scholarly journals Fire Resistance and Mechanical Properties of Intumescent Coating Using Novel BioAsh for Steel

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1117
Author(s):  
Jing Han Beh ◽  
Ming Chian Yew ◽  
Lip Huat Saw ◽  
Ming Kun Yew

Recent developments of intumescent fire-protective coatings used in steel buildings are important to ensure the structural integrity and safe evacuation of occupants during fire accidents. Flame-retardant intumescent coating applied to structural steel could delay the spread of fire and heat propagation across spaces and structures in minimizing fire risks. This research focuses on formulating a green intumescent coating utilized the BioAsh, a by-product derived from natural rubberwood (hardwood) biomass combustion as the natural substitute of mineral fillers in the intumescent coating. Fire resistance, chemical, physical and mechanical properties of all samples were examined via Bunsen burner, thermogravimetric analysis (TGA), carbolite furnace, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared (FTIR), freeze–thaw cycle, static immersion and Instron pull-off adhesion test. Sample BioAsh intumescent coating (BAIC) 4-7 incorporated with 3.5 wt.% BioAsh exhibited the best performances in terms of fire resistance (112.5 °C for an hour under the Bunsen burner test), thermal stability (residual weight of 29.48 wt.% at 1000 °C in TGA test), adhesion strength (1.73 MPa under Instron pull-off adhesion test), water resistance (water absorption rate of 8.72%) and freeze–thaw durability (no crack, blister and color change) as compared to other samples. These results reveal that an appropriate amount of renewable BioAsh incorporated as natural mineral fillers into the intumescent coating could lead to better fire resistance and mechanical properties for the steel structures.

Author(s):  
A.V. Pchelnikov ◽  
◽  
V.V. Korotkikh ◽  
A.P. Ilyasov ◽  
◽  
...  

This paper discusses the current areas of work to en-sure the performance of protective coatings for machinery and equipment in theagricultural industry complex for the conditions of Siberia. The following five main areas were identified: corrosion protection, thermoregulation, fire re-sistance, antistatics and radiation protection. It was found that the most efficient way to ensure the performance of coatings is their nanomodification. The method of fire re-sistance tests developed at the Novosibirsk State Agricul-tural University is presented. The results of preliminary tests in two areas are presented: fire resistance and corro-sion protection. One of the promising nano-additives is bismuth oxide which may improve fire resistance and phys-ical and mechanical properties. According to the research results, when the concentration of bismuth oxide reaches 5%, an extremum is observed for the values of hardness (86-94) and adhesion (3.3-3.6 MPa) of the coating. At the same time, the addition of bismuth oxide in a concentration of 7.5% made it possible to achieve a significant increase in the fire resistance of the coating. Fire resistance and ignition time increased to 240°C and 65 s, respectively. Some of the most effective additives are identified and the further direction of the study is indicated which consists in optimizing the compositions of protective coatings and providing a set of properties for operating conditions in each specific case. It is also necessary to take into account the combined effect of nanomodifiers on the properties of the protective coating.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Longxiao Chen ◽  
Kesheng Li ◽  
Guilei Song ◽  
Deng Zhang ◽  
Chuanxiao Liu

AbstractRock deterioration under freeze–thaw cycles is a concern for in-service tunnel in cold regions. Previous studies focused on the change of rock mechanical properties under unidirectional stress, but the natural rock mass is under three dimensional stresses. This paper investigates influences of the number of freeze–thaw cycle on sandstone under low confining pressure. Twelve sandstone samples were tested subjected to triaxial compression. Additionally, the damage characteristics of sandstone internal microstructure were obtained by using acoustic emission (AE) and mercury intrusion porosimetry. Results indicated that the mechanical properties of sandstone were significantly reduced by freeze–thaw effect. Sandstone’ peak strength and elastic modulus were 7.28–37.96% and 6.38–40.87% less than for the control, respectively. The proportion of super-large pore and large pore in sandstone increased by 19.53–81.19%. We attributed the reduced sandstone’ mechanical properties to the degenerated sandstone microstructure, which, in turn, was associated with increased sandstone macropores. The macroscopic failure pattern of sandstone changed from splitting failure to shear failure with an increasing of freeze–thaw cycles. Moreover, the activity of AE signal increased at each stage, and the cumulative ringing count also showed upward trend with the increase of freeze–thaw number.


2020 ◽  
Vol 2020 ◽  
pp. 1-13 ◽  
Author(s):  
Huren Rong ◽  
Jingyu Gu ◽  
Miren Rong ◽  
Hong Liu ◽  
Jiayao Zhang ◽  
...  

