Date of Award

May 2014

Degree Type

Thesis

Degree Name

Master of Science

Department

Engineering

First Advisor

Hani Titi

Committee Members

Rani El-Hajjar, Habib Tabatabai

Keywords

Geotextile, Puncture Strength

Abstract

Geotextiles are commonly used in pavements, earth retaining structures, and landfills, as well as other geotechnical applications. Various tests are conducted to evaluate and classify geotextiles to determine their suitability for different applications. One of these tests is the puncture strength test. This test evaluates the ability of geotextiles to withstand stresses and loads during construction, which is among the severe conditions that geotextiles can experience. ASTM has recently replaced the standard pin puncture strength test, D4833, with the CBR puncture strength test, D6241. However, many departments of transportation (DOTs) throughout the country and the Federal Highway Administration still refer to D4833. Other state DOTs refer to both D4833 and D6241, or provide a list of alternative test methods to be considered in place of either of these tests. This inconsistency is the result of a missing connection between the old and new ASTMs. The objective of this research is to attempt to correlate the CBR and pin puncture strengths for various categories of geotextiles, regardless of weave type and mass per unit area. Subsequent to this, deterioration of geotextiles due to freeze-thaw conditioning was investigated. Puncture resistances of materials with like mass per unit area and base material but with different weave type were also examined. Five types of polypropylene (PP) geotextiles, three nonwoven and two woven, were subjected to testing in accordance with ASTM D4833 and ASTM D6241 standard procedures. Ten and fifteen samples of each geotextile type were tested using CBR and pin punctures strength tests, respectively. All five types of geotextiles exhibited puncture strength values, whether pin or CBR, that were consistent within each group with coefficients of variation ranging from 2.8 and 13.3%. It should be noted that distinct load-displacement curves were exhibited within each material group. Statistical analyses were conducted to establish a correlation between CBR and pin puncture strength values. Correlations were successfully used to estimate the CBR puncture strength values from the pin test with a reasonable accuracy. The coefficient of determination for this correlation was obtained as R2= 0.78. An attempt was made to investigate the freeze-thaw cycles' effect on geotextile performance with respect to the puncture strength test. Finally, the preliminary testing of geotextiles subjected to freeze-thaw conditioning showed degradation, but further investigation using a greater number of freeze-thaw cycles is required to develop a trend.

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