Fired Clay Bricks Research Articles

Characterization and evaluation of selected kaolin clay deposits in Nigeria for furnace lining application

Kaolin and ball clay samples from four states in Nigeria were examined with the aim of determining their chemical composition as well as testing for their suitability as refractory materials for furnaces lining applications. Three kaolin samples were taken from Ikpeshi in Edo, Kasadi in Kebbi and Alaasan in Osun state, while the ball clay sample used as the binder was taken from Badeggi in Niger state. The kaolin samples were tested and beneficiated in other to improve on their alumina contents after which they were characterized and produced as a refractory brick by mixing each kaolin sample with the ball clay in 70:30 ratio. They were then tested comprehensively for the following refractory properties such as: firing shrinkage, apparent porosity, bulk density, cold crushing strength, thermal shock resistance, refractory under load (RUL), thermal expansion, thermal conductivity, X-ray diffraction and scanning electron microscope. The results were compared with standard refractory properties for fireclay bricks. The values obtained from the three clay samples (A, B, C) which are from Ikpeshi in Edo, Kasadi in Kebbi and Alaasan in Osun state respectively were within the recommended values for fireclay bricks, most especially sample C which has a refractoriness under load (RUL) of 1348 O C which is the temperature at which the bricks will collapse under a constant load of 0.2N/mm 2 . This compared favourably with the RUL of other countries in the world. Keywords: Porosity, clay, brick, refractoriness, kaolin

Integration of Port Dredged Sediments Into the Production of Fired Clay Bricks

Bricks manufactured, based on dredged sediments extracted from Tangier and Larache ports in Morocco were investigated. Chemical, physical, geotechnical, mineralogical and environmental characterizations studies of ports dredged sediments were performed. Partial substitution of natural clay by dredged sediments was achieved with different substitution rates by weight (20%, 40%, 50%, 60% and 70%) to manufacture brick samples at the laboratory scale. The compressive strength was the factor determining the optimal substitution rate of the natural clay. Compressive strength values of fired bricks with different rates of sediments incorporated show that the manufactured bricks have mechanical characteristics relatively close to natural clay until 60% substitution for Larache port dredged sediment (SL) and until 50% for Tangier port dredged sediment (ST). The results in this study confirm that dredged sediments from the ports of Tangier and Larache can be used as an alternative raw materials resource for the manufacturing of fired bricks.

Bond Behavior between Tuff and Fired-Clay Brick Masonry Blocks and SRG Composites

This paper presents the results of single-lap direct shear tests on steel reinforced grout (SRG) strips bonded to fired-clay brick and tuff masonry blocks. For this experimental campaign, fifteen masonry blocks were constructed and reinforced with SRG composite strips. Fired-clay bricks and tuff blocks herein employed were collected from demolished historical structures in Modena and Naples (Italy), respectively. Eight out of fifteen blocks were subjected to an artificial weathering procedure to induce salt crystallization, and therefore reproduce the degradation conditions that the buildings could be subjected to during their life. Bond behavior of unconditioned strengthened specimens (i.e. SRG-masonry joints) was compared with the behavior of conditioned joints. Salt distribution, open porosity, and water absorption of brick and tuff masonry units as well as of the SRG composite matrix were analyzed to understand if and how the salt crystallization influenced the adhesion between the SRG strip and the block.

First Results of a 3D Pull-Out Model of Steel Anchors in Fired-Clay Bricks

The paper reports the results of a numerical simulation performed to study the experimental pull-out behavior of twisted steel connectors inserted in fired-clay brick units. The experimental results obtained in a previous campaign are used to calibrate a 3D refined numerical model developed by means of the finite element program Abaqus. The numerical model is tuned to accurately reproduce the experimental results in terms of loads and bar displacements.

