Many failures of external walls made of porous buildingmaterials are caused by excessive moisture content,particularly after driving rain and under long duration ofmoist conditions. Lack of sufficient protection againstexposure conditions is one of the reasons for external wallsprematurely demonstrating failures, i.e. properties andperformance above/below critical levels. Silicon-based waterrepellants are increasingly used in order to improve theperformance of both old and new buildings. Water repellants areexpected to prolong the service life and improve the durabilityof wall components by preventing or minimising water ingressinto the structure and thus delaying the deteriorating effectsof the atmosphere. To date, various kinds of water repellantshave been developed. However, only limited research has beencarried out, particularly on the long-term field exposuretesting. Existing research is mainly focused on the performanceof surface treatments of concrete structures and the protectionof historical buildings built of stone, brick and wood, and isprimarily based on short-term laboratory testing. The aim ofthis research work is to study the long-term performance,degradation processes and ageing characteristics of renderedautoclaved aerated concrete (AAC) with and without waterrepellants. Investigations are carried out by physical andchemical analysis of fresh samples, samples naturally weatheredby long-term field exposure and samples artificially aged byshort-term accelerated laboratory tests. Two differentapplication of water repellants are employed: impregnation ofrendering surface with an aqueous product and as additive inpowder form mixed into the fresh rendering mortar. Continuousmoisture and temperature monitoring of naturally exposed testsamples are also included in the study. Wetcorr sensors andresistance-type nail electrodes are used to measure the surfacemoisture and the moisture content in the material,respectively. This thesis describes the experimental set-upand presents the results from site monitoring and laboratorytests of unexposed, naturally and artificially exposed samples(freeze-thaw and UV+water). The results from the continuousmoisture measurements are compared with the results obtainedfrom the full-scale test cabin built within the EUREKA-projectE 2116 DurAAC. The test cabin has the same basic measurementinstruments for continuous monitoring of moisture andtemperature. An attempt has been made to develop methods forlong-term performance assessment of water repellants to be usedin service life prediction. The combination of data obtainedfrom the field measurements with data obtained from thelaboratory tests and analysis may also meet practical needs ofthe end-users.

Examined in this study were some physical, mechanical, compositional and durability properties of AAC, its neighboring plasters and jointing adhesive, all of which were produced in Turkey. The compatibility of these materials inside the contemporary wall section and within historic fabric was discussed in terms of their material properties. In addition to the literature survey, laboratory studies were conducted on two types of AAC as G2 and G4, its jointing adhesive and exterior finishing layers as base coat, under coat, finish coat, water repellent finish coat / and some historical traditional construction materials of Anatolia as timber, masonry and infill brick, lime based exterior and interior plasters. The results were evaluated in terms of material properties of AAC, the compatibility of AAC and its complementary elements with each other and with the historic timber framed structures in Anatolia. It was concluded that the use of AAC in repairs of historical structures could be discussed only if the original infill is lost. In addition, its cement-plasters should be avoided from the historic fabric since they introduce salt problems to the structure. In terms of vapor permeability and modulus of elasticity, water repellent finish coat was proper finishing for AAC, and AAC, especially G4, exhibited similarities with historic infill mud brick. Further studies on other compatibility parameters were, however, necessary to decide on the compatibility of AAC with its neighboring materials. Moreover, the integrity of AAC with the historic fabric needed improvement by increasing its pozzolanicity and/or producing a new intermediary repair mortar/plaster.

