scholarly journals The Effect of Density on the Delicate Balance between Structural Requirements and Environmental Issues for AAC Blocks: An Experimental Investigation

2021 ◽  
Vol 13 (23) ◽  
pp. 13186
Author(s):  
Daniele Ferretti ◽  
Elena Michelini

Among other construction materials, Autoclaved Aerated Concrete (AAC) offers several advantages to face the pressing need to build more sustainable and energy-efficient buildings. From the building side, the low thermal conductivity of AAC allows the realization of energy-efficient building envelopes, with interesting savings in terms of heating and cooling processes. The equilibrium between structural performances (related to safety issues) and energy efficiency requirements is, however, very delicate since it is strictly related to the search for an “optimum” material density. Within this context, this work discusses the results of wide experimental research, showing the dependency of the most important mechanical properties (compressive strength, elastic modulus, flexural strength and fracture energy) from density, as well as the corresponding variation in thermal conductivity. In order to identify the better compromise solution, a sort of eco-mechanical index is also defined. The big challenge for future researches will be the improvement of this eco-mechanical index by working on pore structure and pore distribution within the material without significantly reducing the density and/or by improving the strength of the skeleton material.

2021 ◽  
pp. 100101
Author(s):  
Nikolay Aleksandrovich Tsvetkov ◽  
Aleksandr Vital'yevich Tolstykh ◽  
Andrey Nikolaevich Khutornoi ◽  
Stanislav Boldyryev ◽  
Anna Vladimirovna Kolesnikova ◽  
...  

2021 ◽  
Vol 1130 (1) ◽  
pp. 012015
Author(s):  
S. Navakrishnan ◽  
B. Sivakumar ◽  
R. Senthil ◽  
Rajendran Senthil Kumar

Energies ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 6178
Author(s):  
Pierryves Padey ◽  
Kyriaki Goulouti ◽  
Guy Wagner ◽  
Blaise Périsset ◽  
Sébastien Lasvaux

The performance gap, defined as the difference between the measured and the calculated performance of energy-efficient buildings, has long been identified as a major issue in the building domain. The present study aims to better understand the performance gap in high-energy performance buildings in Switzerland, in an ex-post evaluation. For an energy-efficient building, the measured heating demand, collected through a four-year measurement campaign was compared to the calculated one and the results showed that the latter underestimates the real heating demand by a factor of two. As a way to reduce the performance gap, a probabilistic framework was proposed so that the different uncertainties of the model could be considered. By comparing the mean of the probabilistic heating demand to the measured one, it was shown that the performance gap was between 20–30% for the examined period. Through a sensitivity analysis, the active air flow and the shading factor were identified as the most influential parameters on the uncertainty of the heating demand, meaning that their wrong adjustment, in reality, or in the simulations, would increase the performance gap.


2020 ◽  
Vol 307 ◽  
pp. 01022
Author(s):  
Gitanjali Thakur ◽  
Mohamad Asalam ◽  
Mohammed El Ganaoui

One of the major environmental threat in the world today is the increased production of plastic and its usage. The inept plastic waste management system with regard to its recycling and energy recovery in the developing countries creates a global threat as a major land and water body pollutant. However, its durability, thermal properties, and chemical resistance make plastics an alternate choice as a building material. This study investigates the use of plastic in concrete mixture with an objective to improve the thermal performance of the building. The shredded plastic fibers from plastic bottles (polyethylene terephthalate, PET) were used as a partial weight replacement (2.5%, 5%, and 7.5%) of coarse aggregate in concrete blocks. The cubes were cast using the Indian standards (IS 456) and the essential tests were performed. Additionally, experiments were designed to investigate the change in the thermal conductivity of the concrete block due to the varying amount of plastic. It was found that the use of PETs affected the compressive strength and also decreased the thermal conductivity of the concrete blocks. The experimental results suggest that PETs can be used in the construction of energy-efficient building to handle the environmental concerns because of its abundance.


2011 ◽  
Vol 224 ◽  
pp. 104-108
Author(s):  
Ya Guang Sun

Current social development is pressing for energy efficient buildings. The trend of consistent updating of energy-efficient building technology reflects the importance and urgency of energy efficiency in buildings. Through analysis on the current situation of building development, it can be obtained that the energy efficient buildings as well as utilization of renewable energy sources in buildings will be bound to be one of main topics for discussion in future building design.


2012 ◽  
Vol 253-255 ◽  
pp. 564-567 ◽  
Author(s):  
Zhu Ge Yan

This paper will provide a review of the current research on the material characterisation and mechanical behaviour of polymer enhanced silica aerogels. Aerogels have been in existence for many years; however, the engineering applications of aerogels have been limited due to their poor mechanical behaviour. Recently a new type of polymer enhanced silica aerogel, a nanostructured form of silica has been developed. The new material is having a low density, very low thermal conductivity, excellent acoustic insulation and high mechanical which makes it ideal for energy efficient building material. This paper will discuss the start-of-the-art development of this material and issues to apply the material in energy efficient buildings.


Energy ◽  
2010 ◽  
Vol 35 (6) ◽  
pp. 2647-2653 ◽  
Author(s):  
H.J. Han ◽  
Y.I. Jeon ◽  
S.H. Lim ◽  
W.W. Kim ◽  
K. Chen

Author(s):  
Fadi Salah ◽  
Merve Tuna Kayılı

Reducing the energy needs of existing buildings has a significant place in reducing global energy demands. High energy savings can be achieved with passive renovation suggestions in existing buildings. In this study, the effect of the proposed renovations for an educational structure in Safranbolu on the heating and cooling demands of the building was determined with a simulation program. Energy improvements of up to 70 percent have been achieved through passive improvement designs in orientation and insulation material. The highest energy saving (69.31 %) was realized through a scenario of rearranging spaces from the north side to the south side where the number of users is relatively high and selecting a 20 cm aerogel thermal insulation material. While the heating and cooling load, in accordance with the definition of a zero-energy building, could not be reached in this scenario, the study showed the importance of holistic decisions taken in the design phase of the building with respect to energy-efficient building design.


2019 ◽  
Vol 9 (17) ◽  
pp. 3543 ◽  
Author(s):  
Dieu Tien Bui ◽  
Hossein Moayedi ◽  
Dounis Anastasios ◽  
Loke Kok Foong

Today, energy conservation is more and more stressed as great amounts of energy are being consumed for varying applications. This study aimed to evaluate the application of two robust evolutionary algorithms, namely genetic algorithm (GA) and imperialist competition algorithm (ICA) for optimizing the weights and biases of the artificial neural network (ANN) in the estimation of heating load (HL) and cooling load (CL) of the energy-efficient residential buildings. To this end, a proper dataset was provided composed of relative compactness, surface area, wall area, roof area, overall height, orientation, glazing area, glazing area distribution, as the HL and CL influential factors. The optimal structure of each model was achieved through a trial and error process and to evaluate the accuracy of the designed networks, we used three well-known accuracy criterions. As the result of applying GA and ICA, the performance error of ANN decreased respectively by 17.92% and 23.22% for the HL, and 21.13% and 24.53% for CL in the training phase, and 20.84% and 23.74% for HL, and 27.57% and 29.10% for CL in the testing phase. The mentioned results demonstrate the superiority of the ICA-ANN model compared to GA-ANN and ANN.


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