Aerial Lime Research Articles

Characterisation of the Mural Paintings from the <i>Misericordia</i> Church of Odemira (Portugal)

Several mortars from mural paintings were collected from the Misericórdia Church of Odemira and analysed by using different techniques namely X-ray diffraction, thermogravimetric analysis with differential thermal analysis, SEM-EDX, optical microscopy, CHNS elemental analysis and chemical analysis. Microfragments of paint layers were collected and analysed by microchemical analysis. The results showed that the mortars are aerial lime mortars with siliceous aggregates and that the pigments used were mainly pigments from local sources (red and yellow ochre’s and malachite) and small blue.

Development of Biocolonization Resistant Mortars: Preliminary Results / Entwicklung von Mörteln mit hohem Widerstand gegen biologischen Bewuchs: Vorläufige Ergebnisse

Article Development of Biocolonization Resistant Mortars: Preliminary Results / Entwicklung von Mörteln mit hohem Widerstand gegen biologischen Bewuchs: Vorläufige Ergebnisse was published on December 1, 2007 in the journal Restoration of Buildings and Monuments (volume 13, issue 6).

Life cycle analysis of mortars and its environmental impact

AbstractOver the years considerable research has been conducted on masonry mortars regarding their compatibility with under restoration structures. The environmental dimension of these materials may sometimes be a prohibitive factor in the selection of these materials. Life Cycle Assessment (LCA) is a tool that can be used to assess the environmental impact of the materials. LCA can be a very useful tool in the decision making for the selection of appropriate restoration structural material. In this work, a comparison between traditional type of mortars and modern ones (cement-based) is attempted. Two mortars of traditional type are investigated: with aerial lime binder, with aerial lime and artificial pozzolanic additive and one with cement binder. The LCA results indicate that the traditional types of mortars are more sustainable compared to cementbased mortars. For the impact assessment, the method used is Eco-indicator 95

Estimation of Elastic Constants of Restoration Mortars, Used on Historic Masonries Restoration Interventions, VIA Ultrasonic Technique and Correlation to their Mechanical and Microstructure Parameters

ABSTRACTEight syntheses of mortars used for restoration interventions in historic masonry were produced using the traditional materials of aerial lime and artificial pozzolanic additives. The mortars were aged over a 15-month period and then tested for properties related to chemical and mechanical stabilization using the following four analytical techniques: ultrasonic velocity propagation and the mortars' dynamic modulus of elasticity (Ed), mercury intrusion porosimetry for evaluation of microstructural characteristics (percentage open porosity, bulk density, average pore radius, total cumulative volume, and specific surface area), water capillary rise tests for the determination of total cumulative volume accessible to water and capillary rise coefficients of the mortars, and conventional mechanical tests for the determination of the mortars' flexural and compressive strength. Performance is correlated to the mortars' chemical composition, microstructural characteristics (as measure by average pore radius) and mechanical characteristics as measured by dynamic modulus of elasticity (Ed) and flexural and compressive strength (Fc).

Repair mortars for the Byzantine masonries restoration interventions providing earthquake protection

The study of the behavior of Byzantine buildings that have presented excellent behavior under earthquakes, such as Hagia Sophia in Istanbul, and the church of St. Michael in Kiev can become a valuable tool for the understanding of earthquake resistant construction techniques and materials. In this work, taking into account the historic Byzantine mortar nature and characteristics, several syntheses of repair mortars addressed to Byzantine masonries are produced and evaluated, aiming to consider the mechanical compatibility to historic ones and therefore to the monuments earthquake protection. Traditional materials (aerial lime, natural pozzolana, sand and brick fragments) are used for the mortar synthesis production, according to the data obtained by the characterization of historic mortars. The produced mortars were evaluated over periods of 3 and 6 months using mechanical tests (compressive, flexural) for the determination of mechanical strength and an ultrasonic technique for the determination of the dynamic modulus of elasticity. Furthermore, thermal analyses (DTA-TG) were performed for the chemical evolution evaluation of these composite systems in time. The obtained results indicate that the lime natural pozzolana mortar presented a sufficient mechanical behavior, analogous to historic mortars, while the lime presented the lowest ratio of f c /f f , that reveals an elastic behavior. All the examined mortars seem to be in progress after 6 months of curing, a fact that is confirmed by the rate of mechanical evolution and from Ca(OH) 2 conversion.

