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This work investigates the utilization of waste papers (natural and industrial) i.e (citrus aurantium and papers A4) mortars containing specified contents 0.5%, 1%, 1.5% of waste papers were prepared and cured. Mechanical characteristics such as compressive and bending strengths, hardness and water absorption were determined for the mortars mixed with the waste papers and compared with those obtained from the pure mortars. Results showed that the addition of waste paper leads to increase the hardness to (69 - 68.5) shore D for (natural and industrial) wastes materials respectively comparing with pure specimen 66 shore D. The compressed strength of the mortar cement specimen cured for 28 days from 13 MPa to (17-18) MPa for (natural and industrial) wastes materials, respectively.

Essa pesquisa teve por finalidade avaliar um resíduo de lodo de efluentes de indústrias de papel quanto à potencialidade de emprego em matrizes cimentícias. Verificou-se a composição química do resíduo e realizaram-se misturas com adições de 0, 5 e 10%, em relação à massa de cimento. As matrizes cimentícias foram analisadas por meio de calorimetria isotérmica, resistência à compressão, resistência à tração na compressão diametral, absorção de água por capilaridade, densidade de massa aparente e módulo de elasticidade dinâmico. Os resultados obtidos não foram satisfatórios, visto que a adição do resíduo à matriz apresentou aumento no consumo de cimento para atingir a resistência requerida e aumento no consumo de água para manutenção da consistência. The purpose of this study was to evaluate a paper sludge waste obtained from tissue paper industries regarding its potential for use in cementitious materials. The chemical composition of the waste was assessed and mixtures were made with 0%, 5% and 10% additions of the material, by mass of cement. The cement matrices were analysed experimentally by isothermal calorimetry, compressive strength and tensile strength by diametric compression, water absorption by capillarity, apparent mass density and dynamic modulus of elasticity. The results obtained were not satisfactory, since the addition of the paper sludge waste showed an increase in the cement consumption to reach the required compressive strength, as well as a rise in water consumption in order to maintain the mortar consistency.

[EN] In order to mitigate climate change, reductions of energy consumption are required on heating systems for residential and non-residential buildings. Despite radiant floor heating systems are being widely used due to their high thermal efficiency and comfort, further improvements are necessary to reduce the carbon footprint of the mortars used. This paper studies the use of lime mud, a by-product of the paper industry, as a partial replacement of cement to reduce the environmental impact of the resulting mortar. For that purpose, a reference cement mortar is compared to mortars with 10%, 20%, 30% and 40% of cement replacement by weight. Physical, thermal and mechanical properties showed that up to 20% of cement could be replaced by lime mud while maintaining thermal properties of the mortar. Despite the reduction of the mechanical resistance, mortars with up to 20% of cement replacement fulfilled the requirements of EN 1264-4:2010 standard. Finally, tests on laboratory-made radiant floor heating slabs proved that slabs with reference mortar had a similar stationary behaviour to that of the slabs with mortar containing 20% of lime mud, but the latter reach stationary faster due to the lower thermal inertia of its mortar. This work was supported by the the European Horizon 2020 Joint Technology Initiative Shift2Rail, IN2TRACK2 project [grant number 826255]; Basque Government (Elkartek 2019, GOLIAT2 project) [grant number KK-2019/00023]; Basque Government [grant numbers IT919-16, IT1314-19]. We also want to show gratitude to SMURFIT KAPPA NERVION for donating the lime mud used.

