Hollow Bricks Research Articles

Analysis of the thermal behavior of hollow bricks walls filled with PCM: Effect of PCM location

The drastic heat waves intensified by climate change have urged the cooling demand in the building sector. Therefore, thermal comfort in buildings has become a significant energy consumption issue. The building envelope is the primary separator between the conditioned indoor and the unconditioned outdoor environments of the building. This physical separator controls energy exchange and balances the storage capacity of the building. Thermal energy storage can be enhanced using Phase change materials (PCMs). Hence, using these materials can improve the thermal mass of building envelopes. This paper investigated the energy performance of the hollow brick wall filled with phase change materials. It inspected PCM’s behavior by analyzing the impact of PCM placement in a double wall of hollow bricks. In this regard, four PCM positions in hollow bricks were numerically studied in a warm climate city. The results demonstrated the possibility of filling blocks with PCM in selected locations instead of filling the entire brick. Regarding energy savings, the phase change material in locations 3 and 4 saves up to 97% of the energy required to maintain internal thermal comfort at a set temperature of 26 °C.

Passive evaporative cooling through water-filled bricks: a preliminary investigation

Direct evaporative cooling is widely known to be an energy efficient air-conditioning option for arid and semi-arid climates. However, care must be taken on humidity ranges achieved indoors. Existing literature presents several options for integrating evaporative cooling within buildings for passive cooling applications. This work aims at expanding the current knowledge by focusing on the use of water-filled hollow bricks to implement evaporative cooling of air in contact with the brick’s surfaces. A prototype is built and experimentally characterized under controlled air velocity, air temperature and relative humidity conditions. Results on the psychrometric conditions achieved under different geometric arrangements (i.e., with one, two or three rows of four bricks each) are presented and discussed. Insights on likely building integration of the system for passive cooling purposes in farms and agriculture applications are eventually given.

Tracking the material cycle of Italian bricks with the aid of building information modeling

Clay brick masonry is a vernacular construction technique; it continues to be used extensively in Italy and elsewhere. Despite the essential role clay bricks play in construction, they are often overlooked in the environmental literature, and sound production data are hard to obtain. This study integrates material flow analysis (MFA) and building information modeling (BIM) to assess the quantity and use cases of clay bricks and terracotta tiles used for construction in Italy. Material flows for these products were traced from the supply of raw materials to manufacturing, use, demolition, and waste management in Italy in 2006, 2011, and 2016. 3D representations of typical buildings were drawn in BIM and used to create material intensities to investigate functional uses of bricks. Hollow bricks used as infills in external walls and load-bearing bricks were the main products manufactured in all three years of analysis, followed by bricks used in internal walls and floor-forming bricks. In all cases, maintenance and refurbishment of existing buildings was the primary end-use category. From 2006 to 2016, the Italian brick production shrank fourfold, from 20.6 Tg to 5.1 Tg, while direct carbon dioxide emissions from the calcination of calcium carbonate decreased from 2.4 Tg to 0.5 Tg. Functional recycling is rare, and this poses serious challenges to the circularity of the construction sector. The results demonstrate that the integration of MFA and BIM approaches markedly improves the detail, speed, and realism of quantifying the material flows within the urban environment. This article met the requirements for a Gold-Gold JIE data openness badge described at http://jie.click/badges.

Modeling the effective thermal conductivity of hollow bricks at high temperatures

In this work, we derive a model for the anisotropic effective thermal conductivity of bricks based on the unit cell model approach. The presented model considers conduction and surface-to-surface radiation in the brick. Four different radiation models are presented, compared, and validated using fully resolved computational fluid dynamics simulations for three different brick profiles and experiments.Good agreement with fully resolved computational fluid dynamics simulations with and without radiation is found.The validated model was then applied in a global sensitivity study and to simulate the temperature distribution in brick stacks in a tunnel kiln segment under firing conditions.

