Page 132 - SAPEM-Chapter-10-2nd-edition-2014

South African Pavement Engineering Manual
Chapter 10: Pavement Design

Note:
1. The pre-1995 TRH4 traffic classes are used
2. E3 traffic range is 3 – 12 million E80s and not 2 – 12 as indicated
Figure 54. Typical Catalogue Design of Concrete Block Pavements

9.3 Research Based Design Methods
Although many engineers have used tests of prototype interlocking concrete pavements to obtain materials
equivalencies or substitution ratios, only one design method appears to be wholly based on accelerated trafficking
tests. This is the method developed by Shackel at the University of New South Wales for the Cement and Concrete
Association of Australia, first published in 1979. Subsequently, following trafficking tests in South Africa, designed in
part to verify the procedure, the method was slightly revised (Shackel, 1979 and 1980). The method is restricted to
block pavements subjected to highway loadings, and which incorporate unbound granular bases.

It is possible to use accelerated trafficking tests of full-scale prototype block pavements to develop statistically-based
models to relate, for a given subgrade strength, the block and base thickness to measures of performance, such as
rut depth. These models have been extended to cover the full range of subgrade conditions using mechanistic
analyses. Typical design curves are shown in Figure 55. This method has been used successfully in a variety of
climates since the late 1970’s, but has been replaced by mechanistic procedures similar to those described in
Section 9.4.

References for Block Pavements
A good reference for block pavements is:
Brian Shackel, “Design and Construction of
Interlocking Concrete Block Pavements”, 1990.

The Concrete Manufacturers Association (CMA) has
four books on Concrete Block Paving. These books
can be downloaded from www.cma.org.za. The books
are titled:
• Book 1: Introduction
• Book 2: Design Aspects
• Book 3: Specification and Installation
• Book 4: Site Management and Laying

Section 9: Structural Capacity Estimates: Concrete Block Pavements
Page 121