Dissertations / Theses on the topic 'Masonry units'

The UK is committed to reducing the environmental impact of construction, but due to growing population there is a requirement for new domestic housing. The embodied environmental impact is going to become an increasingly significant proportion of the whole life cycle of a building. There is therefore a requirement for research into low environmental impact construction materials. There has been a resurgence of earthen construction techniques as a response to growing environmental awareness and consideration. This has led to a renewed interest in earth construction and an increased use of earth within contemporary architecture. However, there are many barriers to the mainstream adoption of traditional methods of earthen construction, and only with the widespread adoption can the benefits be fully utilised. Extruded earth bricks that are manufactured using the well established fired brick production methods, without the firing can produce consistent, high quality, low cost bricks. As the bricks are of the same dimensions as current masonry there are fewer barriers to the adoption. This form factor, crucial for contemporary construction, relies on wall thicknesses of only 100mm. It has been shown that extruded earth bricks have a suitable strength for typical domestic loading. However, there are concerns about structural use due to loss of strength under elevated moisture contents; representing the greatest barrier to adoption. Stabilisation is a method by which the soil properties can be changed to increase strength under saturated condition. This thesis aim is to develop suitable methods of stabilisation for extruded earth bricks, with a lower environmental impact than existing masonry units. The scope is limited to the extrusion process and the soil currently used for fired brick production. To this extent seven brick soils used in the manufacture of commercially fired bricks were investigated into their physiochemical properties and engineering properties with respect to the identified mineralogy. There has been limited literature focusing on extruded earth bricks which is in part due to the difficulties of specimen manufacture. Two methods of laboratory scale specimen production were investigated and compared to full scale unfired bricks. A small scale extruder was used to make one third linear scale bricks and was shown to be suitable representation for unstabilised conditions. This allowed for laboratory scale testing of extruded specimens. Three categories of chemical stabiliser were investigated including cement, lime and alkali hydroxides. Compressive strength development over 7, 14 and 28 days was determined for specimens tested in ambient conditions and following 24 hours fully submerged in water. Varying mass fractions and initial curing regimes were investigated to determine the effect on compressive strength. Only 5% lime initially cured at 60 ◦C met the required structural criteria of a ‘dry’ and ‘wet’ compressive strength of 2.9 and 1.0MPa respectively. Metakaolin was subsequently added as a secondary stabiliser to improve the strength for all the primary additives. The change in compressive strength was variable, but did enable a total of six specimens to meet the required criteria, all with 5% lime as the primary stabiliser. A cradle-to-gate LCA was undertaken for the unstabilised and stabilised extruded earth bricks. The analysis only considered embodied energy and global warming potential and compared the results to conventional masonry units. Environmental criteria were developed based on the conventional masonry unit with the minimum impact. Considering this criteria, only two mixes were able to offer an improvement of the global warming potential. The reliance on highly processed commercial metakaolin was investigated by the partial thermal treatment of the brick soil. While the investigated chemical properties of this material were comparable to the metakaolin, the particle size distribution was significantly different. This resulted in a decrease in density, and no strength development when used with 5% lime. This study has shown the potential for extruded earth masonry to be used structurally and the requirement for stabilisation. A possible stabilisation technique has been proposed which will allow for the reduction of the embodied global warming potential, whilst meeting the structural requirements.

The concrete masonry unit (CMU) has been a standard in the building industry for the last century, widely utilized for its durability, modular assembly, and its’ relative ease of handling. While there are a variety of sizes, the general form of the CMU has remained unchanged; the same module can be used anywhere in the world. The goal of this project is to increase the aesthetic and thermodynamic performance of CMUs by re-investigating the interior and exterior surface geometries of the unit with the intent of extracting greater thermodynamic performance. This greater performance in turn correlates to user comfort and more ecologically responsible building practices. I propose a modular system of construction derived from the relationship between material, fabrication, and assembly, and results in a unit able to thermodynamically respond to daily and seasonal variations in solar condition. The application for this model is wall system that tempers the environment of the Sonoran desert, where we witness great contrasts in solar conditions throughout the year. Geometry and materiality become points of interaction with the environment, as the Thermal Masonry Unit (Thermal[MU]) provides the capacity to absorb, store, and/or dissipate energy. The Thermal[MU] utilizes these attributes by acting as a filter between environment and user: providing shade and a thermal barrier in the summer and collecting/distributing the heat gain in the winter months. This passive thermal control is important because it makes a more economical use of material properties and forming principles and establishes a direct physical relationship between the user and the environment.

