Showing papers on "Brick published in 2004"
TL;DR: In this paper, the changes in brick porosity upon firing and its relation to the mineralogical composition are examined, showing that the presence or absence of carbonates strongly influences the porosity development and, therefore, the brick texture and physical-mechanical properties.
Abstract: The changes in brick porosity upon firing (700 up to 1100 � C) and its relation to the mineralogical composition are examined. Two types of raw clay with a composition representative of that used in brick-making industry were selected to manufacture the bricks: one contains notable amounts of carbonates, with a grain size of under 1 mm, and the other is predominantly quartzitic and lacking in carbonates. We demonstrate that the presence or absence of carbonates strongly influences the porosity development and, therefore, the brick texture and physical-mechanical properties. The carbonates in the raw clay promote the formation of fissures and of pores under 1 mm in size when the bricks are fired between 800 and 1000 � C. The absence of carbonates results in a continuous reduction in porosity and a significant increase in the pore fraction with a radius (r) > 1 mm as the firing temperature rises and smaller pores coalesce. Porosity and pore size distribution results obtained from the combined use of hydric tests (HT), mercury intrusion porosimetry (MIP) and digital image analysis (DIA) of scanning electron microscopy photomicrographs are compared. A clear correlation between the water absorption and drying behaviour of the bricks and the porosity plus pore size distribution is observed. DIA discloses the evolution of size, shape and connectivity of macropores (r > 1 mm) and evidences that MIP results underestimate the macropore content. Conversely, MIP gives a good estimate of the open porosity and of the distribution of pores with r <1 mm. It is concluded that the combined use of these complementary techniques helps to fully characterise the pore system of bricks. These results as well as the study of the evolution of the speed of ultrasound waves vs. time yield useful information to evaluate the bricks physical–mechanical behaviour and durability. The relevance of these findings in the conservation of historic buildings is discussed. # 2003 Elsevier Ltd. All rights reserved.
446 citations
TL;DR: In this paper, the tensile properties of compacted earth blocks reinforced with natural fibers were investigated using a test procedure developed for this work, and the pre-and post-cracking characteristics of these blocks in direct tension were determined.
Abstract: Many thousands of years after its development, unburnt earth block masonry continues to offer an environmentally sustainable and cost-effective alternative to other conventional wall building materials, such as concrete blocks and clay fired bricks, in both developing and developed countries. However, earth is a brittle building material with low tensile strength, and as a consequence tensile cracks in response to external actions or restrained shrinkage are often observed. Ductility and tensile strength may be improved by adding binders or natural fibers to the soil mixture. In this technical note, initial findings of an ongoing study of the tensile characteristics of compacted earth blocks reinforced with natural fibers is reported. The pre- and postcracking characteristics of compacted earth blocks in direct tension were determined using a test procedure developed for this work.
159 citations
TL;DR: The characteristics of bricks made from steel slag were investigated and slag addition was shown to reduce the required firing temperature and the bricks met ROC national standard CNS 3319 third-class brick for builders.
143 citations
TL;DR: A tendency for a general degradation of brick properties with sludge additions was observed due to its refractory nature, and sludge bricks of this nature are only suitable for use as common bricks, which are normally not exposed to view, because of poor surface finishing.
142 citations
TL;DR: In this article, a glass-fiber reinforced polymer (GFRP) sheet was used to strengthen masonry walls using a combination of vertical preload and in-plane horizontal shear loading.
Abstract: This paper investigates strengthening masonry walls using glass-fiber reinforced polymer (GFRP) sheets. An experimental research program was undertaken. Both clay and concrete brick specimens were tested, with and without GFRP strengthening. Single-sided strengthening was considered, as it is often not practicable to apply the reinforcement to both sides of a wall. Static tests were carried out on six masonry panels, under a combination of vertical preload, and in-plane horizontal shear loading. The mechanisms by which load was carried were observed, varying from the initial, uncracked state, to the final, fully cracked state. The results demonstrate that a significant increase of the in-plane shear capacity of masonry can be achieved by bonding GFRP sheets to the surface of masonry walls. The experimental data were used to assess the effectiveness of the GFRP strengthening, and suggestions are made to allow the test results to be used in the design of sheet GFRP strengthening for masonry structures.
142 citations
TL;DR: In this article, the thermal conductivity of 29 samples of clay bricks was measured and the correlations of the thermal performance with the compositional, physical, and microstructural features of products were investigated.
Abstract: In the present work the thermal conductivity of 29 samples of clay bricks was measured and the correlations of the thermal performance with the compositional, physical, and microstructural features of products were investigated. The results obtained directed our attention toward a better understanding of the role played by some parameters (i.e., mineralogical components and pore size distribution), other than bulk density, in improving or depressing the insulating properties of bricks. Among them, the unfavorable role of quartz, Ca-rich silicates, and amorphous phase came out, while the role of pore size and specific surface should be more accurately evaluated in the structural design of materials.
