The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 20, 2012
Filed:
May. 16, 2011
Ali Regimand, Raleigh, NC (US);
Lawrence H. James, Raleigh, NC (US);
Peter D. Muse, Durham, NC (US);
Keith Landreth, Raleigh, NC (US);
Tianqing He, Cary, NC (US);
Ali Regimand, Raleigh, NC (US);
Lawrence H. James, Raleigh, NC (US);
Peter D. Muse, Durham, NC (US);
Keith Landreth, Raleigh, NC (US);
Tianqing He, Cary, NC (US);
InstroTek, Inc., Raleigh, NC (US);
Abstract
An apparatus and method for determination of susceptibility of asphalt concrete materials to moisture damage. An asphalt sample of known bulk specific gravity (density) is placed inside a chamber filled with water, which is capable of heating the sample to a predetermined temperature. The chamber is pressurized by introduction of air pressure to a flexible membrane that decreases the volume within a chamber containing the sample and water, increasing the pore pressure in the sample. The pressure is then released and allowed to come to ambient pressure. This process is repeated a predetermined number of times (cycles). When a selected number of cycles are complete, the asphalt sample is removed from the chamber and its bulk specific gravity (density) measured again. The difference between the density before and after conditioning is an excellent method of rating the degree at which moisture would deteriorate asphalt samples due to introduction of moisture. The cyclic nature of the increased/decreased pore pressure is observed to significantly decrease bulk specific gravity (density) for poor quality asphalt designs. Furthermore, the sample conditioned by this method can be used for other conventional mechanical test methods, such as tensile strength and modulus determination. Computerized controls are used to automate the procedure and to record and display data from sensors.