Static and dynamic carbonation curing at early age was developed for ordinary Portland cement (OPC) and Portland limestone cement (PLC) concrete masonry units (CMU) production. It is intended to replace conventional steam curing, improve the CMU performance, reduce energy consumption, and permanently sequester carbon dioxide in concrete. Concrete slabs representing the face shell of a 20-cm CMU as well as full sized CMU were used throughout the carbonation process. In static carbonation, it was found that initial air curing was vital to maximize carbonation reaction. After a procedure of casting, air curing, carbonation curing, and water compensation in subsequent hydration, carbonated CMUs had shown equivalent strength to steamed CMU but much better resistance to freeze-thaw damage. Carbonate-reinforced cement matrix played a critical role in improving freeze thaw resistance. In dynamic carbonation, the initial air curing was combined with carbonation with controlled relative humidity. The production cycle was significantly reduced to avoid initial air curing. The process proved to be a valid replacement of the static system in terms of CO2 uptake and compressive strength. While both OPC and PLC concretes displayed the hydration and carbonation products, only OPC concrete demonstrated an intermix of these products in the form of calcium silicate hydrocarbonate and a phase transformation of poorly crystalline aragonite and vaterite into well crystalline calcite. Based on 24% CO2 uptake, the CMU production in US and Canada is capable of sequestering 2 million tons CO2 per year. It is equivalent to 2.5% carbon emission reduction for US and Canada cement industry.<br>La carbonatation par méthode statique et dynamique a été développée pour la cure rapide de blocs de bétons composés à partir de ciment Portland ordinaire ainsi que de ciment Portland à base de calcaire. Cette approche vise à remplacer le procédé traditionnel de cure de blocs de bétons par étuvage afin d'améliorer leur performance, réduire la consommation d'énergie, et séquestrer le dioxyde de carbone de manière indéfinie. La façade extérieure d'un bloc de béton de 20-cm, représenté par une dalle de béton, ainsi qu'un bloc de pleine taille, ont été utilisés durant le procédé de carbonatation. Les résultats indiquent qu'il est essentiel de curer les blocs par air contrôlé avant d'employer la carbonatation statique. Suivant la procédure de moulage, cure à l'air, carbonatation, et compensation de l'eau à travers hydratation suivie, les blocs de bétons carbonatés ont témoigné une résistance comparable à celle de blocs durcis à la vapeur, cependant une résistance supérieure aux dégâts de gel-dégel. La microstructure du ciment carbonaté-renforcé a joué un rôle crucial dans l'amélioration de la résistance du gel-dégel. Dans la carbonatation dynamique, le durcissement initial par étuvage a été combiné avec carbonatation sous une humidité relative contrôlée. Afin de réduire le cycle de production, le durcissement initial par étuvage a été éliminé. La carbonatation dynamique s'est avérée être un remplacement valable du système statique en termes d'absorption de CO2 et résistance à la compression. Bien que le ciment Portland ordinaire ainsi que le ciment Portland à base de calcaire ont confirmé des produits d'hydratation et de carbonatation, seul le ciment Portland a fait preuve de la capacité de ses produits d'hydratation et de carbonatation de se mélanger sous la forme de calcium hydrocarbonate silicate . De plus, de l'aragonite mal cristallisé et de la vatérite ont subi une transformation de phase dérivant en calcite cristalline. Basé sur une capacité d'absorption de CO2 de 24%, la production de blocs de bétons aux États-Unis et au Canada a le potentiel annuel de séquestrer 2 millions de tonnes de CO2. Ce fait signifie que la réduction d'émissions de dioxyde de carbone de ces deux pays dans l'industrie de ciment est égale à 2.5%.

Master of Science<br>Department of Architectural Engineering and Construction Science<br>Kimberly Waggle Kramer and Bill Zhang<br>Concrete masonry units are a common method of construction in the world. Since the masonry units can be constructed with ease. Fifty billion water bottles are consumed every year. Lack of waste management and recycling in third world countries has come to the attention of many organizations. The use of plastic bottles in construction materials has been around for the past twenty years, but with little focus on using full plastic bottles in the materials. The Engineers Without Borders student group on the campus at Kansas State University have found a way to utilize the full 500-mL plastic bottle in the creation of concrete walls. The bottles laid horizontally with concrete on both sides and as mortar between the bottles was used. These bottles create large voids in the wall decreasing the compressive strength of the wall. This thesis presents the results of a study conducted to determine the compressive strength of concrete masonry units with plastic bottle cores. The plastic bottles were used to create the center voids in the masonry units. Concrete was placed around the bottles to encase them in the masonry units. The study utilized 500-mL plastic bottles from five different water companies placed inside masonry units of 7.87-inch wide by 8.26-inch high by 15.75-inch long (200-mm wide by 210-mm high by 400-mm long) in size and analyzed the resultant compressive strength. The testing for compressive strength was determined according to the ASTM C140 standard. Results from this study were deemed reasonable due to the testing of concrete cylinders as a control compressive strength. Determination of the compressive strength of the concrete masonry units allows for further study to continue in concrete masonry units with plastic bottle cores to determine if they are viable in third world countries.

