bluuebunny/crossref_metadata_2025_split huggingface dataset:
Modeling of AAC composition without autoclaving proces
Authors: Łaskawiec Katarzyna , Gębarowski Piotr , Zając Piotr 
Published: September 2023

AbstractAutoclaved aerated concrete (AAC) technology is undergoing continuous development. This development has so far consisted mainly of expanding the palette of raw materials and preparing them accordingly. The breakthrough in AAC technology came as a result of the introduction of automatic control of production processes. The introduction of automation has made it much easier to maintain a proper autoclaving cycle. It allowed precise regulation of temperature rises in the initial phase of thermal processing. More favorable conditions made it possible to produce lightweight varieties of AAC while maintaining adequate strength of building components. For manufacturers, not only the performance characteristics are important, but also the cost of AAC production, especially the price of the binding material: cement and lime, and the energy‐intensive process of autoclaving. Reducing the cost of manufacturing autoclaved aerated concrete can be achieved by using pozzolanic mineral additives. The article presents research of the structure of AAC obtained using geopolymers. This allows both the modification of the raw material composition and the course of the autoclaving process.
Influence of the type of lintel and the method of covering the window opening on the compressive strength of walls made of AAC
Authors: Drobiec Łukasz , Jasiński Radosław , Mazur Wojciech , Rybarczyk Tomasz 
Published: September 2023

AbstractThis article presents the results of tests on the compressive load capacity of AAC walls with a window opening with a clear span of 1550 mm. Different walls were tested in terms of confinement, concrete and the type of lintel. Standard lintels made of ordinary concrete and prefabricated AAC lintels were built in. Models of walls with additional cores placed along the vertical edges of window openings, in which lintel reinforcement was anchored, were also tested. During the study, apart from the load on the walls and deflection of the lintels, the morphology of cracking of the wall models around the lintel was also analyzed.
Comprehensive studies of the influence of superficial strengthening with the FRCM system on the load‐bearing capacity and deformability of AAC walls
Authors: Drobiec Łukasz , Mazur Wojciech , Jokiel Remigiusz 
Published: September 2023

AbstractThis article presents the results of tests on walls made of AAC (autoclaved aerated concrete) strengthened with the FRCM system. The effect of the applied strengthening was determined based on the results of tests on masonry models subjected to compression, diagonal compression and shear. Models of walls without strengthening, strengthened on one and two sides were tested. The research models were built of masonry elements made of autoclaved aerated concrete (AAC) SOLBET OPTIMAL 4/600. The walls were erected on a system thin‐layer mortar, class M5, without filling the head joints. PBO fiber meshes embedded in a mineral matrix were used as superficial reinforcement. The walls were strengthened by applying the PBO‐MX GOLD MASONRY system mortar to the side surfaces of the models and the PBO‐MESH GOLD 22/22 mesh was embedded in it, and then the top layer of the PBO‐MX GOLD MASONRY system mortar was applied. The compressive strength test was performed on 18 models in accordance with the requirements of the PN‐EN 1052‐1: 2000 standard. In the case of compression, additional tests were performed on models weakened by a cut imitating cracking. The diagonal compression test was performed on 18 models in accordance with the requirements of ASTM E519‐81 standard. The shear load test was performed on 27 models in accordance with the requirements of the PN‐EN 1052–3: 2004 standard. A clear increase in load capacity in each type of test was noted in models strengthened on two sides. In models strengthened on one side, the positive effect of strengthening was observed only by increasing the deformability of the wall. Regardless of the test type, the use of surface reinforcement allowed for smoother behavior of the test models after the loss of load capacity in relation to models without strengthening.
SOLBET: An example of an eco‐friendly company
Authors: Walczak Paweł 
Published: September 2023

AbstractEcology and “eco‐friendly” have been a trend for quite some time now. In all sectors of our lives, we would like to leave the lowest footprint possible and introduce sustainable raw materials and energy policies. Increasing energy prices and problems with the availability of natural resources are a challenge for manufacturers of construction materials. This paper presents very interesting solutions implemented by SOLBET as part of its green policy. It shows what the production process of autoclaved aerated concrete may look like under sustainable management of raw materials and electricity: from a wind farm to green hydrogen, the flow of raw materials with in‐house recycling and production optimization with eco‐friendly solutions have been discussed. The solutions presented in the paper prove that going green means not only a reduction of CO2 emissions but also delivering durable and eco‐friendly AAC with top‐level characteristics.
Investigation of the influence of bed joint steel reinforcement on the load‐bearing capacity and deformability of walls made of AAC (subjected to vertical compression). Part 1 zone around the window opening
Authors: Drobiec Łukasz , Mazur Wojciech 
Published: September 2023

