Glass Bricks Research Articles

Bricks non-destructive simulation testing method utilizing neutron radiography facility based on a 7Li(p,n)7Be reaction

The evaluation of non-destructive neutron radiography (NR) for examining the internal composition of various structural materials, has been the focus of extensive research. This manuscript uses non-destructive testing to generate three-dimensional radiographs of three different brick structural materials: glass block, magnesia-chrome, and lead to evaluate their capability to withstand fast neutrons and gammas emitted from a source. When neutrons with thermal or epithermal spectrum are required, the optimum combination for an accelerator was simulated using a 2.8 MeV proton beam on a lithium target. The presented facility tested both thermal and fast neutron radiography. This study examined various aperture diameters and collimator lengths. It found that implementing a special fast neutron filter significantly increased the thermal neutron content (TNC) with minimal impact on the thermal neutron flux. For fast neutron radiography, the study evaluated parameters such as geometric unsharpness, fast neutron flux, and the percentage of the uncollided fast neutron reaching the object. Both neutrons and photons from the source were used to inspect faults in a glass brick.

Structural assessment of translucent walls built with a novel type of insulating aerogel-filled glass bricks

Among a multitude of functions, the façade is responsible for providing sufficient thermal insulation and supplying the building interior with enough natural light. For the latter, transparent glazed areas are essential. However, compromises in terms of the glass-to-wall ratio are often necessary since large glazed areas lead to overheating in summer and heat loss in winter. A novel type of highly insulating translucent glass brick made from annealed glass and filled with aerogel granulate was developed recently as an alternative in this regard. The bricks are not supposed to replace the transparent glass areas, but to offer a translucent alternative for part of the otherwise opaque wall areas. This paper focuses on the structural behaviour of walls composed of such aerogel-filled glass bricks. The components of such a brick and their functions are described. Moreover, two prototype systems for supporting the bricks in translucent walls are introduced—one with interlocking connections and pre-stressed wires, the other with interlocking connections and edge clamping. Both systems are analysed in finite element simulations from a structural point of view under out-of-plane loading. The resulting global deformations as well as occurring stresses in different components are analysed. Based on the findings, advantages and limitations of the different systems are highlighted and suggestions for improved alternative systems for translucent walls with insulating aerogel-filled glass bricks are made.

Integrated assessment of buildings visual and thermal performance with translucent bricks

In response to the growing need to reduce building energy consumption while ensuring occupants’ visual and thermal comfort, the Building Energy Materials and Components Lab at Empa developed a high-performance translucent construction element based on aerogel-filled glass bricks. The translucence and thermal insulation characteristics of this brick allows the exploration of different configurations of opaque and transparent surfaces to improve the integrated visual and thermal performance of the indoor environment. This paper presents a workflow to simulate the building performance in order to investigate the effects arising when the mentioned bricks are embedded in the building envelope. Simulations were conducted on a reference building in a continental climate assuming different orientations and window-to-wall ratios. Results show a clear trade-off between minimizing the cooling demand and maximizing occupant visual and thermal comfort. The application of the brick on the northern façade exhibited the best trade-off in terms of energy and comfort.

Development and evaluation of highly thermally insulating aerogel glass bricks

Since we increasingly spend time indoors, natural light inside of interiors becomes more and more important for visual comfort and overall human health through setting of circadian rhythm, and can additionally help with energy savings. Aerogel glass bricks are a new building component for perimeter walls, combining structural properties of glass and the thermal insulation capabilities of aerogel with the aesthetic and daylight-transmitting qualities of both. This paper describes the development and thermal and structural characterization and simulation of a highly thermally insulating aerogel glass brick. The aim was to create an aesthetically pleasing building component with excellent thermal insulation properties that is capable of transmitting daylight.This paper explores the design, development, and thermal simulations of an aerogel glass brick, as well as guarded hot-plate measurements and a compression experiment. Measurements of thermal insulating properties and simulations revealed that the aerogel glass brick could reduce energy consumption significantly compared to other conventional building materials for perimeter walls, while also transmitting daylight. Additionally, its aesthetic qualities can make it suitable not only for use in modern construction projects, but also in refurbishment of older objects.The measured thermal conductivity is 53 mW/(m·K), in agreement with thermal simulation results of 51 mW/(m·K), and the measured compressive strength of the brick is 45 MPa. These data suggest that the aerogel glass brick is a viable option for architects and engineers looking for a sustainable and efficient construction component for perimeter walls. Structurally, the brick should allow building large and high spans and its thermal insulation properties can significantly reduce energy consumption, while its aesthetic and daylight-transmitting qualities make it visually appealing.