Masonry repair lime-based mortars: factors affecting the mechanical behavior

The increasing use of lime-based mortars for the restoration of historic buildings and structures justifies the research on these materials. The focus of this paper is the effect of technological variables on pore structure and mechanical properties of lime-based mortars. The influence of curing time, binder–aggregate (B/Ag) ratio, aggregate attributes and porosity is discussed. Mortars prepared with aerial lime, varying aggregate types and B/Ag ratios ranging from 1:1 to 1:5 by volume were tested. Compressive and flexural strength measurements, as well as X-ray diffraction (XRD) and thermal studies, were performed after 3, 7, 28, 91, 182 and 365 days. A strong increase in strength of mortar mixtures after 365 curing days (as compared to 28 curing days) is found. In spite of the fact that larger amounts of binder increase the total porosity, the strength of these mixtures is also increased. A good interlocked structure is obtained as binder contents increase. Also, higher porosities allow better portlandite carbonation. A relationship between mechanical properties and pore structure was established. However, in case of binder excess, the increase in voids leads to a strength reduction. The use of calcareous aggregates improves strength more as compared to the use of siliceous aggregates. Factors as grain size distribution and grain shape of the aggregates have also been considered.

Design and evaluation of restoration mortars for historic masonry using traditional materials and production techniques

ABSTRACTCement based mortars used for historic masonry restoration presented unsatisfactory results, due to their chemical and physico-mechanical incompatibility to original buildings. In the present research, several syntheses of restoration mortars are produced using traditional techniques and materials such as binders (aerial and natural hydraulic lime), pozzolanicadditives (natural and artificial pozzolanas) and aggregates (sand and crushed brick). The technical characteristics of the mortars were determined using mechanical tests (compressive and flexural) and mercury intrusion porosimetry measurements at the time of 1, 3, 9, 15 months of curing. Water absorption measurements were performed at the time of 9 and 15 months curing, in order to evaluate mortars microstructural characteristics, their rate of water absorption and the total percentage of absorbed water. The aerial lime - artificial pozzolana mortar presented the best mechanical and microstructural performance. Hydraulic mortars acquired the maximum of the mechanical strength in 1 month, lime - pozzolana mortars in 3 months while aerial lime mortars continue to gain mechanical strength even in 15 months curing. Furthermore, the use of ceramic aggregates produces lightweight and elastic mortars, compatible to historicones.

Compatible Restoration Mortars For HagiaSophia Earthquake Protection

Structural studies to determine the earthquake worthiness of Hagia Sophia in Istanbul have proved that the monument's static and dynamic behavior depends very strongly on the mechanical, chemical and microstructural properties of the masonry mortars and bricks. The results show a decrease of 5-10% in the natural frequencies, as the amplitude of the accelerations increases and returns to their initial values, due to the non-linear nature of the masonry (Cakmak et al 1 ). The analysis of the historic mortars has indicated that the amorphous C-S-H gel-formation between the crystalline phases of the calcite and the dispersed ceramic fragments allows for energy absorption by the structure during an earthquake, without affecting the materials properties irreversibly, while the compatibility of the mortars to the original building units allows for continuous stresses and strains. In the present work the synthesis of restoration mortars has been performed, following the methodology of reverse engineering, i.e. to evaluate and simulate their physico-chemical and mechanical characteristics to the historic ones. During setting and hardening, thermal (DTA-TG), porosimetric analysis and mechanical tests (compressive, flexural strength) were performed. The results indicate that mortar syntheses with hydraulic lime as binding material and being admixed with crushed brick, present a better behavior to those made with aerial lime, or lime-cement, or lime-pozzolanic additives, confronting the criteria set by the analysis of the historic mortars, which have proved to be earthquake resistant.