Vegeblocks are masonry units made from 100% waste materials. They use waste vegetable oil as a binder, and the manufacture process involves heat curing of a block made from a mixture of the binder and waste aggregates. Research into long-term properties and enhancement of the manufacture process of these units requires an understanding of the chemistry that occurs during this process. Analysis of the binder by a mixture of spectroscopy and chromatography indicates that the reactions are characterised by consumption of unsaturated hydrocarbons in the seed oils to form products of hydrolysis, cross-linking and oxidation, supported by the literature concerned with thermal stress and oxidation of vegetable oils. Though strength gain can be directly linked to the consumption of double bonds, other physical properties are more dependent upon the aggregate mixture and manufacture process. This work demonstrates the potential and limitations of several sophisticated techniques used to analyse the material and provides a basis upon which a holistic understanding of the matrix can be built.

This paper serves as a statement accompanying a capstone project for a degree in Information: Science and Technology. It details the work that went into creating the web page dedicated to helping specifications and codes writers to calculate fire resistance ratings of concrete masonry unit (CMU) walls. It briefly examines what a CMU wall is and the calculations that are involved in calculating fire-resistance ratings. The paper delves into how the site itself works, what the user can expect to see when first accessing the page and how to follow the steps in order to get the correct output. Without getting too technical, the paper also describes the four programming languages that were involved with coding the web page and what they handle in accordance with the page’s design and implementation. Finally, the paper concludes with an appendix containing the URL that will lead the reader to the web calculator and provides some practice problems that will allow the reader to test the calculator’s abilities.

The aim of this diploma thesis is to elaborate the project documentation of a new-built home for the elderly, in the cadastre unit of small town Blížkovice. It is a three-storey building with a basement. On the basement there are cellar berths, garage and technical facilities. On the first floor there is facilities, dining rom, a doctor´s surgery, massage, hairdresser´s and pedicure. On the second and third floor there are common areas and a total of twenty-two residentail units (1+kk – eighteen flats, 2+kk – two flats). The vertical loadbearing structures are made of clay blocks and lost formations. The object is insulated by a contact thermal insulation systém. The horizontal loadbearing structures and staircase are made of reinforced monolithic concrete slab. The roof consists of a flat roof with extensive green and terrace. There are ten parking spaces on the ground.

The diploma thesis focuses on the design of a new construction of a multifunctional building in Řečkovice. The construction consists of two separate blocks connected by a basement storey with common garages. Each block has three above-ground storeys. On the first basement storey there are garages and technical facilities. On the above-ground storeys there are commercial units with own entrances from the exterior and own sanitation facilities. Furthermore there are flats of varying sizes: from single-room flats with a kitchenette to four-room flats with a kitchenette. One of the flats has been designed as adaptable (wheelchair accessible). All the flats have a recessed balcony or a terrace facing southwest. The construction is built on shallow foundation constructions. The first basement storey is from monolithic reinforced concrete. The above-ground storeys are built from Kalksandstein sand-lime blocks. The exterior walls are insulated with a contact thermal insulation system. The construction is covered by flat roofs.

The main task of the diploma thesis is to use the open areas between the streets Stefanikova, Reissigova, Sportovni and Pionyrská in Brno for creating a multifunctional urban structure with the appropriate functions. Diploma thesis is based on the urban-architectural design created in the previous semester project. Thesis closely addresses the proposed multipurpose building between the streets Stredni a Stankova. In the object is located school of arts, cultural and leisure center, restaurant, café, music club and rentable units. Under the building are designed collective garages.

Sustainable Built Environments Senior Capstone Project<br>This research examines the viability of tire masonry units as a material for exterior walls in residential construction when compared to other alternative materials (straw bales) and traditional materials and methods (wood frame construction). This comparison is executed via a matrix which assigns scores to each material based on their performance in the following criteria; energy efficiency, human health, environmental health, structural soundness, and monetary costs. Tire masonry units have been offered up as a solution to both tire disposal issues that are detrimental to the environment and the problems posed by the need for virgin materials in housing construction. This research concludes this is not the case, and the use of tire masonry units fails to provide solutions for either of these pressing issues.

