Brick Units Research Articles

Preliminary Results on the Tensile Capacity of Steel Anchors in Brick Units of Different Materials

High strength steel bars are widely used for the strengthening of masonry buildings, in particular to improve the connection between different structural elements, such as orthogonal walls and multi-leaf walls. A particular type of steel connector is the twisted bar, which due to its particular shape works as a self-threading screw, anchoring to the support material without any binder. The effectiveness of such technique mainly relies on the bond between the bar and the substrate, where adhesion, mechanical interlocking and friction play an important role. In this paper, a preliminary experimental study on pull-out behavior of twisted steel connectors inserted in brick units of different materials that can be commonly found in existing masonry buildings in Italy and in Europe is presented. Additionally, mechanical characterization of the materials is conducted to understand the influence of the compression strength and elastic modulus on the adhesion between the connector and the substrate. Preliminary results show that the pull-out response strongly depends on the mechanical properties of the substrate material.

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.

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.

Effect of Brick Prewetting on Masonry Bond Strength

AbstractMasonry walls resist both in-plane and out-of-plane forces through the bond between the brick unit and mortar. Moisture content or saturation level of the brick unit at the time of construc...

DETERIORATION MECHANISMS AFFECTING THE BRICKS USED IN THE BUILDING OF THE WATER WELLS AT KARNAK TEMPLES, LUXOR, EGYPT

The water wells at Karnak temples made of red brick and belonging to different eras, (Graeco-Roman and Byzantine periods). These water wells suffer from several deterioration aspects such as exfoliation, hard crusts, disintegration, spalling, cracks, fractures, salts crystallization, micro-organisms colonization's and vegetation. The aim of this paper is to study the deterioration mechanisms affecting the brick units of these wells to prepare a conservation strategy. Different scientific methods such as Light Optical Microscope (LOM), Polarizing Microscope (PM), Scanning Electron Microscope coupled with an Energy Dispersive X-Ray Spectrometer (SEM-EDX) and X-Ray Powder Diffraction (XRD) have been used to determine the mineralogical composition and the deterioration products. The obtained results have proved that the water wells suffer from salts crystallization of sodium chloride and sodium sulfate (thenardite) due to the severe effects of deterioration factors particularly the dominated environmental conditions, water-soluble salts and mineralogical composition of the brick.

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.

Effect of Using Compressed Stabilized Earth Blocks on the Thermal comfort in Architectural Spaces

The problem of high building materials prices, using traditional building systems, consumes a great deal of energy during manufacturing or operating the facility. Accordingly, many researchers have been taken out recently to find alternatives traditional building systems and materials such as Compressed Stabilized Earth Blocks, which relates on using available natural soil compressed at high pressure, This research aims to evaluate the effect of Compressed Stabilized Earth Blocks as alternative walls for walls made from traditional blocks on thermal comfort in architectural spaces through using (Design builder) for defining energy consumption. Two types of natural soils were used (Sandy soil and Silty soil) and a partial replacement was made to the used soil types by utilizing some materials Aswan clay and Clay soil in order to improve soil performance then adding 8% cement of the total weight for stabilizing the mix. Building blocks were made of best 8 mixes in order to achieve the requirements of Egyptian Code for building by Stabilized Earth Blocks. This study is conducted on a residential sample (Social Housing sample composed of two residential units with a total area of 90 m2 for each) for comparison between building blocks made from stabilized soil and other blocks made from local brick units. Experimental results shown that the usage of building blocks, made from stabilized soil with 8% cement, helps to reduce energy consumption in order to achieve thermal comfort ranging from 5% to 25%, compared with other brick types. It also helps to reduce resources and energy consumption used in manufacturing and to decrease negative environmental impacts resulting from other building materials. Research recommendations refer to the necessity of using soil in producing building blocks in new projects under design for choosing best usage of soil and stabilize it in order to benefit from natural materials, rationalize electric power consumption in buildings

