Test Bricks Research Articles

Use of a Glaciogene Marine Clay (Ilulissat, Greenland) in a Pilot Production of Red Bricks.

Uplifted occurrences of fine-grained glaciogene marine sediments are found throughout the northern hemisphere. These sediments could be used to produce local construction materials, to rely less on imported construction materials from southern regions. In this study, a representative occurrence from Ilulissat, West Greenland, was investigated as a potential resource for local brick production. The study comprised three parts: (1) raw material characterization based on grain size distribution, major element chemistry, including total carbon, sulfur, and chloride concentrations, mineralogy, morphology, and Atterberg limits; (2) the production of test bricks at a Danish brickwork; and (3) testing of the bricks based on total shrinkage, water absorption, hygroscopic adsorption, open porosity, bulk density, compression strength, and mineralogy. The bricks produced proved to have excellent compression strength, low open porosity, and low water absorption. The shrinkage could be reduced by adding 10% chamotte to the marine sediment. Based on the investigated properties, this indicates that this type of clay is highly suitable as a resource for bricks.

An Easy Way for Ceramic Bricks Elaboration to Carry out Basic Technical Measurements

Fired bricks have shown tremendous potential as a construction material due to their properties. However, their use required some specifications in terms of quality, resistance, and durability. In developing countries, the lack of tools to make test specimens leads to many defects in these brick specimens responsible for low durability and weak precision during mechanical tests and shrinkage. In this study, a simple and traditional method of making test bricks is presented. This simple method allows the production of bricks with the required properties. This method is especially efficient for semi-soft consistency pastes. The elaborated handmade pastes present a very different particle-size distribution < 2 mm (clay: 18-66%; silt: 12-53%; sand: 5-65%). The pastes do not stick to the walls of the mould like in the case of steel moulds, and it gives specimens with standard shape, smooth surface, and sharp edges. The resulting fired bricks exhibit high mechanical strength (up to 102 MPa for the compressive strength, and up to 28 MPa for the flexural strength) comparable to and even better than those of conventional methods. The elaborated bricks allowed also the measurement of very important parameters such as drying and firing shrinkage, drying, and firing weight loss, and porosity.

Studies on the strength variation of brick masonry using novel blended masonry mortar mixes and mortar thickness

Building construction using brick masonry is the oldest method of execution and it is widely used globally even though the technology being improved. Latest research works are still going on to upgrade the performance of masonry both technically and economically. Masonry is constructed with two basic materials such as brick unit and mortar. The strength of masonry is governed by the strength of both brick and mortar used for construction. This study was intended to evaluate the strength variation of brick masonry with three different mortar mixes using supplementary cementitious materials (SCM) and two different thickness of mortar. Dolomite powder and silica fume were used for developing ternary blended masonry mortar and 12 mm and 18 mm mortar thickness were considered in this study. Compressive strength of masonry was determined by masonry prism specimen with three layers of bricks and shear bond strength was determined by testing brick triplets. The strength of masonry constructed with blended cement mortar is comparable with cement mortar based masonry. The failure of masonry with 12 mm mortar thickness was observed by crushing of brick units and the shear failure in the bond between brick and mortar was observed in 18 mm thick mortar masonry units.

Research on the use of calcium carbide residue from the acetylene gas manufacturing factory to produce non-calcined brick

In Vietnam, calcium carbide residue (CCR) from the acetylene gas factories are not properly treated, causing serious environmental pollution. Based on mineral composition determined by XRD, calcium carbide residue consisted mainly of portlandite (70-72%), calcite (14-16%), hydrocalumite (6-8%), and chemical composition determined by XRF method composed of CaO (53.02%), LOI (39.72%). This calcium carbide residue can be used as a source of hydrated lime, mixed with fly ash, sand, and cement to produce non-calcined bricks and test results show that brick specimens achieved compressive strength 3.0-7.5 MPa, water absorption 12.3-17.5%, density 1.28-1.80kg/cm3. The test bricks satisfied Vietnamese standards for construction bricks.