The application of cement in various fields of construction makes it a very important engineering material. However, it is very expensive and releases carbon dioxide gas into the atmosphere. Therefore, it is crucial to find cheap and environmentally friendly alternatives to cement. Waste paper pulp ash (WPPA) was found to be one of the most mature cement substitute materials. In this work, the physical and mechanical properties of cement mortar with WPPA as partial replacement of cement were experimentally studied to ensure that the resulting mixes has appropriate mechanical properties. Cement mixes containing various percentage replacements of WPPA (5%, 10%, 15% and 20%) were prepared, and basic properties such as compressive strength, flexural strength, shear bond strength, efflorescence and water absorption were determined and compared with the control mix (0%). The basic mechanical properties of cement mortar containing WPPA are enhanced until the percentage of WPPA reaches 10%. However, a further percentage of WPPA substitution causes the mechanical strength of the mortar to decrease. It is found that the optimal level of WPPA as a cement substitute is 5%. Although the physical properties of WPPA blended paste are improved with the increase of WPPA percentage. Our research provides a typical example of how the use of cement mortar containing WPPA can aid to the development of building materials. In addition to having better mechanical strength, cement-WPPA mixed mortar is a cost effective and environmentally friendly material.

The paper and cellulose manufacturing industry generates significant quantities of waste, including an extremely humid sludge, which is considered to be an effluent with high environmental liability for the manufacturer. Studies have shown that this waste sludge may be utilized in construction material, such as mortar for fixing blocks, as well as for ceiling and wall coatings that use ceramic masonry as a sealant. The recycling of pulp and paper industry waste sludge has important environmental benefits, by preventing soil and water pollution caused by inadequate disposal and by reducing the depletion of natural resources, such as lime, used in cementitious materials. This study analyzed the sustainability of incorporating such waste into cement-based mortars. Tests were conducted replacing lime, one of the most expensive mortar components with high environmental impact, with waste sludge in contents of 5%, 10%, 15%, and 20%. Analysis was then performed on the samples to assess the primary technical characteristics of these incorporated mortars, such as the consistency index, heat of hydration, content of incorporated air, water retention, mechanical strength and the capillarity coefficient. The results were compared with the results of the characterization tests that were performed on the waste material. The results showed that for use in wall and ceiling mortar coatings, the level of incorporation should not exceed 10%, because higher levels yield lower values of mechanical strength resistance, incompatible with market requirements. This result is probably due to the low heat of hydration of the waste material which generates slower reactions. On the other hand, higher levels of waste material content, above 10%, are appropriate convenient for mortar used to fill small repairs in masonry that do not require control of properties.

Lime slaker grits and biomass fly ash are solid wastes produced by the Kraft paper-pulp industry that are commonly disposed of in landfill. However, recent studies and European regulations discourage such disposal practices. This work investigates an alternative and innovative way to recycle and reuse these wastes in the production of green geopolymeric mortars intended for application in the construction industry. Here, biomass fly ash was used as the main source of alumino-silicate in the binder precursor (70 wt.% substitution to metakaolin), and grits (ranging from 1&ndash, 12.5 mm, as provided by the industry) were reused as aggregate. Aggregate granulometry was also completed by using a commercial natural siliceous sand (&lt, 1 mm). Mortars using sand only were prepared for comparative reasons. The implemented mix was designed to investigate the influence of the grits on the mortar&rsquo, s properties such as its binder/aggregate ratio, workability, bulk density, water sorptivity, and compressive strength. At the same time, waste reuse was analysed in light of its limitations and potentialities. Moreover, in the pursuit of sustainability, the manufacturing process that was followed was highly cost-effective in ambient curing conditions (20 &deg, C, 65% RH), which avoided the use of any external source of energy as commonly used in geopolymers processing. The achieved results proved that the combined use of these wastes, which to date has hardly been explored, along with ambient manufacturing conditions increases the material sustainability. The produced mortars are suitable for innovative applications in various fields, with a particular focus on construction and contribute to the circular economy.

This paper present product design and development of waste paper plastering mortars machine. This waste paper plastering mortar is manual machine system. The main element to make mortar is cement, sand, water and waste paper. These machines have two separate tanks, which is the first tank is to produce a pulp and second tank is to mix up the entire ingredient. The objectives of this research are to design a Waste paper plastering machine, to develop a functional prototype of Waste Paper Plastering Machine and also to test the machine by compare the best method by with machine and without machine to make plastering mortar. The testing has been done between preparation and procedure how to make plastering mortar with machine and without machine. This machine can be used in every household. This can save environment and reduce pollution.

