This learning path gives us an insight into constructing a semicircular arc. We're going to see how we draw a semicircular arch, formally place and brick it.
Motivation phase
Marking the semicircular arch.
You can see very clearly in this video how we draw a semicircular arch.
1: Determine the span A - B
2: Take half of this ( the radius) point P
3: Draw the circle
4: Poke point is P
You do the same for making a mold for the semicircular arch.
Making a mold for the semicircle arc.
* Build the mold with two fiberboards on either side and a piece of flexible sheet material to seal the top.
* The width of a mold corresponts to the width of a brick.
* Use a masonry cord and nail as a compass to draw the circle and a jigsaw to cut out the mold.
* You have to support the mold with trellis.
* Secure the mold and adjust it perfectly.
Determining layer size semicircular arc.
1: We do not take 1.2cm as a joint, but 1cm, so the joint at the top does not show so wide.
2: Measuring the circumference of the arc on the formal = the arc field.
3: Subtract 1 joint from this size.
4: Determine the desired layer size, the thickness of the stone + the joint ( 1cm).
5: Calculate the number of layers.
6: Size - 1 joint dividing by the desired layer size= the number of bricks.
7: If the calculation is not correct, round up if the decimal point is higher than 5, lower than 5, round down.
Example:
Arc field = 96.2cm
The size-1joint thickness= 96.2cm - 1 cm = 95.2cm
Thickness of the stone = 5.8cm + 1cm joint thickness = 6.8cm
Number of the stones in the arch= 95.2cm : 6.8cm = 14 stones
New layer size semicircular arc= 95.2cm : 14 stones= 6.8cm ( remains the same)
It is not always the case that the layer size of the arch is the same as the desired layer size( ascending masonry)
* Has a higher stability than a segment arc.
* Does require a solid foundation.
* Also considered ornamental masonry.
* Gives the façade a nicer and more rustic view.
A number of exercises calculate layer size round arch.