Translucent Skylights from Falconnier Glass Blocks

Construction technologies go through several stages: emergence, improvement, decline and revival. Falconnier glass block technology, which was in demand at the very beginning of the 20th century, is now being revived again. Hand-blown and hollow inside, Falconnier glass blocks were widely used for glazing windows, greenhouses, lighting stairs, but of particular interest is their use as a material for glazing translucent coatings of roofs and atriums. Quite often, glass bricks could be found in blank fire walls. In most cases, glass blocks were used for the purpose of zoning spaces while maintaining daylighting, as well as in technical rooms. But Falconnier glass blocks were also used for glazing front facades. But in the mansion of the Tambov manufacturer Aseev, built in 1904–06, a unique cylindrical vault was made from this material, covering the large span of the central living room. On the territory of Russia, it was apparently the only structure of complex configuration made of Falconnier glass blocks. The structure was lost and needs to be restored. According to the results of research, its close analogue is the translucent coating of the atrium of the town hall in Zurich, which is perfectly preserved and, in fact, is very close to the historical design of the lost part of the skylight in M.V. Aseev’s mansion. At the moment, there is every reason to believe that the lost Falconnier technology was practically restored by enthusiasts, which will expand the possibilities in the field of restoration of monuments at the turn of the 19th‑20th centuries. Both of these factors – the existence of a similar constructive solution and the restored technology for manufacturing glass blocks – open up opportunities for recreating a glass barrel vault that completes the atrium of M.V. Aseev’s mansion, which is currently a museum complex.

Korišćenje plastičnog i staklenog otpada pomešanog sa peskom kao alternativni materijali od cigle

Nowadays, the research for innovative approaches to and practices for plastic waste in a circular economy has acquired a big attention. Plastic waste causes a serious environmental pollution concern. Meantime, the cement industry is one of the biggest sources of carbon monoxide and carbon dioxide emissions, which is considered as another environmental challenge to change of climate. All those and others side effects of plastic waste, make the plastic sand glass bricks an attractive alternative material to construction. In this paper, the plastic and glass waste were used at different percentage for replacing cement as a binder to produce non-traditional concretes. The literature review reveals that there is a deficiency of studies that manage the plastic sand glass as a construction material from economic perspective. Plastic sand glass bricks prepared could be a workable solution for combating issues related to solid waste. The results showed that the compressive strength decreased with increasing ratios of plastic to sand. On another hand, it is increased with increasing of sand ratio. Plastic brick prepared poses a density less than the conventional bricks, and acceptable hardness. Low water absorption also reflected that the plastic brick could be used in the construction. TGA and DSC analysis showed that the plastic brick prepared has a good thermal stability and the decomposition is in the limited and acceptable range. Optimization of the two effective variables (plastic/sand and galas ratios) has been made and correlating the results obtained using Box-Wilson statistical method to create a model for describing the predictable properties of a new product.

Get the light & keep the warmth - A highly insulating, translucent aerogel glass brick for building envelopes

Silica aerogels are thermal superinsulation materials that have found increasing application in the building sector in the last ten to fifteen years. While the most common material types are opaque insulating blankets and renders, in its monolithic form silica aerogel can be almost transparent, allowing for composite translucent insulating building system.Here, we developed and characterized a novel modular, translucent and thermally insulating building component based on silica aerogel granules, the aerogel glass brick. Both thermal and mechanical properties were tested and the former were compared to a 3D simulation of the heat transfer through the brick. The glass brick has a measured thermal conductivity of 53 mW/(m·K), corresponding well to the simulation results of 51 mW/(m·K), and a compressive strength of almost 45 MPa. This makes the glass brick the insulating brick with the highest insulation performance reported in literature or available on the market, and at the same time adds the feature of light transmission.The aerogel glass brick is suitable when the requirements combine daylighting, glare protection and the need to protect privacy, e.g. offices, libraries, museums; an analysis of the materials costs indicates that the insulating glass brick can be competitive in such applications. The glass brick provides architecture with new design opportunities to increase daylight inside buildings.