Research on the use of calcium carbide residue from the acetylene gas manufacturing factory to produce non-calcined brick

In Vietnam, calcium carbide residue (CCR) from the acetylene gas factories are not properly treated, causing serious environmental pollution. Based on mineral composition determined by XRD, calcium carbide residue consisted mainly of portlandite (70-72%), calcite (14-16%), hydrocalumite (6-8%), and chemical composition determined by XRF method composed of CaO (53.02%), LOI (39.72%). This calcium carbide residue can be used as a source of hydrated lime, mixed with fly ash, sand, and cement to produce non-calcined bricks and test results show that brick specimens achieved compressive strength 3.0-7.5 MPa, water absorption 12.3-17.5%, density 1.28-1.80kg/cm3. The test bricks satisfied Vietnamese standards for construction bricks.

Incorporation of Fluorescent Lamp Waste into Red-Clay Bricks: Defect Formation, Physical and Mechanical Properties

Once their life-span is finished, fluorescent lamps are usually processed in vacuum crushers because of their Hg content. This procedure generates glass waste and spent phosphor powders, among other residual materials. Due to their composition, glass waste and phosphor powders could be incorporated as secondary raw materials in the formulation of clay-based construction materials for non-structural applications. In this work, this incorporation was studied, focusing on the analysis of the formation of defects in the final product and its impact on the statistical variability of some physical and mechanical properties of the clay bodies, such as: density, linear shrinkage, water absorption, and compressive strength. It was found that a combination of factors, i.e. the presence of Pb and calcium carbonate in the waste glass, concurred to induce the formation of two kind of defects in the fired ceramics: internal blowholes and external glassy exudations. Despite the presence of these defects, the physical and mechanical properties of the test bricks produced were not statistically different from the standard formulation used as control. The implications of these findings on the possible application of spent fluorescent lamps wastes as an ingredient for clay-based bricks were also briefly addressed.

A Proposal for Recycling the World’s Unused Stockpiles of Treated Wastewater Sludge (Biosolids) in Fired-Clay Bricks

Millions of tonnes of leftover biosolids are increasingly stockpiled every year around the globe. Biosolids are a product of the wastewater sludge treatment process. Stockpiles necessitate the use of large areas of increasingly valuable land. Biosolids have many beneficial uses and are currently utilised in agricultural and land rehabilitation applications. However, it is estimated that 30% of biosolids are unused and stockpiled. A second and seemingly unrelated environmental issue is the massive excavation of virgin soil for brick production. The annual production of 1500 billion bricks globally requires over 3.13 billion cubic metres of clay soil—equivalent to over 1000 soccer fields dug 440 m deep or to a depth greater than three times the height of the Sydney Harbour Bridge. This paper investigates and proposes a practical solution for the utilisation of the world’s excess biosolids in fired–clay bricks. The physical, chemical and mechanical properties of fired–clay bricks incorporating 25%, 20%, 15% and 10% biosolids have been tested. Bricks were produced from three different biosolids samples collected at Melbourne’s Eastern Treatment Plant (ETP 22) and the Western Treatment Plant (WTP 10 & WTP 17–29). Compressive strength testing indicated results ranging between 35.5 MPa and 12.04 MPa for the biosolids-amended bricks. Leachate analysis was conducted on the bricks before and after firing, and the results demonstrate that between 43 and 99% of the heavy metals tested were immobilised inside the fired bricks compared to the heavy metals tested in the raw mixture. All leachate concentrations were found to be insignificant for the biosolids-incorporated bricks tested in this study. Biosolids can have significantly different chemical characteristics depending on the origin of the wastewater and the treatment procedure. Suitable leachate analysis should be undertaken on biosolids and test bricks before large-scale production is approved. Scanning Electron Microscopy (SEM) images illustrate that biosolids-amended bricks have a higher porosity than the control bricks, which corresponds to the lower thermal conductivity values recorded for biosolids-amended bricks. In addition, brick firing energy demands are estimated to decrease by up to 48.6% for bricks incorporating 25% WTP 17–29 biosolids due to the higher organic content of the mixture containing biosolids. The emissions study and comparative Life Cycle Assessment results show that the incorporation of biosolids into bricks is a positive and sustainable alternative approach with respect to all environmental impacts arising from the stockpiling of biosolids and brick manufacturing. Based on the results found in this comprehensive study, this paper proposes the inclusion of a minimum of 15% biosolids content into 15% of brick production in order to completely recycle all the approximately 5 million tonnes of annual leftover biosolids production in Australia, New Zealand, the EU, the USA and Canada. This is a practical and sustainable proposal for recycling all the leftover biosolids worldwide. Utilisation of only 15% of biosolids in brick production would reduce the carbon footprint of brick manufacturing whilst satisfying all the environmental and engineering requirements for bricks.

