Recycled sand in lime-based mortars (original) (raw)
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PERFOFMANCE OF MODIFIED LIME MORTAR FOR CONSERVATION OF ANCIENT BUILDINGS
2nd International Conference on Innovative Building Materials, Cairo , 2019
In this paper the efficiency of using different clay based binders was explored to modify the main properties of air lime mortar which is commonly used as binding materials for conservation of ancient buildings. Two different types of Kaolinite and Metakaolin were used for the proposed modification in addition to Hib (Heeba in Arabic), Burned Hib and fine crushed clay bricks (Homra in arabic). The Kaolinite, Hib and Homra were selected as they are usually mixed –locally-with lime mortar to provide suitable binding properties.The influence of burning Kaolinite and Hib on different properties of the binding mortar mixes was explored. On the other hand, different lime replacement ratios were also explored in the proposed mixes. Fresh properties of the proposed mortar mixes were evaluated such as setting time and flowability. On the other hand, main physical and mechanical properties of the hardened mixes were evaluated such as density, water absorption, porosity and strengths (e.g. compressive strength) at different ages. Chemical analysis was performed for the row material used to make the different mixes. During this study, mainly natural materials were used to produce binding mixes having wide range of strengths. Such mixes can be applied for the compatible conservation cases depending on the original ancient material’s strength. On the other hand, all the proposed mixes showed a remarkable reduction of setting time, porosity and water absorption-compared to the control lime mix- providing faster hardening and more durable conservation applications.
Characterization of three recycled materials for alternative use of mortars
Because natural resources in construction are limited, it is advisable to look for new alternatives that meet comparable functions, and likewise, reduce consumption of non-renewable resources. The use of recycled materials is of benefit to the uncontrolled elimination of residues that cause the use of the public resources, such as landfills. In addition, this contributes to the reduction of the environmental impact caused by the industries in the process of obtaining the same ones. Therefore, recycled materials such as concrete or masonry demolished, glass and ceramics different, can be employed in different ways to be used in the construction industry. This work focuses on presenting the initial characterization of three recycled materials as an alternative to use in replacement of natural sand in mortars, this as a first step for further study in different percentages of replacement, as currently his understanding is unknown, or little known.
Construction and Building Materials, 2014
Considering the fundamental importance of preserving the built heritage and of ensuring the good performance achieved by incorporating ceramic particles in lime mortars in ancient times, it is important to study solutions that use materials the available today, in order to produce mortars intended to repair and replace the old ones. Solutions incorporating industrial ceramic waste might be profitable for several reasons, namely for economic, environmental and technical aspects. In this paper, seven ceramic waste products collected from ceramics factories are characterized. Their mineralogy, dimensional features and pozzolanicity were determined. Three of these products, with different particle size fractions (obtained directly from milling, dust only and fragment fractions only), were selected, incorporated into air lime mortars, and their mechanical strength was determined. In the present work, evidence of mechanical efficiency, when common sand or air lime were partially replaced by ceramic wastes, was made clear, drawing attention to the sustainability of this type of mortars, hence, encouraging further research. Highlights: Lime mortars with ceramic dust and fragments have been often used in the past. Solutions for the disposal of waste from the ceramic industry are urgently needed. Dust fraction of industrial ceramic waste may demonstrate pozzolanic activity. Dust and fragments of ceramic wastes increase the mechanical strength of air lime mortars. Ceramic waste incorporated in mortars compositions may work as a natural pigment.