Nonlinear Structural Performance of a Historical Brick Masonry Inverted Dome

ABSTRACT Traditional domes are obtained by double curvature shells, which can be rotationally formed by any curved geometrical plane figure rotating about a central vertical axis. They are self-supported and stabilized by the force of gravity acting on their weight to hold them in compression. However, the behavior of inverted domes is different since the dome is downward and masonry inverted domes and their structural behaviors in the literature received limited attention. This article presents a nonlinear finite element analysis of historical brick masonry inverted domes under static and seismic loads. The brick masonry inverted dome in the tomb of scholar Ahmed-El Cezeri, town of Cizre, Turkey, constructed in 1508 is selected as an application. First, a detailed literature review on the masonry domes is given and the selected inverted dome is described briefly. 3D solid and continuum finite element models of the inverted masonry dome are obtained from the surveys. An isotropic Concrete Damage Plasticity (CDP) material model adjusted to masonry structures with the same tensile strength assumed along the parallel and meridian directions of the inverted dome is considered. The nonlinear static analyses and a parametric study by changing the mechanical properties of the brick unit of the inverted masonry dome are performed under gravity loads. The acceleration records of vertical and horizontal components of May 1, 2003 Bingöl earthquake (Mw = 6.4), Turkey, occurred near the region, are chosen for the nonlinear seismic analyses. Nonlinear step by step seismic analyses of the inverted dome are implemented under the vertical and horizontal components of the earthquake, separately. Static modal and seismic responses of the inverted masonry dome are evaluated using mode shapes, minimum and maximum principal strains and stresses, and damage propagations.

Chemicals Reactions, Making Process and Behaviour of Dry Cement

In this research a number of techniques are studied. The OPC is silicate concrete typically used for solid brick work units and for all uses where the solid isn't needy upon remarkable sulfate risk or where the warmth delivered by the hydration of concrete isn't frightful. It has unfathomable opposition from breaking however has a littler measure of obstruction from substance assaults. Watchwords: OPC, Limestone, clinker and so on.

Cost prediction model based on system dynamics in water resource project

Project’s cost is one of important components in project achievement. Because of the uniqueness of construction projects, cost estimation always differs from project to project. The rate of cost components always change over time make difficult to forecast the cost for the upcoming project. The cost component consists of many influencing variables where there is interrelationship each other affecting to the total project cost. This paper objective is to develop a cost prediction model to assist the project planners in cost estimation for future projects. System dynamic is one of the appropriate methods to analyse system behaviour with interrelationship referring to the historic data, so it is able to predict the future project. Developing the model, primary and secondary data are collected from previous studies, interview with the government planner and survey in Malang Regency. The model simulation is Brick work unit with its components. Data from last thirteen years are used to verify and validate the developed model by causal loop diagram as a basic method in system dynamic. The finding showed that the model is closed to real condition through the validation mechanism. The developed system is useful in decision making of budget planning based on work quantity.

Exploring the musculoskeletal problems and associated risk-factors among brick kiln workers

Purpose Prolonged working in repetitive and awkward postures can result in musculoskeletal disorders among workers involved in labour-intensive jobs like those of brick kiln workers. Unlike other labour-intensive sectors, workers in this particular sector have a lack of awareness about musculoskeletal problems. Therefore, the purpose of this paper is to explore musculoskeletal issues and associated risk-factors among brick kiln workers. Design/methodology/approach A questionnaire survey was conducted among 217 male and 111 female workers aged between 17 and 53 years. They were employed in traditional brick kiln units situated in Rajasthan, India. Postures were analysed by Rapid Upper Limb Assessment and Rapid Entire Body Assessment methods. Binary logistic regression was used to find the association between musculoskeletal problems and risk-factors. Findings For the mould evacuating task, wrist (76.2 per cent) and lower back (56 per cent) issues were the most frequently reported musculoskeletal problems, while in spading task, lower back (62.4 per cent) and shoulder (57.7 per cent) problems were prominent. Musculoskeletal symptoms in one or more body regions were associated with personal and work-related factors including the type of task and experience. Research limitations/implications Kiln workers are exposed to high musculoskeletal and postural risks, particularly in spading and mould filling tasks. To reduce these risks, ergonomic interventions are needed. Originality/value It is recognised that the musculoskeletal health of brick kiln workers is a cause for concern. The present study provides the evidence of the prevalence of musculoskeletal symptoms experienced by brick kiln workers and the association of symptoms with various risk-factors, which has not been addressed in previous studies.