The pulp and paper industry traditionally generates large amounts of wastes at different stages of its production process, such as primary sludge that is extremely wet. The aim of this research is to evaluate a new process methodology aiming the incorporation of primary pulp and paper industry sludge waste, still in its liquid state, into cement and lime-based mortars. This procedure was compared with the incorporation of the waste in its dry state, which results from the traditional beneficiation process based on powder drying. Comparison was performed in terms of technological, durability and environmental performance of both wastes (liquid and dry) incorporated mortars, as well as with reference control mortar without incorporation. Two news models of liquid waste processing, for mortars incorporation, called thin and coarse liquid, were developed in order to evaluate technological parameters such as: consistency, entrained air, water retention, mass density, capillary absorption and mechanical strength. These parameters allow the characterization of durability, life cycle assessment and environmental conditions. Technological properties showed satisfactory results in mortars performance when waste was used as a thin liquid with nominal content (optimal mixture) similar to the reference composition. The air content of the mortar was 12% and the water retention 96.8%. In the hardened state, the optimal mixture had a mass density of 1.76 g/cm3, a capillary coefficient of 20.73 g/dm2.min1/2 and mechanical resistance to compression of 3.7 MPa and to flexion of 1.1 MPa, all results meet the limits of the literature for application in construction. It was found that the beneficiation process, which produces the thin liquid is the most efficient for the incorporation of waste into mortars when compared to the dry method. Indeed, the thin liquid waste incorporated mortars showed improved technological, durability and environmental properties.

The 5th Historic Mortars Conference was held in Pamplona, at the University of Navarra, Spain, during June 19–21, 2019. HMC 2019 hosted more than 150 scientific communications from the five continents. The underlying theme was the interest in the Historic Mortars from multiple points of view: *Analysis of ancient materials, either in archaeological sites or in structures of the Architectural Heritage. *Studies on a wide variety of materials (such as renders and plasters, grouts, masonry materials and coatings) and compositions (earth-based mortars, gypsum plasters, hydraulic mortars, air lime mortars, mortars with pozzolans, natural and Roman cement mortars). *Research works on historic production, processing and application, including lime technologies. *Archaeometry studies. *Conservation issues: diagnosis, decay and damage mechanisms, case studies. *Preservation and repair materials: consolidation products, new mortars with improved properties, additives and admixtures, use of nanotechnology to obtain highly efficient repair products, preventive conservation. *Requirements for repair works and materials and adequacy of the testing procedures.

This study “discusses the benefit of “addition waste paper as a “new cellulose material “in mortar mixes. A partial addition of waste paper by cement weight was achieved to produce cement composite mortar. Pulp and paper is the third major industrial dumper of air, soil and water. In recent year, paper and paperboard constitute a greater portion of many countries’ urban solid discarded generation. Beside, it increases characteristic “strength due to existence “of hydrogen links “in the microstructure of “paper. Furthermore, it consume “better thermal protection. The addition percentages “of waste paper used “in this work were (5%, 10%, 15% and 20%) by “mass of cement to measure and evaluate some “properties of the mortar produced (compressive“, direct “tensile, and flexural) strength, thermal “properties such as (thermal conductivity), and “microstructure investigation “like (scanning electron microscope “(SEM)). The results indicated that the fresh mortar “properties affected expressively with higher wastepaper percent. The mechanical properties (compression, direct tensile and flexural strength) were “reduced by increasing the content of waste paper, it reduces to (74%, 50%, and 86%) respectively, with (20%) addition of waste paper than the reference mix. Moreover, using waste “paper with different percentages “led to noticeable “decrease in thermal “conductivity, especially with increasing addition percentages.

