Changes in physical and mechanical properties of limestone and marble after exposure to different high temperatures

2019 ◽  
Vol 53 (3) ◽  
pp. 378-385
Author(s):  
Weiqiang Zhang ◽  
Chenchen Xu ◽  
Jishi Geng
Keyword(s):  
Mechanical Properties ◽  
Thermal Diffusivity ◽  
High Temperatures ◽  
Mechanical Characteristics ◽  
Heating Temperature ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
High Temperature Treatment ◽  
Peak Strain ◽  
Physical And Mechanical Characteristics

Under or after high-temperature treatment, the physical and mechanical characteristics of limestone and marble change significantly. This study seeks to understand the effect of high temperatures on physical and mechanical properties (such as density, porosity, permeability, P-wave velocity, thermal diffusivity, elastic modulus, uniaxial compressive strength, peak strain and Poisson's ratio) of limestone and marble. The results indicate that, from room temperature to 300°C, most of the physical and mechanical indices of limestone and marble change relatively little, except for thermal diffusivity. Above 300°C (especially at 400–600°C), physical and mechanical characteristics change significantly, corresponding to the changes to minerals between 400 and 600°C. These results confirm the important link between physical and mechanical properties and heating temperature, and can provide the basis of theory and reference for related engineering.

Effect of MgO•Sb2O5 on Fire Resistance and Physical and Mechanical Properties of Cable PVC-Plasticate

2021 ◽  
Vol 899 ◽  
pp. 557-562
Author(s):  
Timur A. Borukaev ◽  
Luiza I. Kitieva ◽  
Abubekir Kh. Shaov ◽  
A.A. Kyarov
Keyword(s):  
Mechanical Properties ◽  
Fire Resistance ◽  
Mechanical Characteristics ◽  
Negative Impact ◽  
Physical And Mechanical Properties ◽  
Antimony Oxide ◽  
Magnesium Carbonate ◽  
Physical And Mechanical Characteristics

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.

Comparative experimental study on physical and mechanical properties of quartz sandstone after water-cooling and natural-cooling under high temperature

2021 ◽  
pp. qjegh2020-181
Author(s):  
Haopeng Jiang ◽  
Annan Jiang ◽  
Fengrui Zhang
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Elastic Modulus ◽  
Uniaxial Compressive Strength ◽  
Heating Temperature ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Water Cooling ◽  
Average Value ◽  
Cooling Methods

Experimental tests were conducted to study the influence of natural cooling and water cooling on the physical and mechanical properties of quartz sandstone. This study aims to understand the effect of different cooling methods on the physical and mechanical properties of quartz sandstone (such as mass, volume, density, P-wave velocity, elastic modulus, uniaxial compressive strength, etc.). The results show that the uniaxial compressive strength (UCS) and elastic modulus(E) of the specimens cooled by natural-cooling and water-cooling decrease with heating temperature. At 800℃, after natural cooling and water cooling, the average value of UCS decreased by 34.65% and 57.90%, and the average value of E decreased by 87.66% and 89.05%, respectively. Meanwhile, scanning electron microscope (SEM) images were used to capture the development of microcracks and pores within the specimens after natural-cooling and water-cooling, and it was found that at the same temperature, water cooling treatment was more likely to cause microcracks and pores, which can cause more serious damage to the quartz sandstone. These results confirm that different cooling methods have different effects on the physical and mechanical properties of quartz sandstone, and provide a basis for the stability prediction of rock mass engineering such as tunnel suffering from fire.

scholarly journals Effects of Temperature and Water on Mechanical Properties, Energy Dissipation, and Microstructure of Argillaceous Sandstone under Static and Dynamic Loads

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Rongrong Zhang ◽  
Dongdong Ma ◽  
Qingqing Su ◽  
Kun Huang
Keyword(s):  
Mechanical Properties ◽  
Energy Dissipation ◽  
Failure Modes ◽  
Split Hopkinson Pressure Bar ◽  
Physical And Mechanical Properties ◽  
P Wave ◽  
Peak Strain ◽  
Hopkinson Pressure Bar ◽  
Stress Strain ◽  
Sandstone Specimen

