Autoclaved aerated concrete (AAC) is a lightweight cellular building material. In Spring 2008, an experimental study was conducted at The University of Texas at Austin to evaluate the load-deflection behavior and capacity of six different factory-reinforced AAC lintel groups. The results the test program are used to evaluate the shear design provisions of ACI 523.4R “Guide for Design and Construction with AAC Panels”. / text

The use of chemically compatible nano and fine particle colloidal consolidants is a new development within the field of cultural heritage conservation and applied most widely so far to the historic built environment. The ability to introduce a significantly higher quantity of chemically compatible consolidant to a substrate in fewer treatments with the possibility for greater penetration and fewer possible side-effects compared to more established consolidants is a significant advantage. This fundamental scientific study examines the effects of a colloidal calcium hydroxide (nanolime) consolidant on medieval and quarried limestone and autoclaved aerated concrete and the efficacy of a colloidal hydroxyapatite treatment on archaeological human bone. Both calcium hydroxide and hydroxyapatite were synthesised. Characterisation of both compounds was performed by X-ray diffraction spectroscopy and particle morphology was confirmed by electron microscopy. Particle size was determined by laser diffraction and particle tracking analysis techniques, used together to study these particle systems for the first time, and electron microscopy. The location of particles within treated substrates was established by electron and optical microscopy whilst effects on water transport were determined by imbibition experiments and numerical modelling. For the first time a modified sharp front model was applied to [particle-material]-material composites to aid the understanding of water transport in such materials. Mechanical testing was used to identify differences in material strength depending on treatment layer thickness and mercury intrusion porosimetry suggested extent of pore blocking. It was found that non-classical effects occur in the calcium hydroxide system synthesised in this study and that particle stability can be influenced by reagent concentration. For the first time material sorptivity properties, modality and pore size distribution of Lincoln stone and archaeological bone are reported. The application of a nanolime consolidant to autoclaved aerated concrete allowed the nature of the particle transport through a highly complex material to be determined, showing that the particle concentration decreases with increasing penetration depth. Shallow nanolime particle penetration into limestone appeared ineffective on compressive strength. In a novel study the prospects of a hydroxyapatite consolidant treatment for bone were also evaluated, finding the results to be inconclusive in this small study. For all consolidants a small reduction in material water sorptivity after treatment demonstrated the permeable nature of the treatment layer and suggests the avoidance of damage mechanisms due to highly restricted water transport. Knowledge of the efficacy and location of treatment particles and their affect on water movement, particularly in weathered material, within limestones and archaeological bone is important and was determined for all materials used in this study. This work adds to the understanding of such treatments and their capabilities and the nature of the porous materials used herein.

Master of Science / Department of Architectural Engineering and Construction Science / Sutton F. Stephens / Autoclaved Aerated Concrete (AAC) is a lightweight concrete building material cut into masonry blocks or formed larger planks and panels. Currently it has not seen widespread use in the United States. However, in other parts of the world it use has been used successfully as a building material for over fifty years. AAC is a relatively new (at least to the United States) concrete masonry material that is lightweight, easy to construct, and economical to transport. Its light weight is accomplished through the use of evenly distributed microscopic air bubbles throughout the material; these bubbles result in a lightweight concrete that is composed of a latticework around spherical voids. This report details the history, physical properties, manufacturing process, and structural design of AAC. This report includes an explanation of the 2005 Masonry Standards Joint Committee (MSJC) Code for the design of AAC members subjected to axial compressive loads, bending, combined axial and bending, and shear. An example building design using AAC structural components is provided. This report concludes that AAC has important advantages as a structural building material that deserves further consideration for use in the United States.

The master´s thesis deals with the possibility of laboratory verification of the influence of feedstock character, especially lime and fly ash, on quality of fly ash aerated concrete. The experimental study involves taking a series of samples autoclaved and non-autoclaved aerated concrete during two pilot plant verification in the factory. After removal of autoclaved and non-autoclaved aerated concrete samples they were tested and compared with results of non-autoclaved aerated concrete produced in the laboratory. Methodology of comparison technologically-produced autoclaved aerated concrete and laboratory-produced non-autoclaved aerated concrete was designed based on achieved findings.

