scholarly journals Adequate Correlation between the Physical and Mechanical Properties of Glass Foam

2021 ◽  
Vol 2 (4) ◽  
pp. 14-26
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Marius Florin Dragoescu ◽  
Felicia Cosmulescu

The paper presents experimental results obtained in the manufacturing process of a glass foam by adequate correlation between its physical and thermal properties (density, porosity, thermal conductivity) and mechanical (compressive strength) by a slight controlled overheating of the foamed material. Using a powder mixture of glass waste (87-91.5 %), coal fly ash (3-9 %) and silicon carbide (4-5.5 %) microwave heated at 935-975 ºC by this unconventional technique, constituting the originality of the work, was obtained a glass-ceramic foam with moderate compressive strength (1.8-2.6 MPa) and very low thermal conductivity (0.058-0.070 W/m·K). The material overheating generated a homogeneous porous structure characterized by closed cells with relatively large dimensions (without the tendency to join neighboring cells) making it difficult to transfer heat across the material. The foamed product is suitable for the manufacture of thermal insulation blocks for the inner or outer walls of the building without excessive mechanical stress, being an advantageous alternative by comparison with known types of polymeric or fiberglass thermal insulation materials.

2021 ◽  
Vol 1 (4) ◽  
pp. 14-26
Author(s):  
Lucian Paunescu ◽  
Sorin Mircea Axinte ◽  
Marius Florin Dragoescu ◽  
Felicia Cosmulescu

The paper presents experimental results obtained in the manufacturing process of a glass foam by adequate correlation between its physical and thermal properties (density, porosity, thermal conductivity) and mechanical (compressive strength) by a slight controlled overheating of the foamed material. Using a powder mixture of glass waste (87-91.5 %), coal fly ash (3-9 %) and silicon carbide (4-5.5 %) microwave heated at 935-975 ºC by this unconventional technique, constituting the originality of the work, was obtained a glass-ceramic foam with moderate compressive strength (1.8-2.6 MPa) and very low thermal conductivity (0.058-0.070 W/m·K). The material overheating generated a homogeneous porous structure characterized by closed cells with relatively large dimensions (without the tendency to join neighboring cells) making it difficult to transfer heat across the material. The foamed product is suitable for the manufacture of thermal insulation blocks for the inner or outer walls of the building without excessive mechanical stress, being an advantageous alternative by comparison with known types of polymeric or fiberglass thermal insulation materials.


Author(s):  
Viola Hospodarova ◽  
Nadezda Stevulova ◽  
Vojtech Vaclavik ◽  
Tomas Dvorsky ◽  
Jaroslav Briancin

Nowadays, construction sector is focusing in developing sustainable, green and eco-friendly building materials. Natural fibre is growingly being used in composite materials. This paper provides utilization of cellulose fibres as reinforcing agent into cement composites/plasters. Provided cellulosic fibres coming from various sources as bleached wood pulp and recycled waste paper fibres. Differences between cellulosic fibres are given by their physical characterization, chemical composition and SEM micrographs. Physical and mechanical properties of fibre-cement composites with fibre contents 0.2; 0.3and 0.5% by weight of filler and binder were investigated. Reference sample without fibres was also produced. The aim of this work is to investigate the effects of cellulose fibres on the final properties (density, water absorbability, coefficient of thermal conductivity and compressive strength) of the fibrecement plasters after 28 days of hardening. Testing of plasters with varying amount of cellulose fibres (0.2, 0.3 and 0.5 wt. %) has shown that the resulting physical and mechanical properties depend on the amount, the nature and structure of the used fibres. Linear dependences of compressive strength and thermal conductivity on density for plasters with cellulosic fibres adding were observed.


2012 ◽  
Vol 535-537 ◽  
pp. 239-242
Author(s):  
Alena Kalužová ◽  
Jan Pěnčík ◽  
Libor Matějka ◽  
Libor Matějka ◽  
Tomáš Pospíšil ◽  
...  

Recycling of materials is an important point of sustainable construction. The aim is to find a compromise between energy saving, economy and ecology. The contribution discusses the production of thermal insulation composite material made of polymers. Uniform dispersion of grains of foamy glass waste (filler) in polymer filling from recycled thermoplastics induces formation of particle composite. The production supports usage of secondary raw materials. Decisive properties in choosing the materials to be applied include mainly the coefficient of thermal conductivity, density, compressive strength and water absorption.


2015 ◽  
Vol 833 ◽  
pp. 48-51 ◽  
Author(s):  
Wei Shi ◽  
Jia Yan Li ◽  
Qi Fan You ◽  
Tong Lu ◽  
Yi Tan

Matrix derived from resin after carbonization in rigid carbon felt thermal insulation has many advantages. The microstructures and properties of these materials were investigated in this paper. Results showed that matrix tend to accumulate at the intersections of fibers. This can improve mechanical properties and have a little influence on thermal conductivities of the composites. The excellent bending strength of 2.66MPa, compressive strength of 0.91MPa and a high thermal conductivity of 0.81W/(m·K) (at 1500°C) with a matrix concentration of 32.7% is achieved. However, high thermal conductivity is harmful for those materials which are used as thermal insulators.


