Magdalini Theodoridou

Physico-mechanical properties and durability performance of natural building and decorative carbonate stones from Cyprus

Abstract Natural stone was the primary building material in Cyprus in the past. Nowadays, its use is mostly confined to decorative purposes and restoration projects. This study represents the first thorough and systematic investigation of the characteristics of local carbonate stone. The variety of the results recorded highlights the complexity of this natural geomaterial and, hence, the particular attention needed before selecting the appropriate lithotype in construction practice. Stones coming from the same geological formation exhibit significant variations in their physico-mechanical properties. The materials’ durability against salt crystallization is explained with reference to their pore structure and flexural strength, revealing that, in many cases, small differences may have a significant impact on stone performance. The study also investigates the use of novel microdestructive techniques in the prediction of the mechanical properties of the stones under study. These techniques can be especially useful in the characterization of monumental stone, where sampling is limited, or when in situ characterization of stone is required.

Geomaterials in construction and their sustainability: understanding their role in modern society

Abstract Inorganic raw materials, here termed geomaterials, derived from the Earths crust and used in construction after appropriate processing make a genetically and functionally varied group of mineral resources. Although their basic functions have remained almost unchanged for centuries, some new attributes, meanings and impacts on society are still emerging. Geomaterials for construction were among the first mineral raw materials exploited, processed and used by man. They helped in the development of technological and artistic skills of humankind. Accessibility, workability and serviceability are considered here as their main functional attributes, being connected with mans skills to find their occurrence, extract and process them, and then use them in the correct way. However, serviceability is a more complex functional attribute as it also encompasses durability of a material in construction. Durability, that is the ability to withstand the action of weathering/decay processes, is an expression of the dynamic interactions between material and the surrounding environment encompassing not only gradual adaptation of materials to current environmental conditions, but also interactions between materials in construction, the history of maintenance/conservation of the structure and the impact of a polluted environment. In the modern world, sustainable use of raw materials, specifically those exploited in the largest volumes such as geomaterials for construction, raises questions of reducing extraction of primary resources and thus minimizing impacts on natural systems, and also employment of materials and technologies to produce less emission of deleterious substances in to the atmosphere. Use of secondary materials such as waste produced during extraction of primary raw materials and/or re-use of existing structural elements and re- or down-cycling can be considered as modern approaches to reducing the pressure on primary resources.