Stabilized Engineered Wood Fiber for Accessible Trails

Preliminary Guidelines for SEWF Installation

Follow manufacturer's instructions for storage and handling of the binder. Binder materials must be stored indoors in cool dry storage out of sunlight. Observe recommended limits on binder shelf life. Read material safety data sheets carefully prior to opening containers. Wear protective clothing and eye gear at all times. Assure a period of 48 h of warm and dry weather for proper curing of the binders. EWF should be moderately dry (less than 30% moisture content).

Mixing Binder With EW

1a. Vitri-Turf binder is mixed with the EWF at the ratio of 77/23 by weight. This equates to approximately 6 liters (1.25 gallons) of Vitri-Turf binder to 0.041 m³ (1.45 ft³) of EWF (depending upon the density of the EWF particles).

1b. Soil-Sement is mixed 77/23 by weight (assuming 100% solids). If it is only 50% solids then the ratio of weights changes to 63/37. This equates to 10 L (2.5 gallons of Soil-Sement) (50% solids) to 0.041 m³ (1.45 ft³) of EWF.

2. Mixing is best done with a mechanical drum mixer. If a small patch is needed for repair, use a trough with a hoe. Be sure that the EWF particles are thoroughly coated. Running a typical mortar or cement mixer for 2 min is usually adequate to achieve good mixing. Check the mixer at the end of each mix to assure that binder and fine wood particles are not accumulating on the paddles or drum.

Application of SEWF

1. Use a wheelbarrow to transport the SEWF mixture. Dump into place and apply the mixed Binder/EWF at a nominal 50% more (uncompacted) depth than the intended compacted thickness using a screed bar or rake.

2. Compact and smooth the surface by using a large trowel or stiff plywood (16 mm or 5/8 in.) of dimension 1.2 by 1.2 m (4 by 4 ft) covered with a heavy-mil sheet of polyethylene as a release. If material sticks, you may lubricate with kerosene, diesel fuel, or soapy water. Do not saturate surface with these lubricants. After compaction the thickness will be approximately 40 mm (1.6 in.).

3. Apply a moderate downward pressure onto the surface so that the mixture compacts tightly. When using the 4- by 4-ft plywood, a 90-kg (200-lb) person stepping in the four quadrants of the panel should provide adequate compaction.

4. Allow to cure in the open air for a minimum of 24 h. Cover only for short periods to protect the surface from direct rainfall.

Cleanup

Clean all tools for Vitri-Turf application immediately with diesel fuel before the surface has dried; use water to clean tools for Soil-Sement application. Once binder has dried it will be difficult to remove from tools, surfaces, or hands.

General Precautions

• Wear protective clothing and eye gear.

• Provide a minimum of 1% slope for all substrates for drainage.

• Ambient air temperature should be 40°F (4°C) or greater and rising when SEWF is applied. Air temperature should remain at 40°F (4°C) or greater for at least 7 days after SEWF application.

• Protect surfaces from rain for a minimum of 48 h after SEWF application.

• Read all material safety data sheets very carefully. If you do not understand the instructions, contact the manufacturer before applying SEWF.

• If binder accidentally comes in contact with eyes, immediately rinse with water and contact a physician.