AbstractReinforcement in masonry structures is usually used to control cracks and increase the load‐bearing capacity of walls. This paper presents results from testing full‐scale walls made of autoclaved aerated concrete (AAC). A new type of reinforcement—steel mesh reinforcement protected against corrosion, was used in these tests. The effect of reinforcement on the zone around a window opening is presented in the first part of this paper. The presented tests are a continuation of previous similar analyses published in the papers. The effect of reinforcement on load‐carrying capacity and crack resistance of walls was found in the described tests. The obtained results were compared with results published in the papers.
Analysis of the impact of horizontal reinforcement on the compression and diagonal compression strength of walls made of AAC
Authors: Drobiec Łukasz , Jasiński Radosław , Mazur Wojciech , Rybarczyk Tomasz , Połubiński Tomasz 
Published: September 2023

AbstractThis article presents the results of tests on walls made of AAC (autoclaved aerated concrete) strengthened with horizontal reinforcement in the form of strips of mesh rolled out from a roll, consisting of steel cords with an interwoven fiberglass roving was used. The effect of the applied strengthening was determined based on the results of tests on masonry models subjected to compression, and diagonal compression. Specimens were tested according to guidelines of PN‐EN 1052‐1:2000 and ASTM ES519‐81 code in case of compression and shear test respectively. The results of the tests were also compared with the results of tests of AAC masonry walls without reinforcement, reinforced with truss‐type reinforcement.
Carbonation resistance of different types of calcium silicate hydrates
Authors: Walczak Paweł 
Published: September 2023

AbstractCarbonation is a natural process and occurs in all building materials based on cement or lime. Re‐carbonation of cement‐based materials is an eco‐friendly process, but this process cannot proceed too fast. Autoclaved aerated concrete is a type of concrete produced using the autoclaving process. Due to the fact that other C‐S‐H phases can be formed under hydrothermal conditions in comparison to the standard hydration process in natural conditions, the durability of those phases, mainly tobermorite, should be higher, which was a subject of many studies. Different raw materials and different Cao/SiO2 ratio of the fresh concrete mix is used to produce different densities. Using different CaO/SiO2 may result not only in different amounts of tobermorite in AAC phase composition but also in different morphology of those crystals. This research program concerns the correlation between CaO/SiO2 and the source of the raw materials used on tobermorite formation under hydrothermal conditions and its resistance to re‐carbonation. The different CaO/SiO2 molar ratios used are reflected in the formulas of different class densities of AAC with different cement‐to‐burnt lime ratios. The impact of CO2 in a climate chamber on the phase composition were tested for all samples. The phase composition test was conducted using the XRD method and a SEM analysis with EDS system.
Effect of alternative fibre‐like secondary raw materials utilization by the preparation of the aerated autoclaved concrete
Authors: Mészárosová Lenka , Černý Vít , Melichar Jindřich , Drochytka Rostislav 
Published: September 2023

AbstractThis article is dedicated to the possibilities of using new alternative raw materials in the structure of aerated autoclaved concrete. Primary sources of raw materials are exhaustible and their price is increasing. According to the ecological requirements of the European Union, it is necessary to find many more ecological ways how to produce building materials. Production of aerated autoclaved concrete is for such utilization potentially suitable. It is well known, that the partial replacement of siliceous constituents is possible. This article is focused on the use of dispersed siliceous waste material with fiber‐like grains (e.g., waste fibers from the production of reinforcement fabrics and glass). The input raw materials are standard aerated autoclaved concrete based (cement, lime, silica sand). As an aerating agent was the aluminum powder. This article is dedicated to the determination of basic physical‐mechanical properties and a suitable amount of filler determination. The amount was determined on the basis of the constructive quality coefficient. It seems that partial replacement of the siliceous constituent by fiber‐like materials leads to improvement of properties.
AAC life cycle: How long can autoclaved aerated concrete buildings be used
Authors: Walczak Paweł 
Published: September 2023

AbstractDue to its very good properties, autoclaved aerated concrete (AAC) is a very popular construction material which is a first choice as a masonry unit in a number of countries. Aerated concrete has been mass‐produced for almost 100 years. Experience and dozens of research programs prove it is a good and durable material, eco‐friendly on top of that. Unfortunately, in many countries, the history of AAC production is shorter. This research program tested different AAC blocks in various density classes, which were stored for many years in natural conditions and regularly tested for all properties. Furthermore, the research program included tests of AAC blocks from demolished buildings and blocks tested in climate chambers with CO2 in the lab. The age of those buildings ranged from 25 to 60 years. The analysis of phase composition and microstructure in all samples allowed the research team to determine the moment when the C‐S‐H phase, mainly tobermorite, will become nearly 100% re‐carbonated. Those calculations can be used to determine the life span of buildings erected using autoclaved aerated concrete.
Synthesis, structural characterization, and thermodynamic properties of 11Å Al‐tobermorite
Authors: Jansen Daniel , Lothenbach Barbara , Yan Yiru , Schreiner Jürgen 
Published: September 2023

