Test Bunkers Cont.

Last Thursday we had the concrete truck finally show up and bring us our new bunker liner, Capillary Concrete.  This new type of liner is a concrete like material that is made up of small gravel, mixed in a binding agent like concrete.  The great thing about this type of liner is that it drains incredibly well because of the large pore spaces.  This good drainage helps the sand to not wash out as badly during bad rains, and also helps from keeping the bottoms of the bunkers too wet and firm.  Here is a picture of us starting to install the Capillary Concrete on the bunker on #4

Here is a good example of the installation procedure.  The concrete truck dumps a load of the material into the green utility cart in the top of the picture.  We then take the cart and dump the material around the perimeter edges of the bunker.  After the material is dumped, it is then spread around the cover the entire surface of the bunker, consistently at a 2 inch depth.  After the material is spread to a depth of 2 inches, a paint roller on an extension stick is used to roll the material smooth and to compact it down.  If you look closely you can see the parts that have been rolled smooth (shiny appearance), and the part that is still rough.  We repeated this process until the bunker was full of the Capillary Concrete, and the entire surface had been rolled smooth.  

Here is another photo of the guys rolling the material smooth.  The lighter colored material is the gravel that makes up the floor of the bunker.  The darker material is the Capillary Concrete.

After all the Capillary Concrete has been installed and rolled, it has to be covered up with a tarp for 24 hours.  This helps to lock in moisture and protect the material while it drys and "cures".

Here is what the liner looks like after we pulled off the plastic.  The material has dried hard and consistent like concrete.  Our staff member is blowing off any loose debris or small rocks that did not bind with the rest of the material.  The next step will be to start adding the new sand.

New sand is added to the bunkers the same way that the Capillary Concrete was added to the bunkers.  Our large utility carts back up to the perimeter of the bunkers and dump the sand.  Then our staff spreads it throughout the bunker at a consistent depth of 4 inches.

We then have a member of our staff wet down all the new sand with a hose.  This loose sand is very fluffy and will need to be tamped down.  The water helps to pack down the sand and makes it easier to work with.

After the sand has been saturated with water, we tamp the entire bunker with a vibratory plate tamp.  This tamp is a large, flat, heavy piece of metal that has a motor on the top which allows the machine to vibrate at a high rate of speed.  This tamp helps to pack down the new sand and try to make it a "firm" but "fluffy" surface.  We will truly need a few good rain storms and to tamp the sand a few more times until it displays its true characteristics.   

Here is a photo of the finished product.  The sand will be a little softer for the next week or two, but will slowly get more compacted and firmer when you walk into the bunker.  The bunkers are ready to play out of and to evaluate now, but please give the sand a few weeks to settle in.  I think you will really like the way the new sand plays!