Experimental work for mechanical properties of brick and masonry panel

The use of Masonry panels in building construction has been popular in most of the parts of the world. However, the use of bricks and brick masonry in different parts of the world being of different nature in terms of quality, size, workmanship of construction, etc. It is yet a topic of interest to researchers to identify the mechanical properties, like Young’s modulus of elasticity and shear modulus of brick masonry panels. It is essential to know the characteristic of brick masonry panels in order to evaluate the responses of masonry walls for any kind of loading. Individual bricks do possess better compressive capacity as compared to masonry walls. Masonry walls are bound together with either mud mortar or by cement sand mortars of various mixes as per the strength requirements. The essential strength properties in engineering are basically the compressive strength and the modulus of elasticity. The American Society for Testing and Materials (ASTM) standard is the most popular for testing bricks and brick masonry for these properties so far. Here, the study has been concentrated in finding the compressive strength of brick, mortar and brick masonry. The study is also done for Young’s modulus of elasticity of brick as well as that of masonry wall. Similarly, the study is extended to find the modulus of rigidity of brick masonry panel. The study is done experimentally for the samples that are generally used in Kathmandu, Nepal. The samples include bricks, cement and sand particularly available in Kathmandu region.

Acoustic emission characteristics of fracture modes in masonry materials

Acoustic emission (AE) is a powerful technique for detection and analysis of the elastic waves produced by the failure mechanisms in construction materials such as masonry. In this study, the different fracture mechanisms are studied in relation to the properties of bricks and mortars. The fracture process is being evaluated using the combination of AE and Digital Image Correlations (DIC) techniques. The isolation of the AE signatures of different types of failure mechanisms is done by testing bricks in flexure and brickwork couplets in compression. AE data are analyzed with a simplified AE parameter-based approach aiming to characterize the fracture mode. This is one of the first times where the relation between the shear and the longitudinal strain field is correlated in masonry with AE. This offers new insight in the material's behavior especially in relation to complicated structural geometries where the dominant stress mode is not known a priori.

NONDESTRUCTIVE METHOD TO DETERMINE MOISTURE AREA IN HISTORICAL BUILDING

This paper presents a nondestructive method of brick wall dampness testing in real building structures. The proposed algorithm was used to determine the moisture of test brick walls on the specially models. The finite element method has been used to solve the forward problem. The algorithm is initialized by using one step methods and topological sensitivity analysis. There was constructed the forward model and solved the inverse for visualization of moisture inside objects.

The Ndop plain clayey materials (Bamenda area – NW Cameroon): Mineralogical, geochemical, physical characteristics and properties of their fired products

The physicochemical, mineralogical and technological properties of clayey materials from the Ndop plain (NW Cameroon) have been investigated, for their ceramic applications. The clayey materials have mixed facies with colour ranging from brown, grey, mottled and yellowish brown. The thickness of the exploitable clay layer is more than 5 m. Their mineralogical constituents are quartz, kaolinite, illite and feldspars, with kaolinite as major clay mineral. Based on the geochemistry, their source rocks might be felsic, with a mafic rock inference. These materials display high percentage in fine particles and high Atterberg limits. For all the firing temperatures, flexural strength (1.2–11 MPa), water absorption (8.03–24.27%), linear shrinkage (2.10%), weight loss (4.88–16.54%) and bulk density (1.57–2.03 g/cm3) indicate good ceramic properties for firing samples between 900 and 1100 °C. Most of the fired test bricks show a brick red colour with good to very good cohesion. The studied clays were thus, suitable as raw materials for roof tiles, light weight blocks and hollow bricks; however, mixing of high clayey and highly silty materials could improve the quality of the products.

New electrical tomographic method to determine dampness in historical buildings

Abstract This paper presents a new, nondestructive method of testing brick wall dampness in wall structures. The setup was used to determine the moisture in a specially built laboratory model. Topological methods and the gradient technique are used to optimize the approach. A forward model of a wall was constructed to solve the inverse problem resulting in moisture buildup inside the wall.