Design of autoclaved aerated concrete (AAC) masonry in the United States is currently based on Appendix A of the 2008 Masonry Standards Joint Committee (MSJC) Code. Those provisions include the design of lap splices, and equations for the nominal capacity in interface shear transfer between grout and AAC. The provisions for lap splices are an extension of the provisions for concrete or clay masonry, modified to neglect the contribution of AAC to splice capacity. This thesis describes a testing program aimed at verifying the current provisions using tests of lap splices in grouted AAC masonry. Based on the results of those tests, the provisions are shown to be appropriate. The provisions on interface shear transfer between grout and AAC require that the transferred shear be checked against a nominal capacity based on limited test results. This thesis describes a testing program aimed at verifying and refining this nominal capacity using pullout tests of grout cores in AAC masonry units. Based on the results of those tests, the currently used nominal capacity is shown to be conservative, and a recommendation is made to increase it. / text

The aim of this study was to investigate the quantifiable planimetric design efficiency of residential buildings designed to be built with &amp / #147 / Autoclaved &AElig / rated Concrete&amp / #148 / (AAC) panels. Focus was on the effects of plan shape, plan size and layout organization and the modularity of vertical AAC wall panels on the planimetric design efficiency of residential buildings. To this end, relevant analyses were conducted on 30 residential building projects obtained from the design office of an AAC panel manufacturing firm in T&uuml / rkiye, AKG Gazbeton. The lengths, widths and areas of building elements (quantitative data) were then calculated from the production drawings of these building. A total of fifteen ratios, which were considered relevant to the study as indicators of design efficiency, were computed by using this quantitative data. This was followed by the construction of frequency distribution tables and histograms showing the variations of the computed ratios. At the final phase, Analyses of Variance (ANOVA) were conducted to determine the source of variation and Chi-Square tests conducted to determine whether or not the distributions could be considered &amp / #145 / normal&amp / #146 / . According to the results of the study, it was found that plan shape and plan size of building projects together with their layout organizations, were the main influential factors on the efficiency of their wall and floor areas. It was also found that the modularity of vertical wall panels used in these buildings was another important factor to be considered in planimetric design efficiency.

The expansion of an industrial area in Näsudden, Skelleftehamn, will require extensive groundwork. An old landfill in the area, partly consisting of autoclaved aerated concrete (siporex), is intended to be used for constructing the new industrial site. The conditions for how the material can be used is, however, controlled by a variety of parameters. This is a part study of the evaluation of how the masses should be treated. The purpose of this study is to evaluate how the presence of siporex affects the mobility of arsenic and lead in the landfill area. Soil and groundwater samples from 10 sample points from the landfill area were collected and analyzed for its metal content. The results were used for calculating the solid/liquid partition coefficient (Kd) for the desorption of samples with or without siporex. Results indicate that the mobility of arsenic is higher in the samples with siporex due to the higher pH in the leachate. No correlation could be found between the influence of siporex and mobility of lead in this study. Further studies are needed in a controlled environment to assess how siporex affects the mobility of arsenic and lead.

High concentrations of heavy metals in the soils have potential long-term environmental and health concerns because of their persistence and accumulation tendency in the environment and along the food chain. This study was aimed at studying the feasibility of heavy metals removal from the soil using plants naturally growing in the surroundings of selected polluted sites in Tanzania and soil application of the sorbent materials zeolite and autoclaved aerated concrete (AAC). The results showed that Sporobolus sp. is a hyperaccumulator of Cu. Four other species, Launea cornuta (Oliv &amp; Hiern) O. Jeffrey, Tagetes minuta (L.), Sporobolus sp. and Blotiella glabra (Bory) Tryon showed high potential for phytoextraction of Cu. No hyperaccumulators of Pb and Zn were identified in the area, but Tephrosia candida and Tagetes minuta (L.) were identified as potential plants for phytoextraction of Pb, while Conyza bonariensis (L.) Cronquist, Launea cornuta (Oliv &amp; Hiern) O. Jeffrey, Tagetes minuta (L.), Blotiella glabra (Bory) Tryon, Pteridium aquilinum (L.) Kulm and Polygonum setogulum A. Rich were identified as potential plants for phytoextraction of Zn. The result from sorbent experiments showed that both materials had a potential for remediating metal polluted soils. The AAC had a higher removal capacity for both Zn and Pb than zeolite. The removal capacity of zeolite and AAC in a mixed metal experiment (Pb and Zn) showed a little difference in the sorption capacity of AAC and Zeolite for Pb and Zn respectively. Speciation of the metal in soil shows that the major part of the metal was associated with firmly attached component of the metal in the soil. Compared with the total metal concentration analysed, the available component accounted for 13-39% for Zn and 31-39% for Pb. It can be suggested to co-remediate polluted soils using reactive sorbent nodules and hyper-accumulating plant species. Identification of the best combinations and designs remains the subject of future research. / <p>QC 20121130</p>

