General Building Materials
A brick is a block of ceramic material used in construction, usually laid using various kinds of mortar. It has been regarded as one of the longest lasting and strongest building materials used throughout history. Brick themselves are a thermal and acoustic insulator which is a straight up advantage because you already have the foundations for some good insulation. The brick is also fire resistant which allows for more security in that respect and also it is flexible in its application. However because of the high weight of brick the foundation that the brick is being built on to needs to be structured well to reduce future problems which will set the costs higher especially in earthquake prone areas. And bricks can also crumble with time.
Usually made of clay, brick has been used in many ancient structures, like the Roman aqueducts, the Pantheon and the Great Wall of China. The Sumerians made the earliest recorded bricks, and we can deduce that those early bricks used in construction were crude, uneven, sun-dried blocks probably made of silt that was deposited when high waters receded after storms. The silt dried naturally to a very hard consistency, and then it was dug up, broken into chunks and used to make the walls of huts and other structures. Some experimentation led to the development of forms and molds to create uniform bricks that could be stacked easily for smooth walls with clean corners. This style of brickmaking is still being used today and is very stable in dry climates. But too much rain and the walls of your painstakingly built hut turn to mud. That’s solved with the application of high heat. These bricks are durable, weather resistant, fire resistant, easy to make and convenient to work with.
Concrete is a composite construction material, composed of cement and other materials such as fly ash, slag cement, aggregate (generally a coarse aggregate made of gravel or crushed rocks such as limestone, or granite, plus a fine aggregate such as sand), water and chemical admixtures. Concrete is a material that does well when it comes to compression and combustion because it is very strong once set. The material can be poured and cured under water if it is needed giving the material that bit more flexibility in its applications. On the other hand concrete can be very weak when put under tension but it can be fixed by combining a steel reinforcement alongside the concrete.
Concrete is an aggregate made up of a number of materials like stones and sand that are mixed with a binder like cement and water. The mixture is then left to dry and harden. It’s a flexible material that can be formed on the spot or poured into molds, hardened and then transported. Even though it had been around for hundreds of years, it wasn’t until 1860, when someone realized that concrete could be reinforced to increase its tensile strength (the amount of force or stress it could withstand), that concrete started gaining wide acceptance.
Reinforced concrete can be formed into many shapes with a supporting structure of narrow steel rods embedded right in the concrete when it’s poured. Rebar reinforcement makes concrete an ideal material for walls, beams, slabs, foundations, frames and many other applications. The use of metal rods and mesh, together with a relatively inexpensive concrete medium, make reinforced concrete a flexible, reliable and economical building choice.
Twentieth century refinements have made reinforced concrete an even bigger player in modern building design and construction. Pre-cast concrete is made under controlled manufacturing conditions that increase its water repelling characteristics and limit its capacity to expand and contract. Pre-stressed concrete, made by placing stretched steel strands in the hardening concrete, increase reinforced concrete’s tensile strength and resistance to downward pressure.
The breeze block is made of cinder aggregate and it is also lighter than the concrete block and has some insulating properties. This type of block is generally used for building interior non-load bearing walls. Breeze blocks differ from concrete blocks because they are made from a slurry of Portland cement and small aggregate, such as small stones or gravel. Whereas breeze blocks are made from a combination of Portland cement, cinders and the dusty remnants of burned coal.
Stone is durable and impressive stuff, but it’s also challenging to quarry, and heavy to move, and it has tension and stress limitations. Where there are resources available to excavate and cut it precisely, stone can be an extremely strong and useful natural material. Unlike brick, it can be stacked without mortar and support heavy vertical loads. Stone resists deforming, weathers the elements well, withstands fire and helps maintain stable interior environments. There are so many extraordinary stone structures that it seems a shame that modern construction uses stone more as decoration than anything else.