Numerical study of phase change material microencapsulated in a typical multilayer wall for a hot climatic zone

AbstractA phase change material (PCM) allows releasing and absorbing energy at the phase change transition. They are employed in building walls to maintain internal thermal comfort and optimize thermal energy storage. However, the hottest cities in Morocco suffer from overheating during peak days. Consequently in this article, the purpose is to evaluate the thermal performance of incorporation of the PCM n‐octadecane paraffin in a typical multilayer wall at three different locations for a Moroccan hot climate zone. Numerical simulation is developed in a two‐dimensional transient in addition to mathematical modeling using the enthalpy‐porosity approach for three wall types. An implicit finite volume method is used for the numerical solution. The effects of PCM location, PCM type, and mass fraction (varying between 15% and 35%) are studied and compared with the reference case (without PCM). The evaluation of mass fraction variation is based on two determining factors of the wall panel's thermal inertia: the time delay and amplitude attenuation. The surface heat fluxes will then be used to quantify the capacity of the multilayer wall to store and release energy. The results showed that to ensure the thermal performance of the wall, it is useless to exceed 20% of mass fraction for all types of multilayer walls. It is shown that the incorporation in a solid matrix of hollow brick is the most optimal scenario, and it makes it possible to have a reduction in the internal surface flux of 32% with a temporal phase shift of 3 h.

Using Phase Change Materials (PCMs) in a Hot and Humid Climate to Reduce Heat Gain and Energy Consumption

Twenty percent of the world’s energy is consumed by the construction sector, including commercial and residential buildings, where 13% is consumed by the residential sector only. Half of the total energy consumed by buildings in Saudi Arabia is specifically attributed to the hot summer season, which, unlike in many other countries in the Middle East, continues for more than 5 months annually. The use of a phase change material (PCM), as an insulator in building materials, can be a solution to provide a comfortable indoor temperature and reduce energy consumption. This study examined two different melting ranges for PCMs RT35 and RT35HC inserted into hollow clay bricks to investigate their thermal behavior and heat storage capacity and compare them with polystyrene foam. To perform this experiment, four chambers were constructed using cement plastering. The data were collected at Jeddah, Saudi Arabia, from mid-November 2020 to the end of February 2021. When the highest temperature was reached during the experiment, PCM RT35 provided a better cooling effect by 13% compared to 24% and 28.56% for PCM RT35HC and foam, respectively, compared to hollow bricks alone. However, when the lowest temperature was reached during the experiment, PCM RT35HC performed better than the other chambers in saving energy and keeping the chamber warm, which was 9.5% for the reference chamber, 7.0% for the foam chamber, and 2.8% for PCM RT35. The maximum energy saving of PCM RT35 was around 1920 kJ, which is around 0.533 kWh, for one wall only, and for PCM RT35HC, it was 2880 kJ, or 0.8 kWh, which can reduce energy consumption of the HVAC system by 97 kWh/m2 and 146 kWh/m2 per year, respectively.

Experimental and numerical assessment of confined infill walls with openings and textile-reinforced mortar

This work's primary objective is to present an experimental campaign, comprised of three full-scale in-plane tests. It was assessed the effect of the openings (central window) and of using textile-reinforced mortar strengthening. The slenderness is also studied by comparing the results herein obtained with other test existing in the literature. The masonry infill walls were built with horizontal hollow clay bricks. All the tests consisted of applying cyclic (loading-unloading-reloading) history of imposed displacements in the in-plane direction employing a top horizontal load. The mechanical properties of the adopted materials are characterized and presented. The results will be presented in terms of in-plane force-displacement responses, damage evolution and energy dissipation capacity. A literature review of numerical modelling approaches to simulate the masonry infill walls seismic behaviour was provided after that. In the end, the experimental tests were simulated in the software OpenSees through a simplified modelling approach. The openings reduced the in-plane maximum strength and energy dissipation capacity by about 40% and 18%, respectively. On the other hand, the textile-reinforced mortar increased the initial stiffness, maximum peak strength and energy dissipation capacity by about 31%, 15% and 38%, respectively.

