Idria
Civil/Environmental
- Mar 19, 2010
- 1
I work with a nonprofit group who is preparing to sponsor an preservation project for the restoration of an historic stone culvert that provides drainage of an ephemeral stream crossing rural dirt road. The previous wood-plank cover failed a couple of years ago and travelers have since filled the culvert with stones and dirt. The culvert is now blocked and the stream overflows onto the road causing severe erosion to about 100 yards of the downhill portion of the road. This is associated with the New Idria Historical Preservation Project
A concern we have about using wood planks, such as used originally, is that it will require period maintenance, which will not occur on this abandoned section of road. One volunteer suggests that a reinforced concrete cap, or bridge, spanning over the 3-foot wide culvert would provide a permanent maintenance-free solution. The road crossing the culvert is 20 feet wide. The culvert opening is 3 feet wide. The idea is that we build seven 3x6 foot 4-inch deep forms in place, isolated from the historic feature with construction felt and appropriate spacers. However, since I know nothing about concrete strength, I fear that a 4-inch thick concrete bridge, or cap, may not provide sufficient strength for the various kinds of vehicles that might pass over it. An additional concern, because the concrete will need to be mixed on-site using bagged concrete mix, is that our water at this location contains magnesium which exhibits as milky turbidity, although not effecting the taste.
Can folks express some opinions on this project for me to present to the group? Is this concrete strong enough? Will the magnesium water deteriorate the project?
A concern we have about using wood planks, such as used originally, is that it will require period maintenance, which will not occur on this abandoned section of road. One volunteer suggests that a reinforced concrete cap, or bridge, spanning over the 3-foot wide culvert would provide a permanent maintenance-free solution. The road crossing the culvert is 20 feet wide. The culvert opening is 3 feet wide. The idea is that we build seven 3x6 foot 4-inch deep forms in place, isolated from the historic feature with construction felt and appropriate spacers. However, since I know nothing about concrete strength, I fear that a 4-inch thick concrete bridge, or cap, may not provide sufficient strength for the various kinds of vehicles that might pass over it. An additional concern, because the concrete will need to be mixed on-site using bagged concrete mix, is that our water at this location contains magnesium which exhibits as milky turbidity, although not effecting the taste.
Can folks express some opinions on this project for me to present to the group? Is this concrete strong enough? Will the magnesium water deteriorate the project?