The aim of this thesis is the development of an eco-binder based on industrial co-products : a wastepapery ash and a ground granulated blast-furnace slag, for the manufacture of dry mortars. On the one hand,this eco-binder was developed to replace partially cement as a constituent of traditional materials, andon the other hand to recycle in large quantities one of these two industrial wastes ; wastepaper fly ashwith considering all the notions of circular economy and eco-design. From literature, there are numerousand relevant research works on the different types of ash and slag, highlighting the characteristics, themineralogy, the reactivity of the wastepaper fly ash and ground granulated blast-furnace slags in details.These two co-products with about 20 wt.% SiO2 and 50 wt.% CaO have a chemical composition veryclose to that of a cement and develop pozzolanic properties that can replace those of cement. Theirvalorization as a binder material is then possible. A complete knowledge of the physicochemical, structuraland mineralogical properties of wastepaper fly ash and ground granulated blast-furnace slag led to anexploratory study of formulations for dry mortars. The mixtures containing 72 wt.% of wastepaper fly ashand 28 wt.% of ground granulated blast-furnace slag were investigated with reference to the formulationof a standard mortar to optimize the water content and compaction energy level. A specific equipment forcompacting prismatic specimens with dimensions 4x4x16 cm3 was used. The effect of adding three types ofactivators i.e. calcium chloride CaCl2, sodium metasilicate Na2O3Si and sodium carbonate Na2CO3, anda small amount of cement i.e. 5 wt.% and 10 wt.% was analyzed. The relation between mechanical strengthand the microstructure of the mixtures has been detailed and discussed. Two optimal formulations wereimplemented and, mineralogy, mechanical strength at 2, 7 and 28 days of curing, microstructure withSEM images, pore distributions and durability have been considered and analyzed. Taking into accountthe satisfactory results obtained, a semi-industrial approach to manufacture 15x15x15 cm3 blocks fromthe two selected formulations was conducted and discussed. The first results show a great interest in themanufacture of blocks of pavement and derived products for the construction of pedestrian or reducedtraffic areas., L'objet des travaux réalisés dans cette thèse concerne la mise en oeuvre d'un éco-liant à base de co-produits industriels : une cendre volante papetière et un laitier moulu, pour la fabrication de mortiers secs. Cet éco-liant a été élaboré pour remplacer partiellement le ciment comme constituant de matériaux traditionnels d'une part, et recycler en grande quantité l'un des deux déchets industriels, la cendre volante papetière tout en intégrant les notions d'économie circulaire et d'éco-conception d'autre part. La littérature fait état de nombreux travaux sur les différents types de cendres et de laitiers mettant en avant les caractéristiques, la minéralogie, la réactivité de ces cendres volantes papetières et des laitiers moulus. Ces deux coproduits avec environ 20% de SiO2 et 50% de CaO (% pondéraux), ont une composition chimique très proche de celle d'un ciment et développent des propriétés pouzzolaniques qui peuvent suppléer celles du ciment. Leur valorisation comme matériau liant est alors envisageable. Une complète connaissance des propriétés physico-chimiques, structurelles et minéralogiques de la cendre volante papetière et du laitier moulu a conduit à une étude exploratoire de formulations. Des mélanges à partir de 72% de cendres volantes papetières et de 28% de laitier moulu ont été étudiés en se référantà la formulation de base d'un mortier pour en optimiser la teneur en eau et le niveau d'énergie de compactage. Un matériel spécifique pour compacter les éprouvettes prismatiques de dimensions 4x4x16cm3 de mortier a été utilisé. L'effet de l'ajout de trois types d'activateurs i.e. chlorure de calciumCaCl2, métasilicate de sodium Na2O3Si et carbonate de sodium Na2CO3, et d'une faible quantité deciment i.e. 5% et 10% a été analysé mettant en relation la résistance mécanique et la microstructure desmélanges. Deux formulations optimales ont fait l'objet d'analyses relatives à la minéralogie, auxrésistances mécaniques à 2, 7 et 28 jours de cure, à la microstructure avec des images MEB,distributions des pores et à la durabilité. Compte-tenu des résultats satisfaisants obtenus, une approcheà l'échelle semi-industrielle de fabrication de blocs 15x15x15 cm3 à partir des deux formulationsretenues a été menée et discutée. Les premiers résultats montrent un grand intérêt pour la fabricationde pavés et de produits dérivés pour l'aménagement de zones piétonnes ou à circulation réduite.