Innovational Construction Materials of LLP “EcostroyNII-PV” Production

The article discusses the experience of recycling industrial waste from the electric power industry and metallurgy. Based on the experience of Ecostroy NII-PV LLP. The proposed technology for manufacturing building products from ash and slag waste provides innovative compositions of raw mixtures. What provides an increase in operational characteristics and labor productivity in construction. The applied technology, in comparison with the existing analogues, provides for the use of local waste (ash and slag waste from the combustion of Ekibastuz coal, bauxite sludge from the Pavlodar aluminum plant, steel-making slags), differing in chemical and granulometric composition. as well as binding properties from other analogs and prototypes. In the manufacture of building products introduced mixture, including, wt %: slag Portland cement - 14.32-17.00; sand - 18.74-25.52, crushed stone - 46.50-49.71, sludge from alumina production obtained during the recycling of bauxite from Kazakhstan - 5-7; self-disintegrating steelmaking slag - 5-7; ash and slag waste from thermal power plants from burning Ekibastuz coals - 5-7. According to the test results, the average tensile strength of building products (paving slabs, curbs, hollow bricks) is 3.2 - 3.8 MPa (strength class V2.5).

Effects of mortar compressive strength on out of plane response of unreinforced masonry walls

In this study, the out-of-plane response of infill walls that are widely used in Turkey and the surrounding regions were experimentally investigated. Several out-of-plane wall tests were performed in the laboratory, with the walls specimens produced with lateral hollow clay bricks (LHCB) and different mortar qualities. The walls were tested in their out-of-plane (OOP) direction under static load conditions and evaluated based on the load-bearing and energy dissipation capacities, crack propagations, mortar strengths, and initial stiffnesses. These walls are experimentally investigated to understand the effects of the mortar strength on the infill wall structural behaviors and to assess the effectiveness of the out-of-plane strength formulations. It was found that when the mortar strength is low, the first major crack occurs at the mortar, however, because of the arch mechanism efficiency in this situation the OOP load-carrying and energy dissipation capacities of unreinforced walls can be significantly increased. When the first major crack in the wall occurs in the brick itself, the arc mechanism is provided with delicate sections in the brick, which leads to strength decreasing in the walls. In this case, excessive deviations occur in the out-of-plane strength formulations estimates. This study shows that the arc mechanism, the damage start region and progress can change significantly unreinforced masonry (URM) infill walls behaviors.

Influence of Different Types of Infill Walls on the Hysteretic Performance of Reinforced Concrete Frames

To study the influence of masonry infill walls on the hysteretic performance of reinforced concrete frames, a cyclic experiment was conducted for three two-story and two-span reinforced concrete frame structures, including one reinforced concrete frame without infill walls and two frames with infill walls. Whether the infill walls were constructed in the frames and the type of infilled material were the main parameters of the test. The major results reveal that: the infill walls clearly changed the mechanical mechanism of the frame structure at the early stage of loading, magnified the stiffness and horizontal bearing capacity of the frame structure, and enhanced the energy dissipation capacity of the frame structure, but reduced the deformation performance of the frame structure. In the later stage of loading, the infill walls would no longer work as one with the frame gradually with the failure of the infill walls, and the above performance of the structure would approach the empty frame structure. Moreover, the initial stiffness, energy dissipation capacity, and horizontal bearing capacity of the frame with infill walls of clay hollow bricks were the highest among the three specimens. But due to the strong diagonal bracing effect, the damage to the top of the columns and beam-column joints was serious, the yield displacement was reduced significantly, and the shear failure of the top of the columns and the joints occurred prematurely, which showed poor performance of deformation and ductility. However, the frame with infill walls of relatively soft aerated lightweight concrete blocks showed better performance of deformation and ductility.

