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•Thermal insulation composites were developed by utilizing bauxite residue.•Composites display superior thermal insulation properties.•Composites show low thermal diffusivity (0.161 ...mm2/s) and low water retention <0.15 %.•Bauxite residue has great positive effect on the thermal stability of the composite.
The objective of this study is to evaluate the possibility of using bauxite residue (BR), which is a highly hazardous waste, as a filler in thermoset polymer matrices for applications in insulating construction materials to minimise heat loss in buildings. Unsaturated polyester resin (UPR) blended with the seawater-neutralised BR in a ratio of 0–60 vol.% was transformed into a solid via a crosslinking process at room temperature. The pristine polyester and BR–UPR composites were characterised to ascertain their structural, physical and thermal properties. The results indicate that BR is a good filler that can be used with UPR to develop thermal insulation/construction materials. The UPR composite containing 40 vol.% BR is considered to be the optimum mixture with respect to the tested physical and thermal properties because it utilises a large amount of filler and shows promising thermal insulation characteristics with a thermal conductivity of 0.096 W/(m∙K), a thermal diffusivity of 0.161 mm2/s, a 24–h water retention of 0.15 % and a bulk density of 1484 kg/m3. Furthermore, the thermal stability of the prepared composites is positively influenced by the incorporation of BR. The overall weight loss upon heating to 900 °C decreased from 99.85 % (pristine polyester) to 46.68 % (60 vol.% BR composite).
This paper presents the results of material tests, experimental tests and statistical analysis of the thermal performance of three types of heat accumulators containing an organic phase-change ...material and two materials of a higher thermal conductivity: a copper mesh and porous coke recyclate. The aim of the research was to empirically and statistically compare the increase in the PCM heat distribution through a copper conductor and coke recyclate. The research was conducted in accordance with an incomplete central compositional experimental design and using the Statistica software. The studies of the structure and chemical composition of the coke recyclate used and the empirical testing of the finished heat accumulators confirmed an improvement in the distribution and storage of heat by the accumulator with the phase-change material and coke recyclate compared to the pure phase-change material and copper-conductor accumulators, as the holding time of a temperature of 20 °C was extended by seven minutes and nine minutes, respectively. Moreover, the results of the statistical analysis provided answers as to which of the assumed input quantities—initial temperature, battery geometry, and heating temperature—were statistically significant for each of the three battery types considered. The determined approximating functions were verified in terms of the statistical validity of their use for all three types of heat accumulators tested. The results obtained are important answers to the current problems in the design and modification of phase-change heat accumulators applied in the construction industry to reduce the emissivity of structures and increase their energy efficiency.
The original test results of abrasive wear resistance of different type of construction polymer materials were presented and discussed in this article. Tests were made on an adapted test stand ...(surface grinder for form and finish grinding). Test samples were made of different types of polymer board materials including RenShape®, Cibatool® and phenolic cotton laminated plastic laminate (TCF). An original methodology based on a grinding experimental set-up of abrasion wear resistance of polymer construction materials was presented. Equations describing relations between material type and wear resistance were presented and discussed. Micro and macro structures were investigated and used in wear resistance prediction.
The design of a three storey steel parking lot under permenant loadings is implemented on the context of the thesis. Suitable sizing of the construction in terms of current regulations is effort. It ...is an necessity that making evaluation of geotechnical and engineering of necessary support structure and definition of suitable excavation and support systems in terms of deformation and strength speciailities of the units that can be emerged on excavation phase. In this regard, design is realised on the parallel of remaining on limitation conditions of unit deplacement values within the executing of necessary braced system. The solution of the braced system is done with the support of PLAKXIS. Ground studies report which is scoped to definition of mechanical and dynamical parameters of ground layers which is going to be confronted on excavation phase and the base ground layer are prepared and the design criterias are specified in terms of this report. Loading values are defined on ETABS structural analysis programs with the highlight of these informations. On this context calculation models are constituted. On the context of this thesis, structural geotechnical interaction is investigated together. Statical and dynamical affects are examined. Structural behaviour in contrast to soil is viewed and the necessities are expressed with detail.
This paper is devoted to research of directional regulation possibility of the properties of a composite based on the Portland cement by using limestone waste. It is shown that the introduction of ...limestone waste contributes to changing the nature of crystallization and structure formation of cement stone. With the introduction of limestone waste, in the amount of 15 % by weight of cement, it is possible to obtain the compositions of the class not less than B25-B35.