RMT-150B rock mechanics and split Hopkinson pressure bar (SHPB) devices were adopted to investigate the physical and mechanical properties, energy dissipation, and failure modes of argillaceous sandstone after different high temperatures under air-dried and saturation states. In addition, SEM and EDS tests were conducted to investigate its microstructure characteristics. Results showed that both the P-wave velocity and density of argillaceous sandstone specimen decreased with the increase of high temperature, while its porosity increased. Compared with static stress-strain curves, there was no obvious compaction stage for dynamic stress-strain curves, and the decrease rate of dynamic curves after peak strain was obviously slow compared with static curves. Both the static and dynamic strengths of argillaceous sandstone specimens decreased with increasing temperature, and the critical temperature point for the strength of argillaceous sandstone was 400°C. At the same temperature, the specific energy absorption under air-dried state was generally smaller compared with that under saturated state. Both the strain rate and temperature showed significant effect on the failure mode. After 100∼1000°C heat treatment, the granular crystals of the clastic structure gradually became larger, and both the number and average size of the original pores decreased, resulting in the deterioration of mechanical properties of argillaceous sandstone specimen.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

scholarly journals SIFAT FISIKA DAN MEKANIKA KAYU JABON MERAH (Anthocephalus macrophyllus) YANG DITANAM DI WONOGIRI, 2 JAWA TENGAH

2020 ◽  
Vol 8 (3) ◽  
pp. 357
Author(s):  
Fanny Hidayati ◽  
Sri Sunarti ◽  
Teguh Setiaji ◽  
Arif Nirsatmanto
Keyword(s):  
Mechanical Properties ◽  
Mechanical Characteristics ◽  
Bending Strength ◽  
Physical And Mechanical Properties ◽  
Wood Properties ◽  
Dry Density ◽  
Improvement Program ◽  
Average Value ◽  
Central Java ◽  
Physical And Mechanical Characteristics

Red jabon is one of the fast growing species. It is growth well in tropical countries. It has a potential to fulfill the demand of wood. Tree imrovement program of this species has been done in Indonesia. However, information of wood properties related to tree improvement program of red jabon is limited. Therefore, wood properties such as physical and mechanical properties of this species at the progeny trial were needed to clarify. The aims of this research were to clarify the variation of physical and mechanical properties of red jabon from 5 families at5-year-old planted in Wonogiri, Central Java and relationship between air-dry density and mechanical properties. As the result, physical and mechanical properties were varied among 5 families. Based on the results, famili number 85 performed good result of physical and mechanical characteristics, eventhough the physical properties were not highest among 5 families but it was abouf the average value. Furthermore, this family showed the best values of all mechanichal characteristics tested. In addition, air-dry density has highly positive significantcorrelation with mechanical properties (static bending strength and compressive strength parallel to grain), suggesting that mechanical properties can be predicted by air-dried density.

scholarly journals REVIEW OF THE PHYSICAL AND MECHANICAL CHARACTERISTICS OF POLYURETHANE NANOCOMPOSITES

2021 ◽  
pp. 23-31
Author(s):  
R. A. Alekhina ◽  
V. E. Slavkina
Keyword(s):  
Mechanical Properties ◽  
Uniform Distribution ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Physicomechanical Properties ◽  
Nano Composites ◽  
Structure And Properties ◽  
Polyurethane Composites ◽  
Polyurethane Nanocomposites ◽  
Physical And Mechanical Characteristics

Polyurethane nanocomposites are promising materials in many industries, they have superior physical and mechanical properties compared to the original polyurethane. This paper presents an analysis of the physical and mechanical properties of polyurethane nano-composites with various types of fillers such as organoclays, carbon nanotubes, polyhedral oligomeric silse-squioxanes, graphene, graphene oxide, polytetrafluoroethylene, and metal nanoparticles. The concentration-dependent effects in changing the structure and properties of polyurethane composites under the influence of the added fillers were also considered. It is noted that the values of physical and mechanical properties are influenced by the uniform distribution of nanofiller particles in the composite and their chemical modification. It was found that with a uniform distribution of nanoparticles in the polymer matrix, the physicomechanical properties of the resulting composites increase.

scholarly journals Theoretical and experimental study of the effect of wollastonite on the physical and mechanical properties of concrete

2021 ◽  
Vol 2094 (2) ◽  
pp. 022077
Author(s):  
S S Dobrosmyslov ◽  
A S Voronin ◽  
Y V Fadeev ◽  
I G Endzhievskaya ◽  
S V Khartov
Keyword(s):  
Mechanical Properties ◽  
Experimental Study ◽  
Specific Volume ◽  
Mechanical Characteristics ◽  
Bending Strength ◽  
Theoretical Study ◽  
Chemical Interaction ◽  
Physical And Mechanical Properties ◽  
Internal Stresses ◽  
Physical And Mechanical Characteristics

