building materials properties performance and applications pdf
This finding was in agreement with calculated values of estimated shear stress at interface between paper skin and foam core. Failure process of the sandwich composites was discussed in relation with load-deflection curves. Hygroscopic behaviour of syntactic foam panels was investigated. Moisture content in syntactic foam was measured to be high for high starch content in syntactic foam panels. No significant moisture effect on flexural strength syntactic foam panels after being subjected to moisture about two months was found. However, substantial decrease in flexural modulus was found for syntactic foam panels made of large microspheres although not much moisture effect was found on that of small microspheres.
Chapter 2 – Soluble salts are one of the main decay agents of building materials, affecting
both natural and man-made products applied in old and new constructions, endangering
cultural significant structures and thwarting the performance of materials in new buildings.
Salts could promote erosive decay (provoking loss of material, mainly by physical action but
there are also references to chemical attack) and could also contribute to the formation of
coatings, such as the (in)famous “black crusts”.
The present review will be focused on the response to salt pollution microscopic of macroscopic features of natural building stones, considering predictions of theoretical models, results of simulation experiments and field observations. Several types of rocks (igneous, sedimentary, metamorphic) will be considered, in order to gain information on the influence of textural, mineral-chemical and structural aspects, such as grainsize, mineralogical composition (specially relevant to understand chemical susceptibility), presence of heterogeneities, natural anisotropy surfaces (such as bedding) and previous weathering state of the stones (weathering state when extracted fromthe quarry, before application, an aspect that is particularly relevant for igneous rocks, specially granites, since it affects properties, such as porosity and capillary rise kinetics, that control migration of salt solutions and influence the crystallization position of soluble salts).
It is hoped that this review will contribute to identify susceptible geological features that
affect the performance of building stones in relation to salt weathering and, in this way,
contribute to the discussion on the basis for recommendations about selection of building
stone, in relation to foreseeable salt contamination conditions.
Chapter 3 – In this chapter, the Boltzmann Transport Equations (BTE) is used to
formulate the transport laws for equilibrium and irreversible thermodynamics and these BTE
equations are suitable for analyzing system performance that are associated with systems
ranging from macro to micro dimensions. In this regard, particular attention is paid to analyze
the energetic processes in adsorption phenomena as well as in semiconductors from the view
point of irreversible thermodynamics. The continuity equations for (i) gaseous flow at
adsorption surface, and (ii) electrons, holes and phonons movements in the semiconductor
structures are stu