Three-dimensionally (3D) printed sand molds for custom glass parts

The presented research investigates a digital fabrication method for custom glass building elements based on three-dimensionally (3D) printed molds. Custom glass parts with specific geometries usually require several steps of manufacturing, highly specialized craft, or machinery. Computer Numerical Control milled steel molds are only suitable for large lot sizes due to their high cost and limited geometric freedom. Lost-wax casting requires several steps of manufacturing and post-processing. This paper investigates an accessible, low-cost process for shaping glass artifacts using 3D-printed molds to close the gap between mass-produced and custom-crafted glass elements. Previous research has demonstrated the potential of using binder jetting with inorganic binders for glass casting. This paper investigates a range of traditional manufacturing methods besides glass casting that can be combined with 3D-printed molds, including foundry and kiln casting, blow molding, and slumping. The aim is to extend the manufacturing possibilities and provide a range of approaches for three-dimensional glass. The goal is to simplify the process from design to production of three-dimensional solid, hollow, or doubly curved sheet glass elements with high precision. This paper presents investigations of binder jetting techniques and material considerations, their heat resistance, compatibility with different glass- making processes, and coatings for mold treatment. Furthermore, the precision of the resulting glass parts is evaluated, and design guidelines for glass typologies are defined. Glass bricks or sheets for facades with geometric features enabled by the presented fabrication method could allow for novel optical, structural, or decorative properties in building elements.

Overview of realized examples in architecture using structural cast glass blocks

In view of the meticulous and lengthy cooling process discussed in the previous chapters, in architectural applications solid cast glass components have been commercialized up to the size range of standard masonry bricks. Owing to their large cross-sectional area, solid glass bricks are promising structural components that can fully exploit glass’s compressive strength. By forming repetitive components, self-supporting, 3-dimensional all-glass structures of undisturbed transparency can be achieved. Nonetheless, at present, little and rather sporadic exploration has been made in the use of casting as a manufacturing method for structural glass in architecture. To a degree, this is attributed to the existence of only a few realized examples of self-supporting structures made of solid cast glass elements. The, so far, limited demand has in turn led to the absence of a standardized manufacturing process, to a lack of consistent engineering data and to a general unawareness of the potential of cast glass in structural applications in architecture. Currently, including the contribution of this dissertation, there are 3 structural systems employed for creating self-supporting structures out of cast glass components: (a) with a metal substructure, (b) adhesively bonded blocks, (c) interlocking glass blocks. The former two have been applied in real structures, whereas interlocking glass blocks are for the first time introduced as a building system through this dissertation. In this chapter, the 3 concepts are briefly presented, analyzed and evaluated in terms of manufacturing, structural system, level of transparency, ease of assembly and disassembly.

Brick and Glass Waste Valorisation in the Manufacture of Aerated Autoclaved Concrete

Autoclaved aerated concrete (AAC) is a light building material with high porosity, used to improve thermal and sound insulation of the buildings. AAC have a much better thermal efficiency than traditional masonry materials (bricks) or reinforced concrete elements; its use reduces the energy consumption (up to 7%) and consequently the carbon footprint of construction sector. The main constituents of autoclaved aerated concretes are portland cement, siliceous material (aggregate), water and different types of admixtures and additives (lime, foaming agent etc.). The aim of the research presented in this paper is to reduce the environmental impact of the technological process of ACC manufacturing; in this respect, one of the main components of AAC i.e. sand (natural raw material) was substituted with two types of inorganic waste i.e. glass (cullet) and waste brick; the sand substitution rate was comprised between 12.5-100% wt. The results indicate that both glass and brick waste can be incorporated into the autoclaved aerated concrete (AAC) structure without major modifications of apparent density (maximum 10% increase in correlation with substitution amount). For similar values of the apparent density, the AACs prepared with glass waste have higher values of compressive strength and thermal conductivity as compared with AAC with brick waste.

