A Self-Learning Manual - Institution of Engineers Mauritius

A Self-Learning Manual
Mastering Different Fields of Civil Engineering Works (VC-Q&A Method) Vincent T. H. CHU
gradients where it stands a high possibility that rain runoff will wash out
infilling sand and sand layers, cement sand should be sued instead.
Similarly, when high pressure jetting is anticipated to be employed
frequently in routine maintenance, sand layers beneath precast paving
block units is not preferable owing to the reason of potential washing out of
sand.
6. Why should edge courses of paving blocks sit on concrete bedding?
(S3)
In pavement made up of paving blocks, the edge courses are normally
designed to sit on concrete bedding and haunching. The reason of such
provision is to prevent lateral movement of paving blocks when subjected
to traffic loads. In essence, the edges formed by edge courses tie the body
of the paving blocks as a single unit and they have to rely on concrete
bedding and haunching to resist the sideway forces generated by moving
traffic.
The concrete bed serves to keep the edge courses in position for surface
level and it provides the dead loads in the retaining structure. On the other
hand, concrete haunching also holds the edge courses in position from the
point of view of lateral movement.
Fig. Edge courses in paving blocks
7. What is the purpose of edge courses in paving blocks pavement?
(S3)
The principal function of edge courses is to form a retaining structure with
concrete bedding and haunching to resist sideway movement arising from
traffic loads. Other functions of edge courses include:
(i) It serves as level guides when carrying out screeding of sand
bedding.
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