<p>Many failures of external walls made of porous buildingmaterials are caused by excessive moisture content,particularly after driving rain and under long duration ofmoist conditions. Lack of sufficient protection againstexposure conditions is one of the reasons for external wallsprematurely demonstrating failures, i.e. properties andperformance above/below critical levels. Silicon-based waterrepellants are increasingly used in order to improve theperformance of both old and new buildings. Water repellants areexpected to prolong the service life and improve the durabilityof wall components by preventing or minimising water ingressinto the structure and thus delaying the deteriorating effectsof the atmosphere. To date, various kinds of water repellantshave been developed. However, only limited research has beencarried out, particularly on the long-term field exposuretesting. Existing research is mainly focused on the performanceof surface treatments of concrete structures and the protectionof historical buildings built of stone, brick and wood, and isprimarily based on short-term laboratory testing. The aim ofthis research work is to study the long-term performance,degradation processes and ageing characteristics of renderedautoclaved aerated concrete (AAC) with and without waterrepellants. Investigations are carried out by physical andchemical analysis of fresh samples, samples naturally weatheredby long-term field exposure and samples artificially aged byshort-term accelerated laboratory tests. Two differentapplication of water repellants are employed: impregnation ofrendering surface with an aqueous product and as additive inpowder form mixed into the fresh rendering mortar. Continuousmoisture and temperature monitoring of naturally exposed testsamples are also included in the study. Wetcorr sensors andresistance-type nail electrodes are used to measure the surfacemoisture and the moisture content in the material,respectively. This thesis describes the experimental set-upand presents the results from site monitoring and laboratorytests of unexposed, naturally and artificially exposed samples(freeze-thaw and UV+water). The results from the continuousmoisture measurements are compared with the results obtainedfrom the full-scale test cabin built within the EUREKA-projectE 2116 DurAAC. The test cabin has the same basic measurementinstruments for continuous monitoring of moisture andtemperature. An attempt has been made to develop methods forlong-term performance assessment of water repellants to be usedin service life prediction. The combination of data obtainedfrom the field measurements with data obtained from thelaboratory tests and analysis may also meet practical needs ofthe end-users.</p>

[pt] O presente trabalho propõe-se a analisar o comportamento mecânico de painéis sanduíche constituídos por duas camadas externas de compósitos cimentícios reforçados com fibras naturais, separadas por um núcleo de concreto celular autoclavado (CCA). Cada placa de material compósito foi moldada diretamente sobre a superfície de um bloco de CCA, por meio da disposição manual de três camadas unidirecionais de fibras longas de curauá. Visando prover maior durabilidade ao compósito, desenvolveu-se uma matriz com baixo teor de hidróxido de cálcio, substituindo uma parcela do cimento por materiais pozolânicos. Ensaios de caracterização da matriz, dos filamentos de curauá e dos blocos de CCA foram realizados para a obtenção de suas propriedades independentes. Os compósitos foram submetidos a ensaios de arrancamento do tecido, tração direta e flexão a quatro pontos para a avaliação de diferentes aspectos de seus mecanismos de fissuração, resistência e capacidade de deformação. Zonas de carregamento foram indicadas em cada caso para demonstrar o comportamento padrão dos compósitos. Os painéis sanduíche, por sua vez, foram analisados em termos de interface, por meio de ensaios de aderência e micrografias da superfície de transição dos materiais, e de desempenho mecânico, por ensaios de flexão a quatro pontos cíclicos e monotônicos. Esses últimos forneceram a rigidez, capacidade de carga e deflexão dos painéis sanduíche, tal como as principais propriedades de seus elementos: para o núcleo, a resistência ao cisalhamento e o módulo de cisalhamento, e para as lâminas, a resistência à compressão e à tração. Os ensaios cíclicos testaram a resistência do material a séries de carregamento-descarregamento, enquanto ensaios de aderência foram utilizados para verificar a interface entre os compósitos laminados e o núcleo de CCA. Os resultados indicaram um desempenho satisfatório dos painéis sanduíche, uma vez que os compósitos foram capazes de lhes fornecer um comportamento de strain/deflection hardening, aumentando sua resistência e tenacidade. A adesão entre lâminas-núcleo mostrou-se eficaz, de maneira que os diferentes materiais compreendidos demonstraram interação adequada entre si, bem como propriedades complementares. Dentre os objetivos desse trabalho, encontra-se o desenvolvimento de um material sustentável, leve, resistente e tenaz, de modo que constitua uma alternativa promissora e de baixo custo a aplicações de Engenharia. / [en] This present work aims to analyze the mechanical behavior of sandwich panels consisting of two outer layers of natural fiber-reinforced cementitious composites separated by a core layer of autoclaved aerated concrete (AAC). The molding of each composite layer was made directly on the surface of an AAC block, by manually arranging three layers of long unidirectional aligned curauá fibers in the mortar. In order to increase the composite durability, a matrix with a low content of calcium hydroxide was developed, where the Portland cement was partially replaced by pozzolanic materials. Characterization tests of the matrix, the curauá filaments and the AAC blocks were performed to obtain their independent properties. The composites were submitted to fabric pull-out tests, direct tensile tests and four-point bending to evaluate different aspects of their cracking mechanisms, strength and deformation capacity. Loading zones were indicated in each case to demonstrate the standard composite behavior. The sandwich panels, on the other hand, were analyzed in terms of interface, through pull-off tests and SEM images of the materials transition surface, and mechanical performance, by means of cyclic and monotonic four-point bending tests. The latter registered the rigidity, load capacity and deflection of the sandwich panels, as well as the main properties of their elements: for the core, shear strength and shear modulus, and for the skin layers, compressive strength and tensile strength. Cyclic tests evaluated the resistance of the material to loading-unloading cycles, while pull-off tests were used to verify the interface between the laminated composites and the AAC core. The results indicated a satisfactory performance of the sandwich panels, since the composite layers provided a strain/deflection hardening behavior to the material, increasing its flexural strength and toughness. The adhesion between the layers and the core proved to be effective, so that the comprised materials displayed adequate interaction between each other, as well as complementary properties. Among the objectives of this work is the development of a sustainable, lightweight, resistant and tough material, in a way that it represents a promising and low-cost alternative to Engineering applications.