Drying and Heating Processes in Arbitrarily Shaped Clay Materials Using Lumped Phenomenological Modeling

This work aims to study the drying of clay ceramic materials with arbitrary shapes theoretically. Advanced phenomenological mathematical models based on lumped analysis and their exact solutions are presented to predict the heat and mass transfers in the porous material and estimate the transport coefficients. Application has been made in hollow ceramic bricks. Different simulations were carried out to evaluate the effect of drying air conditions (relative humidity and speed) under conditions of forced and natural convection. The transient results of the moisture content and temperature of the brick, and the convective heat and mass transfer coefficients are presented, discussed and compared with experimental data, obtaining a good agreement. It was found that the lower the relative humidity is and the higher the speed of the drying air is, the higher the convective heat and mass transfer coefficients are at the surface of the brick and in the holes, and the faster the moisture removal material and heating is. Based on the predicted results, the best conditions for brick drying were given. The idea is to increase the quality of the brick after the process, to reduce the waste of raw material and energy consumption in the process.

The role of the openings in the out-of-plane behaviour of masonry infill walls

This research work aims to present an experimental study concerning the effect of the openings in the out-of-plane (OOP) behaviour of masonry infills in RC buildings. The experimental campaign comprises the OOP testing of three full-scale infill walls made up of horizontal hollow clay bricks, two of them with a central window and the remaining one with a central door. One of the specimens with a central opening was first subjected to a previous in-plane test and, after that, the damaged wall was subjected to an OOP test. All the tests consisted of applying a loading–unloading-reloading history of imposed displacements in the OOP direction through a uniformly distributed load. An innovative setup was used and adapted for each wall typology. The results are presented in terms of OOP force–displacement responses, damage evolution, relative stiffness and energy dissipation capacity. Finally, the test results are compared to each other to assess the effect of: i) the area of the opening; and ii) the previous damage. It was found that the openings reduced the maximum strength of 30% for undamaged panels, and it occurred for lower displacement demands. The increase of the opening area did not affect the peak load; however, it reduced their energy dissipation capacity significantly. The energy dissipation capacity reduced from 42% to 70%.

Confinement effects of glass FRP on circular concrete columns made with crushed fired clay bricks as coarse aggregates

This paper investigates the confinement effects of low-cost glass fiber reinforced polymer composites on circular concrete columns made with crushed fired clay bricks as coarse aggregates. Two types of locally available fired clay bricks such as solid fired clay bricks and hollow fired clay bricks were used to prepare the crushed fired clay brick aggregated. The crushed fired clay brick aggregates were replaced with natural aggregates by 50 %. In this study, a total number of 32 circular concrete columns were constructed and tested under monotonic axial compression. The other research parameters were strength of concrete (i.e., low strength and high-strength concrete) and number of layers of glass FRP composites such as two, four and six layers. Locally available bi-directional glass fiber and polyester resin were used to develop glass FRP composites. The salient features of glass FRP composites are low-cost, high strength and stiffness. The experimental results indicate that the use of glass FRP composite is very suitable to modify the ultimate load carrying capacity and stiffness of the circular concrete columns made with crushed fire clay bricks as coarse aggregates. In general, the confinement effects of glass FRP on circular concrete columns are found higher for concrete made with crushed fired clay hollow bricks as compared to the concrete made with crushed fired clay solid bricks. Also, increase in ultimate load carrying capacity is found lower for high-strength concrete circular columns as compared with the low-strength concrete circular columns. The analytical investigation reveal that the existing ultimate strength models are suitable to approximately predict the ultimate strength of glass FRP confined circular concrete columns made with crushed fired clay bricks as coarse aggregates. However, the existing ultimate strain models are not suitable to accurately predict the ultimate strain of glass FRP confined circular concrete columns made with crushed fired clay bricks as coarse aggregates.

