Adhesion of Rubber and Textiles. IV. Function of Staple Fiber in Rubber to Fabric Adhesion

1950 ◽  
Vol 23 (2) ◽  
pp. 500-511
Author(s):  
E. M. Borroff ◽  
W. C. Wake

Abstract An investigation of the adhesion of rubbers to a series of fabrics woven from spun staple and continuous filament viscose, acetate rayon, and nylon is described. Using the direct tension test, it is shown that adhesion strength is a property of the staple fiber and is directly related to its tensile strength. The number of projecting fibers has been determined and compared with the broken-off ends recovered from a natural rubber cement after stripping from the fabric. The size-distribution histograms of the recovered fiber ends are also given and discussed. Recommendations are made for utilizing the results so far obtained in this investigation for the production of improved rubber-textile articles.

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2776 ◽  
Author(s):  
Wen-Cheng Liao ◽  
Po-Shao Chen ◽  
Chung-Wen Hung ◽  
Suyash Kishor Wagh

Tensile strength is one of the important mechanical properties of concrete, but it is difficult to measure accurately due to the brittle nature of concrete in tension. The three widely used test methods for measuring the tensile strength of concrete each have their shortcomings: the direct tension test equipment is not easy to set up, particularly for alignment, and there are no standard test specifications; the tensile strengths obtained from the test method of splitting tensile strength (American Society for Testing and Materials, ASTM C496) and that of flexural strength of concrete (ASTM C78) are significantly different from the actual tensile strength owing to mechanisms of methodologies and test setup. The objective of this research is to develop a new concrete tensile strength test method that is easy to conduct and the result is close to the direct tension strength. By applying the strut-and-tie concept and modifying the experimental design of the ASTM C78, a new concrete tensile strength test method is proposed. The test results show that the concrete tensile strength obtained by this proposed method is close to the value obtained from the direct tension test for concrete with compressive strengths from 25 to 55 MPa. It shows that this innovative test method, which is precise and easy to conduct, can be an effective alternative for tensile strength of concrete.


Author(s):  
Raj Dongré ◽  
Charles Antle

A statistically robust method was developed using the Weibull distribution to identify and eliminate outliers from the failure stress determinations. The method is applicable to any failure stress data set that follows the Weibull distribution; however, in this application, it was developed for the AASHTO standard test method for conducting the direct tension test (DTT). A large number of stress-at-failure measurements with the DTT were made in the course of instructing users of this device. These data, all for the same asphalt, provided the means for studying the nature of the distribution of the breaking strength of these asphalt specimens. The training database contains more than 900 data points. The current AASHTO practice of eliminating the lowest two stress values was found to be reasonable. However, it is an arbitrary method that may lead to problems in the future. On the basis of the results of this study, the procedure is recommended for use and implementation in the next AASHTO version of the DTT standard.


1974 ◽  
Vol 2 (3) ◽  
pp. 163 ◽  
Author(s):  
SF Etris ◽  
YR Fiorini ◽  
KC Lieb ◽  
IC Moore ◽  
AL Batik ◽  
...  

Author(s):  
Raj Dongré ◽  
John D’Angelo ◽  
Steve McMahon

The redesign and evaluation of the Superpave direct tension test (DTT) are described. The prototype of the DTT device was developed during the Strategic Highway Research Program (SHRP). The DTT device, an integral part of the new Superpave asphalt binder specification, was developed to test asphalt binders and determine their failure properties, such as the stress and strain at failure. The strain at failure is used in the Superpave asphalt binder specification to determine the lowest temperature at which the asphalt can be used to avoid low-temperature thermal cracking. When the SHRP program was completed, an affordable specification version of the prototype SHRP-DTT device was introduced for field implementation. Unfortunately, this version was plagued with mechanical problems, producing excessive variability and inconsistency in data. The device also was less user-friendly than other test devices that were being implemented for the asphalt binder specification. These problems led to implementation delays and difficulties. The problems were addressed by FHWA in cooperation with Instron Corporation of Canton, Massachusetts (a manufacturer of materials testing equipment). On the basis of recommendations made by FHWA, Instron developed a new, easy-to-use specification-type DTT device. This device is compact (approximately one-tenth the size of the original) and uses a fluid-based temperature control system similar to that used in the bending beam rheometer. The new device also employs feedback elongation (strain) rate control. However, unlike the previous device, the new DTT uses an extensometer between the loading pins instead of a laser to measure elongation (strain). The evaluation and resulting recommendations by FHWA, which led to the development of the new specification-type devices are discussed. The repeatability and testing protocols also are discussed.


2020 ◽  
Vol 43 (6) ◽  
pp. 20190308
Author(s):  
Yanrong Li ◽  
Fanfan Guan ◽  
He Su ◽  
Adnan Aydin ◽  
Mary Antonette Beroya-Eitner ◽  
...  

Materials ◽  
2016 ◽  
Vol 9 (7) ◽  
pp. 600 ◽  
Author(s):  
Jun-Feng Su ◽  
Peng Yang ◽  
Ying-Yuan Wang ◽  
Shan Han ◽  
Ning-Xu Han ◽  
...  

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