In order to study the damage characteristics of the yellow sandstone containing pores under the freeze-thaw cycle, the uniaxial compression test of saturated water-stained yellow sandstones with different freeze-thaw cycles was carried out by rock servo press, the microstructure was qualitatively analyzed by Zeiss 508 stereo microscope, and the microdamage mechanism was quantitatively studied by using specific surface area and pore size analyzer. The mechanism of weakening mechanical properties of single-hole yellow sandstone was expounded from the perspective of microstructure. The results show the following. (1) The number of freeze-thaw cycles and single-pore diameter have significant effects on the strength and elastic modulus of the yellow sandstone; the more the freeze-thaw cycles and the larger the pore size, the lower the strength of the yellow sandstone. (2) The damage modes of the yellow sandstone containing pores under the freeze-thaw cycle are divided into five types, and the yellow sandstone with pores is divided into two areas: the periphery of the hole and the distance from the hole; as the number of freeze-thaw cycles increases, different regions show different microscopic damage patterns. (3) The damage degree of yellow sandstone is different with freeze-thaw cycle and pore size. Freeze-thaw not only affects the mechanical properties of yellow sandstone but also accelerates the damage process of pores. (4) The damage of the yellow sandstone by freeze-thaw is logarithmic function, and the damage of the yellow sandstone is a power function. The damage equation of the yellow sandstone with pores under the freezing and thawing is a log-power function nonlinear change law and presents a good correlation.


2020 ◽  
Vol 13 (6) ◽  
pp. 686-696
Author(s):  
Frank Mi-Way Ni ◽  
Abimbola Grace Oyeyi ◽  
Susan Tighe

AbstractProtecting the pavement subgrade to increase the service life of road pavements is an aspect currently being explored. Several alternative pavement subbase materials are being considered, including Lightweight Cellular Concrete (LCC). Due to its lower weight, LCC incorporating industrial by-product, making it sustainable, and ease of use amongst other benefits, is seen as a potential candidate. This paper reports reviewing the potential application of LCC within the pavement structure with a specific application as a subbase. It examines the various properties such as modulus of elasticity, compressive and tensile strength, Water absorption, and freeze-thaw resistance necessary for pavement application. It also assesses its use in the field in Canada considering the design methods utilized. Some limitations and gaps for LCC application in pavements are also established and recommendations on how to further its use and performance. This review concludes that LCC possesses potential as a pavement subbase alternative; however, other mechanical properties like LCC’s fatigue life is essential. A comparative field study is also recommended to monitor actual performance and various factors on performance.


Polymers ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 173
Author(s):  
Alessandro Pistone ◽  
Cristina Scolaro ◽  
Annamaria Visco

The accumulation of marine organisms on ship hulls, such as microorganisms, barnacles, and seaweeds, represents a global problem for maritime industries, with both economic and environmental costs. The use of biocide-containing paints poses a serious threat to marine ecosystems, affecting both target and non-target organisms driving science and technology towards non-biocidal solutions based on physico-chemical and materials properties of coatings. The review reports recent development of hydrophobic protective coatings in terms of mechanical properties, correlated with the wet ability features. The attention is focused mainly on coatings based on siloxane and epoxy resin due to the wide application fields of such systems in the marine industry. Polyurethane and other systems have been considered as well. These coatings for anti-fouling applications needs to be both long-term mechanically stable, perfectly adherent with the metallic/composite substrate, and capable to detach/destroy the fouling organism. Prospects should focus on developing even “greener” antifouling coatings solutions. These coatings should also be readily addressable to industrial scale-up for large-scale product distribution, possibly at a reasonable cost.


2021 ◽  
Vol 899 ◽  
pp. 557-562
Author(s):  
Timur A. Borukaev ◽  
Luiza I. Kitieva ◽  
Abubekir Kh. Shaov ◽  
A.A. Kyarov

Based on magnesium carbonate and antimony oxide (V), MgO•Sb2O5 was obtained. In the formulation of fire-resistant cable PVC-plasticate, antimony (III) oxide was replaced by MgO•Sb2O5 and the fire resistance and physical and mechanical properties of the resulting compound were investigated. It is shown that the replacement of antimony (III) oxide in the composition of PVC cable compound MgO•Sb2O5 leads to the production of a compound that is not inferior in its characteristics to the original plastic compound. In particular, the fire resistance of cable PVC-plasticate, standard industrial formulation and with the obtained MgO•Sb2O5, is practically the same (OI=32%). It has been established that the physical and mechanical characteristics of the cable compound, when replacing antimony oxide (III) with MgO•Sb2O5 in the formulation, remain at the level of the original compound, while MgO×Sb2O5 will have a less negative impact on the environment.


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