An Evaluation of the Binders and Aggregates Used in Artificial Stone Architectural Claddings and Elements in Late 19th-Early 20th Centuries

Abstract

The material defined as 'artificial stone', frequently used on the façades of the late 19th and early 20th century buildings, is a mixture of binder, aggregate and other additives and may either be applied directly as a coating on wall surfaces or precast in moulds and then attached to façades as decorative architectural elements (1). One of the effects of the Industrial Revolution in the 19th century was a tendency to standardize architectural production, which in turn moved away from time-consuming and costly traditional techniques in search of those in accordance with the dynamic social, economic and cultural structure of the period. One of the resulting solutions was the rapidly mass-produced artificial stones that replaced the traditional stone masonry.The aim of this research is to evaluate the use of artificial stone on the exterior façades of buildings dated to turn of the last century in terms of architecture and conservation science, focusing on the classification of their constituent binders and aggregates. The experiments, conducted according to related national and international standards based on research programs recommended for similar mortar and plaster samples in literature, enabled the determination of the physical, raw material and mineralogical characteristics of the samples. Results indicate that all the binders have hydraulic quality, some being artificial cements and/or natural water limes and others being fat limes, mixed with mostly artificial pozzolanic additives. The identification of calcium sulphate enabled the classification cements as opposed to limes. Compared to mortars and concretes, the aggregates are smaller in size and usually lighter in colour, such as white sand, and crushed marble and lime stone. The use of fibrous aggregates as well as artificial pozzolanic aggregates with hydraulic binders including cements, on the other hand, may indicate the continuity of tradition and/or distrust in these new materials.

Analyses of Deteriorating Old Masonry Buildings; Characterisation of Materials for Establishment of their Compatible Repairs

“…Preliminary identification and analysis of the mortars was done through mineralogical X-ray diffraction (Inxitu 3TX (Inovx) instrument working at 2 angle (0 -55 ) following [16] and thermal gravimetric analyses (using XRF) in accordance to [14,17,16]. Confirmation of the evidence of identification was supported by combined methods including physical and chemical analyses (atomic absorption spectrophotometer (Model ICE 3000 AAS)) following [14, and [18].…”