scholarly journals Effect of drying method on compressive strength of straw-based thermal insulations

2021 ◽  
Vol 3 (1) ◽  
pp. 108-116
Author(s):  
Olivér Fenyvesi ◽  
Dániel Csanády
Keyword(s):  
Compressive Strength ◽  
Thermal Insulation ◽  
Length Distribution ◽  
Environmentally Friendly ◽  
Raw Material ◽  
Microwave Drying ◽  
Stem Length ◽  
Natural State ◽  
Conventional Drying ◽  
Thermal Insulations

Most of the thermal insulations in the construction industry market based on fossil raw material or need a huge amount of production energy. Nowadays, sustainable thermal insulation products are more popular, and the demand for these products on the market is increasing. Some of them reach the main material properties of artificial ones but usually not all. Today the reaction to fire is another big challenge in this field. In many cases, producers use chemicals that can increase fire resistance, but on the other hand, increase the environmental impact of insulations too. It is also hard to find a binder which provides proper mechanical parameters and durability and is environmentally friendly too. During our scientific research on environmentally friendly thermal insulation materials, which is running for 4 years, we found that silicate-based adhesives meet many of these criteria mentioned above. In this article, the mechanical properties of straw-based insulation bonded with silicate binder were investigated. The effect of conventional and microwave drying on compressive strength were compared to found the optimal hardening process of binders. During the experiments, straw was applied in a natural state, natural stem length distribution and without microstructure and surface modification. The used binder is a simple silicate-based binder (potassium silicate) without any modification agent. Conventional drying needs a longer time, and during it, many cracks form in the early age of the hardened binder. It is because of shrinkage and the differences in the rigidity of the binder along its cross-section. Besides, the straw stems swell when exposed to moisture (from binder), and after drying they shrink, which decreases the quality of the bond between stems and binder. The microwave drying evenly heats the various points of the specimen, so it is not generated such big differences in shrinkage. The contact between stems and binder are also better. Due to these effects, the microwave dried specimens reached the limit required for step resistance, and they had three-time higher average compressive strength than we got by the conventional drying of the same raw material.

scholarly journals Influence of the Composition and Curing Time on Mechanical Properties of Fluidized Bed Combustion Fly Ash-Based Geopolymer

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2527
Author(s):  
Natalia Wielgus ◽  
Jan Kubica ◽  
Marcin Górski
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Fluidized Bed ◽  
Environmentally Friendly ◽  
Raw Material ◽  
Fluidized Bed Combustion ◽  
Precast Elements ◽  
Ash Disposal ◽  
Fbc Fly Ash

This paper presents novel research on a fluidized bed combustion (FBC) fly ash-based geopolymer as a contribution to the problem of FBC fly ash disposal, and a proposal for a new geopolymer composition—an environmentally friendly material that is possible to use in construction. Geopolymer samples of various composition (containing FBC fly ash as the main raw material, metakaolin and CRT glass as additional components, and sodium silicate and sodium hydroxide as activators) were subjected to flexural and compressive strength tests. An investigation on the effect of the demolding time was carried out on one selected mixture. The test showed that both the composition and the demolding time have a decisive influence on the basic mechanical properties. A mixture containing FBC fly ash to metakaolin in a mass ratio of 3:1, removed from the mold after 14 days, was found to be the best in terms of the mechanical parameters expected from a material that could be used in construction, e.g., for the production of precast elements. According to the results obtained, FBC fly ash is a promising and environmentally friendly raw material for the production of geopolymer, with good mechanical properties and low density. Moreover, a high compressive strength can be obtained by curing the geopolymer at ambient temperature.

Research of the Main Influence Factors of Fly Ash Thermal Insulation Material

2010 ◽  
Vol 156-157 ◽  
pp. 839-843
Author(s):  
Jin Xia Zhang ◽  
Yi Miao Nie ◽  
Shi Chao Li ◽  
Fu Sheng Niu
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Thermal Insulation ◽  
Influence Factors ◽  
Raw Material ◽  
Insulation Material ◽  
Thermal Insulation Material ◽  
Solid Liquid ◽  
The Relationship ◽  
Main Influence

By using fly ash as raw material to prepare thermal insulation material in this research. The relationship between the compressive strength and the influence factors was systematically discussed. The compressive strength of the samples reached max when the dosage of silica fume was 5%, sodium hydroxide 40%,the solid-liquid ratio was 0.75 and the content of foam was 4%. The experimental results provided a good basis for manufacturing the thermal insulation material and improving its property.