Este trabalho tem o objetivo de avaliar a influência das propriedades elásticas da interface bloco-argamassa no comportamento elástico global de paredes de alvenaria. Por ser um material heterogêneo, as propriedades mecânicas da alvenaria são influenciadas pelas propriedades dos seus diferentes componentes, bloco e argamassa, e pela ligação entre eles. As juntas de argamassa constituem planos de fraqueza, desta forma, características como rigidez, direção e o estado de tensão podem influenciar consideravelmente o comportamento global e consequentemente os parâmetros de projeto. O trabalho foi composto por duas etapas, uma experimental e outra numérica. Na etapa experimental um extenso programa de ensaios foi realizado buscando avaliar as propriedades elásticas normais e tangenciais as juntas de argamassa. Nesta etapa também é apresentado um conjunto de procedimentos que possibilita a caracterização dos componentes da alvenaria de forma não destrutiva. Um estudo paramétrico foi realizado na parte numérica, permitindo identificar quais propriedades da interface exercem mais efeito sobre o comportamento elástico da alvenaria. Também foi avaliado como a heterogeneidade da alvenaria pode afetar a distribuição de ações horizontais ao longo de uma edificação. Os resultados obtidos indicaram que a interface bloco-argamassa exerce influência significativa sobre o comportamento elástico da alvenaria, entretanto esta relação depende da razão altura/largura da parede estudada. A distribuição das ações horizontais demonstrou ser bastante afetada pela deformação por cisalhamento, no entanto a consideração da interface não resultou em contribuição significativa.<br>This work aims to evaluate the influence of the elastic properties of unit - mortar interface in the global elastic behavior of masonry panels. As a heterogeneous material, the mechanical properties of masonry are influenced by the properties of its different components, unit, mortar, and the bond between them. The mortar joints are weakness planes, thus features like stiffness, direction and state of stress can greatly influence the global behavior and the design parameters. The study was composed of an experimental and numerical analysis. In experimental analysis an extensive test program was conducted with focus on normal and tangential elastic properties of the unit-mortar interface. In this part of the work a set of procedures that enable the characterization of the masonry components nondestructively is also presented. A parametric study was conducted in the numerical analysis, allowing the identification of which properties of the interface have a greater effect on the elastic behavior of masonry. The effect of the heterogeneity of the masonry in the distribution of lateral loads in a building was also evaluated. Results indicated that the block-mortar interface has a significant influence on the elastic behavior of masonry; however this relationship depends on the ratio aspect of the panel. The distribution of lateral loads was greatly affected by shear deformation; however the consideration of the interface resulted in no significant contribution.

The determination of strain properties of masonry in the direction parallel to bed joints is a fundamental pre-requisite for designing structures, where masonry is subjected to horizontal stresses (e. g. strengthening with prestressing). The diploma thesis summarized techniques of determination of masonry modulus of elasticity presented in available literature. The goal is to suggest suitable methodology of determination of masonry modulus in direction parallel to the bed joints. In the practical part of the diploma thesis is that methodology verified by experimental test and results of tests are analyzed and discussed.

The subject of this thesis is the design and project documentation of a new multifunctional house in Strakonice. The building has four floors, without basement, and is located on a slightly sloping land in the suburban part of the town of Strakonice. It is based on shallow foundations and covered with a flat roof. It is a transverse wall structural system, build with clay block masonry, with the semi-assembled ceiling structures of ceramic and concrete beams and inserts. It is conceived as a double-aisle layout. The ground floor of each wing consists of the establishment of shops and house facilities. The overground floors are designed as six residential units of varying size category. Both tracts have separate entrances to both the residential portion and to individual businesses. The building is designed from traditional building materials. In addition to the architectural construction and civil-engineering design, a part of this project is also a fire safety design and an assessment from the perspective of building physics.

This diploma thesis deals with design of new building multifunctional house in southeastern outskirts of Brno in urban district Holásky. The three-storey building combines purpose of permanent housing, stomatology center and pharmacy. Business premises and technical facilities are located on the ground floor. Overall twelve dwelling units with layout design as one-bedroom flat and two-bedroom flat are placed on above-ground floors. Designed building has rectangular trapezoid shape and copies triangle shape of flat building plot. Parking spaces are perpendicular to adjacent access road. External walls are made of 500 mm thick Porotherm hollow clay blocks with inserted mineral insulation. Ceiling structure is designed as reinforced concrete slab, which is divided into set of smaller two way slabs. Building is roofed with flat roof, on it are placed solar collectors used for water heating and reducing operating costs. Effective management of rainwater which is collected and reused helps decrease environmental impact of building. Total energy consumption of the building is reduced by building compactness. Thesis contains project documentation for the construction.

The thesis summarizes the methods used to test and evaluate the characteristics of vertical masonry structures and further shows the evaluation procedure according to ČSN ISO 13 822. In the second part of this work there is a practical example of brick building assess-ment process, including determining the strength of the walls and the conversion of select-ed critical elements of the existing structure – window pier and wooden beamed ceiling.

The aim of this diploma thesis is trying to solve difficulties connected with administrative buildings. In this thesis we are talking about possibility that administrative building can have low energy footprint. Most of energy consumption of administrative building is not created by heating but mostly by cooling and by consumption of office equipment. That is why there have been used modern equipment of the building as well as automatic control of building equipment.

Master’s thesis theme is mountain hotel project. The hotel has one lower basement and four aboveground floor. It has trditional look and the roof is double-pitched. Floor projection looks like letter "L". Main part has measurements 25,3 x 14,1 m and it has four floor. Extension is on northwest side of main part. It has measuremnts 11,85 x 9,5 m and three floor. Facede of basement and first floor is from stone facing mansory. Facade od second floor of main patr of buildings id timbered looks like curb. Third and fourth floor are attic, gable is vertical timbered. Facade of second floor of extension is plaster on ETICS. The gable od extension is vertical timbered. Roof covering is alpen shingle from larch wood. Foundations of house are shallow. The construction system is walled. The lower basement is built from masonry BS Klatovy BD30 and other wall are from masonry Porotherm . Floor structures are from monolithic reinforced concrete, thickness 220 mm. House stairs are prefabricated double-flight. Partition wall are mostly built from mansory Porotherm 11,5 P+D. Lintols above windows and doors in facadeare made by reverse of floor slab and inside of disposition are made by ceramics lintols Porotherm. Floor structures are floating with impact insulation in whole house. In living rooms wear layers are from oak parquet block and in common rooms, toilets, bathrooms and technical rooms is ceramics paving. Wall’s surfaces are made from patent plaster and in lower basement are made from two-coat work with white coat. Toilets and bathrooms are tilled with ceramic tiles. All distributions of building equipment are covered with gypsum plasterboard ceiling. All windows and doors in facade are made by wooden profile Solid comfort SC78 and glazed by triple glazing unit (Uw,max=0,9 W/m2.K), exception is main entrance door, It is made by aluminum profile and it is automatically opened.

