|Only the minimum of special tools are required for
laying the pavers. They are
- Mecahnical Vibrator for bedding the paving block
and compacting the sub base.
- Hand operated hydraulic stone splitter for cutting
|Typically, there are three layers in block paving
The Sub Base - Laid as for a conventional road, the thickness depending on the nature of the ground and the
amount of traffic. The sub-base must be free of debris or mud and its surface should be level
The Laying Course - A Layer of carefully screeded sand about 50 mm deep. The sand must be washed containing
not more than 3% of slit and clay by weight and not more than 15% retained on a 2.36 mm sieve. To achieve the
best regularity in the finished road surface, the sand should be uniform in both type and moisture content. It is
essential to carry out screeding to the required level which can be done from the kerbs or from temporary screed
rails. The sand used in the laying course must be laid to a surcharge, the amount of which depends on the type
and moisture content of the sand, which is normally in the range of 5-15 mm. This is required as the pavers above
the laying course will be lowered below the initial level by vibration.
The surface course - Each paver has to be placed very carefully so as not to disturb the neighbouring blocks. The
positioning of the first block demands extra care. To give the required pattern, the blocks must be placed at the
correct angle against a firm starting edge such as a row of concrete channel blocks. All blocks must be laid so that
they fit closely together. If joints begin to open, the blocks should be knocked together with a hide mallet. Care
must be taken not to tilt the blocks on the loading edge of the laying face by standing or kneeling on them. Where
blocks do not fit at the edges, the spaces are filled with cut blocks, split using the hydraulic stone splitter.
The pavers are vibrated to their final level with a plate vibrator. A machine with a plate area between 0.2 and 0.3
square maters and a centrified force of approximately 1 tonne is suitable. The vibrator should be guided over the
whole area, avoiding any understrained edge by about a metre. Two or three passes will normally be needed to
vibrate the blocks to the finished level.
|Filling the joints
After the initial vibration, sand is brushed over the surface of the blocks and is vibrated into the joints by a further
two or three passes of the plate vibrator. After all the joints are filled, surplus sand can be swept away