Nanoengineering concrete for sustainable built environment: a review

The construction industry is a major consumer of material and energy sources in the world. Among all the materials used in construction, concrete, which is the most widely used, can have a significant impact. Meanwhile, nanotechnology is one of the most influential technologies in this century and it has significantly impacted the construction sector. Better understanding and engineering cementitious materials at nanometer scale can result in novel construction materials which are more strong and durable than conventional materials. Engineering concrete at the nano meter scale includes the incorporation of nano sized particles into concrete at suitable proportions and methods. Nano Silica is one such nano material which has shown to enhance the overall performance of concrete. Incorporation of nano Silica at smaller volume fractions has shown to result in higher compressive and flexural strengths at early ages, improved hydration characteristics and reduced porosity and water absorption when compared with conventional cementitious materials. The impacts of other nano materials such as CNTs, nano TiO2, nano Al2O3 and nano TiO2 on concrete are also promising. While nano materials acts as fillers and provide nucleation sites for cement hydration, nano SiO2 also acts as a pozzolanic material, increasing the amount of stiff CSH within the hydrated cement paste, resulting an improved microstructure. Nanomaterials can also pave the path to reduce the cement content in concrete than in conventional mixes while maintaining same strength characteristics, which will lead into the production of a „greener‟ concrete. Numerical models of the composite material validated with experimental results can be used to come up with optimum nano material contents and performance. This paper reviews the efforts, current status and effects of nano modification of cementitious materials and numerically modelling strength properties. These innovative materials will be of high performance and less energy consuming, which will lead towards sustainable construction practices

Application of nano insulation materials in the sustainable Built environment

Nanotechnology is widely being used in the built environment for its advantages in many improved engineering properties of the nano materials. Nano insulating materials open up new possibilities for ecologically oriented sustainable infrastructure development. The most widely used nano material in built environment is for the purpose of insulation to improve the energy efficiency namely in the buildings and dwellings. Nanotechnology has now provided an effective and affordable means to increase energy efficiency in pre-existing buildings as well as new construction by increasing thermal resistance. The major advantage of nano insulation materials is its benefit of translucent coatings which increase the thermal envelope of a building without reducing the square footage. The intrinsic property of nano insulating material is it can be applied to windows to reduce heat transfer from solar radiation due it its thermal resistant property and the translucent property allows diffusing of day light. The nano insulating material has significant advantage in reducing the operational energy aspects of buildings due to its valuable insulating properties. This paper examines applicable nanotechnology based products that can improve the sustainable development and overall competitiveness of the building industry. The areas of applying nano insulating material in building industry will be mainly focused on the building envelope. The paper also examines the potential advantages of using nanotechnology based insulating material in reducing the life cycle energy, reduction of material usage and enhancing the useable life span. The paper also investigates the operational energy by simulation methodology and compares the reduction of operational energy consumption

Application of nanomaterials in the sustainable built Environment

Nanotechnology is widely regarded as one of the twenty-first century’s key technologies, and its economic importance is sharply on the rise. In the construction industry, nanomaterials has potentials that are already usable today, especially the functional characteristics such as increased tensile strength, self-cleaning capacity, fire resistance, and additives based on nano materials make common materials lighter, more permeable, and more resistant to wear. Nonomaterial are also considered extremely useful for roofs and facades in the built environment. They also expand design possibilities for interior and exterior rooms and spaces. Nano–insulating materials open up new possibilities for ecologically oriented sustainable infrastructure development. It has been demonstrated that nanotechnology has invented products with many unique characteristics which could significantly provide solutions current construction issues and may change the requirement and organization of construction process. This paper examines and documents applicable nanotechnology based products that can improve the sustainable development and overall competitiveness of the construction industr

Applications of phase change materials in concrete for sustainable built environment : a review

The fast economic development around the globe and high standards of living imposes an ever increasing demand for energy. As a prime consumer of world‟s material and energy resources building and construction industry has a great potential in developing new efficient and environmentally friendly materials to reduce energy consumptions in buildings. Thermal energy storage systems (TES) with Phase change materials (PCM) offer attractive means of improving the thermal mass and the thermal comfort within a building. PCMs are latent heat thermal storage (LHTS) materials with high energy storage density compared to conventional sensible heat storage materials. Concrete incorporating PCM improves the thermal mass of the building which reduces the space conditioning energy consumption and extreme temperature fluctuations within the building. The heat capacity and high density of concrete coupled with latent heat storage of PCM provides a novel energy saving concepts for sustainable built environment. Microencapsulation is a latest and advanced technology for incorporation of PCM in to concrete which creates finely dispersed PCMs with high surface area for greater amount of heat transfer. This paper reviews available literature on Phase change materials in concrete, its application and numerical modelling of composite concrete. However most of the existing TES systems have been explored with wallboards and plaster materials and comparatively a few researches have been done on TES systems using cementitious materials. Thus, there is a need for comprehensive experimental and analytical investigations on PCM applications with cementitious materials as the most widely used construction materials in buildings