Lime mortars with brick dust and grounded particles for ancient masonry: development and evaluation (original) (raw)
Related papers
The influence of brick residues in the behaviour of lime mortars
Mortars have a great repercussion on the durability of a masonry construction due to its protective role. The compatibility among the masonry materials (the masonry units, the mortar of the joints, the plasters and the renders) incites the adequate behaviour of the wall and consequentially an increase in durability. Very often we came across with rehabilitation errors due to the use of incompatible mortars whether with the pre-existing mortar or with the others wall materials, which can origin great pathologies. Repair mortars should be compatible with existent materials. Old mortars were normally air lime based and sometimes had in their composition some other products like brick dust which confer specific properties. Small grains of brick residue can take the role of a particular aggregate and brick dust of a pozzolan, reacting with the calcium hydroxide of the air lime and improving the mortars behaviour. Simultaneously its application has the great advantage of reuse an industrial by-product. With the increasing environmental concerns it is important to find appropriate solutions to the industry residues. In this way we can contribute for a better use of the material resources and to the decrease of deposition of residues in landfills by studying its performance as part of a repair mortar. The propose of this paper is to present the results obtained in an experimental work developed at the University of Coimbra which main goal was to analyze the influence of brick residues coming from an industrial plant in the behaviour of lime mortars to be applied as repair mortars, assuring the compatibility and protection of old masonries.
Sustainability, 2021
Coatings and plasters are an integral part of masonry cladding, having a fundamental protective and aesthetic function. They are exposed to numerous aggressive actions, which produce their degradation over time. The utilization of lime, as a binder in masonry lining mortars, plays an important role in their durability and conservation. The objective of this work is to analyze the fresh and durability properties of lime-based mortars for their application in the restoration of old buildings. Four different kinds of mortars were studied with similar workability, using as binders lime putty, aerial lime, and hydraulic lime. The aggregates used consisted of sand and crushed rock powder. As fresh properties, the consistency (by using the flow table) and water retentivity were determined. With respect to durability-related properties, water absorption by capillarity and by immersion, drying kinetics, and carbonation depth were studied. Bulk density and porosity of the mortars were also ob...
An assessment of lime mortars for masonry repair
2006
Most historic and traditional mortars were made with lime. Due to their nature and function lime mortars weather and need to be replaced. Ordinary portland cement mortars can often be incompatible with historic masonry causing structural and aesthetic damage. Petrographic analysis of original mortars from Clonmacnoise Monastery and Ardamullivan Castle evidenced that they were fabricated with feebly hydraulic and magnesian lime respectively. Within a National Monuments’ conservation programme, the original mortars were replicated and tested and the best performers selected to undertake repairs. This paper investigates mortars made with four types of lime binder: fat, feebly-hydraulic, moderately-hydraulic and magnesian lime. The results indicate that lime mortars conduct moisture to a greater extent than OPC mortars. The feebly-hydraulic lime mortar has the lightest microstructure and highest porosity and absorption, being capable of holding the greatest amount of moisture thus being...
Viability of ceramic residues in lime-based mortars
When we approach the subject of construction and rehabilitation of buildings we necessarily must think about external wall coatings as they are the elements more exposed to climate actions, mechanical and environmental conditions and, consequently, the first to be deteriorated and to need rehabilitation. In what concerns the replacement of old plasters and renders, air lime mortars are normally the ones that are more compatible with the existing elements, but that have some limitations due to its slow setting time. As an alternative we may use natural hydraulic lime mortars. We know that brick dust and grains have been widely used in mortars in the past, improving its characteristics, and that actually there are many kinds of ceramic residues that are byproducts of industry and are normally carried into landfills. Within this context and associating the improvement of mortars characteristics to the necessity of sustainable construction practices, some mortars, formulated based on air lime or natural hydraulic lime, with the addition of ceramic residues, have been recently studied. The aim of this paper is to present the experimental work that has been developed concerning the behaviour of two types of these lime mortars with ceramic residues. Characteristics, particularly in terms of flexural and compressive resistances, capillary water absorption and water vapour permeability will be discussed. Comparison will be made between the characteristics of the mortars made with the two limes, and of mortars made with those limes with partial substitutions of siliceous sand by different types of ceramic residues. It will be possible to draw same conclusions about the interest and viability of recycling the ceramic residues as aggregates, its contribution as pozzolan and filler, and also if natural hydraulic limebased mortars can be a good alternative to air lime-based mortar for ancient masonry.
Analysis of Pozzolanic Mortars for Restoration
2021
Historical centers, clusters of masonry buildings form the major part of the world architectural heritage, which has been mainly built in seismic areas. The last earthquakes have put in evidence its vulnerability and the need of assessment. The performance-based demands of recent seismic codes developed for Cultural Heritage require a deep knowledge of mechanical properties of structural materials, and among them the lime mortars play a key role. The drawing of significant samples of structural mortars from existing buildings is not always a simple task, so that the laboratory reproduction of ancient mortars is the best way to obtain reference values for restoration materials fulfilling code requirements. Based on an historical study of compositions, this paper presents an analysis of strength properties of traditional mortars, composed by lime and pozzolan as an aggregate. The laboratory tests, performed by the authors on different types of pozzolanic lime mortars, are compared to ...
Natural hydraulic lime mortars: influence of the aggregates
Natural hydraulic lime specifications changed with the new version of standard EN 459-1: 2010 and a new Portuguese NHL3.5 appeared in the market. The characteristics of mortars depend on many different parameters such as the type of binder, the type of aggregates, the use of fillers and of superplasticizers; also on mixing and curing conditions. In this paper NHL3.5 mortars with binder:aggregate volumetric proportions1:3 were prepared, varying the aggregates type and proportions between them. Two coarse sands, a medium sand, a river sand, a finer sand, a calcareous filler and a ceramic powder were used. The two last mentioned aggregates were byproducts from industry. Prismatic mortar samples and samples of mortar applied over brick were prepared and conditioned in two different situationsfollowing standard EN 1015-11 and at 65% relative humidity with initial daily water spray. Mortars were characterized in the fresh state and at the age of 28 days. Results showed the influence namely of the curing, particularly in terms of water capillary, of the superplasticizer and of the fillers. They also showed that NHL3.5 mortars seem to be adequate for old masonries conservation and repair and, in some situations, they can be an alternative to air lime based mortars.
Influence of Air Lime type and Curing Conditions on Lime and Lime-Metakaolin Mortars
Building Pathology and Rehabilitation, 2013
Air-lime mortars with or without pozzolanic components were largely used in the past. Due to natural or accidental degradation it is often necessary the application of repair mortars, durable and compatible with the masonries of historic buildings. Within this context and associating the improvement of mortars characteristics to the necessity of sustainable construction practices, mortars formulated with limes and the addition of pozzolans have been studied.