scholarly journals A Novel Approach to Fabricate Foam Ceramics from Steel Slag

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Yu Zheng ◽  
Xudong Luo ◽  
Jinlong Yang ◽  
Wenlong Huo ◽  
Chi Kang
Keyword(s):  
Compressive Strength ◽  
Ph Value ◽  
Steel Slag ◽  
Raw Material ◽  
Solid Loading ◽  
Insulation Material ◽  
Ceramic Foams ◽  
Novel Approach ◽  
The Stability ◽  
First Time

A novel approach is used for fabricating steel slag foam ceramics based on the particle-stabilized foaming method. In this work, steel slag was used as the raw material and propyl gallate (PG) was used as the surface modifier. For the first time, steel slag ceramic foams were successfully fabricated based on particle-stabilized foams. The results show that the stability of the ceramic foams was closely related to the pH value and PG concentration. The porosity and compressive strength could be controlled by changing the solid loading of steel slag and sintering temperature. The porosity of steel slag foam ceramics ranged from 85.6% to 62.53%, and the compressive strength was from 1.74 MPa to 10.42 MPa. The thermal conductivity of steel slag foam ceramics was only 0.067 W (m·K)−1, which shows that it could be used as a thermal insulation material.

Development and Validation of a Green Analytical Method for the Determination of Norfloxacin in Raw Material by FTIR Spectrophotometry

2016 ◽  
Vol 99 (6) ◽  
pp. 1533-1536 ◽  
Author(s):  
Jéssica Sayuri Hisano Natori ◽  
Eliane Gandolpho Tótoli ◽  
Hérida Regina Nunes Salgado
Keyword(s):  
Urinary Tract ◽  
Organic Solvents ◽  
Analytical Method ◽  
Environmentally Friendly ◽  
Raw Material ◽  
Waste Generation ◽  
Ftir Spectrophotometry ◽  
Tract Infections ◽  
Development And Validation

Abstract Norfloxacin is a broad-spectrum antimicrobial agent, widely used in humans and animals for the treatment of urinary tract infections. It is a second-generation fluoroquinolone. Several analytical methods to analyze norfloxacin have been described in the literature. However, most of them are complex and require the use of large amounts of organic solvents. This paper describes the development and validation of a green analytical method for the determination of norfloxacin in raw material by FTIR spectrophotometry. This method does not require the use of organic solvents, minimizing waste generation in the process and its environmental impacts. The development of methods that promote the reduction, prevention, or elimination of waste generation has become highly attractive to the pharmaceutical industry because of the growing demand from civil society and government authorities for environmentally friendly products and services. The FTIR spectrophotometry method was validated according to International Conference on Harmonization guidelines, showing adequate linearity (r = 0.9936), precision, accuracy, and robustness. This validated method can be used as an environmentally friendly alternative for the quantification of norfloxacin in raw material in QC routine analysis.

Incorporation of Wastes from Marble to Produce Brick Materials

2012 ◽  
Vol 174-177 ◽  
pp. 135-139
Author(s):  
Qing Bo Tian ◽  
Li Zong Chen ◽  
Li Na Xu ◽  
Yong Guang Fang
Keyword(s):  
Compressive Strength ◽  
Glass Fiber ◽  
Room Temperature ◽  
Wood Flour ◽  
Raw Material ◽  
Water Addition ◽  
Water Curing

A brick material was prepared with marble wastes as main raw material by pressure forming and water-curing at room temperature. With the increases of the amounts of water additions, the compressive strength increased gradually and obtained a highest value of 34.8MPa in the sample of the ratio of cement: wastes=20:100 at 17.0% water addition, above which the strength had an adverse change and decreased. The addition of glass fiber had small effects on the strength, water absorbing rate and density comparing with that of wood flour. The strengths of sample had changed obviously with the increment of the forming pressures. However, the strength would fall because of the lamination caused by the recovering effects of the wood flour in the sample with replacement of the wood flour to marble wastes, as the forming pressures were higher than 5.0 MPa.

USE OF THE MICROWAVE ENERGY FOR ALUMINUM WASTE FOAMING

2019 ◽  
Vol 25 (4) ◽  
pp. 43-49
Author(s):  
LUCIAN PAUNESCU ◽  
MARIUS FLORIN DRAGOESCU ◽  
SORIN MIRCEA AXINTE ◽  
ANA CASANDRA SEBE
Keyword(s):  
Thermal Conductivity ◽  
Compressive Strength ◽  
Porous Structure ◽  
Powder Mixture ◽  
Aluminum Foam ◽  
Fine Powder ◽  
Microwave Energy ◽  
Raw Material ◽  
Foaming Agent ◽  
Foaming Process