The diploma thesis deals with the use of waste glass powder as an aggregate in thermal insulation plasters for AAC. In the theoretical part, the problem of thermal protection of buildings is discussed first. The production and properties of foamed glass are described. Then the research of plasters, their composition and properties was made. Thermal-insulating plasters are specified and their use has been proposed for thermal insulation of building structures. In the practical part, suitable formulations have been proposed in the form of dry plaster and mortar mixtures (SOMS). Test samples were prepared from them. The physical and mechanical properties were measured. These were compared with the requirements set by standards and technical regulations. To get closer to the behavior of plasters on real buildings an AAC wall was built. The individual recipes were applied on it. It was monitored working with plaster and how it held on the masonry. During ripening crack development was observed. Optimization calculation inculded these aspects and it determined the optimal recipe. All designed recipes can be used as a thermal-insulating plasters.

Autoclaved aerated concrete is a used building material, especially for its thermal insulating properties. During autoclaving, an aerated concrete microstructure produces crystalline CSH phases, primarily tobermorite. The ingoing substances are calcium oxide and silica. In addition to commonly used raw materials, secondary raw materials rich in silicon dioxide can be used for production. The use of secondary raw materials gives the opportunity for the construction industry to be more environmentally friendly. Another benefit is the reduction of financial costs. The work explores the influence of individual secondary raw materials on the microstructure. High-temperature fly ash, fluid fly ash, cinder, ground glass and zeolite were used The raw materials were mixed with unalloyed lime at a molar ratio of calcium oxide to silicon dioxide of 0.73 and 1.0. Autoclaving capsules were used to synthesize tobermorite under laboratory conditions. Autoclave was performed at 170 °C and 190 °C with hydrothermal durations of 4, 8 and 16 hours. The most important influence on the microstructure was high-temperature fly ash, on the contrary, the greatest influence on the mechanical properties is attributed to the ground glass.

Autoclaved aerated concrete is long-time ecological building material with usefull properties. There needs to be done research of its mineralogical compound for reengineering the production. The main mineral compound of AAC is tobermorite, it increases its mechanical properties. In the presence study, we examine the usage of nature and artificial silicious materials. Also, we investigate the influence of sulfate and alumina admixtures, as well as fluidized bed combustion ash, which can be used as the lime and gypsum replacement. Closure of the study is design of the optimal raw material composition, also hydrothermal treatment of autoclaved aerated concrete. In relation to its mechanical properties, mineralogical composition and cost.