Paper sludge generated from the paper industry is classified as solid waste, comprising primarily wood fiber with excellent toughness and CaCO3 with low thermal conductivity. The purpose of this work was to investigate the adaptability of paper sludge with wood fiber into cement-based insulation mortar. The addition of paper sludge with wood fiber was found to be beneficial for optimizing the performance of cement-expanded polystyrene (EPS)/paper sludge (CEP) mortar. In detail, the addition of paper sludge with low fiber content in the range of 2.5% to 7.5% improved the toughness and softening coefficient of CEP mortar. In comparison, an increase of wood fiber content notably improved the properties of CEP mortar when its addition level reached 15%. Additionally, paper sludge with different fiber contents decreased the thermal conductivity of CEP mortar, ranging from 0.0897 to 0.0885 W/(m·K). In conclusion, paper sludge with wood fiber exhibited good adaptability in CEP mortar.

This study deals with the application of the filter paper method to determine water retention curves for mortar and concrete samples. A water retention curve exhibits the relationship between water content and energy state in interstitial water, normally expressed as a negative value when compare to normal conditions of temperature and pressure, being referred to as suction. Considering the water retention curve as a basic characterization tool for unsaturated soils, its usage in the engineering field concerning most of the construction materials remains as a pending task. However, stating that not only permeability, but also the water retention curve performs a significant role for water and soluble substances flow through a material's pores makes this observation essential for life-span estimation in cases like reinforced-concrete structures. This research paper offers results for water retention curves obtained in mortar and concrete samples. The experimental curves went through a fitting adjustment process using Van Genutchen's [1] model, showing consistency with the obtained results. Furthermore, the water/cement mix ratio does not indicate or suggest a direct influence for water retention curves. Resumo Este trabalho trata do uso da técnica do papel-filtro para a obtenção, em laboratório, de curvas de retenção de água em corpos de prova de argamassa e concreto. A curva de retenção correlaciona o conteúdo de água de meios porosos com o estado de energia da água intersticial, que em condições não saturadas (vazios não totalmente preenchidos por água) é normalmente negativo em relação às condições normais de temperatura e pressão, sendo denominado de sucção. Embora possa ser descrita como uma ferramenta básica de caracterização de solos não saturados, o uso da curva de retenção em concretos e argamassas ainda não foi introduzido na prática da engenharia para a maioria dos materiais de construção. Pode-se dizer, contudo, que não somente a permeabilidade, mas também a curva de retenção desempenha um papel fundamental no fluxo de água e substâncias solúveis pelos poros do material, sendo imprescindível o seu conhecimento, para, por exemplo, estimar a vida útil das estruturas de concreto armado. São apresentados resultados de ensaios de sucção total pelo método do papel-filtro, os quais permitiram determinar curvas de retenção para corpos de prova de concreto e argamassa. Estas curvas foram ajustadas segundo o modelo de Van Genutchen [1], o qual apresentou boa aderência aos valores experimentais. Não foi possível observar influência significativa da relação água-cimento nas curvas de retenção obtidas.

