Cleat and joint system evaluation and coal characterization of the Castlegate A coal, Beaver Creek No. 8 Mine, Carbon County, Utah

Joint sealants as indispensable filling systems in jointed plain concrete pavements (JPCP) are permanently exposed to various stresses during their service life, which often leads to a replacement of the sealing after approx. 7 to 10 years. Aside from seasonal unsteady climatic changes, the cyclical stresses caused by traffic and the ageing of joint sealants are especially significant. Considering the rising number of damages that occur within the overall "joint" system, an increased demand for a durable solution is requested as it is a relevant element for the life cycle costs of concrete pavements. In this context, a testing and ageing method was developed which comprises of the entire "joint" system, including the saw-cut concrete joint flanks, the primer as well as the joint sealant. This procedure depicts the decisive scenarios of in-situ stresses and allows the characterization of joint sealants. For this purpose, specimens were subjected to horizontal and vertical loads (static/cyclic) as well as to various ageing effects (temperature conditioning, UV-conditioning and freeze-thaw-cycles). After conditioning, a significant influence of the artificial ageing on the residual strength was observed in the tensile/shear tests. By comparing the artificially aged samples tested in the laboratory with extracted and in-situ aged samples, a reliable correlation was determined. Considering these system tests an initial approach was established which enables the evaluation of joint sealants in both unaged and artificially aged conditions on the basis of scientific parameters and limits.

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Dielectric characterization of coals

Canadian Journal of Physics ◽

10.1139/p02-125 ◽

2003 ◽

Vol 81 (3) ◽

pp. 599-610 ◽

Cited By ~ 15

Author(s):

J M Forniés-Marquina ◽

J C Martín ◽

J P Martínez ◽

J L Miranda ◽

C Romero

Keyword(s):

Room Temperature ◽

Elemental Carbon ◽

Time Domain Reflectometry ◽

Electromagnetic Analysis ◽

Characteristic Parameters ◽

Static Permittivity ◽

Dielectric Characterization ◽

Coal Characterization ◽

5 Ghz

Application of an electromagnetic analysis for coal characterization is attempted. By time domain reflectometry (TDR), dispersion spectra in the DC 5 GHz range of a wide variety of coals are obtained for room temperature. Static permittivity and relaxation frequency of the different samples are compared with parameters obtained by chemical analysis. Comparison reveals the usefulness of the electromagnetic characterization for the establishment of coal rank, and shows how an analysis of the dielectric characteristic parameters can provide approximate ideas about moisture, elemental carbon, hydrogen, and sulphur contents. PACS Nos.: 39.30+w, 82.53Kp, 77.22Gm

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