140 citations
TL;DR: In this article, a genetic approach based on primary analysis of field data was used to identify the genetic types of efflorescence encountered during the field study, and a more detailed discussion of one special issue regarding the carbonation of ettringite as potential source for sulfate efflorscence.
120 citations
TL;DR: The physical, mechanical, and chemical properties of the bricks that were supplemented with various proportions of dried sludge from 10 to 40 wt% and generally complied with the General Specification for Brick as per the Malaysian Standard MS 7.6:1972.
Abstract: Bricks produced from sewage sludge in different compositions were investigated. Results of the tests indicated that the sludge proportion is a key factor in determining the brick quality. Increasing the sludge content results in a decrease in brick shrinkage, bulk density, and compressive strength. Brick weight loss on ignition was mainly due to the contribution of the contained organic matter from the sludge being burnt off during the firing process, as well as inorganic substances found in both clay and sludge. The physical, mechanical, and chemical properties of the bricks that were supplemented with various proportions of dried sludge from 10 to 40 wt% and generally complied with the General Specification for Brick as per the Malaysian Standard MS 7.6:1972, which dictates the requirements for clay bricks used in walling in general. A standard leaching test method also showed that the leaching of metals from the bricks is very low.
117 citations
88 citations
TL;DR: In this article, a new analytical approach for the evaluation of shear strength and cracking pattern of masonry infill panels is introduced based on minimizing the factor of safety with reference to the failure surfaces.
Abstract: This paper introduces a new analytical approach for the evaluation of shear strength and cracking pattern of masonry infill panels. This method is based on minimizing the factor of safety with reference to the failure surfaces. This approach can also be used to determine the shear strength parameters and the modulus of elasticity of brickwork material. The paper also presents the results of experimental and analytical investigations on repaired and strengthened brick infilled steel frames. Two main repair techniques were examined in which the corner material is replaced with concrete or a concrete cover is placed on the panel. Both experiment and analysis have confirmed the efficiency and adequacy of these techniques.
TL;DR: The possibility of using clayey tailings from a borax concentrator in red brick manufacturing was investigated and up to 30% by weight tailings addition was found to improve the brick quality.
TL;DR: In this article, a series of five large scale clay brick masonry structural walls are subjected to in-plane simulated seismic forces, and the results of the tests as well as results of a simple analysis method for prediction of wall capacity are presented.
Abstract: A series of five large scale clay brick masonry structural walls are subjected to in-plane simulated seismic forces. The walls utilize posttensioning steel to provide flexural strength. The primary objective of the research is to investigate five basic configurations of posttensioning to determine which has the most desirable characteristics for seismic performance. In the study, the variables of interest were ! 1" bonded versus unbonded posttensioning steel, ! 2" confined versus unconfined masonry, ! 3" grouted versus ungrouted masonry, and ! 4" application of supplemental mild steel for energy dissipation. Following the results of the tests, it was shown that the best performing configuration utilized unbonded posttensioning and confinement. By utilizing unbonded posttensioning, walls have little residual deformation after loading, thus yielding structures that would require very little repair, even after large seismic events. Such behavior comes with the price of reduced energy dissipation, however. Presented in the paper are the results of the tests as well as results of a simple analysis method for prediction of wall capacity.
TL;DR: In this paper, the effects of high temperatures on the properties of concrete made with crushed clay bricks as the coarse aggregate were investigated and two types of bricks of different strength were crushed to coarse aggregate that was used to produce concretes.
Abstract: This paper presents the results of an experimental investigation into the effects of high temperatures on the properties of concrete made with crushed clay bricks as the coarse aggregate. Two types of brick of different strength were crushed to coarse aggregate that was used to produce concretes of different strength. Natural granite aggregate was also used to produce concretes in order to compare results. The paper presents the results for brick unit uniaxial compressive strength, aggregate impact value, aggregate relative density, brick and aggregate water absorption, aggregate porosity, concrete density, and concrete strength before and after exposure to high temperatures. The results showed that concrete could be produced using crushed clay bricks as the coarse aggregate and at high temperatures clay brick concrete preformed similar or even better than granite concrete.
Abstract: This work aimed to help establish the use of high volumes of fly ash, bottom ash, and used foundry sand in manufacture of precast molded concrete products such as wet-cast concrete bricks and paving stones. ASTM Class F fly ash was used as a partial replacement for 0 (reference), 25, and 35% of portland cement. Bottom ash combined with used foundry sand replaced 0, 50, and 70% of natural sand. Tests for compressive strength, freeze-thaw resistance, drying shrinkage, and abrasion resistance were conducted on the wet-cast concrete masonry units manufactured at a commercial manufacturing plant. It was concluded that all wet-cast bricks could be used for both exterior and interior walls in regions where freezing and thawing is not a concern, and for interior walls in regions where freezing and thawing is a concern. No wet-cast paving-stone mixtures, including the reference mixture, met all ASTM requirements for paving stones.
