Papers by Keyword: Consolidation

Abstract: Egyptian faience is one of the most important archaeological materials that contain a lot of historical and technical information about ancient Egyptian civilization. Unfortunately, the Egyptian faience objects subject to many deterioration factors, especially humidity. Water has a direct role in dissolving the soluble components, it accelerates the physiochemical deterioration processes. In the present study, four types of ready to use nanoproducts were evaluated. It was done to select the best of them to consolidate and protect some archaeological faience from Matteria magazine. The properties of the treated samples, were comparatively investigated by colormetric measurements, static water contact angle, total immersion water absorption, compressive strength, and scanning electron microscope.

Abstract: In recent years, the development of new procedures and solutions in the field of conservation has been very significant. The purpose of this article is to collect the main contributions of nanotechnology, in its multifunctional solutions applied in heritage, to offer a global vision of the state of the matter for both scientists and restaurateurs.Nanomaterials offer some advantages over traditional products, improved compatibility and efficiency and reducing the use of toxic organic solvents for humans and the environment. Solutions have been developed for both inorganic supports and organic supports for artistic, architectural and archaeological heritage. Especially relevant are the advances in consolidation processes, pH regulation and / or cleaning / elimination of alteration products on murals, frescoes or stone and in materials composed of cellulose and collagen.Also, nanotechnology is still a recent science and has yet to answer certain questions about its use protocols and reduce the possible risks to health.

Abstract: Nanostructured ceramic materials and compositions based on them find an increasing application in all branches of science and technology. At the same time, the performance properties of new ceramic nanomaterials (strength, adhesion, optical and others) are significantly different from properties of traditional ceramics, which were used before. The qualitative characteristics of nanoceramics are largely determined by the initial structure and methods of nanopowder synthesis, as well as by the characteristics of conditions and methods for their consolidation. This work is devoted to the synthesis of nanopowders and effective method of its sintering for the production of nanoceramic materials which have special mechanical properties, e.g. components with increased modulus of elasticity ("ceramic steel"), etc. It makes it possible to effectively use them in aerospace industry.

Abstract: Multi-leaf masonry walls constitute the construction typology most widely adopted in historic buildings. This aspect, together with the intrinsic structural complexity, heterogeneity and irregularity, directs the present research towards a topic not yet sufficiently investigated by the research community of architects and civil engineers. In this paper, the case of multi-leaf masonry wall has been investigated, and with the aim of reproducing historical buildings structural elements, three different typologies of multi-leaf masonry walls have been considered: (i) full infill, (ii) damaged infill, (iii) consolidated infill. A comparative analysis has been performed and results of experimental tests have been compared with numerical ones obtained by means of Finite Element (FE) models.

Abstract: The cemented soils are typically produced and cured under confining pressure of soil. The cemented soil properties are, however, obtained from laboratory tests on the cement admixed clay samples cured under atmospheric pressure. Thus, the parameters of cemented soil obtained from laboratory tests are not representative of the actual values in the field. In this research, a series of consolidation tests using oedometer apparatus on cement admixed clay samples with different curing pressure conditions was carried out. The samples was cured under pressure values of 0 kPa (atmospheric pressure) and 50 kPa. The test samples with values of cement content of 0, 1 and 2 percent were cured for 28 days before testing. The compression curves of cement admixed kaolin showed the elasto-plastic deformation in all cases of the tests. It was found that the range of void ratio of the samples with curing pressure of 0 kPa (atmospheric pressure) was higher than that of the samples with curing pressure of 50 kPa. With increasing curing pressure and cement content, the value of recompression index decreased while the value of compression index was approximately constant. It was also observed that the preconsolidation pressure increased with increasing cement content for both cases of curing pressure. It should be noted that the values of preconsolidation pressure increased with increasing curing pressure. Moreover, the values of coefficient of consolidation decreased with increasing effective vertical stress in all cases. It was also found that the values of coefficient of consolidation increased with increasing curing pressure and cement content.