Overview of realized examples in architecture using structural cast glass blocks

In view of the meticulous and lengthy cooling process discussed in the previous chapters, in architectural applications solid cast glass components have been commercialized up to the size range of standard masonry bricks. Owing to their large cross-sectional area, solid glass bricks are promising structural components that can fully exploit glass’s compressive strength. By forming repetitive components, self-supporting, 3-dimensional all-glass structures of undisturbed transparency can be achieved. Nonetheless, at present, little and rather sporadic exploration has been made in the use of casting as a manufacturing method for structural glass in architecture. To a degree, this is attributed to the existence of only a few realized examples of self-supporting structures made of solid cast glass elements. The, so far, limited demand has in turn led to the absence of a standardized manufacturing process, to a lack of consistent engineering data and to a general unawareness of the potential of cast glass in structural applications in architecture. Currently, including the contribution of this dissertation, there are 3 structural systems employed for creating self-supporting structures out of cast glass components: (a) with a metal substructure, (b) adhesively bonded blocks, (c) interlocking glass blocks. The former two have been applied in real structures, whereas interlocking glass blocks are for the first time introduced as a building system through this dissertation. In this chapter, the 3 concepts are briefly presented, analyzed and evaluated in terms of manufacturing, structural system, level of transparency, ease of assembly and disassembly.

Experimental investigation of mortar mechanical properties for glass brick masonry

The main advantage of solid bricks over hollow blocks is substantially higher compressive strength. On the other hand, solid bricks have much higher thermal conductivity, which would lead to major heat loss when used for exterior walls. Masonry pillars and walls are usually loaded in compression and/or bending resulting from the eccentricity of vertical load or wind load. In case of solid glass bricks, compressive strength is about ten times higher than tension strength therefore the limiting factor of the glass masonry is tensile stress resulting from the bending. Whether compared to ceramic or concrete bricks masonry, the glass bricks have a smooth and non-absorbent surface and the adhesion of the mortar to the glass surface is the critical parameter. Presented paper is focused on the experimental investigation of mortar applicable for glass brick masonry with regard to use for load bearing brick walls or columns. Shear, compression and tension tests have been recently performed. Shear and tension resistance and failure modes of brick bed joint were determined during series of tests using various mortar composition, two types of surface treatment and different thickness of the mortar joint. Significant influence of the joint thickness on the resistance was found. The compression tests were performed on two small pillars to determine the compression resistance and failure mode of glass bricks walls and pillars. In parallel to these tests, several small-scale tests have been performed to determine flexural and compressive strength of hardened mortar.

Catholic like Orthodox, Orthodox like Catholic. On the history of establishing new religious rites and new architecture of the Orthodox churches in interwar Poland

The text shows the phenomenon of searching for completely new forms for the use of the Eastern rite in the north-eastern territories of interwar Poland, that is, in the historical area of the Grand Duchy of Lithuania. Religion and religious rites became a tool in opposing political actions conducted simultaneously by the Polish state and Vatican in this ethnically and religiously diverse region. In the plans for the future, eastern Poland was supposed to form a bridgehead for the prospect missionary action in Russia after the fall of the Bolsheviks. The Congregation of Jesuits was entrusted with a task to introduce the so-called Bizantine (or Neouniate) rite, which would faithfully keep to the liturgical forms of the Russian Orthodox Church and preserve all its typical architectural forms as well as icons, iconostases, paraments, etc. The Jesuit ministry centre was installed in Albertyn near Słonim (now Belarus) in 1926, where in 1936–1937 missionaries were furnished with a complex consisting of a Latin Church and an Eastern Orthodox Church, designed by architect Tadeusz Majewski. The temples, both serviced by the Jesuits, were placed symmetrically along two sides of the court, which was to symbolise the equality of both rites in the Roman-catholic universe. The Orthodox Church followed the eastern forms and most of its elements resembled a typical Russian temple in its décor, although figures of the Jesuit saints were introduced to the iconography of some of the icons. From the point of view of the Polish state authorities, the Neouniate action had a harmful effect due to propagating Russian, Belarusian or Ukrainian languages in the rite, which might have sapped the strength of Polishness in the eastern borderlands of the state. Therefore, since the mid-1930s, the state authorities, with a large share of the army, promoted the creation of a “Polish Orthodox Church” with services to be celebrated in Polish. In contrast to the Neouniate action, in which the Catholic rite was to be masked under the forms as close as possible to the Russian Orthodox Church on the basis of kind of “mimicry”, in the Polish Orthodox Church all the elements of religious cult had to be as far as possible from the Russian tradition and would be transformed into a “native” Polish rite. Besides, a new iconography was to be created. To this end, it was decided to build a prototypic “Polish Orthodox Church” in Grodno. Its construction began in 1938 (on the occasion of the twentieth anniversary of regaining independence), but was not completed on account of the outbreak of war. As a result of competition, a design by architect Rościsław Rumiancew was selected. It represented an unusual, modern form, quite different from typical Orthodox Churches erected in the region before the World War I. Some extravagant modifications were introduced: among others, a glass dome, several large stained-glass windows and an iconostasis built from glass bricks.