An Experimental Investigation on Pull-Off Tests Conducted on FRP Composites Applied to Brick Units

In the present study, a series of pull-off tests is performed to determine the bonding properties of fiber reinforced polymer (FRP) composites applied to a brittle substrate. Pull-off test is simple, fast and cheap and it is generally employed to evaluate the bond strength between the composite and the substrate. It is a procedure that can be easily performed on-site for checking the quality of the reinforcement adhesion.A steel composite made of a unidirectional steel fabric embedded in an organic matrix (bi-component epoxy resin) was applied to the surface of fired-clay bricks. A shallow core perpendicular to the surface was realized in the test specimen, leaving the core attached to the brick. A steel dolly was glued to the external surface of the core using epoxy adhesive. A loading device was employed to apply the tensile force until failure. The effects of moisture presence on the substrate and shape of the cores on the pull-off strength were investigated.

Thermal and mechanical properties of fired clay bricks made by using grapevine shoots as pore forming agent. Influence of particle size and percentage of replacement

For decades, the construction industry has focused on developing new materials to minimise environmental impact and improve building insulation envelopes. The use of certain wastes as additives for construction materials (e.g. concrete, clay, steel) has been shown to be a feasible alternative that may improve both the current waste management strategy and the properties of construction materials. Among others, the fired clay brick (FCB) industry has been highlighted as an optimal sector for incorporating such residues, due to the large amount of mass flow involved, the use of firing temperatures above 900 °C and the observed positive effects of FCB thermal conductivity (TC) when organic residues are added. Although the properties of fired clay are closely related to the firing curves and the mineral and chemical composition of raw materials, the effect of particle size is also a key factor that directly impacts on the economic and technical feasibility. This paper therefore assesses the addition of wood chips from pruned grapevine shoots as an additive for manufacturing FCBs, and considers three particle sizes (up to 0.5 mm, above 1.5 mm and between 0.5 and 1.5 mm) and variations in the added percentage on a dry basis. Several samples were tested in order to determine the mechanical and thermal behaviour of FCBs, and it was concluded that the maximum of 10% wood chip content is limited by both the compressive strength values and the water absorption. At this percentage, TC is reduced by up to 50%. The particle size seems to have no effect on the thermal properties, but gives rise to significant variations in terms of the mechanical response.

The ageing effect of raw materials on the final properties of high alumina refractory grog

High alumina ceramics is a part of the refractory ceramics in SiO2-Al2O3 binary system. The aim of this paper is to characterize the effect of ageing raw materials and its influence on final properties of fired refractory grog. Refractory grog is very important component in production of refractory materials, such as fireclay, mullite and andalusite bricks. Refractory grog is manufactured generally from clay, claystone and kaolin, nowadays is mainly burnt in rotary and shaft kilns. The primary objective of this article is to determine an influence of ageing effect, which has impact on mineralogical composition of raw material which obviously results in different mineralogical composition of fired grog. Raw material with different age was used for the mixtures and properties of fired samples were investigated, considering the influence of the raw materials mixtures. Specifically, the apparent porosity, water absorption, bulk density, apparent porosity, mineralogical composition and pore distribution were investigated.

Investigation of Metal Air-Cooling Process as An Element of Thermal Processing

<p>Background: Nowadays on metal tempering and annealing its air cooling (AC) is realized inside furnace with forced coolant delivery. Scientific tools lack for metal AC study and design is substantiated. The aim of this work is to investigate technological and design furnace parameters influence on metal AC duration, as well as disclosure of metal AC heat engineering regularities. Materials and method: For study mathematical model of metal AC is used. It bases on solving the differential non-stationary heat conductivity equation in one-dimensional form for cylindrical ingots and lining. Results: For three lining design types and different technological parameters operation acceleration possibility due to lining design change was studied. It is found that with ceramic fibers on walls and roof acceleration is 31-45% and with all lining made of ceramic fiber it is 44-52% as compared with fireclay brick lining. For a furnace with hearth of fireclay bricks and ceramic fiber on the walls and roof, convective component varies from 10 to 30%; for lining completely consisting of ceramic fibers it is 10 - 25%. When using fireclay brick lining parts their inner temperature is higher than for ceramic fiber up to 50 °C. Conclusions: Significant furnace lining materials type influence on metal AC intensity is proved. Heat removal mechanism on metal AC in furnace is disclosed, by establishing heat proportion directly removed from metal by convection. It is found that radiant heat transfer between metal and fireclay brick part of lining goes less intensively than with ceramic fiber part. </p>

