Estimation of Mechanical Properties and Mass Density of Al-Malwiya Masonry

This paper presents the first estimation for the mechanical properties and the mass density of the masonry of Al-Malwiya heritage minaret. Many approaches are investigated in order to estimate the modulus of elasticity, shear modulus, Poisson’s ratio, and the mass density for this historic masonry. The mechanical properties are estimated by using empirical formulas and analytical equations, while the mass density is estimated after carrying out experimental tests for the extracted samples of the historic mortar. The estimated properties showed relatively low values compared with the newly constructed masonries, but they were interpreted as reasonable for such a historic construction.

FRESH STATE PROPERTIES OF LIME MORTARS WITH FLAX OIL ADMIXTURE

Flax oil has been used as mortar improving, hydrophobic, admixture already in ancient times. The paper describes the identification of flax oil in mosaic mortar from ca. 1900 by help of FTIR spectroscopy. This historic mortar was reproduced by nowadays raw materials and the influence of flax oil on consistency and air entraining of fresh mortar was tested. It was found that already small amount of oil caused significant air entrainment, which, simultaneously with water repellency action, may contribute to higher durability of mortar with oil admixture. The flux oil influenced also consistency of mortar; its presence caused higher flow value of mortar. Moreover, the introduction of the paper summarizes principal knowledge about action of natural admixtures in lime mortars and plasters on basis of current literature.

Quantitative Analysis of Historic Mortars by Digital Image Analysis of Thin Sections

In restoration work, the compatibility between old and new building material is the key point for sustainable repair of buildings or monuments. Consequently, conservation scientists are looking for an alternative method to the traditional procedures to determine the aggregate grading curve and the binder/aggregate-ratio of the historic material. The problem of using the traditional methods is the frequent major intervention in an existing building. These destructive methods are not allowed. Whereas, to get information about the historic mortar, a new technique, the digital image analysis (DIA), is applied in this paper. Moreover, small amounts of the historic material have already been prepared as thin sections and analysed with a microscope. Modern microscopy techniques allow investigations of quantitative and qualitative composition of historic material. Incentive of this work was to get all the required information to recreate the historic mortar by using the DIA with an open source program only at one thin section. In addition, to examine the accuracy and the significance of the DIA, all results were compared with a known mixture, and in a second test series, the results of the DIA were compared with the traditional methods. The results show that the DIA of thin sections of a historic mortar is highly effective for analysing decisive factors like the binder/aggregate-ratio and the grading curve of the aggregates. Furthermore, it is possible to analyse the mortar only by having one thin section using an open source program ImageJ. Especially in the case of carbonate rock as aggregate, DIA is the only method to analyse these characteristics of a mortar.

The method of research and structure analysis of the historic mortar. Part I – the macroscopic and microscopic - in visible light and electron microscopy

The former construction mortar differ significantly from the currently used. In many cases the historic mortar have very good physical-chemical properties. Therefore, the method of preparation of these mortars are still interesting for modern technology. But there is no precise guidance in archival technology. Therefore, attempting to re-create the old recipes make it sometimes very difficult. Set of methods in the study of historic mortars allow comparative analysis, as well as the reproduction of ancient recipes for modern conservation and technology of construction materials.