Experimental analysis on the glass-interlayer system in glass masonry arches

In the last decade there has been an increased usage of cast glass as structural element. Within this respect, a 14 m span glass masonry arch bridge is planned to be constructed at the TU Delft Campus. This paper focuses on part of the experimental analysis that was executed to develop the concept of this bridge. Since it is an arch, the applied loads will be transferred as compressive forces, hence the suitability of glass. Adhesive bonding is not required, since the arch is in compression under its own weight. Application of cast glass bricks in a bridge is a new concept, therefore several aspects with respect to the structural behavior are unknown. Two experimental tests are presented in this paper. First, an experiment with a stacked glass column with varying interlayers is loaded to investigate the stiffness of the interlayer. For PVC interlayers the time-dependent behavior is significant, whereas for polyurethane it is minimal. Furthermore the interlayer’s equivalent modulus of elasticity is dependent on the thickness, due to a difference in the occurring contact areas. Second, a small-scale glass masonry arch is loaded till collapse to investigate the failure behavior and the stresses distribution. It was concluded that a certain robustness is present in the system. Furthermore the brick geometry and the occurrence of sliding are the main aspects that determine the stress distribution. Therewith a stiffer interlayer results in higher stresses in the glass.

Thermal behavior of a translucent superinsulated latent heat energy storage wall in summertime

This paper investigates the thermal performance of a translucent solar wall providing, concurrently, storage and restitution of heat, super thermal-acoustic insulation and daylighting to the interior environment. The wall is composed of glazing, silica aerogel used as a transparent insulation material (TIM) and glass bricks filled with fatty acid, an eutectic phase change material (PCM). To assess the TIM–PCM wall thermal behavior, experimentations were conducted in-situ in a full-sized test cell located in Sophia Antipolis, southern France. Experimental data shows that the tested wall is more effective in winter and might cause overheating during the summer mainly due to solar gains and un-cycling behavior of PCM which remains in liquid state. To enhance the energy performance of the wall in summertime, a numerical model describing the heat transfer mechanisms occurring in the PCM layer in combination with the other transparent wall layers is developed. Then, the model of the wall is linked to TRNSYS software to assess the thermal performance of the whole building. The numerical model is validated experimentally and a good agreement is shown comparing the simulated values with the measured data for seven consecutive days in summer and winter. The importance of considering the natural convection effect in the liquid PCM is also demonstrated. Moreover, it was shown that shading devices can effectively reduce overheating while natural night ventilation decreases the indoor temperature without affecting the PCM performance since the outdoor temperature is always higher than the phase change temperature. The use of a glass with selective solar reflection properties depending on the season instead of the ordinary glazing is shown also to be very effective way to overcome the overheating problem. Finally, the TIM-PCM wall is tested under different climate conditions and passive solutions are given to ensure thermal comfort in summer season.

Melting of a phase change material in presence of natural convection and radiation: A simplified model

In this article, a simplified model for melting of a phase change material (PCM) in presence of natural convection and radiation is presented. A modified enthalpy method is adopted to solve the phase change problem, the natural convection occurring in the liquid PCM is accounted for using the enhanced thermal conductivity approach coupled with the scaling theory, and the absorbed shortwave radiation flux is added into the energy equation as a source term using a simplified solution algorithm. Two dimensional implicit finite volume method is used to solve the energy equation. First, the simplified model for melting with natural convection is validated using a CFD model, in addition to experimental and numerical benchmark solutions for a test case. Then, the simplified model for melting with combined natural convection and radiation is applied to the melting of a fatty acid eutectic filled in glass bricks, which will be used later to model the annual thermal behavior of a special translucent façade. This complete model is validated against the lattice Boltzmann-discrete ordinate method LBM-DOM. It was shown that (1) the proposed simplified model is simple to implement and its simulations run significantly faster than those of CFD models and LBM-DOM model. Consequently, it can be easily integrated into an energy simulation tool for yearly performance evaluation, (2) during PCM melting process, natural convection has a noteworthy role as it enhances the average fraction of liquid and the position of the melting front, (3) shortwave radiation enhances the average liquid fraction.