Analysis of the production conditions of geopolymer matrices from natural pozzolana and fired clay brick wastes

Abstract The improvement of the mechanical properties of geopolymer matrices relies on the characteristics of the source materials as well as in proper optimization of the alkaline activating solution and curing conditions during geopolimerization. This study presents the optimization analyses carried out to determine the proper production conditions of Fired Clay Brick (FCB) and Natural Pozzolana (NP)-based geopolymers. The results indicate that high compressive strengths of up to 37 MPa and 26 MPa can be obtained for FCB and NP-based geopolymers, respectively when the proper production conditions are employed. The optimum alkaline solution for FCB consisted of Ms = 0.60, Na2O content of 8%, water/binder ratio = 0.27 with oven curing conditions between 65 and 80 °C for 7 days. On the other hand, NP-based geopolymers with the highest mechanical properties were obtained with an alkaline solution composed of a Ms = 1.08, 8% Na2O content and 0.52 of water/binder ratio cured in an oven at 65 °C for 7 days. The methodology for the optimization of production conditions of geopolymer matrices validated in this study demonstrated to provide consistent results and, therefore, could be applied for the analysis of the production process of geopolymers based on other aluminosilicate sources.

Thermochemical conversion of cashew nut shells, palm nut shells and peanut shells char with CO2 and/or steam to aliment a clay brick firing unit

Experimental gasification studies are reported for highly reactive peanuts, palm and cashew nut shells chars from Ziguinchor area in order to aliment a local clay brick baking unit. The gasification tests were operated in a fixed bed reactor under steam and/or carbon dioxide at three different temperatures (950 °C, 1000 °C and 1050 °C), in order to investigate the experimental conditions of three samples at different particle size. The gasification of char conversion at different temperatures is found to be dependent on gasifying agent, nature of the sample, and can be explained by the Arrhenius equation, thus suggesting the use of three different models: Volume Reaction Model (VRM), Random Pore Model (RPM), and Shrinking Core Model (SCM) in order to interpret the carbon conversion data and to determine the kinetics parameters.From the results obtained, temperature has a positive effect on the kinetic conversion. Further, the gasification under mixed atmosphere of steam and carbon dioxide showed that the reactivity of the different chars depends on the increase of steam concentration in the mixture. The gasifying char types has some effects in the determination of the kinetic parameters (activation energies obtained ranged between 110 and 126 kJ/mol for peanut shell, 104–125 kJ/mol for the cashew shell and 116–150 kJ/mol for the palm shell). By using different models, the experimental results shows that the kinetics reaction of the cashew shells char, and peanuts shells char, are faster than those from palm shells char. At the same time, results showed that the char-steam reactivity, char - CO2 reactivity and their mixture (char-steam and char - CO2) are different. The experimental measurements also show the influence of temperature on the Lower Heating Values (LHV) of the gas. The LHV of gas obtained are between (8–12 MJ/Nm3) and that, these values (LHV) are inversely proportional to the particles size of the biomass. While, based on the Europe Environment and Energy Management Agency (ADEME) standards on Lower Heating Value of gas, these gases obtained under all experimental conditions can be safely used to operate motor functioning with to gas.

Residential energy transition and thermal efficiency in an arid environment of northeast Patagonia, Argentina

We have studied changes in energy use and practices due to a program which partially replaced firewood by fossil fuels. The program has been running for nearly five years in rural dwellings in Patagonia Argentina, where limited provision of fuelwood and social vulnerability are found. As a case study we focused on the community of Laguna Blanca, Province of Río Negro, located in the Patagonian steppe. Dwellings are one-family houses which were built with no energy efficiency measures, exposing reinforced concrete structures, fired-clay bricks, metal roofs and single-glass windows to severe weather. Since 2014, a government program fully subsidized the refilling of Liquid Petroleum Gas (LPG) to vulnerable rural communities, which were provided with a 200-kg gas tank and a gas heater in each household. An expected decrease in the use of fuelwood was observed, along with a very high consumption of LPG (around 650 kWh/m2 year), which can be for the first time assessed due to the known amount of LPG provided. The lack of energy efficiency policies led to very high operational costs and environmental impacts. Based on the dwellings' characteristics, we have also found that the LPG subsidies saved in 2.2 years would return the investment for a thermal insulation that would reduce 50% the gas consumption and substantially improve comfort.