Today, there are cheaper and more efficient building materials that have usurped the position of stone in modern building construction, not the least of which are decorative stone veneers. It seems humbling, but steel, wood and concrete construction with a thin layer of decorative stone on the outside is more in keeping with modern budgets and standards of construction than the impressive, towering stone edifices of historical buildings. Newer synthetic materials are even mimicking the look of stone in much lighter weight, inexpensive incarnations, eliminating the need even for veneers.
Stone is still popular for its esthetic value, and it’s unlikely that it will ever be completely eliminated. Stone has probably been around since the first Stone Age settlers reached for a few rocks to hold down their tent flaps, and as a decorative element in human design, it’s bound to be a part of our structures for a long time
Cast iron has some architectural advantages, and some weaknesses. It is strong in compression, but weak in tension and bending. Its strength and stiffness deteriorate when subjected to high heat, such as in a fire. In the early era of the industrial revolution cast iron was often used in factory construction, in part owing to the misconception that such structures would be fireproof. Cast iron was strong enough to support the heavy machinery but was vulnerable to the frequent fires that would occur in the factories. There were also numerous building collapses caused by fracture of brittle cast iron beams.
Iron and Steel
Once man started building up instead of out, stronger building materials became necessary to support taller structures. And tall buildings place a lot of weight on load-bearing walls; some sort of support framework was needed to carry the load.
We can see here that steel has a dual role in our builder’s toolkit. It can be embedded in concrete to provide support or become a foundation in itself. Steel can easily be prefabricated to make for a fast and easy installation. It can be welded, bolted or riveted in place. It can be up to 100 percent recyclable, too, which is important with newer green building practices. Steel is a relatively economical commercial building choice which is making inroads in residential construction, as well.
The advent of steel technology that allows man to design and build taller structures has changed the face of architecture and expanded the way we find creative solutions to our building challenges.
As a construction material, wood has a lot going for it. It can be used as a primary material, as seen in log cabin construction or blended with other building materials and used as either a decorative element or support structure. Wood is lightweight compared to stone, and it’s strong once it’s been seasoned to remove moisture. It can also be cut to length easily. Wood does have some disadvantages, though. It decays eventually, and it’s vulnerable to moisture damage like dry rot and predation by insects like termites. Fire is a big problem, too. Even with these vulnerabilities, wood buildings can survive a long time. Just how long may surprise you. The oldest wood building in existence is the Horyu-ji temple in Japan, which dates to the 8th century
In its natural form, bamboo as a construction material is traditionally associated with the cultures of South Asia, East Asia and the South Pacific, to some extent in Central and South America and by extension in the aesthetic of Tiki culture. In China and India, bamboo was used to hold up simple suspension bridges, either by making cables of split bamboo or twisting whole culms of sufficiently pliable bamboo together. It has long been used as scaffolding; the practice has been banned in China for buildings over six stories but is still in continuous use for skyscrapers in Hong Kong. In the Philippines, the nipa hut is a fairly typical example of the most basic sort of housing where bamboo is used; the walls are split and woven bamboo, and bamboo slats and poles may be used as its support. In Japanese architecture, bamboo is used primarily as a supplemental and/or decorative element in buildings such as fencing, fountains, grates and gutters, largely due to the ready abundance of quality timber.
Clay Coated Straw
One of the best low-cost insulating materials is clay-coated straw (or other lightweight plant materials). A light coating of clay acts as both a binder and preservative. Clay-coated straw has been shown to last over 700 years as a non-deteriorating insulation. As the clay dries, it binds the straw together in a surprisingly rigid mass. It’s a “natural Styrofoam”. Other excellent insulating materials include expanded natural ceramics, such as expanded clay, slate, and shale. These materials are sold as perlite, vermiculite, and other expanded products. Other insulators include cellulose in many forms such as balled newspaper, “fluffed” newspaper (processed through a hammer mill), or any light, dry plant material such as rice hulls, or other agricultural waste. Coat with a light clay slurry or soak in a dilute boric acid solution to keep from deteriorating. Basically, insulation is just trapped air. Fibrous composites (papercrete, fibercrete, etc.), can also be very insulating, depending upon their design density, but can have structural capabilities as well.
