Comparison of California Bearing Ratio and Pin Puncture Strength Testing Used in the Evaluation of Geotextiles

Abstract

Geotextiles are commonly used in pavements, earth retaining structures, and landfills, as well as in other geotechnical applications. The puncture strength test evaluates the ability of geotextiles to withstand stresses and loads during construction, which are among the severe conditions that geotextiles can experience. ASTM has recently replaced the standard pin puncture strength test, D4833, with the California bearing ratio (CBR) puncture strength test, D6241. However, many state departments of transportation and the FHWA still refer to ASTM D4833. Other state departments of transportation refer to ASTM D4833 and to D6241 or provide a list of alternative test methods to be considered in place of either of these tests. The objective of this research was to correlate the CBR and pin puncture strengths for various categories of geotextiles, regardless of weave type and mass per unit area. Five types of polypropylene geotextiles, three nonwoven and two woven, were subjected to testing in accordance with ASTM D4833 and D6241 standard procedures. Ten and 15 samples of each geotextile type were tested with CBR and pin puncture strength tests, respectively. All five types of geotextiles exhibited puncture strength values, whether pin or CBR, which were consistent within each group. Similarly, distinct load-displacement curves were exhibited within each material group. Statistical analyses were conducted to establish a correlation between the CBR and pin puncture strength values. The correlations were successfully used to estimate the CBR puncture strength values from the pin test with reasonable accuracy (R² = .78).