Date of Graduation

5-2016

Document Type

Thesis

Degree Name

Master of Science in Civil Engineering (MSCE)

Degree Level

Graduate

Department

Civil Engineering

Advisor/Mentor

Clinton M. Wood

Committee Member

Michelle Bernhardt

Second Committee Member

Micah Hale

Keywords

Applied sciences, Asr, Masw, Ndt

Abstract

The purpose of this research is to establish a recommended procedure for performing multichannel analysis of surface waves (MASW) on pavements as well as evaluating the ability of MASW to detect a change in shear wave velocity as damage in concrete increases. The tests for establishing a recommended procedure for performing MASW on pavements was conducted at five sites at the University of Arkansas Engineering Research Center in Fayetteville, Arkansas. The five sites consisted of three materials: asphalt, concrete, and soil (two sites were on asphalt, two were on concrete, and one was on soil). The methods evaluated at these sites include the source type, distance from the source to the first receiver in the array (i.e., source offset), the spacing between receivers in the array, and the minimum number of receivers in the array. It was determined that for the data collected on asphalt, the optimum procedure included a 230g metal-tipped hammer, 2.5 cm receiver spacing, a minimum of 24 receivers, and source offsets of 12.5 cm, 25 cm, and 50 cm. For concrete, the optimum procedure included a 230g metal-tipped hammer, 5 cm receiver spacing, a minimum of 18 receivers, and source offsets of 12.5 cm, 25 cm, 50 cm, and 75 cm. For soil, the optimum procedure included a 230g metal-tipped hammer, 5 cm receiver spacing, a minimum of 12 receivers, and source offsets of 12.5 cm, 25 cm, and 50 cm. Additionally, it was determined from a limited data set of six tests, that MASW has the ability to detect a decrease in shear wave velocity as damage increases up to a strain level of at least 0.09%. However, MASW testing done on concrete with expansions of 0.09% and 0.29% showed only a 2% difference in shear wave velocity between the two large strain sections. Given the data collected it cannot be determined if MASW can be used to differentiate between concrete sections with strains larger than 0.09% (i.e., sections with heavy damage).

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