It's Fun to Choose the Right Paving Materials
Paving materials can be concrete, asphalt, unit pavers, or loose aggregates. For public projects, paving material needs to be smooth enough for people with walking disabilities and easy for maneuvering in wheelchairs. To be smooth, there can be no uneven tree roots, freezing and thawing cracks, slippery gravel, or clumpy bits of mulch. Choose paving materials that can provide long-term stability for a walking or driving surface.
The sub base for paving must be solid and unshifting. For areas without ground that freezes, landscape sub base material can be compacted soil or a mixture of soil and cement. For colder climates, a sub base of deep gravel and even reinforced concrete is required to keep the paved surface safe and navigable.
The installation process for concrete can determine the usability of the surface. Concrete must be textured to prevent slipping. Concrete uses reinforced rods for strength, and these characteristics are very important for vehicular areas. It can be colored with dry shake powders (which fade) or color can be incorporated into the concrete mixture of Portland cement and aggregates prior to pouring. Concrete has to be finished and floated. Special forms are required to hold newly poured concrete in place before it cures. Other special forms can be used to imprint artistic textures into the surface. All of this fuss makes it expensive, but durable. As a designer, you shouldn’t propose concrete without having learned the installation process from start to finish.
Asphalt is a bit easier to install, but has some drawbacks. The mixture of aggregates and oil must be heated, poured, and then pressed flat and even, much like a ribbon of taffy is formed into candy. It’s a sticky mess at first, but creates an attractive, dark, semifluid surface. If asphalt doesn’t receive regular traffic, it can fall apart at the edges. Smaller equipment is available for asphalt, so it is a good option for the installation of extensive woodland and bicycle paths.