Key Engineering Materials Vol. 666

Abstract: In this chapter a critical analysis about natural materials to enhance energy performance and thermal comfort in indoor and outdoor spaces is dealt with. In particular, thermal insulation and passive cooling application in buildings are analyzed. The physical properties permitting to achieve these benefits are presented, as well as the method and the international standards to measure them. Benefits deriving from these materials’ employment as insulation layers or buildings envelope in general of, or in the case of urban paving, are described and then the single materials are illustrated.Experimental and numerical data, as reported in the bibliography, support the dissertation with examples from the most recent research contributions.

Abstract: The growing environmental concern throughout the globe has led architects & engineers to design energy efficient buildings. Consequently, they are looking for building materials that can reduce the energy consumption in buildings to maintain the comfort level. Use of proper thermal insulating materials can reduce the energy required for heating or cooling of the buildings. Presently mineral wool and various foams are used for this purpose. Efforts are being made to use wastes in making thermal insulation materials so that the impact on environment can be further reduced. Cork granules are obtained as waste from the cork processing industries that make ‘bottle stoppers’ as a main product. These granules have a low density and could be used as lightweight aggregates for making concrete with low thermal conductivity. This article describes the physico-mechanical properties of lightweight cementitious composites made using cork granules. Further, environmental benefits of their application in thermal insulation of buildings has been discussed.

Abstract: An experimental investigation on different clay-based plasters with straw (lightweight plaster) and lime (stabilized plaster) was carried out. The aim of the study was to increase the knowledge on earthen materials in terms of final performance in building applications. In the first part of the study different thermal and hygric parameters were measured: thermal conductivity, specific heat capacity, sorption capacity, water vapour permeability. Furthermore, in order to test the suitability of the unfired clay as mortar, an analysis on the mechanical strengths was carried out, measuring the compressive and the bending strength. The results show, on one hand, that when straw is added to the basic mixture a significant improvement of the sorption capacity occurs, while, the addition of lime enhances the thermal properties. On the other hand, no significant improvement of mechanical strengths can be appreciated when using these additives. Nomenclature

Abstract: With the Industrial revolution and modernization, many other issues related to it are also increasing. Problems of resource exploitation, pollution etc. has emerged as global issue and matter of high concern. Out of various industries, construction industry is one such sector which contributes highly for problems like emission of green house gases into atmosphere. Materials like cement, steel, bricks are highly energy intensive materials. Many of the conventional materials and technology options for building construction do not meet sustainability criteria. Lesser use of theses material and alternative environmentally friendly material contributes significantly in reducing CO₂ gas emission and problems associated with it. The strategy of 3R that is Reduce, Reuse and Recycle is one of the important techniques in the construction industry to achieve the sustainability. The same strategy is applied in this research work for finding appropriate substitute for major construction resource that is concrete and on basis of experimental strength results and property findings, the structural stability of various waste mix concrete elements is analyzed and designed so as to find corresponding changes in RCC design if any appears. The comparative results of analysis and design for various such percentage replaced waste mix concrete is highlighted. The analysis and design results obtained on the basis of innovative materials having specimen properties are fair enough for utilizing in construction practices.

Abstract: This paper presents a study on the current condition of the First Peoples House, located at the University of Victoria in British Columbia. The building houses two rammed earth walls that exemplify the use of stabilized rammed earth as a modern construction material. These rammed earth walls have been exposed to 7 years of natural weathering in a wet climate. A rebound hammer, infrared camera, and a new method developed to quantify surface deterioration were used in Non-Destructive Testing (NDT). The results provided insight into the compressive strength, thermal envelope and surface condition of the walls. Relationships between wind direction and wind speed are presented. It is postulated that the wall that is most exposed to a combination of both effects will exhibit the largest forms of deterioration. This hypothesis was addressed using results from NDT and local wind data.

Abstract: Current modern technology in construction can dramatically reduce energy consumed in buildings for mechanical heating and cooling. The application of the latest advancements in various technologies including developments in material science, and using environment friendly building materials is of prime concern. The reductions in building envelope heat losses combined with optimized material configuration and the proper amount of thermal insulation and thermal mass in the building envelope help to reduce the building cooling and heating energy demands and building related CO₂ emission into the atmosphere. The selection of appropriate building material helps us to use the energy efficiently. This paper presents a brief study about the building physics and material characteristics that helps in selecting proper building materials.

Abstract: Sustainable building management is a complex problem which needs effective, adequate and suitable assessment tools and methods to address issues of incommensurability and complexity, always considering the prevailing environmental policies and legislation. Within the frame of this paper, green certifications building schemes have been described, compared to each other and evaluated, against the background of the standards provided by the International Organization for Standardization. Emphasis have been placed on information referring to construction materials environmental evaluation based on the Life Cycle Analysis methodology and the role of construction materials selection to green building certification schemes. Finally, the impact of green certification schemes on the construction market, mainly as a tool of energy management, has also been examined in relation to the absence of mandatory international standardization in sustainable building management.

Abstract: Ferrocement plate with steel meshes incorporating fibers in an identical matrix were tested under bending. The main objective of the study was to investigate the effects of combining reinforcing steel meshes with discontinuous fibers as reinforcement in thin mortar matrix. The variable parameters were chosen as (a) number of mesh layers, single and double (b) the types of fiber i.e steel and polyethylene terephthalate (PET). Everything else being equal, the test results shows that addition of steel fibers to the matrix of ferrocement can effectively increase its flexural strength and energy absorption to failure. Cracking and spalling of mortar cover also significantly reduced. On the other hand, the contributions of same volume fraction of PET fibers are not significant compared to steel. However, addition of PET fibers control the early cracking of thin mortar and showed slight improvement in flexural strength and energy absorption to failure compared to control specimens. Reinforcing ferrocement plates incorporating steel or PET fibers is recommended for providing technical and economical advantages as no negative effect was observed.

Abstract: Emerging crises for resources and energy has became one of the major global issues. Unstoppable population and urban growth is demanding shelter. The figure for estimated housing shortage across the world according to the internationally recommended standards is 428,700,000 units. By the year 2030, an additional 3 billion people, about 40 percent of the world’s population, will need access to housing. This translates into a demand for 96,150 new affordable units every day and 4000 every hour.(United Nation –Habitate:2005)(128). All this unstoppable global population growth is resulting in high demand supply gap between resources and thus present trend concentrate to satisfy and minimize this gap. This shooting urbanization problem is leading towards diversion for easy and fast construction methodology.Along with this the problems associated to it are also increasing globally. The problem of Urban Heat Island and Urban Canyon Effect, CO2 emission , Green House Effect , Resource depletion and all such problems are demanding global attention to overcome it and make habitant sustainable for safeguarding future generations to come. The major hurdle for application of sustainable construction is barrier of human mind who concentrates more on initial cost of construction and negligence towards operations energy cost and pay back period calculations.The aim of the paper is to show feasibility of application of waste in construction elements like wall by analysing thermo resistive property of such waste filled cavity wall and equivalence cooling effect calculations for conventional clay brick wall , AC sheets , cavity wall and various waste filled cavity wall by making model and process of simulation using Ansys Fluent .The results of research work shows feasibility of adopting cavity wall and waste fill cavity wall for construction of wall because of its high thermoresistive property so as to mitigate global problems like Urban Heat Islands and operational energy consumption.