Page 18 - SAPEM-Chapter-10-2nd-edition-2014

South African Pavement Engineering Manual
Chapter 10: Pavement Design

shrinkage cracking may also be controlled by installing reinforced steel in the concrete pavement. This type of
concrete pavement is generally referred to as Continuously Reinforced Concrete Pavements (CRCPs). Hybrids such
as Jointed Reinforced Concrete Pavements (JRCP) also exist. The different types of concrete pavements are
illustrated and discussed in Chapter 2: 2.4 or Chapter 9: 12.2.2.

In concrete pavements, moisture enters the pavement through joints and cracks. This causes erosion of the
subbase, loss of support of the slab and slab failures. The design of the subbase is essential to mitigate erodibility.
This is generally achieved by good material selection and by stabilizing the subbase.

2.3 Block Pavements

Concrete block pavements fall somewhere between flexible and a rigid pavements. The layer of paving blocks
provides a surfacing that is stiffer than those provided by bituminous materials (asphalt or seals), but not as stiff as
concrete. The load spreading characteristics of a concrete block pavement are thus between that of flexible and rigid
pavements.

Block pavements are considered as very cracked concrete pavements, with the cracks filled with sand to enhance
load transfer between blocks. In essence, they are similar to thin concrete slabs with discontinuities. As with
concrete pavements, therefore, the quality and strength of the blocks must be adequate to carry the load. The
bedding sand should be permeable and not erodible, comprising of a, preferably, high quality crushed material.

Section 2: Design Principles
Page 7