Abstract: Abstract: Oxidized and non-oxidized SiC particulates were mixed with Al powder respectively and the two kinds of mixed powders were consolidated at 250°C by equal channel angular pressing and torsion (ECAP-T), which belongs to severe plastic deformation. The interfacial bondings of as-consolidated composites were characterized by SEM images, corrosion morphology and fracture morphology. The results show that after severe plastic deformation, the interfacial bonding between non-oxidized SiC and Al is a kind of mechanical bonding and the consolidation is not firm enough so that the composite has a weak corrosion resistance and its tensile sample has a brittle fracture. However, the composite containing oxidized SiC has a dense microstructure, high corrosion resistance, ductile fracture due to the metallurgical interface.

Abstract: In the present article we report a study on using microemulsion contains triton 100 to clean the surface of the wall paintings in saint Jeremiah monastery in Saqqara (4^th century) , Being these systems mainly composed of water (more than 80% by weight), it is using in a poultice or when the microemulsion added to the nano gel to improve it's performance , Fourier Transform Infra Red spectroscopy (FTIR),and The consolidation by nano lime dispersed in ethanol is used by brushing through Japanese paper and injecting the cracks.

Abstract: When starches / proteins are added to the ceramic matrix, they originate pores whose morphology and sizes are varied. However, ceramic final properties are influenced by the interaction kinetics amongst particulate materials. This work was designed to analyze the interactions between proteins and disaccharides and their influence on the properties of TiO₂ ceramics. Compositions containing protein and protein-sucrose were added to TiO₂ powder. Rheological parameters, shear stress and viscosity were studied in order to understand the protein behavior. Furthermore, sintered ceramics were characterized as for porosity, roughness and image analysis by light microscopy. The dispersions produced with sucrose-protein showed lower viscosity and shear stress values and characteristics of a Newtonian fluid. The samples, from compositions which used 40% solids (80 wt% protein and 20 wt%), showed a higher apparent porosity (23.28%) and larger pore sizes (4947.07 μm²).

Abstract: Extending the range of finished product sizes from a given ingot or concast bloom or billet section is often limited by the minimum area reduction required to ensure effective central consolidation and final mechanical properties. Predicting effective consolidation or level of remnant porosity for a range of steel grade, billet size, pass schedule/roll design and thermo-mechanical conditions has always been an important issue on plant, much more lately in view of recent trends for larger ingots and development of combined forging/rolling strategies. This paper will focus primarily on a fast analytical technique based on roll gap shape and consolidation factors obtained from Finite Element (FEM) Models. New developments based on FEM submodelling are presented briefly. Healing capabilities based on diffusion bonding can be obtained from [1-3].

Abstract: Silicic acid esters have been used as stone consolidants for 50 years now. During this time they became the most popular consolidants for building materials, mainly thanks to their good properties during application. Despise all these positives, the use of alkoxysilanes brings also some drawbacks. The gel of the silicic acid esters, which is responsible for the consolidation, cracks and decays during several years after the treatment so that the consolidation has to be repeated. To suppress the cracking, the alkoxysilanes are often modified. In recent studies, we focused on modification of silicic acid ester gels by SiO₂ and Al₂O₃ nanoparticles. Some of the prepared mixtures cracked less than the unmodified mixture under ambient condition. This work builds on these experiments and works with the selected modified mixtures. As the consolidants are widely used outdoors, it was necessary to compare the degree of cracking of modified gels under various conditions. In this experiment we focused on their cracking under different levels of relative humidity. As the objective evaluation of cracking was needed, we believe to come up with partial solution to this problem – to assort the extent of cracking to some defined category. The categories were defined according to our former experiences with observation of cracking states of the gels. We found out, that the change of relative humidity has huge impact on the way and extent to which the gels cracked. Knowing this information we may be able to prepare the modified consolidant, that better withstands outdoor conditions and thus to preserve our cultural heritage for longer time.