AbstractIn the present paper, the structure as well as the solubility and thermodynamic data of synthesized Al‐tobermorite is discussed. 29Si NMR and XRD prove the successful synthesis of an Al‐tobermorite with a ratio of Al/(Al + Si) = 0.1. The aluminum is incorporated in the branching (Q3) sites of the silicate chains. Solubility of the synthesized Al‐tobermorite can be calculated from the measured ionic concentrations from storage in aqueous solution, which show little variation over time. The tobermorite remains stable in aqueous solution. Consequently, an equilibrium between aqueous solution and the synthesized Al‐tobermorite can be assumed. On the basis of the experiments, thermodynamic data for Al‐tobermorite can be estimated and presented in the present paper.
Specific solutions for reducing energy consumption in existing and new AAC plants
Authors: Pottin Frank 
Published: September 2023

AbstractThe life cycle analysis of AAC has shown that the majority of CO2 emissions is caused by the binding agents: cement and quicklime. Only 16% are generated during the production process. However, the warning of gas shortages, power black‐out scenarios and the enormous increase in energy costs are now drawing attention to implement more energy‐saving measures into the production process. Considering renewable energy sources, e.g. photovoltaic or wind power, there are legitimate concerns regarding high consumers, like the sand mill or slurry agitators and their load peak, especially when starting the machines. Before installing renewable electrical energy producers, it is essential to minimise the basic load, avoid load peaks and use existing electrical “energy producers”. Although large energy savings like autoclave steam transfer, heat recovery systems, energy saving motors, LED‐lights are already standard in most plants, a lot of energy is still wasted in the industry. This seminar will demonstrate with specific examples additional new energy saving measures like: intelligent start/stop automatic energy recovery or storage energy efficient machine design smart lighting control predictive maintenance algorithms. Each individual measure does not seem to have a big influence but it may come as a surprise how much energy saving potential there is in the sum of these individual measures. Specifically, tested and implemented energy‐saving measures in WEHRHAHN AAC plants will be explained, giving answers to: How can existing AAC plants be even more updated in an energy‐efficient manner? What does a modern, energy‐efficient AAC plant look like?
Transformation pathway to a green lime offer
Authors: Cnop Tom , Verhelst Frederik , Pavlík Jaroslav , Lempertz Ulrich 
Published: September 2023

AbstractThe Autoclaved Aerated Concrete (AAC) industry has announced an ambitious decarbonization roadmap to 2050 to keep its place as a reference product in the future market of building materials. AAC raw materials are contributing to a large share of the CO2 footprint of AAC and need to be carefully assessed. Lime is today an essential raw material in the production of AAC and will remain so in the future as, unlike some other raw materials, it cannot be interchanged by a less carbon‐intensive alternative. Lime is essential in the formation of Tobermorite and provides the alkaline conditions required for the formation of the hydrogen bubbles structuring the mineral foam. Lime is produced by the calcination of limestone (CaCO3) releasing carbon dioxide (CO2). The CO2 footprint of lime is considerable, and the production process is considered hard‐to‐abate. Today roughly two‐thirds of the CO2 is inherent to the production process while only one‐third of the CO2 is due to the required fuel. Lhoist has developed a Carbon Action 2030 plan with a range of low‐carbon and carbon‐neutral lime solutions. The approach is based on the principle of three pillars: Avoiding, Reducing, and Compensating with a pipeline of effective carbon reduction initiatives behind each pillar. The paper will provide a status update on the key projects in Belgium, France, and Germany. The transformation to low‐carbon lime has triggered projects in energy improvement, sustainable fuels, the usage of hydrogen, kiln electrification, oxyfuel kilns, carbon capture, and storage as well as CO2 utilization. Once the CO2 is captured during the production of lime, the carbonation of the AAC will lead to a carbon‐negative building material. Our roadmap will position Lhoist as a preferred partner for the AAC industry in the future. Our lime product portfolio ranging from Level|Blue™ to Level|Green™ will support the AAC industry to consolidate and develop its referential position in the building materials industry.
Future ready limes for the AAC industry
Authors: Peter Ulrike , Walter Diethelm , Crinière Guillaume , Pust Christopher , Leszczynski Marcin , Verhelst Frederik 
Published: September 2023

