scholarly journals Numerical Analysis of the Impact of Thermal Spray Insulation Solutions on Floor Loading

2020 ◽  
Vol 10 (3) ◽  
pp. 1016 ◽  
Author(s):  
Anna Szymczak-Graczyk

The paper presents the effect of considering the substrate under the floor—insulation in the form of closed-cell polyurethane spray foam, which is used for insulating surfaces particularly exposed to mechanical impact. The layer of thermal insulation was made by spraying, which prevents the occurrence of thermal bridges due to tight filling of the insulated space. It seems extremely important to adopt the appropriate material characteristics of an insulating layer. The basic thermophysical properties of polyurethane foam justifying its choice as an insulation material were the values of its thermal conductivity coefficient (0.022 W/(mK)) and density (36 kg/m3). However, what was the most important for the calculations provided in the work was to determine the stiffness of the foam subgrade so as to assess its impact on the floor load capacity. The paper includes calculations for a floor slab characterized by a static diagram, with all edges free (unfixed), loaded in strips circumferentially. The reinforced concrete slab was 6 × 6 m long, 0.25 m thick, and made of C20/25 concrete resting on an elastic substrate. Calculations were made for two variants taking into consideration two values of subgrade stiffness. The first variant concerned the subgrade stiffness for sprayed polyurethane foam insulation. On the basis of laboratory tests in situ made according to the standard procedure, its average value was assumed as K = 32,000 kN/m3. The second, comparative, computational variant included the subgrade stiffness equal to K = 50,000 kN/m3. A variation approach to the finite difference method was used for static calculations, adopting the condition for the minimum energy of elastic deformation while undergoing bending that was accumulated in the slab resting on a Winkler elastic substrate. Static calculations resulted in obtaining the values of deflections at each point of the discretization grid adopted for the slab. The obtained results have proved the necessity of calculating the floor as a layer element. For the reference substrate with the subgrade stiffness K = 50,000 kN/m3 that was adopted in the work, the value of the bending moment was 17% lower than when taking into account that there was thermal insulation under the floor slab, causing an increase in the deflection of the slab and an increase in its bending moment. If a design does not include the actual subgrade stiffness of the layer under the floor slab, it results in an understatement of the values of the bending moments on the basis of which the slab reinforcement is designed. Adherence of insufficient concrete slab reinforcement may cause subsequent damage to floor slabs.

2018 ◽  
Vol 163 ◽  
pp. 08004 ◽  
Author(s):  
Ewa Sudoł ◽  
Dawid Dębski ◽  
Renata Zamorowska ◽  
Barbara Francke

In the paper the results of an experimental program intended to determine factors influencing the impact resistance of the External Thermal Insulation Composite Systems (ETICS) were presented. For the research the systems based on polystyrene have been chosen. The insulation material was faced with a rendering consisting of base coat reinforced with standard or armored glass fibre mesh and silicone or silicone-silicate binders as finishing coats. The influence of various renderings components was evaluated with respect to resistance to hard body impact and resistance to hail. The test results were discussed in the context of the possible impact level on ETICS in use.


2011 ◽  
Vol 328-330 ◽  
pp. 1377-1380 ◽  
Author(s):  
Xiao Gang Zhao ◽  
Yi Zhou ◽  
Shi Xiang Pan

According to application of thermal insulation materials in the practical construction of electrical heat tracing in viscous oil pipeline, impact factors of rigid polyurethane foam widely used as new insulation material are systemically analyzed by Grey Relational Analysis (GRA) in the theory of Grey System to find out priorities among those factors. To further study their performances and to improve the quality of constructions, ten field experiments were carried out in Tanggula Mountain. The foaming conditions and the performances of the rigid polyurethane foam were recorded to be analyzed by GRA. The analysis results, acting as scientific guidance for construction, show that the insulation quality of rigid polyurethane foam is mainly determined by the ratio of components, thus the priority is to control such dominant factor and overall consideration of other factors should be taken to ensure insulation quality in the foaming process. More field experiments prove that the ratio should be controlled between 1.15 and 1.18 to ensure the thermal insulation.


2014 ◽  
Vol 564 ◽  
pp. 315-320 ◽  
Author(s):  
Maatouk Khoukhi ◽  
Mahmoud Tahat

The impact of the thermal conductivity (k-value) change of polystyrene insulation material in building envelope due to changes in temperature on the thermal and energy performance of a typical residential building under hot climate is investigated. Indeed, the thermal and energy performance of buildings depends on the thermal characteristics of the building envelope, and particularly on the thermal resistance of the insulation material used. The thermal insulation material which is determined by its thermal conductivity, which describes the ability of heat to flow cross the material in presence of a gradient of temperature, is the main key to assess the performance of the thermal insulation material. When performing the energy analysis or calculating the cooling load for buildings, we use published values of thermal conductivity of insulation materials, which are normally evaluated at 24°C according to the ASTM standards. In reality, thermal insulation in building is exposed to significant and continuous temperature variations, due essentially to the change of outdoor air temperature and solar radiation. Many types of insulation materials are produced and used in Oman, but not enough information is available to evaluate their performance under the prevailing climatic condition. The main objective of this study is to investigate the relationship between the temperature and thermal conductivity of various densities of polystyrene, which is widely used as building insulation material in Oman. Moreover, the impact of thermal conductivity variation with temperature on the envelope-induced cooling load for a simple building model is discussed. This work will serve as a platform to investigate the effect of the operating temperature on thermal conductivity of other building material insulations, and leads to more accurate assessment of the thermal and energy performance of buildings in Oman.