Estimation of Cooling Load Temperature Diffrence for Exterior Walls of Buildings Located in Tripoli, Libya

A good estimate of the cooling load is one vital aspect for achieving the optimal level of comfort and energy effiency in buildings. Due to its relative simplicity, the Cooling Load Temperature Diffrence (CLTD) method is still used both in education and industry for cooling load calculations. However, one downside of using this method is the limited number of walls and roofs which do not represent effctively all commonly used wall and roof constructions. In this research, a transient heat transfer model was developedto fid the (CLTD) values, for the most common external walls of buildings that have widespread use in Tripoli, Libya. Th Finite diffrence method was used to solve the governing partial diffrential equations with appropriate initial and boundary conditions. A MATLAB program has been developed and used to solve the system of algebraic equations produced by applying the fiite diffrence method to the governing diffrential equations. A comparison has been made between the computed results and ASHRAE CLTDvalues. At standard conditions specifid in ASHRAE handbooks for the same wall with a default composition, a reasonably good agreement was found between computed and ASHRAE CLTD values for this wall. CLTD values have been generated for three diffrent types of walls; Hollow concrete block, Limestone block, and Hollow brick. With these values, the cooling load calculation of buildings can be easily and manually performed with more accuracy. It is also concluded from the transient analysis that the limestone block walls provide the best therm.

Integrating PCM into hollow brick walls: Toward energy conservation in Mediterranean regions

Nowadays, cooling demand in the building sector is increasing in cooling-dominant climates because of extreme heat waves reinforced by climate change. As the demand for thermal comfort in buildings continues to grow, energy consumption increases accordingly. The application of phase change materials (PCM) to building envelopes can improve thermal energy storage, thus they can be used to increase the thermal mass of buildings. This article shows the efficiency of using PCMs to mitigate building cooling demands in eight cities representing the Mediterranean region: Al Hoceima (Morocco), Malaga (Spain), Marseille (France), Taher (Algeria), Naples (Italy), Tripoli (Libya), Ankara (Turkey), and Port Said (Egypt). The energy performance of three types of building: single-family, collective housing and hotel housing, built with hollow bricks, with and without PCMs, is evaluated in these cities using a numerical model based on the apparent heat capacity. A wide range of PCM melting temperatures is studied (from 22 °C to 32 °C). The results confirm that climate profoundly influences the storage/release process of PCMs. Regardless of the building typology, energy savings can reach 56% in the North-East Mediterranean cities using a PCM with a 26 °C melting temperature, while no energy savings have been noted for the South-East cities. Finally, a correlation between the energy savings and the Cooling Degree Day is demonstrated, resulting in the recommendation of a PCM with a 26 °C median melting temperature in a given location.

Experimental investigations on the structural behaviour of reinforced geopolymer beams produced from recycled construction materials

Concrete requires a vast amount of aggregate and cement production. Although there are some efforts in the literature to reduce the amount of Portland cement in the concrete mixture to lessen the greenhouse gas release, a limited number of studies were conducted to investigate the possibility of using this geopolymer mixtures to serve as a structural component. Therefore, this study firstly aimed to produce geopolymer concrete from construction and demolition waste-based precursors, including masonry units (red clay brick, roof tile, hollow brick, etc.) and glass. In addition, recycled aggregates produced from the concrete waste portion of the CDW were used to obtain 100% recycled construction material on the scale of the binder and aggregate phase. Then, this study investigated the possible use of this proposed geopolymer concrete to produce structural components that perform similar to conventional concrete. Therefore, the structural properties of reinforced geopolymer concrete beams produced from the recycled construction demolition wastes were evaluated in this study by conducting laboratory experiments. To this end, bending tests were performed on reinforced conventional concrete beam specimens and reinforced geopolymer concrete beam specimens. The test observations clearly showed that construction demolition waste could be recycled to produce new constructional components, considering its advantage of promoted sustainability.

Experimental Investigation of The Optimal Location of PCM Capsules in a Hollow Brick Wall

In this paper, an experimental investigation of the integration of PCM capsules as insulation material into the outer or inner rows of hollow brick to find out the optimum location of the PCM capsules that give the best thermal performance of a wall. A test model consists of two identical cubical rooms was designed and fabricated to test the wall with and without PCM in a natural outdoor condition in Diwaniyah city in Iraq during the summer. The results show that the PCM will reduce the temperature of the inner side of the test wall and test room by 2.7℃ for the PCM capsules in the inner row while the reduction in both the inner surface temperature and the room due to the use of the capsules in the outer row was 1.9℃. The time lag for the two cases was 1 hour. So that, the inner row location of PCM is the optimum location.