1 Jan 2004
TL;DR: In this paper, the authors propose to replace the masonry with a material that has the same behaviour (or very near) as masonry, where expansion joints play an important role in refractory linings.
Abstract: Expansion joints play an important role in refractory linings as they reduce stresses during heating. It is therefore necessary to take them into account in a mechanical analysis. In the case where the lining is a masonry construction (made up of bricks), it would require an excessive number of elements to model each brick and joint. The proposed solution is to replace the masonry with a material that has the same behaviour (or very near) as masonry. Since it is difficult to perform experimental tests on a set of bricks (to identify the parameters of the equivalent material), these loads were simulated on an elementary cell using a model developed at a local scale (scale of the components, bricks and joints). At this scale, the joints are represented as contacts (with normal and tangential behaviour). The parameters of a simplified equivalent material were obtained by an inverse identification. This model was validated by a thermomechanical test on a real structure.
TL;DR: In this article, the approach of using "magnetic bricks" to build up different sorts of networks via supramolecular interactions is discussed, and two sorts of magnetic bricks, with 3 and 12 linked Cu(II) centers, respectively, are used to illustrate this idea.
TL;DR: In this article, monthly observations were made over one year at a two-storey brick kiln in central Japan, where products of weathering that had fallen were collected and weighed; salts were identified using XRD and the moisture content of the brick was measured at its surface using a portable infrared optical moisture meter.
Abstract: To clarify the mechanism of salt fretting of a brick building, monthly observations were made over one year at a two-storey brick kiln in central Japan. Products of weathering that had fallen were collected and weighed; salts were identified using XRD and the moisture content of the brick was measured at its surface using a portable infrared optical moisture meter. Gypsum (CaSO4·2H2O) was found at the bottom of the first floor wall in the warm and humid season. Thenardite (Na2SO4) is dominant on the first floor wall; it is abundant in the cold and dry season but sparse in the warm and humid season. Magnesium sulphate is dominant on the second floor wall; epsomite (MgSO4·7H2O) was observed in the dry-to-wet season and hexahydrite (MgSO4·6H2O) in the wet-to-dry season. Seasonal changes in salt abundance result from the temperature dependence of the solubilities and equilibrium relative humidities (ERH) of each salt. The amount of brick decay material due to salt weathering is much greater from the second floor wall than from the first floor wall and is greater from spring to the end of summer. These seasonal and spatial variations of the rate of brick decay can be explained by a combination of factors: (1) the types of salt, (2) efflorescence or sub-florescence and (3) salt deliquescence.
Patent•
29 Dec 2004
TL;DR: In this article, a composite heat insulating brick consisting of inner polystyrene block, the mixture layer of cement and glue in the weight ratio of 1 to 0.8-1.2 outside the polystructure block, reinforcing rib layer outside the mixture layers, and cement layers outside the reinforcing rib layers.
Abstract: The present invention relates to one kind of composite heat insulating brick with less weight and strengthened heat insulating effect and its production process. The composite heat insulating brick consists of inner polystyrene block, the mixture layer of cement and glue in the weight ratio of 1 to 0.8-1.2 outside the polystyrene block, the reinforcing rib layer outside the mixture layer, and cement layer outside the reinforcing rib layer. The present invention has the advantages of high sealing performance, excellent heat insulating performance, high heat energy utilization, saving in energy source and reduced wall weight and construction cost.
1 Jan 2004
TL;DR: In this article, the thermal performance of two purpose built masonry modules (one brick veneer and one cavity brick) on the University campus of the University of Newcastle was investigated.
Abstract: Masonry housing in Australia is typically of brick veneer or cavity brick construction. The increased emphasis on energy conservation and reduction of greenhouse gas emissions has resulted in the thermal performance of housing systems coming under increasing scrutiny, with a “star” rating system (based on energy efficiency) being implemented. Little information exists on the thermal performance of masonry under Australian climatic conditions. To address this problem, The University of Newcastle, in conjunction with the Clay Brick and Paver Institute, has embarked on a testing program to study the thermal performance of two purpose built modules (one brick veneer and one cavity brick) on the University campus. This paper gives an overview of the instrumentation and data collection and, presents typical results obtained during the first year of monitoring.
TL;DR: In this article, the porosity, density, matrix density, thermal conductivity, equilibrium moisture content, water vapor permeability, water absorption coefficient, liquid diffusivity and air permeability of six types of bricks and four mortar mixes that are commonly used in North America.