Lime mortars with brick dust and grounded particles for ancient masonry: development and evaluation
Lime mortars with brick dust and grounded particles have been largely used in many regions of the world as plasters, renders and in masonry joints and repointing. In Portugal this type of pozzolanic mortars has been introduced at least since the Roman period, particularly when hydraulic characteristics were needed. Brick dust, a source of silica and also of alumina, react with the calcium hydroxide of the lime, resulting on silicates and aluminates of calcium hydrates. The brick particles (grounded to appropriate dimensions) will act as a specific aggregate. The lime mortars with brick material are supposed to achieve hydraulic characteristics and increment their mechanical resistances and durability, compared to pure lime mortars. Also the mortar behavior in face of water (liquid and vapor) will be changed. Lime mortars with brick material also present compatibility with ancient supports, what does not happened with cement mortars. Within this context and associating the improvement of mortars characteristics to the necessity of sustainable construction practices, some mortars formulated with lime and the addition of industrial by-products have been recently studied by several researchers. To present pozzolanic reactivity, the brick material should be in an amorphous form, obtained from a low thermal industrial process. It also should be finely grounded, so that there is a big surface of pozzolanic particles to react. The aim of this work is to present the evaluation of the influence of brick dust and of brick particles in lime mortars. Characteristics, particularly in terms of flexural and compressive resistances, capillary water absorption and water vapor permeability will be discussed. The repair mortars requirements of compatibility with the ancient masonries and their protection will be analyzed. Considering the increase of some characteristics revealed by some mortars with brick dust and with brick particles, when compared with a pure lime mortar, it is possible to evaluate the benefits of the addition of this type of pozzolan and aggregates in lime mortars, and the viability of this industrial by-product reutilization.
Evaluation of lime mortars for the repair of historic buildings
Structural Studies, Repairs and Maintenance of Heritage Architecture XI, 2009
The repair and rehabilitation of old historic structures involve a complex interaction of existing and new elements. Several difficulties are encountered by researchers and design engineers in this effort. Engineering judgment, perception, and experience have been used in many cases due to the lack of technical guidelines in a worldwide context. Consequently, a research studying different restoration mortars became a necessity. To fulfil this need, this research attempts to evaluate the performance of some of the currently used mortars and develop new ones. Several tests were conducted on lime based mortars using white cement, gypsum, lignin sulfonate, and silica fume that are used to enhance the mortars' performance. These mortars were tested for compressive, tensile, and shear strengths at 7, 28, and 56 days from mixing. As a durability test, weight loss of mortar cubes subjected to wetting and drying cycles was measured. In addition, models of wall prisms were built using these mortars and tested under in-plan compressive loads to study the composite structural behaviour and bonding of stones and mortars. Based on the results of these tests, it was found that lime based mortars prepared using silica fume yielded the highest compressive, tensile, and shear strength. On the other hand, lime based mortars prepared using lignin sulfonate have attained the best results concerning wetting and drying cycles and the highest load capacity for the model wall, which resembled structural behaviour and bonding.
Evalautions of Lime Mortar and Conservation Techniques in Traditional Elements
Architecture and construction methods have been developed by the people who have been living around the word through centuries. Unlike now, in the past the quality of building materials were so different, because of lack of process control and variability in the local sources. Hence each place had different building materials comparing to other places. For many years, lime mortar had been used as the main mortar material in Sharjah traditional masonry. The source of the lime was mainly from coral and lime stones which could be found on the coastal area. This paper aims to prove the compatibility between existing and old lime plus the efficiency of using lime mortar in Sharjah restoration projects. The study has three aims: The first aim is to identify and examine the chemical components of old mortar samples that exist in different heritage buildings in Sharjah by XRF and SEM tests. The second aim is to prepare a new mortar samples with components based on the first aim and examine ...
Properties of masonry mortars manufactured with fine recycled concrete aggregates
Construction and Building Materials, 2014
Properties of masonry mortars made with recycled concrete aggregates were studied. A cement-to-aggregate ratio of 1:7 and pozzolanic cement CEM-IV was used. Five replacement ratios in volume were evaluated: 0%, 5%, 10%, 20% and 40%. Replacement ratios up to 40% are a viable alternative for masonry mortars. Workable life and water vapour permeability were the most critical properties.
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.
The role of aggregates on the structure and properties of lime mortars
Cement and Concrete Composites, 2005
Lime mortars have been used for centuries in civil engineering construction. Considering ancient monuments and historical buildings it seems that these mortars have proved to be durable and reliable materials although they are of low strength in comparison with cement mortars. Nowadays, they are used for the repair of monuments and for the manufacture of renderings and plasters.