In this dissertation, the seismic behavior and design of AAC-infilled steel moment frames are investigated systematically. The fundamental vehicle for this investigation is the ATC-63 methodology, which is intended for the establishment of seismic design factors for structural systems. The ATC-63 methodology is briefly reviewed, including the concepts of archetypical structures, design rules and mathematical models simulating the behavior of those archetypes. A limited experimental investigation on the hysteretic behavior of an AAC-infilled steel moment frame is developed, conducted, and discussed. Using the experimental results of that investigation, the draft infill design provisions of the Masonry Standards Joint Committee (MSJC) are extended to AAC infills, and a mathematical model is developed and calibrated to simulate the behavior of AAC infills under reversed cyclic loads. Prior to application of ATC-63 methodology to AAC-infilled steel moment frames, the methodology is applied to an example steel moment frame to demonstrate the methodology and verify understanding of it. Then, archetypical infilled frames to be evaluated by the ATC-63 methodology are developed using a series of pushover analyses. Infill configurations whose total lateral strength in a particular story exceeds about 35% of the lateral strength of the bare frame in that story are observed to provoke story mechanisms in the frame. Based on this observation, archetypical infilled frames are selected conforming to two infill configurations: uniformly infilled frames, and open ground story frames. Each infill configuration includes archetypes whose ratio of infill strength to bare-frame strength at each story is less than 35%, and archetypes whose ratio is greater than 35%. The former archetype is typical of steel moment frames infilled with AAC; the latter archetype is typical of steel moment frames infilled with conventional (clay or concrete) masonry. The ATC-63 methodology, specialized for application to infilled frames, is applied to the archetypical infilled frames developed above. The performance of those archetypical infilled frames is evaluated, and seismic design factors are proposed for AAC-infilled steel moment frames. The extension of this work to other types of infilled frames is discussed. / text