Synergistic effect of RHA and FCW in alkali-aggregate reaction mitigation

Abstract Pozzolans rich in silica, such as Rice Husk Ash (RHA), contribute to compressive strength gain but at the same time might increase alkali-aggregate reaction (AAR) in mortar mixtures. Pozzolans that have aluminates, such as Fired Clay Brick Waste (FCW), can be efficient to mitigate AAR but tend to lead to a slower compressive strength development. The association of different types of pozzolans, however, may result in a synergistic effect, compensating individual deficiencies. This paper presents a study of mixtures containing RHA, FCW and these two materials combined, aiming to obtain benefits in the mechanical behavior and in the durability regarding AAR. A substitution rate of 20% Portland cement by pozzolanic material was used. Through accelerated AAR tests and compressive strength measurements, it was found that while RHA is considered harmful to AAR - even when using an innocuous aggregate - FCW presents benefits, also avoiding this deleterious effect when combined with RHA. The same occurs in the compressive strength development, where RHA compensates a small loss of compressive strength associated with the use of FWC alone.

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.

Possibility and Effects of Recycling Vinyl-Banner Waste Into Fired-Clay Bricks for Home Industry in Lampung

Bricks are regarded as important material in building constructions. Basically, brick is processed by mixing clay and water then burnt under high temperature for a certain duration. Previous study in Indonesia shows that mixing local clay with additional materials could improve its characteristic, especially in terms of water absorption potentiality. Lampung has home industries which run brick making business traditionally. Moreover, this year Indonesian government has been organizing regional elections which attract campaigners to produce more vinyl banners as advertising media. As the event has already passed, vinyl banners eventually become environmental issue since they are not yet well managed. The aim of this study is to investigate the possibility and effect of red bricks mixtures along with vinyl banner waste. Fired-clay bricks dimensions including length, width, and height are 19 cm, 9.5 cm, and 5 cm respectively. Measurement has done by employing water absorption tests. Waste-added bricks absorb more water than the conventional one, about 11% higher. However, rice-husk-ash-added bricks perform similar to the normal bricks, it has slow rate of water absorption. Absorption rate of waste-added bricks also fast and exceed the conventional and RHA-added bricks. Modified red bricks surfaces are uneven, they show cracks and rough edges.

Utilization of ceramic materials in the process of electromagnetic wave conversion to heat usable for space heating of residential facilities

The work is dedicated to converting microwave radiation to heat. The article analyses different ways of heating residential and utility areas. Attention is paid mainly to infrared heating. Ceramic materials suitable for converting microwave radiation to heat from refractory ceramic composites are disclosed. The cooling curves of these materials after microwave heating are characterized in detail. The paper also presents a description of a microwave reactor with a fireclay brick together with the parameters of the living room heating.

Manufacturing, Physical and Chemical Characterization of Fire Clay Brick Value Added with Cow Dung Ash

Aim of this study was to introduce an eco-friendly, low cost and durable clay bricks with partial substitution of Cow Dung Ash (CDA). Five types of clay brick, consist CDA percentages 0, 5 10, 15 and 20% to the total weight of mixture, were manufactured by employing traditional method of dimension (18.5×8.5×6.5) cm3. The clay and CDA were well mixed with the addition of sufficient amount of water to form a good workability. Green molded bricks were allowed to dry under sunlight for two days and then fired in the traditional brick kiln. Physical properties of the burned red bricks were then tested and analyzed with Sri Lankan and British Standard Specifications. The average density, water absorption, compressive strength and flexural strength for 10% Cow Dung Ash (CDA) are 1447 kg.m-3, 17%, 150 kg.cm-2 and 0.82 kg.cm-2 respectively. These physical properties were compared with the standard brick purely manufactured from clay. From the results, clay-CDA bricks are obviously superior to the control brick; those are available in the Eastern region markets.

