California shipped approximately 18 million boxes of fresh peaches and nectarines in 1975. Seven test shipments were conducted in 1975 to determine if fruit could be shipped successfully in ...fiberboard boxes with net weights of 35 instead of 25 pounds. We also compared the relative advantages of Bliss-style and tray-style design corrugated fiberboard boxes. During 40 hours of transit, peaches averaged 54° F (12° C) in 25- and 35-pound fiberboard boxes. Nectarines averaged 48° (9° C) in the 25- and 35-pound fiberboard boxes during 96 hours of transit. However, these temperatures were higher than recommended for fruit shipments. All containers were in good condition on arrival, and no significant difference in fruit quality was detected between the fruit packed in the 25-pound fiberboard box or that packed in the 35-pound fiberboard box. About $1.5 million a year could be saved by using 35- instead of 25-pound corrugated fiberboard boxes for peaches or nectarines.
This article proposes to use the acoustic emission (AE) method to evaluate the degree of change in the mechanical parameters of fiber–cement boards. The research was undertaken after a literature ...review, due to the lack of a methodology that would allow nondestructive assessment of the strength of cement–fiber elements. The tests covered the components cut out from a popular type of board available on the construction market. The samples were subjected to environmental (soaking in water, cyclic freezing–thawing) and exceptional (burning with fire and exposure to high temperature) factors, and then to three-point bending strength tests. The adopted conditions correspond to the actual working environment of the boards. When applying the external load, AE signals were generated, which were then grouped into classes, and initially assigned to specific processes occurring in the material. The frequencies occurring over time for the tested samples were also analysed, and microscopic observations were made to confirm the suppositions based on the first part of the tests. Comparing the results obtained from a group of samples subjected to environmental and exceptional actions, significant differences were noted between them, which included the types of recorded signal class, the frequency of events, and the construction of the microstructure. The degradation of the structure, associated with damage to the fibers or their complete destruction, results in the generation under load of AE signals that indicate the uncontrolled development of scratches, and a decrease in the frequency of these events. According to the authors, the methodology used allows the control of cement–fiber boards in use. The registration and analysis of active processes under the effect of payloads makes it possible to distinguish mechanisms occurring inside the structure of the elements, and to formulate a quick response to the situation when the signals indicate a decrease in the strength of the boards.
The paper aims to determine selected basic material and elasticity constants of cement fibre boards (CFB) with organic cellulose fibres produced with the use of Hatschek process and thus extend ...potential field of application of CFB in the field of civil engineering for supporting structure designs. Modulus of rupture and modulus of elasticity determination was performed with the use of a three-point and four-point bend test, and tensile strength and compressive strengths were tested. During loading the orientation of testing specimens was distinguished, while taking into account the production method. The loading was applied with regard to a potential use of the boards in supporting structures perpendicularly or parallel to the mid-plane of the board. An innovative approach to distinguishing board orientation during loading was selected in order to extend the scope of application of this special group of cement composites even outside the usual field of application, particularly with a focus on bearing structures of building construction.
The testing specimen orientation had a significant effect on failure and course of loading diagrams. The biggest differences occurred under tensile loading, when delamination of thin layers (monolayers) of the cement fibre board occurred during perpendicular loading to the board mid-plane.
Highly environmentally-friendly fibreboards were manufactured by hot-press moulding using
wastes and a partially biobased epoxy resin as binder. Fibreboards with a constant fibre content of 70 wt % ...were successfully manufactured by thermo-compression. The effects of a conventional alkali treatment were compared to the synergistic effects that additional silanization with two silanes (amino and glycidyl) can exert on the mechanical and thermo-mechanical properties of fibreboards. The results revealed a remarkable improvement of the mechanical properties with the combination of the alkali treatment followed by the silanization. Scanning electron microscopy also revealed increased resin-fibre interactions due to the synergistic effect of both amino- and glycidyl-silanes. These fibreboards represent a formaldehyde-free solution and can positively contribute to sustainable development as the lignocellulosic component is a waste and the binder resin is partially biobased.
This paper considers a technology of obtaining wood-fiber boards (WFB) by the dry method with the use of urea–formaldehyde resin of UFC-FF grade modified with a fusel fraction (a mixture of ...alcohols). It also studies the effect of the modified binder on physical and mechanical properties of the obtained materials.
This book was proposed and organized as a means to present recent developments in the field of testing of materials and elements in civil engineering. For this reason, the articles highlighted in ...this editorial relate to different aspects of testing of different materials and elements in civil engineering, from building materials to building structures. The current trend in the development of testing of materials and elements in civil engineering is mainly concerned with the detection of flaws and defects in concrete elements and structures, and acoustic methods predominate in this field. As in medicine, the trend is towards designing test equipment that allows one to obtain a picture of the inside of the tested element and materials. Interesting results with significance for building practices were obtained.
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