Abstract As part of the work, an experimental and theoretical study of the effect of adding wollastonite on the physical and mechanical characteristics of concrete was carried out. The internal stress was calculated according to Hooke’s law. The change in the specific volume was determined from the change in the volume of the hydrated phase. The calculation of the chemical interaction was carried out within the framework of thermodynamic equilibrium. According to the results of the work, it was shown that the addition of wollastonite leads to a linear decrease in the value of internal stresses, which is consistent with experimental results on the increase in compressive and bending strength.

scholarly journals Industrial Heat Treatment of Wood: Study of Induced Effects on Ayous Wood (Triplochiton scleroxylon K. Schum)

Forests ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 730
Author(s):  
Emiliano Gennari ◽  
Rodolfo Picchio ◽  
Angela Lo Monaco
Keyword(s):  
Heat Treatment ◽  
Laboratory Tests ◽  
Mechanical Characteristics ◽  
Brinell Hardness ◽  
Basic Density ◽  
Physical And Mechanical Properties ◽  
Temperature Treatment ◽  
High Temperature Treatment ◽  
Dry Density ◽  
Physical And Mechanical Characteristics

High-temperature treatment of wood is a useful method for improving certain physical characteristics, ensuring durability without biocides, and improving the performance of wood when exposed to degradation agents. This work aims to determine the effects induced by a heat treatment performed industrially on ayous wood (Triplochiton scleroxylon K. Schum) from Cameroon, through the study of the main physical and mechanical characteristics. The heat treatment at 215 °C for three hours with a slight initial vacuum determined a reduction of the mechanical characteristics (compression strength 26%, static bending 46%, Brinell hardness 32%) and some physical properties (dry density 11%, basic density 9%), while it improved the behaviour towards variations of environment moisture. The anti-shrinkage efficiency was 58.41 ± 5.86%, confirming the increase of the dimensional stability. The darkening (ΔE 34.76), clearly detectable (L* 39.69 ± 1.13; a* 10.59 ± 081; b* 18.73 ± 1.51), was supported almost equally by both the lightness parameter (L*) and the a* chromatic parameter. The data collected during the laboratory tests were then subjected to statistical analysis to verify correlations between the characteristics examined. Statistical differences were highlighted between each physical and mechanical properties of ayous wood modified or not.

LABORATORY STUDY OF PHYSICAL AND MECHANICAL PROPERTIES OF PHOTOPOLYMER RESINS FOR REMOVABLE PROSTHETICS

2021 ◽  
pp. 17-21
Author(s):  
Ertesyan A.R. ◽  
Sadykov M.I. ◽  
Nesterov A.M.
Keyword(s):  
Mechanical Properties ◽  
Laboratory Study ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
New Materials ◽  
Denture Base ◽  
Base Resin ◽  
3D Printers ◽  
Denture Base Resin ◽  
Physical And Mechanical Characteristics

The search for new materials that would improve the physical and mechanical properties of basic plastics is very urgent. The aim of this study was to study the physical and mechanical characteristics of photopolymer resins for removable prosthetics. To study the physical and mechanical characteristics, experimental and laboratory tests of photopolymer resins (type 4) for SLA printing on 3D printers NextDent Denture 3D +, Dental Pink and Denture Base Resin were carried out, based on ISO. Conclusion. Laboratory study of the physical and mechanical properties of base plastics, on samples of photopolymer resins for SLA printing on a 3D printer "NextDent Denture 3D +", "Dental Pink" and "Denture Base Resin" based on ISO, allow us to conclude that all test indicators samples exceed the minimum values specified in ISO 1567: 1999.

scholarly journals COMPARATIVE EVALUATION OF BND 50/70 ROAD BITUMEN MODIFIED WITH SKEPT-60 AND SKN-26 ELASTOMERS

2021 ◽  
Vol 0 (4) ◽  
pp. 12-19
Author(s):  
E.А. Guseinova ◽  
◽  
V.A. Mammadova ◽  
X.Ch. Abıyev ◽  
◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Comparative Evaluation ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Flash Point ◽  
High Concentrations ◽  
Composite Samples ◽  
Physical And Mechanical Characteristics

The article provides information on the physical and mechanical properties of polymer-bitumen compositions obtained by modifying road bitumen BND 50/70 with elastomers SKEPT-60 and SKN-26 and determination of the obtained polymer-bitumen composites. The properties of composite samples of various concentrations (2.5, 3.0, 5.0%, 6.5 and 7.0%) were determined: needle depth, softening, brittleness and flash point, stretching and adhesion. It was determined that the physical and mechanical characteristics of polymer-bitumen composite materials obtained at high concentrations (6.5, 7.0%) are improved

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