The Resistance Tests of Glass-Cement Plates in High Temperatures

2013 ◽  
Vol 586 ◽  
pp. 182-185
Author(s):  
Michaela Kostelecká ◽  
Miroslav Vokáč ◽  
Daniel Dobiáš
Keyword(s):  
High Temperatures ◽  
Bending Strength ◽  
Precast Concrete ◽  
Point Of View ◽  
Test Method ◽  
Bending Test ◽  
Technical Requirements ◽  
Glass Fibre Reinforced ◽  
Reference Samples ◽  
Strength In Bending

The glass-cement plates have made great progress today. They extend the possibilities of technical requirements in solutions of complex structures. The higher aesthetic requirements are available with the plates and in another point of view they contribute significantly to economic aspect in construction. The article describes the tests of high temperatures resistances of glass-cement plates. The first part is focused on determining the values of tensile strength in bending for samples subjected to annealing at temperatures 200, 300, 400 and 500 ° C in endurance at the highest temperature level for 24 hours. The results will be compared with values obtained for the reference samples. The bending strength was performed according to the norm ČSN EN 1170-4 Precast concrete products - Test method for glass-fibre reinforced cement - Part 4: Measuring bending strength, "Simplified bending test" method. The mean strength in bending of reference samples was equal to 11.3 MPa. The strength is decreasing with temperature of firing and dependence is very closed to linear relationship with slope approx. 1.87 MPa per 100 °C. Furthermore, the thermal dilatometric analysis was performed on the plates in the temperatures till 540 °C in the second part.

Investigation of Glass Fibre Reinforced Cement (GFRC) Material Exposed to High Temperatures

2014 ◽  
Vol 923 ◽  
pp. 37-41
Author(s):  
Michaela Kostelecká ◽  
Miroslav Vokáč ◽  
Daniel Dobiáš
Keyword(s):  
Tensile Strength ◽  
High Temperatures ◽  
Glass Fibre ◽  
Bending Strength ◽  
Temperature Level ◽  
Dilatometric Analysis ◽  
Reinforced Cement ◽  
Glass Fibre Reinforced ◽  
Fibre Cement ◽  
Strength In Bending

In this paper we present the tests of high temperatures resistances of glass fibre cement plates. The aim of the research was to determine the values of tensile strength in bending for samples subjected to annealing at temperatures 200, 300, 400 and 500 °C in endurance at the highest temperature level for 24 hours. The bending strength was performed according to the norm EN 1170-4. The thermal dilatometric analysis was performed in the temperatures till 540 °C.

Evaluation of Impact Bending Strength of Ceramic Composites at Ultra-High Temperatures from 1500-2000 °C in Air

2013 ◽  
Vol 591 ◽  
pp. 145-149 ◽  
Author(s):  
De Tian Wan ◽  
Yi Wang Bao ◽  
Hua Zhao ◽  
Yuan Tian
Keyword(s):  
High Temperatures ◽  
Bending Strength ◽  
Impact Load ◽  
Ceramic Composites ◽  
Test Method ◽  
Bending Test ◽  
Dynamic Force ◽  
Maximal Load ◽  
Impact Bending ◽  
The Impact

In this work, a new and novel test method was developed to determine the impact bending strength of ceramic composites at ultra-high temperature from 1500-2000 °C in air. Three-point impact bending test was carried out through a SiC pressure head with a dynamic force sensor fixed on a slider and movable along a guide rail. The impact load was adjusted by different saving energy and the impact speed was lower than 0.5 m/s. The center of the sample was heated up to about 1500-2000°C by oxygen-assisted spray combustion. An impact load was put on the specimen and the impact force was recorded automatically. The impact bending strength can be calculated from the maximal load and the sample size. To check the availability and reliability for this method, several ceramics including SiC, ZrB2/SiC and C/C fiber reinforced composite without coating, were used as the testing samples. The results indicate that this method is a good and feasible method for evaluating the mechanical properties of the ceramic composite at ultra-high temperatures.

A New Method for Determining Strength and Fracture Toughness of Ceramic Materials in Air at 1500-2000 °C

2014 ◽  
Vol 633 ◽  
pp. 447-450 ◽  
Author(s):  
De Tian Wan ◽  
Yi Wang Bao ◽  
Yuan Tian ◽  
Yan Qiu ◽  
Hua Zhao
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
High Temperatures ◽  
Bending Strength ◽  
Ceramic Materials ◽  
Ceramic Composites ◽  
Test Method ◽  
Sic Fiber ◽  
Bending Load ◽  
Ceramic Components

Evaluation of the mechanical properties at ultra-high temperatures for ceramic composites is necessary and important for the safety of designing the ceramic components. In this work, a new and novel test method named as local ultra-high temperature together with applied load method (LUHTAL), was developed to determine the tensile, compressive, bending strength and fracture toughness of ceramic composites. The four point bending load was conducted to measure the bending strength and fracture toughness of ceramic composites after the center of the sample was heated up to about 1500-2000°C by oxygen-assisted spray combustion. To check the availability and reliability for this method, typical ceramic materials including ZrB2/SiC and C/SiC fiber reinforced composite coated with Si, were used as the testing samples. It is indicated that this method is good and feasible for evaluating the mechanical properties of the ceramic composite at ultra-high temperatures in air.