Submitted by Maicon Juliano Schmidt (maicons) on 2015-05-29T18:30:06Z No. of bitstreams: 1 Ângelo Cezar Fumagalli Rostirola.pdf: 4315210 bytes, checksum: ff48e5f928774ac2545c3ae6774d5dcf (MD5) / Made available in DSpace on 2015-05-29T18:30:06Z (GMT). No. of bitstreams: 1 Ângelo Cezar Fumagalli Rostirola.pdf: 4315210 bytes, checksum: ff48e5f928774ac2545c3ae6774d5dcf (MD5) Previous issue date: 2013-10-24 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / SINDUSCON-NH - Sindicato das Indústrias da Construção Civil Novo Hamburgo / A construção civil atualmente é a indústria com maior crescimento no Brasil, fomentada por financiamentos e programas do governo federal. É também uma das indústrias que mais consome recursos naturais e energia, além de ser a principal geradora de resíduos sólidos urbanos. Grande parcela destes recursos naturais consumidos pela construção é formada pelos agregados. Uma alternativa econômica e ambientalmente correta, para diminuir a extração deste material, é a sua substituição por algum outro material, se possível por um resíduo, como apontam várias pesquisas. A busca por materiais e produtos ecologicamente corretos está em uma crescente, assim como os estudos para a reciclagem de diversos resíduos. A união entre produtos que consomem um volume menor de matéria-prima com o emprego de resíduos na sua produção parece uma saída viável para um desenvolvimento mais sustentável. Artefatos para a construção civil produzidos com concreto celular autoclavado (CCA) utilizam até quatro vezes menos materiais quando comparados a produtos com características semelhantes, produzidos com concreto convencional, cerâmico, entre outros. Além do menor consumo dos materiais constituintes, o concreto celular possui outras propriedades interessantes, como: suficiente resistência à compressão; isolamento térmico e acústico; baixa densidade; resistência ao fogo. Esta pesquisa teve como objetivo principal avaliar a influência da substituição parcial do agregado natural por agregado reciclado de concreto (ARC) na produção de concreto celular autoclavado. Após realização de estudos-piloto, optou-se pelo emprego da proporção de Cimento e Agregado Natural (AN) de 67% e 33% e sobre estes 0,45% de Cal e 0,3% de Alumínio com relação água/sólidos igual a 0,32. Foram empregados Cimento Portland CP-V ARI, Cal calcítica, areia natural e agregado fino reciclado de concreto, em teores de 0%, 25% e 50%. A dimensão máxima do agregado empregado na produção de CCA é de 150 µm. A cura foi realizada em autoclave após um tempo de espera de 24 horas a partir do início da mistura, por um período de 6 horas. Foram avaliadas a resistência à compressão, a absorção de água capilar, a massa específica e a porosidade. Os ensaios de resistência à compressão foram realizados em 48 e 72 horas, e a absorção de água, em corpos de prova preparados e acompanhados pelo período de 96 horas. A microestrutura dos CCA produzidos foi caracterizada por microscopia eletrônica de varredura (MEV). Verificou-se que existem expressivas alterações nas propriedades do CCA produzidos com ARC em substituição do AN, com a tendência de aumentar a densidade de massa aparente, bem com a resistência à compressão, a medida que aumenta-se o teor de ARC. Na análise dos resultados, percebeu-se que o uso de ARC alterou as propriedades dos concretos produzidos neste estudo exploratório, sem, entretanto, inviabilizar o seu emprego. Com um ajuste da dosagem, pode ser obtido um CCA produzido com ARC, cujo comportamento seja compatível com o comportamento de CCA produzido somente com o AN. / In the last years, the Brazilian construction industry is among those of national production sectors that have been having a great growing, mostly due to the incentive from the government and due to financed resources by private and public agents. This industry is also one of the major consumers of natural resources and energy, besides being the main generator of solid waste. One of these natural resources used in the constructions is sand. An environmentally friendly and economical alternative to reduce the extraction of natural resources is the use of recycled waste. The associated use of low volume of raw materials with alternative materials, like waste, is one of the ways to get more sustainability in the construction sector. Construction and building components made with autoclaved cellular concrete (ACC) employ four times less material than others with the same function. Other advantage of ACC is the performance of its properties like compressive strength, thermal and acoustic behavior, lower density, fire resistance. The aim of this research was to investigate the use of fine grains from recycled concrete aggregate (ARC) as partial sand replacement in the production of autoclaved aerated concrete. With the goal to find the mix proportion some pilot studies were made. After this, it was chosen a relation of 67% of cement and 33% of natural fine aggregate (sand). The lime was used in the amount of 0.45% of total cement and sand, and 0.3% of aluminium. The water to total solids ratio was 0.32. It was employed Portland cement type V according to Brazilian standards, calcitic lime, natural sand and ARC passing in sieve with 150 micron opening. The replacement rate of sand by ARC was 0%, 25% and 50%. From 24 hours after the mixing of materials, the samples were submitted to steam curing in an autoclave chamber for 6 hours. It was evaluated the compressive strength, the density, the capillary water absorption and porosity. The compression strength tests were performed at 48 and 72 hours. Water absorption tests were conducted for 96 hours after samples preparing. The capillary porosity was calculated with the capillary water absorption data. ACC's microstructure analysis was done by scanning electron microscopy (SEM). The results showed in general that the behavior of ACC produced with ARC differs significantly from the ACC produced with natural aggregate. When the ARC rate increases the apparent specific gravity also increases as well as the compressive strength. The observed increase in the apparent specific gravity is not desired. However this behavior of ACC done with RCA does not prevent the use of this recycled aggregate. An optimized study of pre-wetting of RCA could improve its performance as aggregate for use in ACC, once its grain size showed to be appropriated for this kind of use.