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Laying Guide
How to
use Concrete Blocks
1. Dry Units Essential
: Concrete masonry blocks should never be-wetted as is
customary with bricks as concrete block will give drying
shrinkage of the joint mortar. However, water may be sprayed on the joints
for curing from the next day.
2. Mark the courses on the columns
: before starting the block work
mark the courses on columns and try to adjust the first course in a way as
to avoid any gape at the beam bottom. This can be achieved by marking
courses with a stick which has 20cm marks on it
3.
Arrange the blocks in the First Course : After levelling the surface as
above start vy arranging th blocks between two columns so as to arrange
the vertical gaps equally or use a half or one fourth block
4.
Use Cement - Lime Mortar 1:1:6 (1 cement : 1 lime : 6 sand) : After having
adjusted the first course start spreading mortar by lifting one by one
block form the first course. Lime adds plasticity and makes joint water
tight. Instead of lime one can use air entraining agent or both for best
water tight joints.
Prepare
mortar strictly that can be consumed in an hour. keep the gauging water at
the minimum.
5.
Face shell bedding in enough : The mortar need be applied only on the face
shell and not on the full shell as even with face shell bedding the factor
of safety is 4.2 which far exceeds a factor of safety of 2.8 achieved in
brick masonry with full mortar bedding. This also will break the
continuity of passage of rain water to the inner face of the block through
the joints.
6.
Avoid wastage of mortar and make 1 cm thick joint : By making a "Manson's
Float" of the width equal to the width of the crores with a 25mm thick
plank. one can achieve the final thickness of joint as 1 cm and avoid
falling of mortar into the cores.
7.
Tool the joints to make them water tight : the mortar in the joint has
been compacted vertically by the weight of the block by tooling with 16mm
rod one can compact from the side and make a concave grrove making the
joint water tight.
8.
Consealed Wiring is possible in Gurjari's block without any short or
grooving or chasing or pre-planning & can be changed at a later date also
without damaging the plaster or paint.
9.
Provide a hexagonal wire mesh or a single leg 3 mm stirrups at inter
section of walls : provide wire mesh or stirrups at every 3rd layer of
inter seeting walls and preferably fill those two core with concrete
10. Fixing of doors & windows : This is possible by using special
lintel blocks for receivingthe hold fasts and then concreting the end
cores after placing a 6 mm bar.
11. Protection from rain : It is recommanded to do external plaster
preferably with a integral water proofing compound or apply coat of
silicone based transparent water repellant coat or both for protection
from rain water. It is recommended to use inverted lintel blocks in the
closing course at the beam bottom.
Paver
Installation
Installation of paving stones is very simple and gives lasting area that
can be removed and relaid at a later date if repair is necessary or to
accommodate service lines without usual ugly scars is now common with
concrete or asphalt monolithic surfacing.
Preparing
your base
A good
base is the essential requirement for a durable job. Special care should
be taken in preparing the base to assure a permanent installation. The
depth of the base will be determined by the load facctor and the condition
of the soil.
Determine
Depth of base
For a
patlo, or sidewalk around the home, a 4" to 6" (10 to 15 cm) depth is
usually sufficient. This should be a sharp concrete sand, stone dust or
limestone screeing.
For
driveways a 6" to 10" (15 to 26") gravel base should be well compacted in
layers of approximately 8" (20 cm) with a vibrating type compactor. This
should consist of a good grade "A" road gravel with particles upto 3/4"
(2cm). This should then be covered with 1" to 2" (2.5 cm to 5 cm) of sharp
sand, stone dust or limestone screenings and screeded level but not
compacted remember there i no definite rule of depth, but the above
suggestions will help as a guide or consult to Gurjari
Levelling
the Base
This is
an important step in your installation to achieve a good level job when
finished. You must make sure the base is levelled properly. Generally the
most popular method of levelling is with a skreed which is usually a long
2"x6" board. It is very important that commercial jobs skreeding bars or
pipes may be used. A frame is required to maintain the base. These could
be gurjari blocks for added strength and beauty or simply the surrounding
soil or a wooden frame. the levelling of this frame will indicate the
level of your area.
Placing
Gurjari paving stones
Stones
should be placed in the desired pattern close together. The spaces between
stones should not exceed 1/8" (3mm) the spacing should be consistent. This
will help maintain a uniform pattern. When laying each row the installer
should stand on the previously laid stones cutting of stones where
necessary can be done with a splitter chisel or masonry saw as required.
Completing the Job
The
pavers should then be tamped down and levelled with a vibrating plate
compactor. This will bring them to their true grade as well as level the
stones. Sand will be forced into spaces to make stones firm and free of
movement. Finish the job by sweeping dry fine sand into the joints. Now,
call your friends and celebrate.
Installing Blended colours
To
produce pleasing blend select from 3 bundles simultaneously working
vertically down the rows. these stones should be mixed again when laying.
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