This article describes a study on the viability of using waste from the paper industry: biomass boiler ash and green liquor dregs to fabricate mortars and concretes. Both types of ash were characterized by obtaining their chemical and mineralogical composition, their organic matter content, granulometry, adsorption and other common tests for construction materials. Seven different mortars were fabricated, one for reference made up of cement, sand, and water, three in which 10, 20, or 30% of the cement was replaced by biomass ash, and three others in which 10, 20, or 30% of the cement was replaced with dregs. Test specimens were fabricated with these mortars to conduct flexural and compression tests. Flexural strength is reduced for all the mortars studied. Compressive strength increases for the mortars fabricated with biomass ash and decreases for the mortar with dregs. Finally, 5 concretes were made, one of them as a reference (neither biomass ash nor dregs added), two of them with replacements of 10 and 20% of biomass ash instead of cement and another two with replacements of 10 and 20% of dregs instead of cement. The compressive and tensile splitting strength increase when a 10% of ash is replaced and decrease in all the other cases. The modulus of elasticity always decreases.

This work is part of a broad research conducted to study the re-use of industrial wastes in an economical and environmentally sustainable manner. Re-use of lightweight ash from the paper mill industry in the manufacture of plaster blends is examined in this study. Lightweight ash is produced during the combustion process of de-inking sludge. Studies demonstrate that lightweight ash is an excellent ingredient in the production of cement mortars and/or pozzolanic mortars to be used as plaster. In this research, ash valorization was researched by investigating the efficacy of the ash as it is, as a substitute for very fine sand. If properly mixed at an optimal mix proportion, the mechanical strength ranges from 4÷10MPa with specific gravity between 1150 and 1350 Kg/m 3 . Water absorption may be reduced to a very low level with silane-based surface treatment.

In a recent paper, Zhu et al. used bender element-type ultrasonic actuator in order to generate S-waves transmission through mortar samples. New criteria for determining the initial and final setting are proposed. The developed methodology leads to the conclusion that these criteria are more reliable than previously published material. Several points would require further discussion, such as the consideration of the effect of temperature, the shear wave onset detection algorithm, or the curve fitting strategy. These considerations might undermine the reliability of the suggested method, and explain the divergence of results obtained in contrast with previously published material., SCOPUS: no.j, info:eu-repo/semantics/published

The objective of this research was to develop lightweight cement mortars with good thermal-insulation properties by incorporating expanded polystyrene (EPS) and paper sludge ash (PSA), both of which are problematic waste materials. The mortars formed had low thermal conductivity and low bulk density compared to control samples. Ground EPS produced lower thermal conductivity samples than powdered EPS. Resource efficient mortars containing up to 20% PSA, and 60% of EPS are considered suitable for use in rendering and plastering applications. The authors wish to thank the Spanish Ministry of Science and Innovation and European Union (FEDER) for project funding (BIA2007-61170), and the FPI scholarship (BES-2009-012166) award to Verónica Ferrándiz Mas which allowed her to develop her doctoral thesis. This research was carried out in the Civil and Environmental Engineering Department at Imperial College London, with funding from the Spanish Ministry of Economy and Competitiveness (EEBB-I-12-0574) to support Verónica Ferrándiz Mas.

The influence of the application of residues from the cellulose and paper industry in construction mortar was investigated. Mortars were prepared with CPI-S-32 or CPII-Z-32 Portland cements and sand in a 1:3 proportion. Four solids residues, i.e., Fiber, Dregs, Bottom Ash and Grit, were incorporated in the mortars in varying proportions. The bottom ash and dregs were used in place of cement, while fiber and grit were used to replace sand. The aging time of the samples was varied from 7 to 28 days. The results demonstrated that the type of cement and the aging time exerted a strong influence on the samples' microstructure and resistance to axial compression. The best values were obtained at 28 days of age with the CPI-S-32 cement. On the other hand, the type of residue and its concentration also affected microstructure and resistance to axial compression. The best results were obtained from bottom ash and grit.