Experimental and numerical investigation of PCM capsules as insulation materials inserted into a hollow brick wall

In this study, an experimental and numerical work aims to analyze and investigate PCM capsules' use as an insulation material into the hollow bricks that form a wall. A novel model of plug and play wall system consisting of two identical rooms was designed and fabricated to test two southern walls with and without PCM in the outdoor natural condition. The mathematical model was used to investigate the novel wall's detailed performance, not just verifying the results. Therefore, a three-dimensional mathematical model using the FORTRAN language based on a finite volume scheme with enthalpy method was built and used to analyze the walls and natural convection inside the rooms. The numerical results were matched well with experimental measurement. Compared with the not treated wall, the results show that the encapsulation of PCM in the treated wall will lead to reduce the inner surface wall and room temperature by about 4.7 °C, increase the time lag by 2 h, reduce the temperature fluctuation by 23.84% and the decrement factor was 0.7.

Construction and demolition waste-based geopolymers suited for use in 3-dimensional additive manufacturing

This paper focuses on the evaluation of ambient-cured 100% construction and demolition waste (CDW)-based geopolymers in terms of rheological properties for 3-dimensional additive manufacturing (3D-AM). The CDW-based precursors used for geopolymer production were hollow brick (HB), red clay brick (RCB), roof tile (RT) and glass (G) activated by different combinations of sodium hydroxide (NaOH), calcium hydroxide (Ca(OH)2) and sodium silicate (Na2SiO3). Rheological properties were evaluated via empirical tests such as flow table, vane shear test, modified mini-slump test and compressive strength test for mechanical characterization. Based on these results, the extrudability performance of selected CDW-based geopolymer mixtures was analyzed with a ram extruder, and finally, a single mixture was selected to be used in laboratory-scale 3D-printing. The geopolymer mixture activated by 6.25 M NaOH and 10%-Ca(OH)2 exhibited the best performance in terms of rheology and compressive strength, and it was therefore selected for use in laboratory-scale 3D-printing. 3D-AM application at the laboratory scale showed that ambient-cured 100% CDW-based geopolymers can be successfully used for 3D-printing, with adequate rheological and mechanical properties and without any additional chemical admixtures, and that the empirical test methods used are effective in assessing the suitability of CDW-based geopolymers for 3D-AM applications. The outcomes of this work are believed to contribute to the current literature significantly, as they combine the advantages of green material development, waste upcycling, reduced raw materials and easy/fast/accurate producibility.

Trace level electrochemical detection of mesalazine in human urine sample using poly (N-Vinyl)-2-Pyrrolidone capped Bi-EDTA complex sheets incorporated with ultrasonically exfoliated graphene oxide

Trace level detection of drugs and hazardous analytes is more critical in electrochemical sensor. In this work, a simple sonochemical-assisted synthesis of Bismuth-EDTA complex/GO flakes was achieved and was developed to analyze mesalazine (MSA) sensing. The 3D hollow bricks were obtained for the Bi-EDTA complex without PVP. Surprisingly, PVP influenced the formation of broken glass-like structured for PVP with Bi-EDTA complex. Bi-EDTA complex modified GCE was developed to determine the role of PVP and its activity in electrochemical sensors. The results obtained by modifying the electrode Bi-EDTA complex with PVP showed good electrochemical performance compared to bare and other controls like GO and Bi-EDTA complex without PVP. The synergetic effect and high electroactive sites of Bi-EDTA complex/GO modified sensor implied low LOD (0.55 nM) and wide linear range from 0.005–585 µM. Furthermore, Bi-EDTA complex/GO showed an excellent selectivity in sensing MSA. Moreover, the Bi-EDTA complex exhibits advantages such as good stability, reproducibility, and repeatability. The modified Bi-EDTA complex/GCE sensor has been practically done to determine trace levels of MSA in human urine samples containing mesalamine tablets with satisfactory results.