Developing Lightweight Clay Brick Units Using Waste Materials

Developing Lightweight Clay Brick Units Using Waste Materials

Strength characteristic of novel mesh embedment technique for new brick construction with least expensive material

An extensive experimental study aims to enhance the structural performance of masonry by using meshes on the surfaces of brick units and bed joints. The novel mesh embedment technique of masonry units is supported with the least expensive meshes. They are 0.71 mm thick GI expanded wire mesh (EWM), 0.41 mm thick SS stainless steel mesh (SSM) and 0.33 mm thick SS poultry netting mesh (PNM) or chicken wire mesh are the three types of embedded mesh used in this novel approach. The mesh embedded masonry technique (MEM) administers by alternative sides of bricklayer that passes through bed joints. To envisage brickwork quality, reasonable trial programs are necessary like the compressive strength of twenty masonry prism with height to thickness ratio of 1.6 as per the ASTM C1314, the flexural bond strength of thirty three masonry prism as indicated by the ASTM E518 Test method A and small-scale diagonal shear (Tension) test on six masonry panel as per the ASTM E519. The present study concedes that the embedment of meshes increases the strength and ductile performance of masonry units.

Derivation of the out-of-plane behaviour of masonry through homogenization strategies: Micro-scale level

Two simple and reliable homogenized models are presented for the characterization of the masonry behaviour via a representative volume element (RVE) defined at a structural level. An FE micro-modelling approach within a plate formulation assumption (Kirchhoff-Love and Mindlin-Reissner theory) using Cauchy continuum hypotheses and first-order homogenization theory is adopted. Brick units are considered elastic and modelled through quadrilateral finite elements (FEs) with linear interpolation. Mortar joints are assumed to be inelastic and reduced to zero-thickness interface FEs. A multi-surface plasticity model governs the strength envelope of mortar joints. It can reproduce fracture, frictional slip and crushing along the interface elements, hence making possible the prediction of a stepped, toothed or de-bonding failure pattern of masonry.Validation tests on the homogenized procedures are undertaken to conclude on the correct identification of the elastic stiffness properties, in the ability to reproduce the masonry orthotropic behaviour and the effect of potential pre-compressive states. Furthermore, the approaches are extended to characterize a case study of an English-bond masonry wall. Both the validation and application steps provide excellent results when compared with available experimental and numerical data from the literature. Conclusions on the influence of three-dimensional shear stresses and the effect of potential discontinuities along the thickness direction are also outlined.The two homogenized approaches are, for the running- and English-bond masonry cases, integrated within a FE code. By providing reliable and low computational cost solutions’, these are particularly suitable to be combined within multi-scale approaches.

Innovative and easy-to-implement moisture monitoring system for brick units

The system measures the change in electrical resistance due to the presence of water. It is composed of an electronic board and brick (P20) instrumented with graphite electrode-couple sensors. It is mainly designed for the laboratory evaluation of rain penetration in masonry components. The system successfully monitors the change in moisture content correctly detecting storage and transport mechanisms. Compared to similar systems it is cost-effective with easy fabrication and installation, fostering non-destructive, repeatable measurements with adequate space and time resolution, identifying transient conditions at different depths into building components. Application to real structures is proposed as future work.

Artificial Nacre from Supramolecular Assembly of Graphene Oxide.

Inspired by the "brick-and-mortar" structure and remarkable mechanical performance of nacre, many efforts have been devoted to fabricating nacre-mimicking materials. Herein, a class of graphene oxide (GO) based artificial nacre material with quadruple hydrogen-bonding interactions was fabricated by functionalization of polydopamine-capped graphene oxide (PDG) with 2-ureido-4[1 H]-pyrimidinone (UPy) self-complementary quadruple hydrogen-bonding units followed by supramolecular assembly process. The artificial nacre displays a strict "brick-and-mortar" structure, with PDG nanosheets as the brick and UPy units as the mortar. The resultant nanocomposite shows an excellent balance of strength and toughness. Because of the strong strengthening via quadruple hydrogen bonding, the tensile strength and toughness can reach 325.6 ± 17.8 MPa and 11.1 ± 1.3 MJ m-3, respectively, thus exceeding natural nacre, and reaching 3.6 and 10 times that of a pure GO artificial nacre. Furthermore, after further H2O treatment, the resulting H2O-treated PDG-UPy actuator displays significant bending actuations when driven by heat. This work provides a pathway for the development of artificial nacre for their potential applications in energy conversion, temperature sensor, and thermo-driven actuator.

Mechanical and bond properties of solid clay brick masonry with different sand grading

To evaluate the performance of unreinforced masonry buildings under different loading conditions such as lateral seismic load, the mechanical properties of masonry materials are required. Masonry is a composite material which consists of brick units and mortar joints bonded together. On the other hand, sand is the main ingredient of mortar and its characteristics such as grading can affect the physical and mechanical properties of mortar. In this research, a comprehensive experimental study was conducted to assess the effects of sand grading on the properties of mortar as well as masonry. Considering the main standard tests recommended for masonry as a composite material, the behaviors of masonry assemblages and prisms fabricated using three mortar mixes with coarse and fine sand grading were assessed to examine compressive strength, diagonal-shear strength, and brick-mortar shear and flexural bond strengths.