碩士<br>國立中興大學<br>土木工程學系所<br>97<br>To produce masonry units by high performance concrete ,this research adopts light aggregate which are burn from domestic reservoir''s sediments, cement and slag powder which replaces part of cement. To assure the masonry units meet the standard requirements. The research test the unit weight of masonry units, the compressive strength,the absorption capacity, the maximum water-absorptivity rate, the thermal conductivity, the fireinsulation and fire integrity. The research also try different materials and thickness of coating for masonry units to verify water of ability and to find out optimum materials and thickness. The test results reveal the unit weight is between 1,530 kg/m3 and 1,620 kg/m3, the compressive strength is between 193 kgf/cm2 and 287 kgf/cm2(Parallel stress direction) ,and 241kgf/cm2 ~419kgf/cm2 (vertical stress direction) ,absorption capacity is between 0.09 g/cm3 and 0.12 g/cm3, maximum water-absorptivity rate is between 53 percent and 59 percent and thermal conductivity is between 0.29 kcal/m.℃.hr and 0.36 kcal/m.℃.hr.,the fireinsulation qualified effectiveness is situated between 125 minutes and 208 minutes, the fire protection effectiveness is 2 and 3 hours. With combination of 1.5cm thickness cement mortar water-repellent, the coating can achive some certain water proof ability. The test result of this research shows masonry units meet the most specifications. The results of compressive strength and insulation properties are much more outstanding.

碩士<br>國立中興大學<br>土木工程學系所<br>96<br>In this study, using the reservoir sludge burn lightweight aggregates as the main material, the manufacturing technology of concrete masonry units is made. The engineering properties of concrete masonry unit such as unit weight, compressive strength, absorption capacity, water permeability, maximum water-absorptivity rate and thermal conductivity are analyzed. It is shown that unit weight is between 1585 kg/m3 and 1745 kg/m3, compressive strength is between 86 kgf/cm2 and 191 kgf/cm2 , absorption capacity is between 0.05 g/cm3 and 0.13 g/cm3, water permeability is between 0 cm and 20 cm, maximum water-absorptivity rate is between 30 percent and 60 percent and finally thermal conductivity is between 0.23 kcal/m.℃.hr and 0.35 kcal/m.℃.hr. Unit weight of lightweight aggregate concrete masonry unit is about that of common concrete 70%~75%. Thermal conductivity of lightweight aggregate concrete masonry unit is about that of common concrete 25%.

博士<br>中興大學<br>土木工程學系所<br>99<br>This study aimed to discuss the manufacture technology and engineering nature of lightweight aggregate concrete and have fire insulation property research of lightweight aggregate concrete. The research was plan for three parts: First, with low-pressure grouting method, adjust the ratio of the composition of different paste materials for precasting lightweight masonry hollow bricks. The less than 1000 kg/m3 unit weight aggregate is used in the research with different water-glue ratio and different cement replacement ratio of pozzolanic materials to discuss the unit weight, compressive strength, and other constructional nature changes of light-weight masonry hollow brick. Second, replace part of cement by slag powder with appropriate ratio to have manufacture technology research of high-performance concrete masonry brick and inspect unit weight, compressive strength, water absorption, moisture containing ratio of maximum water absorption, thermal conductivity coefficient, heat resistance, flame resistance and other features of masonry bricks based on the regulation. The last is to increase different thickness and material of the surface material on the product surface and test its waterproof properties.Third, launch the research of fire insulation properties for lightweight masonry components which contains the basic heat insulation properties of lightweight aggregate concrete and fire resistance test of light-weight masonry component. On the other hand, filling a normal weight concrete specimen with the same strength for comparison analysis. The test result of masonry hollow brick production technology and engineering properties show that the specimen produced by the test engineering methods can effectively reduce the physical unit weight to below 800 kg/m3 which is one-third of the general normal weight concrete. The compressive strength range is approximately between 7 MPa to 11 MPa which can also meet the basic strength requirements of non-structural hollow bricks. The test result of high-performance lightweight aggregate concrete masonry brick showed that unit weight of masonry brick is between 1,530 kg/m3 ~ 1,620 kg/m3. Compressive strength is between 193kgf/cm2 ~ 287kgf/cm2 (parallel to the force direction) and 241kgf/cm2 ~ 419kgf/cm2 (vertical force direction). Water absorption is between 0.09 g/cm3 ~ 0.12 g/cm3 and the maximum water absorption of the moisture contenting ratio is between 53% to 59%. The thermal conductivity coefficient is between 0.29 kcal/m.℃.hr ~ 0.36 kcal/m.℃.hr and heat resistance is between the qualifying time of 125 minutes ~ 208 minutes. The fire resistance time is 2 and 3 hours. Cement mortar waterproofing agent of surface layer material was better with the thickness of 1.5cm to achieve a certain water effect. The test results of lightweight masonry structures fire insulation properties showed that the thermal conductivity coefficient of lightweight aggregate concrete ranged from 0.690 kcal/m.hr.℃ ~ 0.750 kcal/m.hr.℃ while normal weight concrete ranged from 1.330 kcal/m.hr.℃ ~ 1.425 kcal/m.hr.℃. The thermal conductivity coefficient of lightweight concrete is only 53% of normal weight concrete which compacted with conducive performance of energy-saving and heat insulation. When lightweight concrete specimens are under fire test, case flaking would occur due to the steam pressure and even lead to board damage if the specimen is not completely dry. There are less likely to have case flaking in normal weight concrete beams or specimens. If the specimen is dry, the fire performance of lightweight concrete is usually better than normal weight concrete.

