Phase 1 of the C-LTPP project involved the construction and
initial performance testing of 24 highway test sites on the major provincial highway
system across Canada. Unlike the US-LTPP experiment where the performance of various
types of pavement structures is studied, the C-LTPP project targeted a single type of
pavement structure: new asphalt concrete (AC) overlays constructed over an existing AC
pavement with granular base coarse.
The design of the C-LTPP experiment was strategically
conceived to permit paired comparisons of adjacent highway test sections. Each test
site contains a minimum of two to a maximum of four adjacent test sections for a total of
65 pavement sections (see the Test Site Map section of this
website).
The use of adjacent sites allows for the comparison of
different rehabilitation methods under identical traffic loading, climate and soil
conditions. The alternative rehabilitation strategies employed on the C-LTPP test
sections include:
- variable overlay thickness,
- hot and cold-mix recycling,
- milling,
- inclusion of performance enhancing additives, or
- a combination therof.
The specific experiments under study are presented as
follows:
| Experiment Type Code |
Experiment Description |
No. of Sites |
| 1 |
Performance Comparison of Overlay Thickness (HMAC) - 2
adj. sections |
14 |
| 2 |
Performance Comparison of Overlay Thickness (RAP) - 2
adj. sections |
0 |
| 3 |
Performance Comparison of Overlay Material Type, HMAC
vs. RAP - 2 adj. sections |
0 |
| 4 |
Performance Comparison of Overlay Thickness (HMAC) - 3
adj. sections |
2 |
| 5 |
Performance Comparison of an Overlay Additive or Mix
Variation - 2 adj. sections |
1 |
| 6 |
Combination of Experiments 1, 2 and 3 |
2 |
| 7 |
Combination of Experiments 1 and 3 |
1 |
| 8 |
Combination of Experiments 1, 3 and 5 |
2 |
| 9 |
Combination of Experiments 1 and 5 |
2 |
| |
TOTAL: |
24 |
The C-LTPP project attempted to design and build the test
sections across Canada so as to cover the widest range of experimental factors such as
traffic loading, environmental region and subgrade type. This ensured that C-LTPP
would encompass the majority of conditions under which pavements are constructed in
Canada. The locations of the 24 C-LTPP Test Sites are
listed with the As-Built Site Matrix, displaying the
experimental design of the test sections with regard to the above rehabilitation
strategies. Again, see the Test Site Map section of this
website for a graphical display of the test sections.