2018 ◽  
Vol 27 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Jakub Jura ◽  
Małgorzata Ulewicz

The article presents the results of research aimed at using glass waste and ash from biomass. The tests were carried out for cement mortars samples with using glass cullet, ash from biomass and using both wastes in 50/50 proportions. The physical and mechanical properties of the standard mortar and modified mortars were tested. Standard mortar and cement mortar samples were made in which 10, 20 and 30% of the cement mass was used as part of the standard sand. The samples were made of CEM I 42.5R. Mortars containing fly ash addition had an increased compressive strength and a smaller drop in compressive strength after frost resistance tests than standard mortar. The use of glass cullet in the amount of up to 20% did not reveal any changes in the mechanical properties of mortars, but using them in a larger amount resulted in unfavorable results. The use of a mixture of these two waste materials did not improve the results. The research has shown the possibility of using this waste to modify cement mortars.


2020 ◽  
Vol 13 (1) ◽  
pp. 32-38
Author(s):  
J. C. AMARAL JR ◽  
W. G. MORAVIA

Abstract Concrete is one of the materials most used by the construction industry. Reinforcing this material with fibers is a technique used to improve its mechanical properties. Steel and polymer fibers are the main types used in this application and there are few studies about the influence of polymer fibers on the thermal properties of concrete. In order to analyze this influence, the present work carried out thermal conductivity, thermal expansion, and compressive strength after exposure to a temperature of 200 °C on specimens made of concrete with addition of polypropylene (PP) fibers and concrete with addition of high modulus polyethylene (HMPE). It was also conducted thermogravimetric analysis (TGA) on PP and HMPE fibers. The results show that the addition of polymer fibers alters the thermal properties of the concrete, reducing its thermal expansion, for example.


Author(s):  
Rim Zgueb ◽  
Amal Brichni ◽  
Noureddine Yacoubi

Sorel cements is a promising building material for insulation applications. Indeed, the effect of polyvinyl acetate polymer on cements has been investigated. The polyvinyl acetate polymer was added to the cement matrix with a percentage of 0, 5, 10, 15 and 20% by weight of Sorel cement. The thermal properties of Sorel cement were determined by photothermal deflection technique. Thermal properties such as thermal conductivity and thermal diffusivity are measured by coincidentally the experimental curves of the photothermal signal with the best corresponding theoretical curves. The results revealed that the incorporation of polyvinyl acetate polymer enhance the thermal insulation and reduce the compressive strength of Sorel cement.


2015 ◽  
Vol 668 ◽  
pp. 263-269 ◽  
Author(s):  
Marilia da Silva Bertolini ◽  
André Luis Christoforo ◽  
Francisco Antonio Rocco Lahr

The concept of sustainable buildings addresses the environmentally efficiency, with respect to energy consumption, by adopting products that offer thermal insulation. Moreover, use of wastes from different materials also contributes to obtain products for this application. The volume of wastes from timber industry and those from tires are an environmental problem. This study aimed to production and characterization of particleboards using wastes from wood and tire rubber with castor-oil polyurethane resin. Panels were produced containing only wood and also with addition of tire rubber. The properties determined were density, modulus of rupture (MOR) and modulus of elasticity (MOE) in bending, according to Brazilian Code NBR 14810-3 (2006), and thermal conductivity. Statistical analysis was conducted in physical and mechanical properties. Panels containing wood were classified as low density (0.55 g/cm³), while those with wood and tire rubber resulted in medium density (0.78 g/cm³). For mechanical properties, the addition of rubber resulted in increased of MOR and reduction for MOE. Superior performance for thermal conductivity was achieved for panels produced only with wood. However, samples with a mixture of wood and tire rubber also showed consistent thermal conductivity with similar products. Considering the results obtained, panels containing wood and tire rubber addition have potential for application as thermal insulation.


2021 ◽  
Vol 7 (7) ◽  
pp. 1222-1234
Author(s):  
Mohammed Salah Bouglada ◽  
Noui Ammar ◽  
Belagraa Larbi

The paper aims to study cellular concrete with a new approach of formulation without an autoclave, with the use of aluminum waste and incorporation of mineral additions into the sand and evaluate its physical and mechanical properties. In this experimental study, two types of cellular concrete are prepared, based on crushed and dune sand with the incorporation of 15% of the slag and 10% of pozzolana, as sand replacement. An experimental program was performed to determine the compressive strength at 28 days, the density and thermal conductivity of the confected cellular concrete. The obtained results showed that concretes prepared with crushed sand developed better mechanical resistance compared to the dune sand. It is also noted that the concretes containing the mineral additions provide a substantial increase in compressive strength in particular slag. Furthermore, cellular concretes with sand dunes offer better thermal conductivity, compared to those with crushed sand. The use of the additions reduces the Water/Binder (W/B) ratio and leads to a lower thermal conductivity regardless of the used sand nature. The outcome of the present study here in could present a modest contribution for the production of cellular concrete with local materials in particular dune sand, active mineral addition and aluminum waste. The physical and mechanical properties obtained from this new composition are estimated acceptable compared to those of the industry-prepared cellular concrete product. Doi: 10.28991/cej-2021-03091721 Full Text: PDF


2018 ◽  
Vol 24 (1) ◽  
pp. 30-35
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
BOGDAN VALENTIN PAUNESCU

Experimental results obtained in the process of manufacturing dense glass foam using the microwave energy are presented in the work. The glass foam is produced from bottle glass waste, calcium carbonate as foaming agent and borax as fluxing agent. The high compressive strength (2.5 - 6.2 MPa) is the main mechanical feature of this product, which together with other physical and morphological features (apparent density 0.60 – 0.90 g/cm3, porosity 59.1 – 72.7%, thermal conductivity 0.081 – 0.105 W m K, water absorption 0.5 – 1.0%, pore size 0.5 – 3 mm), are appropriate for using as a substitute for similar building materials existing on the market.


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