C O N C R E T E , S O I L , W O O D, A N D OT H E R M AT E R I A L S
Two walls made with rock with very different appearance are shown in Figure 8.14. The wall in Figure 8.14A was constructed first by building a wooden form. Native rocks of different shapes and sizes gathered from the surrounding landscape were placed in the form as a wet concrete mix was being poured into the form. Wood strips were nailed inside the form so that after the concrete had set, the forms were pulled away from the concrete. The wood strips left an impression in the face of the exposed wall surface. The garden walls, much of the pavement, and the building architecture used a similar system, furthering the architect’s desire to blend the structures in with the natural landscape. The wall in Figure 8.14B used a gabion wall system. A gabion is modular system, essentially wire baskets made from welded wire mesh. The baskets are filled with loose stones and later secured in place by a lid on the top. The lid is secured shut with wire after the baskets are filled. The baskets are generally constructed of a consistent dimension for a specific project. The stone-filled baskets are then stacked like bales of hay or bags of sand to construct the wall. The baskets remain held in place by gravity. The stone used in making the wall pictured came from a quarry, was crushed to the desired size, then transported, and placed in the wire baskets at the project site.
Brick: Another Type of Manufactured Modular Material Bricks have been used in building construction in regions around the world for many thousands of years. Early cultures produced bricks using clay soil, sometimes mixed with sand and straw, then left in the sun to dry. The bricks from this method are referred to as adobe and, while suitable for wall construction, the material was susceptible to erosion if left unprotected. Covering the surface with a protective slurry material reduced the destructive erosion from rain. The slurry could easily be reapplied as weathering occurred. Bricks used in masonry construction today are fire-hardened in kilns and are not susceptible to erosion. Fired bricks are one of the longest-lasting, most durable, and strongest materials used for landscape and architectural purposes. Bricks are produced in numerous sizes, shapes, and colors. The color is a result of the type of clay and other ingredients used, as well as the method and duration of the firing. Brick units are individually laid in courses (layers) and patterns. Mortar is used to bind the bricks together. Generic brick is made from clay as opposed to other modular unit products that may look similar to clay brick but are usually made from concrete. The walk shown in Figure 8.15 uses two materials: poured-in-place concrete and brick. The concrete has no color additive but does have a light exposed aggregate surface. The brick pattern was applied after the concrete had been poured and hardened. Pre-cast light-colored concrete squares were also laid at the same time as the brick. The brick and concrete units were laid over a concrete slab, then mortared in place. Brick is an amazingly flexible material in terms of patterns that can be created. The patterns can be “large-grained” with bold, repeated 167
