picture 1: formwork.
the layout is based on 1) the cement board dimensions mentioned above, 2) the spacing for grass to grow in the seams is the width of two 2x4s to minimize waste 3) the spacing of car and truck wheels 4) the size of the grasspave block to minimize labor and waste
picture 2: concrete placing
it took eight guys all day to place and trowel finish the concrete.
picture 3: retarder. to give the concrete a sandblasted texture a retarder was sprayed on after the concrete was troweled. the retarder inhibits the chemical bonding of the cement on the surface of the concrete. after a couple hours it is washed off and takes the top 1/16" of cement with it. the retarder is the the white layer in the background of this photo.
picture 4: final pavers. this is the final product about 8 hours after it was poured. the retarder has been washed off to expose the aggregate. besides giving the concrete a more natural look this also eliminates the squeal of turning tires like you hear in parking garages. the next step is to place the base which the grasspave sits on and then start with the grasspave.