Comparing Erosion Control Products’ Performance Results from Field and Large-Scale Laboratory Testing

Abstract

This study compares soil loss performance results from both field and large-scale laboratory experiments on five rolled erosion control products and one spray-on bonded fiber matrix. Beginning in 1990, erosion control products to be used on Texas highway embankments required evaluation of their soil erosion control effectiveness in a field laboratory developed jointly by Texas Department of Transportation (TxDOT) and Texas A&M Transportation Institute (TTI). Products were tested on 6.1-m (20-ft) wide test plots on an embankment of either a 33 % (21.3 m long) or 50 % (15.2 m long) slope during vegetation growing seasons, using simulated rainfalls. Products that performed well received the approval for Texas highway application. This field testing program was revised in the end of 2001 and transformed to be conducted in an indoor large-scale laboratory. The standard test plot size was reduced to 1.8 × 9.1 m (6 × 30 ft). Tested slopes remained at both 33 and 50 %. The comparison of field and large-scale indoor laboratory data indicates that in all four combined test conditions, average sediment loss ratio between field and indoor performance data remained almost the same, which supports the notion that large-scale test data could be fair indicative of actual field performance. The effects of rainfall magnitude, raindrop size, and test plot size are discussed.