The paper presents an aluminum foam experimental technique using the microwave energy. The raw material was recycling aluminum waste processed by ecological melting and gas atomizing to obtain the fine powder required in the foaming process. The powder mixture was completed with dolomite as a foaming agent. The products had a fine and homogeneous porous structure (pore size between 0.4-0.9 mm). The density (1.17-1.19 g/cm3), the compressive strength (6.83-7.01 MPa) and the thermal conductivity (5.71-5.84 W/m·K) had values almost similar to the foams made by conventional methods.

scholarly journals Synthesis of Geopolymer from Inorganic Construction Waste

2013 ◽  
Vol 30 ◽  
pp. 45-51 ◽  
Author(s):  
Arbind Pathak ◽  
Vinay Kumar Jha
Keyword(s):  
Compressive Strength ◽  
Coal Fly Ash ◽  
Chemical Society ◽  
Raw Material ◽  
Curing Temperature ◽  
Alkali Concentration ◽  
Curing Time ◽  
Mass Ratio ◽  
Construction Waste ◽  
Alumino Silicate

Recently, the demolition of old houses and the construction of new buildings in Kathmandu valley are in the peak which in turn generates a huge amount of construction waste. There are two major types of construction wastes which are burden for disposal namely cement-sand-waste (CSW) and the coal fly ash (CFA). These construction wastes are rich source of alumino-silicate and thus used as raw material for the synthesis of geopolymer in this study. Geopolymers have been synthesized from CSW and CFA using NaOH-KOH and Na2SiO3 as activators. Some parameters like alkali concentration, amount of Na2SiO3 and curing time have been varied in order to improve the quality of geopolymeric product. The geopolymerization process has been carried out using 3-8M KOH/NaOH solutions, Na2SiO3 to CFA and CSW mass ratio of 0.25-2.00 and curing time variation from 5-28 days. The curing temperature was fixed at 40ºC in all the cases. 6M NaOH and 7M KOH solutions were found appropriate alkali concentrations while the ratio of sodium silicate to CSW and CFA of 0.5 and 1.75 respectively were found suitable mass ratio for the process of geopolymer synthesis. The maximum compressive strength of only 7.3 MPa after 15 days curing time with CSW raw material was achieved while with CFA, the compressive strength was found to be 41.9 MPa with increasing the curing time up to 28 days.DOI: http://dx.doi.org/10.3126/jncs.v30i0.9334Journal of Nepal Chemical Society Vol. 30, 2012 Page:  45-51 Uploaded date: 12/16/2013    

Performance of Nano-Silica Insulation Material Enhanced by High Humidity-Reinforcement Method

2016 ◽  
Vol 697 ◽  
pp. 433-436
Author(s):  
Shi Chao Zhang ◽  
Yu Feng Chen ◽  
Wei Wu ◽  
Hao Ran Sun ◽  
Guang Hai Wang ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Raw Material ◽  
High Humidity ◽  
Insulation Material ◽  
Condensation Polymerization ◽  
Drying Process ◽  
Nano Silica ◽  
Insulation Materials ◽  
The One ◽  
Strength Improvement

In this paper, fumed nano-silica as the main raw material, nano-silica insulation materials were prepared by the dry processing. Research on humidity-reinforcement of nano-Silica insulation materials has been carried out and analyzed. When hygroscopicity of samples reach to 23%, the compressive strength 1.65MPa is at twice the one without high humidity-reinforcement, while the thermal conductivities are almost the same. Then, the action mechanism of high humidity-reinforcement method was analyzed. In humidity-reinforcement method, as vapor enters, silica sol is formed in the gap between one aggregate particle and another, and various condensation polymerization occurred in the drying process, which lead to aggregates connection and compressive strength improvement.

Influences of Emulsion on Water Resistance of Vitrified Micro Bubbles Thermal Insulation Material

2013 ◽  
Vol 662 ◽  
pp. 433-436
Author(s):  
Jiang Zhu ◽  
Guo Zhong Li
Keyword(s):  
Compressive Strength ◽  
Polyvinyl Alcohol ◽  
Stearic Acid ◽  
Thermal Insulation ◽  
Water Resistance ◽  
Insulation Material ◽  
Molding Process ◽  
Thermal Insulation Material ◽  
Improve Water Resistance ◽  
Softening Coefficient

Vitrified micro bubbles thermal insulation material was made of vitrified micro bubbles, cement, fly ash, gypsum and sodium silicate, by molding process. VAE emulsion and stearic acid-polyvinyl alcohol emulsion were added to improve water resistance of the material. Mixed with 10% VAE emulsion and 5% stearic acid-polyvinyl alcohol emulsion, properties of the material are followed as: flexural strength 0.64MPa, compressive strength 1.35MPa, softening coefficient 0.71 and 2h volumetric water absorption 6.9%.

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