Loading Basics : 5 Layers

The preparation of the base is the final element in the successful load carrying capacity of concrete pavers. Although this is not a visible “design” element it is an important general principle that must be considered during initial conceptual design phases. The previous two principles deal primarily with the surface layer which is the top layer of the five total. The remaining four exist below the surface of the pavers.

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1. PAVED SURFACE
   Sand or spacers between units to develop shear (friction) between units
2. SAND BASE
   Leveling bed, even distribution of load to base through the use of a consistent, level surface
3. BASE
   Leveling and distribution of load to subbase. Smaller particles prevent the sand from seeping into it. Base materials are compacted to increase their load bearing capacity.
4. SUB-BASE
   Well compacted and sometimes made of larger aggregate for overall stability on soft wet soils. Depth depends on quality of soil and load bearing capacity. Sometimes the sub-base is omitted and its absence is compensated by a thickened base.
5. SUB-GRADE EARTH
   The natural load bearing capacity of the existing earth at the site must be sufficient to endure the loads placed upon the pavement, and base. The sub-grade earth is often compacted prior to the installation of the layers above. For Weaker soils, the stronger bas and sub-base materials disperse the loads across the soil to minimize deformation.

5 Layers: 1. PAVED SURFACE 2. SAND BASE 3. BASE 4. SUB-BASE 5. SUB-GRADE EARTH

Test your Understanding

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Other Lesson Components ::

Overview

Edge Restraint

Continuous

A Guide for Design Integration of Concrete Pavers, Anton C. Harfmann, AIA; Gary E. Day, RA.
color layer image : www.angelusblock.com/products/pavers-permeable_systems.cfm