This research project describes the impact resistance of masonry units bound with fibre-reinforced Type S mortars and hydraulic lime mortar. The dynamic impact factor and stress rate sensitivity were evaluated for the flexural strength of the mortar and the bond strength, and further, the pattern of failure was noted for each mix and loading rate. Results show that the impact resistance of the masonry units increased in the presence of fibres. However, the stress rate sensitivity of the bond strength decreased with an increase in fibre content. Also, whereas the mode of failure in those masonry units bound with plain Type S mortars was through fracture at the mortar-block interface, the addition of fibres transferred the failure plane to within the masonry block. For hydraulic lime mortar, fibre reinforcement retained the sacrificial nature of mortar and also increased the flexural toughness factor of the joint even under dynamic loading.<br>Structural Engineering

An experimental program was conducted to investigate some aspects of in-plane behaviour of masonry infilled steel frames. Eight concrete masonry infilled steel frames, consisting of three fully grouted and five partially grouted infills, were tested under combined lateral and axial loading. All specimens were constructed using one-third scale concrete masonry units. The in-plane lateral load was gradually increased at the frame top beam level until the failure of the specimen while an axial load was applied to the top beam and held constant. The parameters of the study included axial load, extent of grouting, opening, and aspect ratio of the infill. The experimental results were used, along with other test results from the literature, to evaluate the efficacy of stiffness and strength predictions by some theoretical methods with a focus on Canadian and American design codes. Cracking pattern, stiffness, failure mode, crack strength, and ultimate strength of the specimens were monitored and reported. Presence of axial load was found to increase the ultimate strength of the infilled frame but had no marked effect on its stiffness. Two specimens exhibited “splitting failure” due to axial load. Partially grouted specimens developed extensive diagonal cracking prior to failure whereas fully grouted specimens showed little or no cracking prior to failure. An increase in grouting increased the ultimate strength of the frame system but reduced its ductility. Presence of opening reduced the ultimate strength of the infilled frame and increased its ductility but its effect on the stiffness of the frame system was not significant. A review of current Canadian and American design codes showed that the Canadian code significantly overestimates the stiffness of infilled frames whereas the American code provides improved predictions for stiffness of these frame systems. Both design codes underestimate the strength of masonry infilled steel frames but grossly overestimate the strength of masonry infilled RC frames.<br>Masonry infilled steel frames tested under combined axial and lateral loading. Behaviour as affected by axial load, grouting, aspect ratio and openings discussed. Correlation between axial load level and the infill lateral resistance examined. Efficacy of the Canadian and American masonry standards on infill design was examined.

Italy is characterized by high seismicity and the recent earthquakes have highlighted the high vulnerability of the Italian real estate, mainly composed of historical and old masonry buildings. The greatest damages mostly occurred in the historical centres, where masonry buildings in aggregate are the prevalent structural typology. This circumstance has renewed the need of procedures for the seismic risk assessment and the unitary planning of strengthening interventions, according to a specific methodology appropriate for the masonry aggregates, in order to achieve safety standards and reduce the losses. Indeed, in the seismic vulnerability assessment, the identification of a determined building (i.e., structural unit) as an independent structure can become difficult, since it is often in adjacency to others and the same boundary walls are shared. Consequently, it is known that these systems do not have an independent structural behaviour, given the reciprocal interactions with adjacent structures during a seismic event (namely, the “aggregate effect”), and their analysis is naturally affected by several sources of uncertainties. Hence, this research project aims at understanding how the “aggregate effect” should be modelled for a more accurate assessment of the global seismic performance of the masonry buildings in aggregate, reducing the uncertainties related to too extensive knowledge process and providing tools for the definition of new guidelines for the masonry aggregates. To this end, a new procedure, referred to as “target structural unit approach”, is proposed, aiming at identifying the optimal portion of the aggregate that best represents the “aggregate effect” for the investigated building, i.e. the Minimum Unit of Analysis (M.U.A.).