[EN] This work deals with the frost resistance of blended cements containing calcined paper sludge (source for metakaolin) as partial Portland cement replacements. Freeze–thaw tests were performed on blended cement mortars containing 0%, 10% and 20% waste paper sludge calcined at 650 °C for 2 h. Cement mortar specimens were exposed to freezing and thawing cycles until the relative dynamic modulus of elasticity fell below 60%. The performance of the cement mortars was assessed from measurements of weight, ultrasonic pulse velocity, compressive strength, mercury intrusion porosimetry and SEM. Failure of the control cement mortar occurred before 40 freeze/thaw cycles, while cement mortar containing 20% calcined paper sludge failed after 100 cycles. After 28 and 62 freezing and thawing cycles, cement blended with 10% and 20% calcined paper sludge exhibited a smaller reduction in compressive strength than the control cement.

In the last few decades, considerable research effort has been spent on the utilization of industrial by products (marble powder) and natural resources (limestone powder) as partial replacement of Ordinary Portland cement (OPC). The benefits of addition of supplementary materials to Ordinary Portland cement are well documented. Limestone powder substitution for cement makes perfect sense in these lower w/c concretes, saving money and energy and reducing carbon dioxide emissions. The use of marble powder as mineral addition for mortars and concretes, in the presence of a superplasticizing admixture provided maximum compressive strength at the same workability level, comparable to that of the reference mixture after 28 days of curing. This paper describes about the Properties of Concrete Incoparted with Mineral Admixtures – Limestone Powder and Marble Powder. Limestone Powder and Marble Powder are partially replaced with Ordinary Portland Cement for certain Percentages. Limestone powder (LMSP) and Marble Powder (MBP) was used as a compensating material with different ratio of cement include 0, 10, 15, 20, 25 and 30 %.

[EN] The present study is based on the influence of the addition of a pozzolanic material as a result of the activation of an industrial waste coming from the Spanish paper industry on the heating as well as hydration heat of the cement mortars made with 10 or 20% of active addition. Once the sludge has been calcined at different temperatures (700–800°C) and stays in furnace (2 and 5 h), the calcined products showed high pozzolanic activity. The maximum activity corresponded to the paper sludge calcined at 700°C for 2 h (S1). Besides, it can be proved that there was an increase both of the heating and also of the hydration heat in the first 23–25 h for both additions (10 and 20% of S1) regarding the reference cement mortar. This behaviour would be related to the influence of different effects: filler and pozzolanic during the first hours of reaction, and by the dilution effect for longer hydration times, mainly when 20% of S1 was added.

The strength of concrete mix is dependent on many parameters like cement type, coarse aggregate and the interface between aggregate and mortar. However, generally the coarse aggregate is treated as an inert material and only its physical properties like shape, size, water absorption and specific gravity are studied. Whereas, as we increase the quality of mortar mix, the strength of coarse aggregate also comes into picture. In case of high performance concrete, the type of coarse aggregate used has a great influence on the strength and elasticity modulus of concrete. For high strength concrete with compressive strength above 40 MPa, which are generally cast with water-cement ratio less than or equal to 0.4, the strength of mortar and the interfacial bond strength may be comparable to the strength of aggregate. This paper presents a comprehensive review of the past research work done on the effect of using different types of coarse aggregate on various properties of concrete mix like its compressive strength, tensile strength and elasticity modulus.

Masonry component products are increasingly made industrially with reduced variation in mechanical properties. The joint is the only part of the masonry that is affected by manual action and so the load bearing capacity is not only determined by the quality of the bricks and mortar used but moreover by the way the masonry has been built and cured. As a result, it may be expected that the largest material variations are at the brick–mortar interfaces. This has been observed as irregular interface bonding with a bonded central area surrounded by fissures. As a consequence of the final shape of the joint, forces concentrate in the central part of the joint and strain variations occur near fissure tips which result in spalling of bricks in experiments. This paper demonstrates the need for detailed deformational measurements in the brick–mortar interface region. To overcome the limitations with traditional measuring instruments, a refined methodology based on the laser speckle technique is introduced in a companion paper [Canadian Journal of Civil Engineering, 34(11), 1467 (2007)] by the authors of this paper.