Stabilized Engineered Wood Fiber for Accessible Trails

Test Procedures

Field Observation Reports

The sites were not under direct supervision or observation by park staff or other responsible personnel. However, on-duty staff noted any public concerns and changes at the site and reported them when we visited. Forest Products Laboratory staff visited the sites at least weekly for the first 2 months and at least monthly thereafter (if the ground was thawed) to complete the rotational penetrometer testing and to observe and annotate any maintenance needs.

Impact Attenuation Tests

Impact tests were completed on the beach path only as an adjunct to tests conducted at a playground at another park. For the beach path, we were interested if the impact standard could be met when SEWF was placed over sand. The impact was conducted by a cooperator (Zeager Bros. Inc., Middletown, Pennsylvania) 8 weeks after installation. ASTM F 1292-99 test specifications (ASTM 1999a) and F355-95 test methods (ASTM 1995) were used at a test drop height of 3.05 m (10.0 ft) and 1.83 m (6.0 ft), respectively. Maximum g levels and head injury criteria (HIC) were measured.

Accessibility and Durability Measures

The beach path surfaces were periodically measured with a rotational penetrometer. This device subjects the test surface to a low-speed rotational bearing test meant to simulate the weight and action of a front caster wheel on a wheelchair. The procedures are based on the draft national standard test method for the firmness and stability of ground and floor surfaces (RESNA 2000), which uses an average of five readings. This test provides objective measures of surface firmness and stability. Although no literature has been published on this subject, the use of the rotational penetrometer data allows an inference to the durability of the binder-EWF surface. The test effectively detects the loss of bond strength during the stability (rotation of caster wheel) portion of the test. The firmness measure is a means of inferring changes in overall stiffness of the bonded layer as well. It has been correlated to the work measurement of ASTM F1951 (ASTM 1999b), "Accessibility of Surface Systems," for a wide array of surfacing and floor coverings. The test was performed 1 week after surface installation and as often as once a week initially, using a Beneficial Designs, Inc. (Minden, Nevada) rotational penetrometer and protocol for assessing the bearing/rotational indentation on each surface (Axelson and Chesney 1999).