair material (lime mortar) and application (render), but also with the study of the repair mortar in the laboratory and on site. Firstly, the original materials of the wall were characterized to ensure compatibility with the new repair mortars. Secondly, the suitability of different mortar mixes, made with lime and calcareous aggregate, was assessed by characterizing their properties after 15 months. At the same time, the repair mortars were applied in testing panels, and their behaviour under environmental conditions was studied and compared with that of the laboratory mortars. Mortar properties (shrinkage, adhesion, mineralogy, microstructure and texture) developed differently according to the curing conditions. The carbonation degree was higher in mortars cured on site (especially those with higher aggregate content), although in both cases it depended on mortar porosity. Testing the type of application on site was helpful to define the best performance of the designed mixes and to choose the most suitable one among them, which was found to be the 1:6 binder-to-sand ratio mortar applied in both layers of the render.

Abstract This work highlights the importance of applying suitable methods for the design of air-hardening lime mortars with the correct water dosage and binder-to-aggregate ratios. To this end, the recently developed ‘wet packing method’ has been used to assess the optimum water-to-binder ratio at which the packing density is achieved in lime mortars with different binder-to-aggregate proportions. To support the validity of this method, it has been compared with other standardized methods of determining the bulk density of the dry granular components and the consistency of the mortar pastes. The reliability of the wet packing method has then been verified by studying the mineralogical, textural and mechanical properties of mortars after 2 and 6 months of carbonation. Results showed that although the wet packing method seems to be more realistic than the majority of standards used for the determination of the packing density and workability in granular mixtures, it is not totally suitable for the preparation of air-hardening lime mortars with good performances in the fresh and hardened state.