Mineralogical and physicochemical characterization of Ngaye alluvial clays (Northern Cameroon) and assessment of its suitability in ceramic production

This study reports the physicochemical analysis of three alluvial clastic clays from the Ngaye River in northern Cameroon. X-ray diffraction, infra-red spectroscopy, scanning electron microscopy and thermal analysis are used to establish the mineralogical composition. It is found that the main clay minerals in these samples are kaolinite, muscovite-illite and smectite associated with quartz, goethite, feldspars and anatase. This mineralogical assemblage is in accordance with the chemical analysis which further confirmed the high quartz proportion. The low content in fluxing agent is indicated by the low contents in Na2O, K2O, MgO and CaO. The low content in fluxing agent and high sand proportion result in poor vitrification in ceramic testing brick obtained at 900 °C, 1000 °C and 1100 °C. For all the firing temperatures, linear shrinkage varied from 0.7% to 2.6%, weight loss varied from 3.5% to 7%, bulk density varied from 1.6 to 1.8 g/m3, water absorption decreased from 20.7% to 12.7%, and flexural strength (σ) varied from 0.60 to 2.07 MPa.

Comparison between experimental methods for evaluating the compressive strength of existing masonry buildings

In this study, the suitability of determining masonry compressive strength by using the following two moderately destructive techniques was evaluated: (i) testing bricks and mortar, separately, and then using formulas available in literature for calculating masonry compressive strength; (ii) testing cylindrical cores, completed with cement mortar castings above and beneath the core, according to a procedure recently proposed by the authors. Two sets of masonry specimens were purposely constructed in laboratory conditions, using bricks and mortar with different mechanical characteristics. From the results of the study, an evaluation of the reliability of the two testing techniques was possible.

Gap formation in a transosseous rotator cuff repair as a function of bone quality

BackgroundThe transosseous approach has been well known for a long time as a valid repair approach. Over time, various criticisms have been raised over this technique principally classifiable in two main categories: technical difficulty and related reproducibility in an arthroscopic environment, and repair stability (in the suture–bone contact area). About cyclic performance, several authors have conceived test setups with the aim of simulating a real environment in dynamic load conditions. The aim of this study was to monitor gap formation in a cyclic test setup. MethodsThe performance (measured as gap formation) has been monitored as a function of bone density to verify the effect of the latter. The test blocks have been shaped using sawbones® test bricks (Malmo, Sweden) of different densities, and the following values have been tested: 10, 15, 20, 30 and 40pcf. FindingsThe comparison has been made between the two groups: traditional transosseous and new approach with an interposed device. Regarding the traditional transosseous approach in a 10-pcf environment, not even the first loading cycle was completed, the whole bone bridge was destroyed in the first loading ramp and no further loading capability was present in the repair. By increasing the block density, the surface damage in the suture-block contact decreased. InterpretationWith this work, it has been demonstrated how the traditional transosseous approach is strongly influenced by the bone quality up to the point where, in certain conditions, a safe and reliable repair is not guaranteed.

Corrosion of Basic Refractories in Contact with Cement Clinker and Kiln Hot Meal

This paper investigates the new phases formation in the magnesia-spinel, magnesia-zirconia-cal- cia and magnesia-hercynite refractory products as a result of their reaction with kiln hot meal and cement clinker (both rich in SO3 and Cl ions) at the temperature range 1200°C - 1450?C. The labor- atory corrosion tests were conducted by means of pulverous method and by special coating test. The phase identity of the products as well as the mixes after corrosion tests was established by powder X-ray diffraction method. The microstructure development of the contact zones between coating and the products were studied using scanning electron microscopy SEM with EDS spectroscopy. The differences in the reactions proceeding between the phases of the test bricks and the phases of kiln hot meal and cement clinker in dependence on the temperatures have been discussed.