Impact of Indoor Air Quality by Incorporating Agricultural Waste Into Fired Clay Brick

The demand for edible oil from all over the world has generated a huge amount of solid waste. Due to that, the problem of disposal method has become a constraint by the authorities. Therefore, this study is focusing on the incorporation of palm kernel shell (PKS) into fired clay brick in terms of indoor air quality assessment. The brick was incorporated with 0% and 5% of PKS and fired at 1050°C with heating rates of 1°C/min. Preliminary analysis was conducted with X-Ray Fluorescence test to determine chemical composition of raw materials used in the study. A further experiment of indoor air quality was obtained by measuring gases emission of total volatile organic compound (TVOC), carbon dioxide (CO2), carbon monoxide (CO), ozone (O3), formaldehyde (HCHO) and particulate matter (PM10) in Walk in Stability Chamber with controlled temperature and relative humidity. All parameters were compared with Industry Code of Practice on Indoor Air Quality standard. The result shows that incorporation 5% of PKS into fired clay brick complied with the standard requirement for use as building materials. As the conclusion, the use of palm kernel shell as clay replacement could reduce the waste disposal in landfills whilst providing low-cost building materials.

Leachability of Fired Clay Bricks Incorporated with Sewage Sludge by Using Tank Leaching Test

This research was conducted to fully utilize the sludge that rich in dangerous heavy metals and at the same time act as low cost alternative materials in brick manufacturing. Different series of sludge and clay proportioning ratios were studied, which exclusively involved the addition of sludge with ratios of 0, 1, 5, 10, 20 and 30% of the total weight of sludge-clay mixture. Each molded brick were oven-dried at 105˚C for 24 hours followed by heating at 1050˚C. The investigation includes determination of heavy metal concentration of the sludge and clay using XRF and heavy metals leachability of the bricks by using Tank Leaching Test according to NEN7345 that has been analyzed by using ICPMS. The leaching behavior of several heavy metals (As, Ni, Cu, Pb, Zn, V, Ba, and Cr) from incorporated sludge into fired clay bricks shows to be insignificant and far below the USEPA regulations limits which fulfill the general requirement for usage of clay brick in construction and comply with the leaching standard limit. As a conclusion, the utilization of sewage sludge can reduce the disposal to landfill and reduce the leachability of sludge which can effect environment and human.

Physical Properties, Mechanical Strength and Microstructure of Fired Clay Brick Waste and Metakaolin Geopolymer Mortars

This paper presents a study related to the application of geopolymers cements as a binder on production of mortars for construction and building materials. Geopolymeric cements were produced from metakaolin, clay brick waste and activator consisting of potassium hydroxide and potassium silicate. The mixtures were prepared using standard production processes according Brazilian standards. Hardened properties of density, water absorption, 7-day and 28-day compressive strength were evaluated on samples of cured mortars. Selected samples of fractured specimens were subjected to microstructural characterisation via scanning electron microscopy, X-ray diffraction and thermal analysis. The results for the 7-day and 28-day compressive strength of geopolymer mortars showed that these materials have properties as good as those obtained from Portland cement mortars. Microstructural characterization of fractured pieces showed a morphology usually found in the category of geopolymers product structures.

The use of mineralogical indicators for the assessment of firing temperature in fired-clay bodies

Abstract Fired-clay bricks are frequently object of conservative actions aimed at the preservation of cultural heritage. Information on firing conditions is relevant for the production of custom made replacement bricks, since, as a widely accepted principle, they should be close match to the pre-existing ones. In this work, the mineralogical and microstructural evolution of fired-clay bodies is described using a combination of analytical techniques, and an approach for the assessment of firing temperature using calibration curves built from the results of X-ray powder diffraction quantitative phase analysis with the Rietveld method, is presented. The weight fractions of hematite, mullite and the amorphous fraction, from two raw clays fired in the laboratory at different temperatures, have been used to assess the firing temperature of two industrially produced bricks. The values derived applying these three methods were in good agreement with the nominal temperatures of the industrial cycles. This approach might be of interest for the assessment of the firing conditions of a broader range of historical/archaeological fired-clay materials.