1966 ◽  
Vol 1966 (120) ◽  
pp. 236-245
Author(s):  
Shiro Watanabe ◽  
Akira Kamimura ◽  
Yoshiyuki Izutsu ◽  
Masaru Ishida

2015 ◽  
Vol 666 ◽  
pp. 17-29 ◽  
Author(s):  
Sukhdeo R. Karade

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.


2013 ◽  
Vol 7 (1) ◽  
pp. 13-19
Author(s):  
Torben Valdbjorn Rasmussen

A new principle for radon protection is currently presented which makes use of a system of horizontal pressurised air ducts located within the lower part of the rigid insulation layer of the ground-floor slab. The function of this system is based on the principles of pressure reduction within the zone below the ground-floor construction. For this purpose a new system of prefabricated lightweight elements is introduced. The effectiveness of the system is demonstrated for the case of a ground-floor reinforced concrete slab situated on top of a rigid insulation layer (consisting of a thermal insulation layer located on top of a capillary-breaking layer) mounted in turn on stable ground. The new system of prefabricated lightweight elements consists of the capillary-breaking layer and a pressure-reduction zone which is working as the radonsuction zone. The radon-suctioning layer is formed from a grid of horizontal air ducts with low pressure which are able to remove air and radon from the ground. Results showed the system to be effective in preventing radon infiltrating from the ground through the ground-floor slab, avoiding high concentrations of radon being accumulated inside houses. For the system to be effective, the pressure within the ducts must be lower than the pressure inside the house. The new principle was shown to be effective in preventing radon from polluting the indoor air by introducing low pressure in the horizontal grid of air ducts. A lower pressure than the pressure inside the building must be established. The prefabricated lightweight elements were integrated into the insulation layer below the material of the ground-floor slab. The element and the insulation material were made of expanded polystyrene. The new element can be handled by one man on site.


2014 ◽  
Vol 563 ◽  
pp. 41-47
Author(s):  
Zhang Lu ◽  
Dan Xia ◽  
Zhen An

The foaming reaction so that all water-gel reaction and foaming reaction to reach equilibrium, the excellent thermal insulation material was prepared by the regulation of the catalyst, a nucleating agent and an isocyanate. By experiment we know that the amount of stannous octoate catalyst 6%, 4% of the amount of nucleating agent CaCO3, and the case of 100% of the amount of isocyanate, the density of the foam material and the mechanical properties of the insulation material to achieve the best value.


2019 ◽  
Vol 111 ◽  
pp. 02049 ◽  
Author(s):  
Qianwen Guo ◽  
Ryozo Ooka ◽  
Wonseok Oh ◽  
Wonjun Choi ◽  
Doyun Lee

Appropriate insulation materials, with unique physical properties and of moderate thickness, are essential for energy savings in residential buildings. However, the impact of thermal insulation on indoor thermal comfort with floor heating systems has not been studied extensively. In this study, simulations of a typical Japanese detached house were conducted with four different thicknesses of insulation material in the walls, ceiling, and floor to estimate the mean air temperature (MAT), mean radiant temperature (MRT), floor temperature, predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD). The results showed that increasing the thickness of thermal insulation increased the MAT and MRT by 1.4 – 4.0 ℃ and 1.3 – 4.4 ℃, respectively. Moreover, as the thickness of the thermal insulation increased, the floor temperature rose and exhibited smaller fluctuations. Finally, it was found that increasing the thickness of thermal insulation improved the indoor thermal comfort environment, as evidenced by an increase in the PMV from –1.0 to 0.3, and a decrease in the PPD from 25.1% to 9.5%.


Author(s):  
V. B. Essien ◽  
Christian A. Bolu ◽  
Imhade P. Okokpujie ◽  
Joseph Azeta

The prediction and application of Polyurethane Foam in developing roofing sheets cannot be over-emphasized when considering the environmental changes coursed by thermal radiation. This paper presents an artificial neural network application to model and predict the indoor temperature resistance of polyurethane (PU) roofing in residential buildings. The study employed a data logger to measure the indoor and outdoor temperatures for three simulation environments (i.e., morning, afternoon, and evening) for two hours each. Furthermore, the authors employed the Levenberg-Marquardt algorithm to transform and predict the indoor temperature obtained in the residential building's polyurethane roofing house. The result shows that the PU roofing system could absorb the heat and reduce the house model's temperature with 6.9% in the morning, afternoon 15.8%, and 6.8% in the evening when compared with the temperature outdoor environment. The ANN was also able to train, test, and validate the experimental temperature results with 92.86%, 93.92%, and 95%, respectively. The mean square error and a testing error occurs at 0.1707 and 0.1689. Therefore, this study concluded that ANN's application in predicting the thermal insulation material such as the PU roofing system is highly efficient and will increase the manufacturer's performance evaluation. It has also created significant awareness of the community in employing the PU roofing system for residential buildings, which will reduce the rate of energy consumption in buildings.


2014 ◽  
Vol 1061-1062 ◽  
pp. 1167-1170
Author(s):  
Xiao Gang Zhao ◽  
Yi Zhou ◽  
Jian Yu Zhao ◽  
Xiao Yuan Yang ◽  
Xing Zheng

With the rapid development of petroleum industry in China, the electrical heat tracing becomes very important for viscous oil transportation, while the heat insulation acts as the key to the application of electrical heat tracing. Rigid polyurethane foam has been widely used in long-distance pipelines for its advantages as the heat insulation material. However, there is also a lack of systematic analysis on the impact factors of such material, thus it is urgent to find out a practical method to distinguish the major impact factors. This paper introduces the Grey Relational Analysis (GRA) with its C# program, and it is proposed to analyze the actual impact factors of rigid polyurethane foam. The application shows that this method is practical, simple, rapid and accurate, so it suitable for similar applications in other fields.


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