Refractory Wear Mechanisms in the Nonferrous Metal Industry: Testing and Modeling Results

Nonferrous pyrometallurgical processes today operate at a high intensity requiring the best standards for the furnace refractory systems. From one plant to another, there is a range of process conditions such as temperature, slag chemistry, and feed types, and each of these parameters can influence refractory life. It is generally understood that process changes at plants can impact refractory life. The ability to test and understand refractory responses to a wide range of furnace operating conditions is therefore important. The RHI Technology Centre in Leoben, Austria is well equipped with laboratory and pilot plant facilities to evaluate refractory suitability over the range of conditions encountered in modern nonferrous pyrometallurgical systems. This article describes refractory testing at the RHI Technology Centre of the impact of two metallurgical slags on a number of different RHI test bricks. The slags were a fayalite slag and a calcium ferrite slag supplied by two smelter plants. High-temperature corrosion tests were carried out in a 250-mm-diameter induction furnace and a 165-mm-diameter short rotary kiln; each unit was lined with a number of refractory bricks and tested against attack by the particular slag. After testing, the refractory bricks were subjected to several laboratory tests to determine the extent of corrosion. Optimal refractory choices for the customers’ plants were developed based on the test results.

The use of small diameter cores for assessing the compressive strength of clay brick masonries

Abstract In order to define the seismic vulnerability of ancient brick masonries and to design restoration and retrofitting interventions, the estimation of masonry mechanical properties (e.g. Young's modulus, compressive strength, shear strength, etc.) is of primary importance. The use of actual masonry specimens (i.e. small portions of wall) to be tested either in situ or in laboratory can be performed only in few particular cases, hence many moderately destructive or non-destructive techniques have been proposed so far for indirect evaluation of masonry mechanical properties, primarily compressive strength. In this study, the suitability of using 100 mm diameter cores for evaluating the compressive strength of brick masonries was investigated. For a study case represented by a masonry arch-bridge, the compressive strength value resulting from testing cylindrical cores was compared to values obtained from testing bricks and mortars, separately, and from testing small masonry portions, used as reference. A FEM model of the cores was also developed to evaluate the stress/strain regime inside the cores and analyze the influence of the possible presence of the vertical mortar joint in the centre of the core. The results obtained by testing cylindrical cores, bricks and mortars and small masonry portions exhibit very good agreement, which suggests that using small diameter cores could be a promising method, which has the advantage of using cores more easily available than large diameter (150 mm) cores.

Durability of Bricks Cast With Industrial Sludge

Recovery of waste constituents from industrial waste is a cost effective solution in control of environmental pollution. Present investigation deals with the feasibility of usage of sludge obtained from sand beneficiation treatment plant in the production of bricks and their durability. The experimental results show that the brick earth can be replaced with treatment plant sludge up to 40% by weight without loss in strength and other brick characteristics considered satisfactory for conventional purposes. Apart from that when reference specimens and test bricks (5% Sludge) were immersed in various concentrations of hydrochloric acid (HCl) solution at different immersed ages, the loss of weight is found to be less in test bricks than that in reference bricks. Hence, at 5% of replacement, the quality of bricks is superior to the bricks made from earth alone and can be used for superior work of permanent nature. Keywords-Brick, Sludge from sand beneficiation treatment plant, Compressive strength, HCL, weight loss

Identification of moisture content in brick walls by means of impedance tomography

PurposeThis paper aims to present a new non‐destructive method of brick wall dampness testing in real building structures. The electrical impedance tomography (EIT) method makes it possible to obtain a distribution of wall dampness. The paper aims to give basic information about the measuring system, including prototype equipment. The setup was used to determine the dampness of test brick walls on a specially built laboratory test rig. The paper seeks to compare test results obtained by the non‐destructive impedance tomography method with the results obtained by the conventional destructive dry‐weight method.Design/methodology/approachThe paper adopts a tomography approach to control humidity inside of the brick walls. In case of brick walls other nondestructive methods fields, for example, the ultrasonic tomography is useless. On the other hand the most popular dry‐weight method is strictly forbidden for historical buildings. As a forward solver, functionally graded material boundary element method was used.FindingsThe paper proves that diffuse tomography could provide reliable results with respect of humidity content inside the brick walls. This method could provide 3D humidity distribution inside of the brick walls.Research limitations/implicationsIt is expected that the technique's impact will be limited to site inspection of building following floods or to evaluate older damp buildings.Practical implicationsThe presented technique can eventually lead to much simpler, cheaper and more efficient evaluation of the moisture content in walls. This can revolutionize some procedures in civil engineering.Social implicationsThe application has commercial potential and could result in more cost‐effective repair of old buildings, which has an economic impact on society.Originality/valueThe authors propose application of the diffuse tomography for nondestructive investigation of brick walls. According to the authors' best knowledge this is a novel approach.