AbstractLime is an essential raw material for the production of Autoclaved Aerated Concrete (AAC). Its functionality is triple in this application: The mineral phase giving rise to the mechanical strength of AAC (tobermorite) is formed by the reaction of quicklime (calcium oxide, CaO) with silica (silicon dioxide, SiO2) under hydrothermal curing. Lime is also providing the alkaline conditions required for the formation of the hydrogen bubbles structuring the mineral foam. Finally, the exothermic hydration (“slaking”) reaction with water is providing the required energy input in the system. Lime is produced by the calcination of limestone (CaCO3) releasing carbon dioxide (CO2). Today's limes appreciated for the production of AAC are showing slow reactivity, with t60 values typically higher than 8 and up to 16 min and more. Those limes are obtained by severe calcination, so‐called “hardburning,” which requires a higher amount of energy compared to standard high reactive limes, releasing more CO2 accordingly. Seeking for improving the carbon footprint of its product portfolio, Lhoist investigates different pathways to produce limes suitable for the production of AAC. This paper presents new lime qualities under development, their slaking behavior, and impact on the typical AAC process steps. The new limes show smooth while modified slaking profiles. The use of such lime qualities will allow for a progressive shift from today's formulation technologies towards formulations with highly improved environmental profile.
Experimental characterization of AAC masonry in shear: Effect of block density, mortar, and test setup
Authors: Michelini Elena , Cerioni Roberto , Riva Andrea , Boretti Giovanbattista , Casillo Alfredo , Ferretti Daniele 
Published: September 2023

AbstractThe paper discusses the results of an experimental program devoted to the characterization of AAC masonry in shear, by studying the effect of different key parameters: test setup, block density, and mortar type. As for ordinary masonry assemblages, shear parameters of AAC masonry can be determined from either shear tests on triplets or diagonal compression tests. However, the extension of these methodologies to AAC blocks with low densities is not so straightforward and highlights some critical issues. To evaluate the influence of block density (and block strength) on the shear parameters and on the observed modes of failure, masonry triplet and diagonal compression tests were performed for AAC blocks characterized by two different densities (300 and 480 kg/m3). Moreover, for the higher density class, tests were repeated by also varying the mortar type. Although most of Standard codes mainly relates the shear resistance of thin‐layer masonry to the block material, the obtained results highlight that also the mortar type and the surface treatment before mortar application may have a not negligible influence on the final behavior.
Application of binders with lower carbon footprint in the AAC production
Authors: Straube Berit 
Published: September 2023

AbstractAutoclaved aerated concrete (AAC) is a building material that mainly contains calcium silicate hydrate phases, especially 11 Å tobermorite. For forming these mineral phases, calcium ions from the binders and silicon ions from the milled sand are necessary. Currently, hard‐burnt lime and Portland cement are used as binders for AAC production. Both raw materials contribute significantly to the carbon footprint of AAC products. On the way to climate neutrality of AAC production, it is thus necessary to replace hard‐burnt lime and Portland cement with binders with a lower CO2 impact. Therefore, tests with middle‐burnt lime in combination with different Portland limestone cement were carried out to investigate their influence on processing, material properties, and the mineral phase composition. It can be concluded that both these lower CO2 impact raw materials can be used for AAC production, as there are no changes in material properties and mineral phase composition.
Elements subject to control during construction with AAC
Authors: Rybarczyk Tomasz 
Published: September 2023

AbstractAutoclaved aerated concrete has a 100‐year tradition. As a structural masonry material, it has been known and used for years. It goes without saying that when constructing energy‐efficient and sustainable buildings, everything should be done correctly and in line with the best construction practice, with all weak spots addressed. Building using an aerated concrete system opens such possibilities, as AAC is the easiest masonry material to build, offering exceptional properties. It allows dozens of experienced contractors to deliver development projects to the highest standard, error‐free. The material also offers opportunities for new and inexperienced contractors. In either case, construction supervision performed by a site manager and the investor's supervision inspector will be helpful. Manufacturers, too, can help by creating a checklist for aerated concrete masonry work and thus achieving a quality advantage over other materials. This paper highlights elements to be inspected during the construction of AAC masonry walls, a process in which the work is constantly being covered up and thus must be inspected. The author provides clearly formulated guidelines on how to erect masonry walls and what to pay special attention to when erecting and inspecting AAC masonry. This is the knowledge that must be available and reminded to contractors and site supervisors all the time.
Circular construction with AAC—recycling of an industrial hall made of Hebel elements in Munich‐Puchheim
Authors: Kreft Oliver , Pfanz Andreas , Franke Joachim , Osterried Johannes 
Published: September 2023

AbstractIn Germany, construction, and demolition waste accounts for more than half of the waste generated, which means that valuable raw materials are lost for high‐quality recycling. But there is a solution: switching to a closed material cycle in which discarded products are reprocessed so that they can be used to manufacture the original or at least an equivalent product. A pilot project near Munich in Germany is demonstrating how discarded Xella products can be recycled into new products of equal value—with pioneering results. An old industrial hall made of prefabricated Hebel AAC‐wall elements was demolished, the material collected and processed into AAC powder, which was subjected to the production of new AAC. In the meantime, a new hall made of AAC has been built on the same site.