Masters Research - Master of Philospohy (MPhil)<br>It has been shown that masonry material properties, in particular, unit flexural bond strength (ft), vary significantly throughout masonry structures, despite the fact that often only one type of brick and mortar are used. Unit flexural bond strength was previously identified as one of the most important material parameters contributing to the strength of clay brick unreinforced masonry (URM) walls in flexure. It was the objectives of this research, in the context of clay brick URM walls subject to vertical bending, to examine how unit flexural bond strength varied spatially in a clay brick URM wall, determine a best fit probability distribution function which can describe expected variability in unit flexural bond strength and determine how this variability and other factors affect wall behaviour and failure load using 3D non-linear finite element analysis (FEA). It was hoped that modelling a full sized clay brick URM wall subject to vertical bending using a 3D non-linear FEA model would more accurately predict wall failure load (compared to current analytical methods) and allow the examination of crack pattern development as the wall progresses to failure upon being laterally loaded. The first part of the research project was to conduct an experimental program to examine unit-to-unit spatial strength correlation within six full sized clay brick URM walls and to characterise a unit flexural bond strength probability distribution. It was observed that although weak correlation in unit flexural bond strength exists in some courses and between courses, these locations were difficult to predict and didn't follow any particular pattern relating to for example, mortar batch. Therefore, although somewhat counter-intuitive, the results indicate that statistically significant correlation between adjacent unit flexural bond strengths is not likely to be observed. It was also observed that clay brick wall unit flexural bond strengths obtained for all of the walls tested best fit a truncated Normal probability distribution. Strength of the brick/mortar interface appeared to be governed by factors relating to workmanship (and therefore mortar quality and moisture content), weather (which can affect material characteristics like brick suction rate) and inherent material variability. It would appear that brick suction rate can significantly affect the overall strength of a URM wall. Stochastic analysis was conducted for walls with and without uncorrelated spatial variability in unit flexural bond strength and associated tensile fracture energy (GfI ). It was found that the TNO DIANA 9.2 FEA package could be used to implement spatial variability of various material parameters and reasonably accurately model failure of clay brick URM walls in vertical bending. From the non-linear FEA model development stage, it was observed that because the brick/mortar bond has significantly more strength capacity in compression, it appears that the lateral load resistance of the wall comes from a combination of the ability of the brick/mortar bond to tensile soften while providing significant compressive resistance at the compressive edge. It was found for a spatial stochastic analysis with spatial variability in bond strength (referred to from now on as a spatial stochastic analysis), with COVs of 0.1, 0.3 and 0.5, that COV of wall failure loads were relatively small, being 0.02, 0.04 and 0.06 respectively. For the non-spatially varying stochastic analysis with fully correlated bond strength (now referred to as non-spatial stochastic analysis), with COVs of 0.1, 0.3 and 0.5, COV of wall failure loads were 0.07, 0.20 and 0.32 respectively. For the spatial stochastic analysis, it was found that with a bond strength COV increase from 0.1 to 0.5 the mean wall failure load dropped from 2.25 kPa to 2.0 kPa (an 11% reduction). Despite the relatively small drop in magnitude of the mean wall failure load with increase in bond strength COV, the mean wall failure loads were statistically different to one another. For the non-spatial stochastic analysis, mean failure load stayed relatively constant at 2.24-2.25 kPa. These results could be explained by examining the 3D wall progression to failure. For walls with spatial variability in bond strength, it is expected that wall failure load COVs would be smaller because those walls would consistently be composed of smaller valued bond strengths which would consistently contribute to weakness in the wall. For the non-spatial wall simulations, this effect would not occur as failure load is determined by one uniform weak or strong bond strength. It was proposed that failure of a clay brick URM wall is not governed by one course only cracking, but rather, instability in the wall is governed by several courses in the vicinity of locations of large bending moment. It was shown that various current stochastic approximations which employ a unit failure hypotheses in combination with a linear/elastic approximation for first cracking load all underestimated wall capacity significantly. The reason for this is suggested as being because all hypotheses only assume failure is governed by one course and linear/elastic theory only considers the tensile capacity of a joint and neglects strength capacity available as a result of joint tension softening and the resistance to failure provided by compressive strength on the compression side of the wall. The hypotheses also don’t take into consideration factors which affect overall wall bond strength mean which result from influences such as workmanship, weather and material variability factors, such as (for example), variation in brick suction rate due to weather conditions which can make the overall strength of the wall stronger or weaker. Based upon a comparison in wall failure load COV for the spatial and non-spatial stochastic wall analysis results, a more realistic approach for future modelling attempts of spatial variability in masonry material properties is suggested. This would address the issue of external factors such as workmanship and weather on the overall strength of the wall, as well as the inherent bond strength variability due to material variability. For walls with spatial variability in bond strength, upon examination of numerous wall simulation results, several crack patterns were witnessed and are discussed.