Glass Masonry - Experimental Verification of Bed Joint under Shear

Glass is considered as a traditional material for building industry but was mostly used for glazing of the windows. At present, glass is an integral part of contemporary architecture where glass structural elements such as beams, stairs, railing ribs or columns became popular in the last two decades. However, using glass as structural material started at the beginning of 20th century, when masonry from hollow glass blocks were used. Using solid glass brick is very rare and only a few structures with solid glass bricks walls have been built in the last years. Pillars and walls made from solid glass bricks are mainly loaded by compression and/or bending from the eccentricity of vertical load or wind load. Due to high compressive strength of glass, the limiting factor of the glass masonry is the joint between the glass bricks as the smooth surface requires another type of mortar / glue compared to traditional masonry. Shear resistance and failure modes of brick bed joint was determined during series of tests using various mortars, two types of surface treatment and different thickness of the mortar joint. Shear tests were completed by small scale tests for mortar – determination of flexural and compressive strength of hardened mortar.

The construction of the Crystal Houses fa\xe7ade: challenges and innovations

A novel glass brick façade has been designed and engineered to reproduce the original brick façade of a former townhouse in Amsterdam. Based on the original design the resulting façade comprises more than 6500 solid glass bricks, reinterpreting the traditional brick pattern, and elaborated cast glass elements for the replication of the window and door frames. To achieve unhindered transparency, the 10 by 12 m glass block façade has to be self-supporting. Previous experimental work by Oikonomopoulou et al. (J Facade Design Eng 2(3–4):201–222, 2015b. doi:10.3233/fde-150021) concluded that it was necessary to use a clear, UV-curing adhesive of high stiffness as bonding material. Experimental work on prototype elements indicated that the desired monolithic structural performance of the glass masonry system, as well as a homogeneous visual result, are only achieved when the selected adhesive is applied in a 0.2–0.3 mm thick layer. The nearly zero thickness of the adhesive together with the request for unimpeded transparency introduced numerous engineering challenges. These include the production of highly accurate glass bricks and the homogeneous application of the adhesive to achieve the construction of the entire façade with remarkably tight allowable tolerances. This paper presents the main challenges confronted during the construction of the novel façade and records the innovative solutions implemented, from the casting of the glass units to the completion of the façade. Based on the conclusions of the research and the technical experience gained by the realization of the project, recommendations are made on the further improvement of the presented glass masonry system towards future applications.

Autonomous self-healing structural composites with bio-inspired design.

Strong and tough natural composites such as bone, silk or nacre are often built from stiff blocks bound together using thin interfacial soft layers that can also provide sacrificial bonds for self-repair. Here we show that it is possible exploit this design in order to create self-healing structural composites by using thin supramolecular polymer interfaces between ceramic blocks. We have built model brick-and-mortar structures with ceramic contents above 95 vol% that exhibit strengths of the order of MPa (three orders of magnitude higher than the interfacial polymer) and fracture energies that are two orders of magnitude higher than those of the glass bricks. More importantly, these properties can be fully recovered after fracture without using external stimuli or delivering healing agents. This approach demonstrates a very promising route towards the design of strong, ideal self-healing materials able to self-repair repeatedly without degradation or external stimuli.

Verification of specific grinding parameters and strength activity index of glass and clay brick

The aim of this paper is to verify activity index (pozzolanic reactivity) of finegrained waste glass and clay brick. First part of this work consists from milling process with variation in milling parameters (time, grinding ratio) and determination (analysis) of the grain size distribution. Subsequently strength activity index is assessed for samples of particles size 50-60 μm. According to EN 450-1 method, tested samples does not reached an appropriate limit values as 25% substitute of cement. This result does not disqualify this type of construction and demolition waste as active additive in building materials but it is necessary improving their input parameters.