PENGEMBANGAN ENTERPRENEUR MAHASISWA DALAM USAHA BATAKO DI WORKSHOP PTB UNS

Concrete brick is a kind of non structural brick which can be used for street, parking lot, sidewalk, park and another necessity. Concrete brick is made of the mixture of portland cement type one, water and aggregate as the filler materials. The ussage of concrete brick is more eco friendly compared with brick, moreover the ussage of concrete brick grows rapidly, especially in Solo lately because of the rapid growth of housing estate and bisnis area.<br />Observing the expansion of the concrete brick necessity so Pendidikan Teknik Bangunan (PTB) workshop develop it to concrete brick entrepreneurship program. This program was aimed through college entrepreneurship which is managed by the unversity students to study about entrepreneurhip. The college developing program are entrepreneurship training for the students, form a concrete brick production unit, incubation of the concrete brick bisnis and creating a new entrepreneur as the result. PTB workshop has and enough place for the development of the college entrepreneur. From the result of entrepreneurship activity the students can develop cncrete brick bisnis unit so it can be used as a additional income.<br />The result of college entrepreneurship activity has made a concrete brick bisnis unit and management office in Pabelan Campus UNS. This activity is involving ten university students from various major, mostly from PTB major. There are two kinds of concrete brick that has been made; Rejal concrete brick and hollow concrete brick. Six hundred concrete brick has been made with the size 10 cm x 15 cm x 30 cm and 10 cm x 20 cm x 40 cm. This size is usually used as a wall or building to adjust the needs of the society.<br />Keywords : concrete brick, entrepreneurship, college, workshop

Characterization of the clay masonry units and construction technique at the ancient city of Nippur

Abstract This paper describes a programme of experimental measurements performed in support of a parallel programme of field investigations to evaluate the construction methods used at the site of the ancient city of Nippur. The experimental programme investigated both the mechanical properties and durability of the ancient clay masonry units used in the construction of buildings at Nippur including tests for dimensional consistency and flatness, density, compressive strength, initial rate of water absorption and thermal properties. The test results have been compared with those for modern brick units available nowadays in Iraq and with hard natural stone samples. The field investigations showed that the important buildings were constructed using composite walls inclusion firing clay masonry units with two nominal dimensions (30 × 30 × 7) cm and (30 × 15 × 7) cm (l, w and h). The formulation of working design technique was followed to achieve the member stability under applied loads. Layers of bitumen material were used as a binder for both bed and head joints in order to provide the desired strength level for the masonry wall. The experimental results show that the ancient brick units and stone samples exceed the tolerance and range of dimensions limits recommended by current EN Standards. Lower density values were recorded for the ancient brick units compared with that for both modern clay brick and stone specimens and these values showed agreement with the modern classification of high density (HD) units. Approximately similar values of compressive strength were observed for both ancient brick units and natural stone samples reaching about 17 MPa, whilst modern clay brick samples showed lower compressive strength value suitable for application of partition walls. The initial rate of water absorption increases with an increase of the soaking time, but tends to decrease after 90 min for both ancient and modern brick units. Superior performance in terms of thermal conductivity, thermal resistance and durability under fire action were observed for the ancient brick samples compared with modern clay brick and stone samples.

PERFORMANCE OF CONCRETE MADE WITH CRUSHED CLAY BRICKS AS COARSE AGGREGATE

Because of economic considerations and thermal insulation requirements, it seems necessary therefor to produce lightweight concrete obtained by crushing an enormous tons of building demolition wastes have been produced. In this study, it is gintended to investigate smashed and the possibility of using crushed clay bricks to replace the coarse aggregate (gravel) in concrete mies. Four nominal normal concrete mixes and four more mixes of crushed clay brick aggregate were prepared and tested. The crushed clay brick aggregates were produced by crushing the brick units (locally available and manufactured in Iran) manually and collected into described size (20 mm). From the analysis of the results, it was found that the unit weight of the crushed brick concrete ranged from (1685-1760) kg/m3 and its compressive strength was about 61% of that of the natural aggregate concrete while the flexural strength was 70% of natural aggregate concrete. Also, the relation between compressive and flexural strength for the lightweight concrete produced is similar to that of normal concrete. Moreover, the results indicated the suitability of the crushed clay brick aggregate concrete to be used in buildings.