This book focuses on fundamental and applied research on polymer processing and its effect on the final surface as the optimization of polymer surface properties results in the unique applicability ...of these over other materials. The development and testing of the next generation of polymeric and composite materials is of particular interest. Special attention is given to polymer surface modification, external stimuli-responsive surfaces, coatings, adhesion, polymer and composites fatigue analysis, evaluation of the surface quality and microhardness, processing parameter optimization, characterization techniques, among others.
Bauxite residue (BR) is one of the most commonly generated industrial wastes in the world. Thus, novel techniques for its proper utilization must be urgently developed. Herein, seawater-neutralized ...BR–unsaturated polyester resin (UPR) composites are presented as insulating construction materials with promising mechanical performance. Composites with different BR content (0–60 vol.%) were prepared to evaluate the influence of BR content on the compressive, tensile, and flexural strengths as well as the moduli of BR–UPR composites. Experimental results revealed that adding BR particles to the polyester matrix increased the compressive properties (strength, modulus, and strain). The composites containing 20 vol.% BR showed the maximum compressive strength (108 MPa), while the composites with 30 vol.% BR exhibited the maximum compressive modulus (1 GPa). Moreover, the reduction in tensile and flexural strengths with an increase in the BR content may be attributed to the lower efficiency of stress transfer between the BR particle–polyester interface due to weak adhesion at the interface, direct contact between particles, and presence of voids or porosity. Although the tensile strength and failure stress decreased with increasing filler content, the produced composites showed outstanding tensile strength (4.0–19.3 MPa) compared with conventional insulating materials. In addition, the composite with 40 vol.% BR demonstrated a flexural strength of 15.5 MPa. Overall, BR–UPR composites showed excellent compatibility with promising mechanical properties as potential insulating construction materials.
Due to pozzolanic characteristics, fly ash is commonly used as a cement
replacement in construction composites. Addition of natural clays with
sorption ability (i.e. zeolite and bentonite) in to the ...fly ash based
construction materials is of both scientific and industrial interest. Namely,
due to the application of sorptive clay minerals, it is possible to
immobilize toxic heavy metals from the composite structure. The thermal
compatibility of fly ash and zeolite, as well as fly ash and bentonite,
within the composite was observed during sintering procedure. The starting
components were used in 1:1 ratio and they were applied without additional
mechanical treatment. The used compaction pressure for the tablets was 2
t?cm-2. The sintering process was conducted at 1000?C and 1200?C for two
hours in the air atmosphere. The mineralogical phase composition of the
non-treated and sintered samples was analyzed using X-ray diffraction method.
Scanning electron microscopy was applied in the analysis of the
microstructure of starting and sintered samples. The thermal behavior was
observed via DTA method. The influence of temperature on the properties of
fly ash-zeolite and fly ash-bentonite composites was investigated.
Thermal insulation composite foams were prepared from the natural rubber as a matrix phase and an eggshell powder as a calcium carbonate dispersed phase, using chlorinated polyethylene acting as a ...flame retardant and curing agent at the vulcanization temperature 150°C in a two-roll mill. The main composition of eggshell is calcium carbonate which is more than 96.35 wt%. The obtained composite rubber foams with 50 phr eggshell added possessed the thermal conductivity, compression set, crosslink density, bulk density, and relative foam density values equal to 0.070 W/m.K, 45.0%, 6.95 × 10
−5
mol/cm
3
, 0.58, and 0.63, respectively. The obtained composite rubber foams were of good thermal resistance, good compression set, short curing time, good crosslink density, and light weight, suitable for various applications such as automobiles, storage tank, and transport packaging. Furthermore, the scanning electron micrographs, X-ray diffraction patterns, specific heat, and physical properties (bulk density, crosslink density, and relative foam density) were taken or measured to investigate the microstructures, phase compositions, thermal properties, and characteristics of the insulating composite foams and were reported here.
This book represents a collection of major research contributions over the last decade in the area of composite materials and sandwich structures supported by the U.S. Office of Naval Research. It ...contains over thirty chapters written by recognized experts in their fields and serves as a reference and guide for future research. Topics covered include: mechanical and failure characterization of composites under static and dynamic loading, failure modes and failure criteria, environmental effects, dynamic effects, post impact behavior, multiscale modeling, nanocomposites, characterization of core materials for sandwich structures under static and fatigue loading, mechanical behavior and failure of sandwich structures, fatigue behavior and durability of composite materials and sandwich structures, core joints in sandwich structures, characterization and failure of marine materials and structures under impulse loading, failure of interfaces under dynamic loading, delamination failure of composite materials and sandwich structures, response of composites and sandwich structures to blast loading and underwater explosions.
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