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.

abstract: The main objective of this study is to develop an innovative system in the form of a sandwich panel type composite with textile reinforced skins and aerated concrete core. Existing theoretical concepts along with extensive experimental investigations were utilized to characterize the behavior of cement based systems in the presence of individual fibers and textile yarns. Part of this thesis is based on a material model developed here in Arizona State University to simulate experimental flexural response and back calculate tensile response. This concept is based on a constitutive law consisting of a tri-linear tension model with residual strength and a bilinear elastic perfectly plastic compression stress strain model. This parametric model was used to characterize Textile Reinforced Concrete (TRC) with aramid, carbon, alkali resistant glass, polypropylene TRC and hybrid systems of aramid and polypropylene. The same material model was also used to characterize long term durability issues with glass fiber reinforced concrete (GFRC). Historical data associated with effect of temperature dependency in aging of GFRC composites were used. An experimental study was conducted to understand the behavior of aerated concrete systems under high stain rate impact loading. Test setup was modeled on a free fall drop of an instrumented hammer using three point bending configuration. Two types of aerated concrete: autoclaved aerated concrete (AAC) and polymeric fiber-reinforced aerated concrete (FRAC) were tested and compared in terms of their impact behavior. The effect of impact energy on the mechanical properties was investigated for various drop heights and different specimen sizes. Both materials showed similar flexural load carrying capacity under impact, however, flexural toughness of fiber-reinforced aerated concrete was proved to be several degrees higher in magnitude than that provided by plain autoclaved aerated concrete. Effect of specimen size and drop height on the impact response of AAC and FRAC was studied and discussed. Results obtained were compared to the performance of sandwich beams with AR glass textile skins with aerated concrete core under similar impact conditions. After this extensive study it was concluded that this type of sandwich composite could be effectively used in low cost sustainable infrastructure projects. / Dissertation/Thesis / M.S. Civil and Environmental Engineering 2012

This master´s thesis studies qualities of aerated concretes, is monitoring influenece concrete composition, quantity of aerating admixture and plasticized admixture on the durability of concrete. It is monitored especially air flow and his influence on durability on concrete. In theoretical part are explained mechanisms of damage concrete, phenomena, which influence compressive strength of concrete and then there are the results of resistance against the influence of chemical defrosting substances. In experimental work were designed, mixed and tested recipe of concerete. We investigated different atribute, especially resistance of the chemical defrosting and air flow in hardened concrete. The result of master´s thesis is effect of flow air in concrete on the durability.

The thesis deals with the development of new type of lightweight floors based on secondary raw materials. In the introduction, the current knowledge in the field of lightweight building materials, especially screeds and lightweight porous concrete, is presented. The thesis describes brief history of production of aerated concrete and its development up to the present. Further, the thesis describes the procedure of design and testing of new lightweight materials for use in floors. The proposed recipe has been thoroughly tested and the best combination of components for use in lightweight porous concrete floor screed has been selected. The thesis also examines the microstructure of the material being developed. The main result of the dissertation is the developed product, which is already used in practice and is produced and sold on the market as part of the system of lightweight building materials.