scholarly journals Compression Strength and Modulus of Elasticity Parallel to the Grain of Oak Wood at Ultra-low and High Temperatures

BioResources ◽  
2014 ◽  
Vol 9 (2) ◽  
Author(s):  
Jinghui Jiang ◽  
Jianxiong Lu ◽  
Yongdong Zhou ◽  
Youke Zhao ◽  
Liyuan Zhao
2013 ◽  
Vol 742 ◽  
pp. 187-191 ◽  
Author(s):  
Pavel Padevět ◽  
Romana Lovichová

Paper describes properties of cement paste included addition of the fly ash. Firstly is described the preparation of the cement paste. Next part is focused on the testing of the properties. Results of the testing are summarized in properties like a compression strength, Modulus of elasticity and strength in bending. Finally the relation between material properties and volume weight is discussed. An article is described paste made from the same amount of cement and fly ash and water coefficient of 0.4.


BioResources ◽  
2020 ◽  
Vol 15 (2) ◽  
pp. 2869-2881
Author(s):  
Agnieszka Laskowska

Oak (Quercus robur L.), iroko (Milicia excelsa (Welw.) C.C. Berg), and tauari (Couratari spp.) wood were subjected to cyclic thermo-mechanical treatment (CTMT). The densification temperature amounted to 100 °C or 150 °C. The greatest changes in the modulus of rupture (MOR) value of the iroko wood, depending on the number of thermo-mechanical modification cycles, were noted. The MOR of the iroko wood, densified at 100 °C or 150 °C, after second thermo-mechanical modification cycle was twice as high as before the modification. No significant differences were observed between the modulus of elasticity (MOE) of oak wood before and after one modification cycle. Similar dependencies were noted in iroko wood. The thermo-mechanical modification performed over two cycles led to the highest increase, by about 56%, in MOE in oak wood densified at 150 °C. It was demonstrated that modification at 150 °C had a negative impact on iroko wood, which was manifested in the lower compression ratio of iroko at 150 °C than at 100 °C.


2012 ◽  
Vol 12 (3) ◽  
pp. 139-142 ◽  
Author(s):  
S. Żymankowska-Kumon

Abstract The criteria, with which one should be guided at the assessment of the binding properties of bentonites used for moulding sands, are proposed in the paper. Apart from the standard parameter which is the active bentonite content, the unrestrained growth indicator should be taken into account since it seems to be more adequate in the estimation of the sand compression strength. The investigations performed for three kinds of bentonites, applied in the Polish foundry plants, subjected to a high temperature influences indicate, that the pathway of changes of the unrestrained growth indicator is very similar to the pathway of changes of the sand compression strength. Instead, the character of changes of the montmorillonite content in the sand in dependence of the temperature is quite different. The sand exhibits the significant active bentonite content, and the sand compression strength decreases rapidly. The montmorillonite content in bentonite samples was determined by the modern copper complex method of triethylenetetraamine (Cu(II)-TET). Tests were performed for bentonites and for sands with those bentonites subjected to high temperatures influences in a range: 100-700°C.


2014 ◽  
Vol 969 ◽  
pp. 212-217 ◽  
Author(s):  
Pavel Padevět ◽  
Tereza Otcovská ◽  
Ondřej Zobal

Paper describes properties of cement paste included addition various kinds of the fly ash. Firstly is described the preparation of the cement paste. Next part is focused on the testing of the properties. Results of the testing are summarized in properties like a compression strength, Modulus of elasticity and tensile strength in bending. Finally the relation between material properties and volume weight is discussed. An article is described paste made from the same amount of cement and fly ash and water coefficient of 0.4.


2011 ◽  
Vol 261-263 ◽  
pp. 389-393
Author(s):  
Xiao Ping Cai ◽  
Wen Cui Yang ◽  
Jie Yuan ◽  
Guo Hui Xia ◽  
Yong Ge ◽  
...  

Mechanical properties at low temperature (-5°C, -20°C and -30°C) including compression strength, flexure strength, splitting tensile strength and modulus of elasticity of concrete with fly ash were investigated. In order to remain the temperature of the specimens unchanged during the test, a new insulation device was designed. In addition, the effects of curing ages on mechanical properties of concrete were studied. The results showed, at low temperature, all of the mechanical properties were improved; as the temperature decreases, the growth ratio increased continuously. The relative growth ratios of compression strength and flexure strength achieved the maximum value when the temperature decreased from -5°C to -20°C, and the relative growth ratios of splitting tensile strength and modulus of elasticity kept increasing during the whole process of cooling. At -35°C, all of the mechanical properties were improved at each curing age.


2021 ◽  
Vol 42 (3) ◽  
Author(s):  
Tomislav Sedlar ◽  
Bogoslav Šefc ◽  
Srđan Stojnić ◽  
Tomislav Sinković

This study quantified the physical and mechanical properties of sycamore maple (Acer pseudoplatanus L.) as a basis for assessing wood quality. The physical properties of oven-dry density, density at 12% MC, green density, basic density, longitudinal, radial, tangential and volumetric shrinkages were tested and the mechanical properties of bending strength, modulus of elasticity at bending, compression strength parallel to grain and compression strength in radial and tangential direction as well as of Brinell hardness on the cross, radial, and tangential section were determined. Five sycamore maple trees from Medvednica region were selected for the purposes of this research. The results were compared with known literature data on sycamore maple wood, beech wood from the same sight, and beech wood from Gorski Kotar region. For a better understanding of sycamore maple physiology, as well as for assessing the quality of wood products, the distribution of wood properties within the tree radius, from pith to bark, was investigated. There was a general bell shaped distribution, in the radial direction, in wood density, and mechanical properties of sycamore maple wood. Shrinkages decreased from pith to bark, except for tangential shrinkage with bell shaped pattern. All investigated wood densities of sycamore maple from Medvednica were similar to the findings of studies known in literature, as well as shrinkages, except for the lower longitudinal shrinkage. Investigated mechanical properties of sycamore maple wood were similar to the findings of studies known in literature, except for the lower bending strength and modulus of elasticity (MOE). Investigated sycamore maple indicated better dimensional stability than beech wood from two locations in the region, although it did not match the beech wood regarding mechanical properties, especially wood hardness.


2016 ◽  
pp. 37-47
Author(s):  
Miroslava Marković ◽  
Snežana Rajković

The paper examines the effects of a brown rot agent-Coniophora puteana (Schumach.) P. Karst on the mass loss and compression strength of sessile oak (Q. petraea agg) wood. The wood mass loss of Q. petraea agg., caused by C. puteana amounted to 1.5, 2.12 and 2.23 after 2, 4 and 6 months respectively. The obtained values indicate that the biggest mass loss of wood occurred in the first two months. Compression strength also decreased under the influence of C. puteana. In comparison to its initial value (100%), it amounted to 92.13, 90.72 and 76.25 after 2, 4 and 6 months. The analysis of the correlation between the sessile oak mass loss-G m and compression strength decrease- p (dependent variables) and the incubation time (T-independent variable) revealed a strong correlation between the variables and the following regression equations were obtained: G m = 0.0638492 + 0.954107 x T  p = 96.328-2.666 x T


Sign in / Sign up

Export Citation Format

Share Document