Laboratory apparatuses measuring 3D displacement fields involved in distortion of commercial size wood products due to moisture content change.

2003 ◽  
Vol 61 (3) ◽  
pp. 173-181 ◽  
Author(s):  
T. Constant ◽  
É. Farré
Keyword(s):  
Moisture Content ◽  
Wood Products ◽  
Displacement Fields ◽  
Content Change ◽  
Commercial Size ◽  
Moisture Content Change

Research on the Process of Concrete Damage under Frost Action

2010 ◽  
Vol 163-167 ◽  
pp. 3406-3410
Author(s):  
Kai Zhi Ma ◽  
Jian Guo Hou ◽  
Ji Yao Jia
Keyword(s):  
Moisture Content ◽  
Test Range ◽  
Freeze Thaw ◽  
Frost Action ◽  
Content Change ◽  
Concrete Damage ◽  
Moisture Content Change

This paper summarizes the theories of the concrete damage under frost action. Based on experiments done by researchers in and abroad, the water conversion and the moisture content change in the concrete during the freeze-thaw cycles are analyzed. In this paper, the affection of the expansion and contraction of ice on concrete at temperatures in the usual freeze-thaw test range is particularly taken into consideration. At last, a qualitative process of the concrete damage under frost action is proposed.

scholarly journals Drying kinetics of RDF: Experimental investigation and modeling

2018 ◽  
Vol 10 ◽  
pp. 02030 ◽  
Author(s):  
Karolina Słomka-Polonis ◽  
Bogusława Kordon-Łapczyńska ◽  
Jarosław Frączek
Keyword(s):  
Moisture Content ◽  
Waste Treatment ◽  
Calculated Data ◽  
Alternative Fuel ◽  
Moisture Diffusivity ◽  
Air Velocity ◽  
Hot Air ◽  
Content Change ◽  
Air Dryer ◽  
Moisture Content Change

An experimental study was performed to determine the drying characteristics of an oversized fraction of RDF alternative fuel using a laboratory scale hot air dryer at a variety air temperatures and a constant air velocity. For this research the industrial RDF was derived from a Regional Municipal Waste Treatment Facility near the city of Kraków, Poland. The samples of RDF were prepared in two forms: ovesized (unmodified condition) and shreded in a two-drum crusher. In addition, the RDF was sorted into three groups of samples: paper, plastic, textiles. Each form of RDF and each group of samples were dried in hot air dryer at temperatures of 50, 70 i 90 °C and a constant air velocity of 1,5 [m·s-1]. The loss of the the samples mass were measured in a continues manner until the equilibrum moisture content was reached. The effective moisture diffusivity [m2·s-1] and activation energies [kJ·mol-1] was amounted. The analysis of the course of moisture content change concludes that that the drying of the RDF alternative fuel occured mainly in the II period of the process during which the transport of water content was carried out by diffusion. And, to a lesser extent, with the surface heat transfer in II period. Based on the calculated data there was a model determined which presented the best possible matching of the course of moisture content change.

Effect of Thermal Modification on the Physical Properties of Populus ussuriensis

2012 ◽  
Vol 476-478 ◽  
pp. 1889-1892
Author(s):  
Dong Xing ◽  
Min Xu ◽  
Jiang Tao Shi ◽  
Jian Li
Keyword(s):  
Heat Treatment ◽  
Moisture Content ◽  
Treatment Process ◽  
Drying Shrinkage ◽  
Dimensional Change ◽  
Thermal Modification ◽  
Heat Treatment Process ◽  
Content Change ◽  
Populus Ussuriensis ◽  
Moisture Content Change

Heat treatment is an environmental method of wood modification. The density of Populus ussuriensis, dimensional change and equilibrium moisture content change were tested through the different temperature processing, and get the influence of heat treatment process on the performance of the wood. The results show that heat treatment is an effective way to improve wood dimensional stability and shrinkage properties. With the improvement of heat treatment intensity, the equilibrium balance moisture content of wood will then gradually reduced. When treating temperature reaches 180°C above, the wood drying shrinkage properties greatly decreased, and trend to stable.

scholarly journals Improving the accuracy of wood moisture content estimation in four European softwoods from Spain

2021 ◽  
Vol 30 (1) ◽  
pp. e002
Author(s):  
Juan I. Fernández-Golfín ◽  
Maria Conde Garcia ◽  
Marta Conde Garcia
Keyword(s):  
Relative Humidity ◽  
Moisture Content ◽  
Electrical Resistance ◽  
Solid Wood ◽  
Wood Products ◽  
Wood Moisture Content ◽  
Accurate Estimation ◽  
Wood Moisture ◽  
Mathematical Functions ◽  
Measured Moisture Content

Aim of study: To obtain improved models to predict, with an error of less than ± 2.0%, the gravimetric moisture content in four different softwoods commonly present in the Spanish and European markets, based on electrical resistance measurements. This improved moisture content estimation is useful not only for assessing the quality of wood products, especially in the case of laminated products, during the transformation and delivery process, but also for accurately monitoring the evolution of moisture in wood present in bridges and buildings, which is of great importance for its maintenance and service life improvement.Area of study: The study was carried out on samples of Scots, laricio, radiata and  maritime pines of Spanish provenances.Material and methods: On 50x50x20 mm3 solid wood samples (36 per species, 9 per condition), conditioned at 20ºC (±05ºC) and 40±5%, 65±5%, 80±5% or 90±5% Relative Humidity (RH), electrical resistance and oven-dry moisture content was measured. The Samuelsson's model was fitted to data to explain the relationship between the two variables. The accuracy of the model was evaluated by the use of an external sample.Main results: With the proposed mathematical functions the wood moisture content can be estimated with an error of ±0.9% in the four species, confirming the effectiveness of this nondestructive methodology for accurate estimation and monitoring of moisture content.Research highlights: our results allow the improvement of the moisture content estimation technique by resistance-type methodologies.Keywords: Resistance-type moisture meter; species correction.Abbreviations used: MC: Moisture content; RH: relative Humidity; R: electrical resistance; RP: wood electrical resistance measured parallel to the grain; RT: electrical resistance measured perpendicular (transversally) to the grain; GM-MC: gravimetrically measured moisture content.

Sign in / Sign up

Export Citation Format

Share Document