Curved Concrete Bench





Introduction: Curved Concrete Bench

Hi, my name is Adam and I study Industrial Design.
This is my first instructable here, my recent work presented:
Curved bench made from ​​white concrete, Which weights approx 150. kg

Step 1: Tool List and Materials Needed for This Project

- Carpenter's level (All work surface must be leveled properly before starting work)
- Drill with mixer head
- Zwaluw High Tack
- A Formica/HPL covered wood plate (iv used approx 60" x 80" or 2m x 1.5m)
- A lot of supporting wooden - made easily with
DEWALT DW777 Compound Cross Cut Mitre Saw (makes the making of the supporting wooden MUCH EASIER)
- Acetone
- Sandpaper 80-140-240 GRIT
- Fine Brush
- Concrete sealer
- some screws
- Work Gloves
- Disposable gloves
- Goggles
- Dremel tool
- 2 PVC Pipes (for the legs)
- 6mm Steel wire
- Polystyrene board 20mm thick
- some Clamps
- Steel Brush
- Sandbag
- White cement bag
- Fine Gravel bag
- some old buckets
- Spatula
- Gas Burner
- Duck Tape
- Grindstone angle

Step 2: Sketch & Calculations

Work plans were prepared and printed using SOLIDWORKS

Step 3: Placing Up Wooden Support

Place the supporting wood without glue.
Glue it only after you have checked the correct position on "dry mode"

Step 4: Finish Reinforcement

Reinforcement finalized by screws, and some silicone adhesive

Step 5: Adding the Frame and Styrofoam Blocks

Concrete Frame is made from 6mm steel wire hand twisted
Styrofoam blocks is the 'trick' here, making the cut holes inside, we will Dissolving Styrofoam in Acetone on the next few steps.. 

Step 6: Mixing the Concrete

Start by using a shovel to mix well the mixture, and only than use the electric drill for the final mixing

Step 7: Pouring the Concrete

Gently pour the concrete to the mold with a small spatula

Step 8: Attaching the P.V.C Pipes

Carefully cut the styrofoam to flat level as the concrete and clean the area from concrete leftovers and place the P.V.C tubes in the exact sitings were the iron frame is protruding.
secure it with silicone and than pour concrete inside.

Step 9: Removing the Styrofoam

removing the styrofoam with acetone, USE GLOVES
allso, I did make some holes with screwdriver in the styrofoam, resulting increase in the acetone etching speed.

Step 10: Unscrewing

Take off the walls first, by removing all of the odds and ends, screws and so.
for the legs iv used a dremel disc to start 'pinch point' while heating that point with a torch gun and pulling with Pliers until it riven apart.

Step 11: Brushing, Sanding, Cleaning

After removing all the dirt off the bench.
Pour a lot of water and soak in the concrete during each brushing and polishing process.
Time to start brushing with a wire brush.
Then, with three levels of sandpaper 80-140-240 GRIT

Note: The Chamfer is made by starting with dremel sanding drum and than polished by hand with fine sandpaper.

Step 12: Concrete Sealer

And now the final part of this instructable:
Impregnation of the bench in 'concrete sealer'
Just use a gentle brush to apply on all over the surface.
This step will ensure years of brilliant white color
And resistance to rain and dirt

Step 13: TIP:

if you left with extra concrete you have nothing to do with - DONT TROW IT - instead make beautiful garden rocks simply:
1. pour concrete into a sandbag
2. slam it with a stick to align it
3. let it set and come check tommorow youre new garden rock! 

Thanks for reading my instructable  + if you like it let me know ;)



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    Awesome design. was the Polystyrene board 20mm thick used for the sides? Can that be purchased at Home Depot? In step 4 what is that middle picture of? Did you spray anything on the sides and bottom to make removal easier? Do you mind if I make something similar? Thanks

    Actually, you could make a stepping stone or two with the leftover cement as well.

    Beautiful piece. Very good instructions. Ty.

    A wonderful project and a very well thought through design with a clear step by step design for others to use.

    Possibly I would reexamine the pedestals/feet, either enlarge the diameter of them or amend their shape to that of a more rectangular shape.

    Hey thank you for youre good words,
    You are right and I am about to make a new skech for the legs.

    Dissolving styrofoam is good fun, but you get a gummy liquid. When sides are straight it should be easy to chip it out with a screwdriver.

    I did so utill the middle but it was stuck down deep so i had to dissolve it

    My house is built in a way, that there are alot of sharp edges between the outer walls, so i was looking for a decorative way to make it look more smooth and curly by making the bench curly and placing it between the walls

    I too studied industrial design. What was the problem you solved by creating this curved bench? Where should it be placed?