Abstract: Hygrothermal models are emerging as practical building design tools. These models require a set of reliable inputs to provide results that are meaningful to the designers. One of these inputs is the set of heat, air and moisture transport properties of materials. For any given class of building materials the properties may vary within a broad range. This paper reports the porosity, density, matrix density, thermal conductivity, equilibrium moisture content, water vapor permeability, water absorption coefficient, liquid diffusivity and air permeability of six types of bricks and four mortar mixes that are commonly used in North America. The experimental and analytical procedures follow either international standards or well-established methodologies.
15 Aug 2004
Patent•
22 Oct 2004
TL;DR: In this paper, simulated stone, masonry and brick textured siding panels are obtained when specially selected materials are properly admixed and formed via molding techniques using synthetic polymeric materials.
Abstract: Simulated stone, masonry and brick textured siding panels are obtained when specially selected materials are properly admixed and formed via molding techniques. These siding panels are manufactured from suitable molds according to a prescribed process methodology using synthetic polymeric materials in addition to stone and masonry and brick materials. Prerequisite surface textures are produced that effectively simulate the corresponding actual stone, masonry and brick panels.
TL;DR: In this paper, the Boundary Element Method (BEM) is used to compare the steadystate heat and moisture diffusion behavior across double brick walls provided by two different models: in the first one, the brick wall is assumed to be composed of a set of homogeneous layers bonded together, which is the model frequently used to predict internal condensation; in the second model, the geometrical modelling and hygrothermal properties of the individual bricks are taken into account.
Dissertation•
1 Jan 2004
TL;DR: In this article, the authors present an acknowledgment of the authorship of the author's work.Acknowledgements and acknowledgements of the contributors are given. But they do not discuss the authors' methodology.
Abstract: ............................................................................................................................. iii Acknowledgements............................................................................................................. v
1 Sep 2004
TL;DR: The benefits of increased brick recycling are identified, but it is noted that in order for this to be achieved improved technology to allow more efficient recovery of bricks would be necessary.
Abstract: The paper assesses the current brick recycling industry in the UK, and highlights the low rate of brick recycling that is currently achieved. The benefits of increased brick recycling are identified, but it is noted that in order for this to be achieved improved technology to allow more efficient recovery of bricks would be necessary.
TL;DR: In this paper, the authors investigated the watertightness of single-wythe brick masonry in historic windmills in the Netherlands and provided insight into a variety of reasons that play a role in the water-tightness problems that were observed.
TL;DR: In this paper, a method for measuring the rate of diffusion of salt in ceramic material was presented and applied to the measurement of diffusivity of NaCl in different brick materials.
Abstract: This is our second article concerning salt diffusion measurements in porous brick materials. In the first article a method for measuring the rate of diffusion of salt in ceramic material was presented and applied to the measurement of diffusivity of NaCl in different brick materials. In this work the same method was applied to other water-soluble salts commonly found in building materials. The binary diffusion coefficients were measured for KCl, NaNO3, CaCl2, Na2SO4, MgCl2 and Na2CO3. The result for the diffusivity of 0.05 molar salts in water in new Finnish red brick varied between (0.271–0.544)*10−5 cm2/s at a temperature of 25 ± 0.05°C. The effect of temperature and concentration on the diffusivity of NaCl in new red brick was also measured. The rate of change of diffusivity as a function of temperature, concentration and the type of salt was very similar to that in free solutions. However, the values of the diffusion coefficients were lower in the porous medium than in solution. A mutual relation between the binary diffusion coefficient and the viscosity of the salt-water solution was observed in the porous brick.
Patent•
26 May 2004
TL;DR: In this article, an external insulation back anchorage pasting surface brick wall body, an anti-crack consolidation layer comprising a galvanized steel wire mesh, polymer anticrack mortar and an anchorage expanding bolt is fixed outside the successively pasted base course wall, interface layer and insulating layer.
Abstract: The utility model relates to an external insulation back anchorage pasting surface brick wall body; an anti-crack consolidation layer comprising a galvanized steel wire mesh, polymer anti-crack mortar and an anchorage expanding bolt is fixed outside the successively pasted base course wall, interface layer and insulating layer; the galvanized steel wire mesh is arranged between the inner layer and the outer layer of polymer anti-crack mortar; one end of the anchorage expanding bolt is anchored in the base course wall, the other end of the anchorage expanding bolt is fixed to the galvanized steel wire mesh; a face brick bond coat and a face brick facing layer are bound outside the anti-crack consolidation layer. The base course wall can be a reinforced concrete wall, a solid brick wall, a hollow brick wall, a porous brick wall, an aerated concrete block wall or various block walls. The insulating layer can be an adhesive polystyrene granule insulating layer, a polyurethane foaming layer, a foam glass, a polystyrene board or other material. The utility model solves the technical problem of the inapplicability in the practice of nail shoot nail facing brick on aerated concrete block walls, porous brick walls and various block walls with poor material densification, and enables the application of insulating facing brick technology in the base course walls of various types buildings.