In our previous post we provided a comprehensive guide to the required ground preparation steps before Cabro blocks installation in Kenya. Just to recap, there were three factors to consider namely; soil stabilization, surface runoff management then lastly edge restraining. Once all the three stages are achieved, the ground is now ready to receive cabro paving blocks.
In this article we are going to explain in detail the Cabro blocks installation in Kenya and specifically, cabro fixing process that entails three stages the first being levelling of the bedding layer then laying of the cabro blocks and lastly equipment finishes.
Cabro blocks installation in Kenya: BEDDING LAYER
The material used in this stage of cabro blocks installation in Kenya ranges from quarry chipping & quarry dust which are both byproducts of the ballast making process and lastly river sand. The most popular material is the quarry chipping locally referred to as mchele as it is cheaper & firmer. The essence of this stage is to provide a level bed for the cabro blocks to lay on since the ground even though levelled still has some unevenness.
The workmen first take their levels to ensure the surface runoff will be directed where required and with the right gradient. The bedding layer is achieved using the levels taken. They then use steel square tubes to level a quarry dust bed of thickness not exceeding 40mm; we have provided illustrations of this stage on our YouTube channel for those interested in a visual of the same.
CABRO BLOCK LAYING
As soon as the bedding layer is levelled, it is immediately covered by laying the paving blocks over it. Here is why this is important as part of Cabro blocks installation in Kenya. It is done immediately so as to prevent loss of levels of the bedding through rain, wind or people/pets on site walking over it. The blocks are carted into site by casuals from the point they were offloaded then staggered in a herringbone pattern which guarantees interlocking by the cabro technicians. It’s a seamless process that is quite the site to behold, almost like a real-life jigsaw puzzle as the team lays block by block until the entire area is covered
Once the entire area is laid with the paving blocks, the edge cutting process begins as the next step of cabro blocks installation in Kenya. You see where the cabro blocks terminates on all ends they meet an edge. The edge may be a road channel, a kerbstone, perimeter wall or verandah edge, now along this edge the cabro blocks running along leave gaps in between. This is where the cabro cutting machine comes in handy as it cuts to size the paving blocks to the required fit. Now this process is done the entire edge perimeter until all gaps are full.
The surface is swept clean of all debris and cabro cutting offcuts then the plate compactor is brought in to proceed with the next step in cabro blocks installation in Kenya. A plate compactor is 100kgs in weight , its first purpose is to vibrate over the paving blocks so as to remove air pockets from our levelled bedding layer. Its second purpose is to force river sand into the joints/ crevices in between the interlocked cabro blocks again by vibrating.
The plate compactor operator runs the machine the first time over the swept surface to ensure a compact surface in cabro blocks installation in Kenya. Before he runs it the second time, two things happen. The first being the checking process, here a technician walks around looking for any broken or deformed paving blocks, undoes them then replaces with a proper cabro block. This is why it is important to factor in a certain percentage of the area while estimating to cover for breakages after compaction. The second thing that follows is river sand is brought in and spread over the entire area, the river sand has to be dry & free from any debris. Once spread and levelled, the operator runs the plate compactor one last time thereby forcing the river sand partially into the crevices.
The river sand is left on top of the surface and given time to fill the crevices either by way of wind moving it , rain or human/vehicle movement.