Masters Research - Master of Philospohy (MPhil)<br>It has been shown that masonry material properties, in particular, unit flexural bond strength (ft), vary significantly throughout masonry structures, despite the fact that often only one type of brick and mortar are used. Unit flexural bond strength was previously identified as one of the most important material parameters contributing to the strength of clay brick unreinforced masonry (URM) walls in flexure. It was the objectives of this research, in the context of clay brick URM walls subject to vertical bending, to examine how unit flexural bond strength varied spatially in a clay brick URM wall, determine a best fit probability distribution function which can describe expected variability in unit flexural bond strength and determine how this variability and other factors affect wall behaviour and failure load using 3D non-linear finite element analysis (FEA). It was hoped that modelling a full sized clay brick URM wall subject to vertical bending using a 3D non-linear FEA model would more accurately predict wall failure load (compared to current analytical methods) and allow the examination of crack pattern development as the wall progresses to failure upon being laterally loaded. The first part of the research project was to conduct an experimental program to examine unit-to-unit spatial strength correlation within six full sized clay brick URM walls and to characterise a unit flexural bond strength probability distribution. It was observed that although weak correlation in unit flexural bond strength exists in some courses and between courses, these locations were difficult to predict and didn����t follow any particular pattern relating to for example, mortar batch. Therefore, although somewhat counter-intuitive, the results indicate that statistically significant correlation between adjacent unit flexural bond strengths is not likely to be observed. It was also observed that clay brick wall unit flexural bond strengths obtained for all of the walls tested best fit a truncated Normal probability distribution. Strength of the brick/mortar interface appeared to be governed by factors relating to workmanship (and therefore mortar quality and moisture content), weather (which can affect material characteristics like brick suction rate) and inherent material variability. It would appear that brick suction rate can significantly affect the overall strength of a URM wall. v Stochastic analysis was conducted for walls with and without uncorrelated spatial variability in unit flexural bond strength and associated tensile fracture energy (GfI ). It was found that the TNO DIANA 9.2 FEA package could be used to implement spatial variability of various material parameters and reasonably accurately model failure of clay brick URM walls in vertical bending. From the non-linear FEA model development stage, it was observed that because the brick/mortar bond has significantly more strength capacity in compression, it appears that the lateral load resistance of the wall comes from a combination of the ability of the brick/mortar bond to tensile soften while providing significant compressive resistance at the compressive edge. It was found for a spatial stochastic analysis with spatial variability in bond strength (referred to from now on as a spatial stochastic analysis), with COVs of 0.1, 0.3 and 0.5, that COV of wall failure loads were relatively small, being 0.02, 0.04 and 0.06 respectively. For the non-spatially varying stochastic analysis with fully correlated bond strength (now referred to as non-spatial stochastic analysis), with COVs of 0.1, 0.3 and 0.5, COV of wall failure loads were 0.07, 0.20 and 0.32 respectively. For the spatial stochastic analysis, it was found that with a bond strength COV increase from 0.1 to 0.5 the mean wall failure load dropped from 2.25 kPa to 2.0 kPa (an 11% reduction). Despite the relatively small drop in magnitude of the mean wall failure load with increase in bond strength COV, the mean wall failure loads were statistically different to one another. For the non-spatial stochastic analysis, mean failure load stayed relatively constant at 2.24-2.25 kPa. These results could be explained by examining the 3D wall progression to failure. For walls with spatial variability in bond strength, it is expected that wall failure load COVs would be smaller because those walls would consistently be composed of smaller valued bond strengths which would consistently contribute to weakness in the wall. For the non-spatial wall simulations, this effect would not occur as failure load is determined by one uniform weak or strong bond strength. It was proposed that failure of a clay brick URM wall is not governed by one course only cracking, but rather, instability in the wall is governed by several courses in the vicinity of locations of large bending moment. It was shown that various current stochastic approximations which employ a unit failure hypotheses in combination with a linear/elastic approximation for first cracking load all underestimated wall capacity significantly. The reason for this is suggested as being vi because all hypotheses only assume failure is governed by one course and linear/elastic theory only considers the tensile capacity of a joint and neglects strength capacity available as a result of joint tension softening and the resistance to failure provided by compressive strength on the compression side of the wall. The hypotheses also don’t take into consideration factors which affect overall wall bond strength mean which result from influences such as workmanship, weather and material variability factors, such as (for example), variation in brick suction rate due to weather conditions which can make the overall strength of the wall stronger or weaker. Based upon a comparison in wall failure load COV for the spatial and non-spatial stochastic wall analysis results, a more realistic approach for future modelling attempts of spatial variability in masonry material properties is suggested. This would address the issue of external factors such as workmanship and weather on the overall strength of the wall, as well as the inherent bond strength variability due to material variability. For walls with spatial variability in bond strength, upon examination of numerous wall simulation results, several crack patterns were witnessed and are discussed.