Material such as wood allow the concrete to expand
An "expansion joint" is a joint left in between sections of the same material, like concrete or steel, that allows movement as the material heats up or cools down. Without it, concrete, for example, can expand and crack in hot temperature.
Lets' look at this from a simplistic point of view. The predominant factors when dealing with a bridge is strength and weight. The strength of the bridge is how much load it can handle. The weight is how much the bridge weighs before loads (such as cars) are applied. The weight of the construction material must be included when considering the total strength of the bridge. For instance, if a bridges strength is 110 pounds, and the weight of material is 100 pounds, then you can only put 10 pounds on the bridge before failure. Bridges can be made from any material. Wood is commonly used on hiking trails, Composite (Plastics) have been used on some small bridges. However, the two most popular are Steel, and reinforced concrete (Reinforced Concrete has steel rods inside the concrete to increase the strength). The reason for this is because of the incredible strength of the steel or concrete per pound of material. This allows for a very strong structure that does not generate a lot of weight. This means that the load carrying capacity of the bridge is maximized. Furthermore, the structural design of a bridge allows for load shifting. This explains the grid pattern above, or below, some bridges, the big arch under some concrete bridges, or the characteristic look of suspension bridges.
Prevent or reduce cracking of the concrete due to thermal expansion. Most materials expand when heated and contract when cooled. The strips are usually a fibrous material that allows the concrete expand and contract without breaking. Without those strips, random and irregular cracks would occur.
Young's modulus describes the relationship between stress (sigma) and strain (epsilon) in a material that obeys Hooke's law. Concrete is such a material and knowing this property allows one to plan and design the use of concrete as a building material safely.
It allows the girders to be lighter. If you took a solid piece of steel in a square shape and exposed it to stressed, you would discover that the stress in the metal is on the top face and the bottom face. The middle sections do not add to the structural strength of the beam, they simply add weight.
- MRT and Railway tracksif a continuous track of metal is used, it will expand in hot weather and bent. trains running on bent tracks may be derailed. to prevent this, railway tracks are laid in sections with expansion gaps between them. A sliding joint between adjoining rails allows them to expand without bending.- bridgesboth concrete and steel bridges are built with allowance for expansion and contraction due to changes in the surrounding temperatures. Rollers and sliding joints allow for the movements of the bridges as it expands and contracts
the plasma membrane allows certain material to pass in and out.
the answer is transparent material
allows the use of higher slump of concrete which results in stringer concrete
Sections of the lungs are called lobes. The right lung has 3 lobes and the left lung has two, which allows room for the heart.
It allows for the expansion of the concrete during hot weather and provides a water block during rains and that prevents water freezing (and expanding) during the winter. Ice expanding in those cracks would damage the cement slabs.
Translucent materials allows light to pass through it. Windows is a translucent material because it allows light to pass through it