Experimental Study on the Size Effect on Flexural Behavior of Larch Glulam Beams

2016 ◽  
Vol 847 ◽  
pp. 3-9 ◽  
Author(s):  
Xian Yan Zhou ◽  
Lei Cao ◽  
Dan Zeng
Keyword(s):  
Size Effect ◽  
Large Scale ◽  
Bending Strength ◽  
Weibull Model ◽  
Test Method ◽  
Flexural Behavior ◽  
Bending Test ◽  
Glulam Beam ◽  
Bending Modulus ◽  
Size Adjustment

At present, design values in codes and regulations are mainly based on test results of small size specimens, which are different from large-scale members used in practical engineering, therefore size adjustment coefficients are needed to be established. The four-point bending test method was adopted to investigate four groups of different sizes of Larch Glulam beams in their flexural behavior. Experiment data such as ultimate bearing capacity, deflection, strains and others are obtained, and the failure pattern and failure mechanism of bending members are analyzed. The research results indicate that the bending modulus of elasticity of Larch Glulam beam is not affected by the size. Bending strength of the Larch Glulam beam show a declining trend as the size of specimens increases, however, the ultimate bending moment increases. In addition, by means of a two-parameter Weibull model, a so-called size effect coefficient has been calculated by the slope method, thus providing a basis for the design and application of Larch Glulam beams.

scholarly journals Mechanical Characterization of DCPD and ENB Healing Systems in Glass Fibre Composites

2020 ◽  
Vol 57 (1) ◽  
pp. 278-289 ◽  
Author(s):  
Ionut Sebastian Vintila ◽  
Teodor Badea ◽  
Sorin Draghici ◽  
Horia Alexandru Petrescu ◽  
Andreia Cucuruz ◽  
...  
Keyword(s):  
Composite Material ◽  
Thermal Cycling ◽  
Glass Fibre ◽  
Bending Strength ◽  
Mechanical Characterization ◽  
Bending Test ◽  
Glass Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

The present paper is focused on evaluating the mechanical characterization of dicyclopentadiene (DCPD) and 5-ethylidene-2-norbornene (ENB) healing systems synthetized by in-situ polymerisation. Both healing systems were embedded in glass fibre reinforced polymer (GFRP) composite and subjected to three-point bending test regime. Microstructural and FT-IR analysis showed the formation of microcapsules and a successful integration in the composite material. To observe the influence of temperature variation, some specimens were exposed to thermal cycling (-20oC to +100oC) for 12 hours and tested in the same conditions. It was observed that the addition of microcapsules in the composite material decreased its mechanical properties by 8% and 10% for DCPD system and ENB system respectively. Thermal cycling suggested a drop of 24% on bending strength for DCPD system and 17% for ENB. Resting after 24 hours showed a healing recovery of 74% for DCPD healing system and of 97% for ENB system.

scholarly journals A Method for Assessing Axial and Temporal Effects of the Leaf Sheath on the Flexural Stiffness of the Maize Stem

2021 ◽  
Author(s):  
Jared Hale ◽  
Spencer Webb ◽  
Nathan Hale ◽  
Christopher Stubbs ◽  
Douglas D Cook
Keyword(s):  
Bending Strength ◽  
Statistical Significance ◽  
Temporal Patterns ◽  
Leaf Sheath ◽  
Test Method ◽  
Bending Test ◽  
Flexural Stiffness ◽  
Spatial And Temporal Patterns ◽  
Three Point Bending ◽  
Non Destructive

Abstract Background: The leaf sheath of many plants has been observed to influence both stiffness of the stem and ultimate strength. The leaf sheath has been implicated in studies of maize “greensnap” (or “brittle-snap”) failure. However, but the influence of the sheath is still not well understood and few methods exist for studying the influence of the sheath. The goal of this study was to develop a method for assessing longitudinal and temporal patterns of sheath influence on flexural stiffness. This metric of flexural stiffness was chosen because it is non-destructive and has been shown to be highly predictive of bending strength. Results: A three-point bending test method was successfully developed for assessing the influence of the sheath on flexural stiffness. The method relies upon comparisons between pairs of tests at the same location (sheath present vs. absent). The influence of the sheath was statistically significant in all varieties tested. The test method provided insights into the longitudinal and spatial variation of sheath influence: sheath influence appears to be closely related to maturity since both spatial and temporal patterns of influence mirror the sigmoidal maturation patterns previously observed in maize stalks. Conclusions: The paired nature of this test method increases statistical significance while the non-destructive feature of this test allows for multiple tests along the length of the stalk. This method can be used to provide new insightsregarding how the leaf sheath influences stalk flexibility (and therefore strength). Preliminary results indicate that the influence of the sheath changes over the life span of the plant in parallel with maturation patterns. However, further studies will be needed to confirm this hypothesis more broadly and to study additional issues such as heritability and the influce of genotype and environment on sheath influence.

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