The word cellulose comes from the French word for a living cellule and glucose, which is sugar. Building insulation is low-thermal-conductivity material used to separate the internal climate and sounds of a building from external climate and sounds. Cellulose insulation is plant fiber used in wall and roof cavities to separate the inside and outside of the building thermally and acoustically. Thermal conductivity of loose-fill cellulose is approximately 40 mW/m•K (an R-value of 3.8 per inch) which is about the same as or slightly better than glass wool or rock wool. Noise reduction is achieved in three ways with cellulose. The first is that cellulose completely fills cavities leaving few air pockets for sound to travel in. The second is the cellulose material’s ability to trap air. The significant difference between noise reduction with cellulose and fiberglass is its density. Cellulose is approximately three times denser then fiberglass. This helps deaden the sound through walls and between floor levels. It also reduces utility costs reducing bills from 20 to 50 percent.
Natural rubber is an elastomer (an elastic hydrocarbon polymer) that was originally derived from latex, a milky colloid produced by some plants. The plants would be ‘tapped’, that is, an incision made into the bark of the tree and the sticky, milk colored latex sap collected and refined into a usable rubber. The purified form of natural rubber is the chemical polyisoprene, which can also be produced synthetically. Natural rubber is used extensively in many applications and products, as is synthetic rubber. It is normally very stretchy and flexible and extremely waterproof.
The term plastic covers a range of synthetic or semi-synthetic products that can be molded or extruded into objects or films or fibers. Their name is derived from the fact that in their semi-liquid state they are malleable, or have the property of plasticity. Plastics vary widely in heat tolerance, hardness, and resiliency. Combined with this adaptability, the general uniformity of composition and lightness of plastics ensures their use in almost all industrial applications today.
Rammed earth is a technique for building walls using the raw materials of earth, chalk, lime and gravel. It is an ancient building method that has seen a revival in recent years as people seek more sustainable building materials and natural building methods. Rammed-earth walls are simple to construct, incombustible, thermally massive, strong, and durable. They can be labour-intensive to construct without machinery (powered tampers), however, and they are susceptible to water damage if inadequately protected or maintained. Rammed-earth buildings are found on every continent except Antarctica, in a range of environments that includes the temperate and wet regions of northern Europe, semiarid deserts, mountain areas and the tropics. The availability of useful soil and a building design appropriate for local climatic conditions are the factors that favour its use.
Unplasticised Polyvinyl Chloride is a modern synthetic material which is used in the manufacture of windows because it is a low maintenance material. The UPVC can be used as a substitute for painted wood mostly for window frames and sills. It has many other uses including fascia, siding or weatherboarding. The same material has almost entirely replaced the use of cast iron for plumbing and drainage, being used for waste pipes, drainpipes, gutters and downspouts. Although due to the environmental concerns the use of PVC is discouraged by some local authorities in countries such as UK, Germany and the Netherlands.
More recently synthetic polystyrene or polyurethane foam has been used in combination with structural materials, such as concrete. This particular material is light weight, easily shaped and also a good insulator. It is usually used as part of a structural insulated panel where the foam is sandwiched between wood and cement or insulating concrete forms. However to make this foam a lot of different raw materials are used which renders the material insufficient.
Clear windows have been used since the invention of glass to cover small openings in a building. They provided humans with the ability to both let light into rooms while at the same time keeping inclement weather outside. Glass is generally made from mixtures of sand and silicates, in a very hot fire stove called a kiln and is very brittle. Very often additives are added to the mixture when making to produce glass with shades of colors or various characteristics (such as bulletproof glass, or light emittance).
The use of glass in architectural buildings has become very popular in the modern culture. Glass “curtain walls” can be used to cover the entire facade of a building, or it can be used to span over a wide roof structure in a “space frame”. These uses though require some sort of frame to hold sections of glass together, as glass by itself is too brittle and would require an overly large kiln to be used to span such large areas by itself.