The building materials in construction

These are the materials that are used in the construction industry. There are different types, sourced both natural and man-made, and over time have been created for new, more effective. Obviously, each material has specific properties that make it more or less suitable for different purposes for which it could be used in a building.

Historical Background

The first materials used by man to build the tents in which they lived were the skins of animals, were later used mud and clay raw, the straw huts, and different types of rock. There are many Aboriginal and nomads who, in different parts of the world still use these materials for their homes, in industrialized countries instead he's lost almost all uses.

One of the techniques of building is the oldest drywall, which is built with blocks of stone placed in supportive way alone, without the use of binders. An example of this type of construction are nuragheses Sardinian, which date back to the second millennium BC, the pyramids of pre-Columbian civilizations in South America and the ancient Greek and Roman buildings. Around 2,600 BC They spread the use of granite, with which the ancient Egyptians built the outside of the red pyramid, that of Mycerinus is instead built with granite and limestone blocks. The American Indians, however, used skins and birch bark for building their huts, called teepee, with typical conical shape, which could be dismantled, transported and reassembled on another site. Even today in Mongolia there are peoples who live in yurts, typical housing structures built with a wooden frame and a cover made of felt carpets, which is a tissue of animal hair.

In the mid-twentieth century stem, instead, the marquees, the first dating back to 1958, at the Sidney Myer Music Bowl in Melbourne. For their implementation, are used in load-bearing structures of glass fiber, coated with polytetrafluoroethylene, polyester canvas and polivinilcloruri.

In the construction sector was also frequently used asbestos, especially for thermal insulation of buildings as well as means of transport, until the conclamazione its carcinogenicity in the mid-eighties.

 

The choice of material

Are the materials, and more specifically their mechanical, structural, thermal and mass that often affect the realization of objects, tools, until you get to the same buildings. The choice of material to be used, then, is never left to chance, because of the profound differences between the same materials, often also belonging to the same family of merchandise.

Especially in recent years, exploited the building materials that could be found in nature, such as clay, sand and wood. They were often used in the raw state, without it being necessary an additional processing.

With the passing of the years and with the evolution of technology, these materials have been integrated with other production materials artificial, such as glass, concrete, plastic and metal alloys. These materials come from the processing and specific treatments of raw materials found in nature. The same materials that were used in their crude form, with years begin to undergo processes of machining and processing, an example is wood, whose surface is treated with various systems including sandblasting, or clay, which is transformed into terracotta through baking in the oven.

The materials for the construction industry can be divided into the following categories:

-       woods

-       rocks

-       ceramics

-       metals

-       composite

-       brick

-       polymers / plastics

-       glass

-       ice

Another key component to the choice of a material than another is, of course, its price.

 

 

Types

Wood

The different types of wood differ between them both for the species they belong to both the type of growth of the tree from which they come. The so-called structural wood is a material very versatile and easy processing, widely used in the building sector for the realization of structures of different types is mainly used for the construction of load-bearing frames and for coatings. From the stem of the plant can in fact get axes of different thickness, which are often joined together with the use of glues, screws or steel hinges from carpentry. The main disadvantage of this material is, of course, its high inflammability.

Granite

Mainly used in flooring is a material characterized by a high resistance to acids.

Marble

It is a material that is often used in the form of plates to achieve the finishes, such as floors or, at times, even the walls. Because of its porosity, and consequently to its tendency to absorb the oily substances, sometimes undergoes specific protection treatments.

Chalk

Its main feature is the lightness, given by a specific weight less than the average of the other materials; lightness but this is also accompanied by minor, mechanical properties, which relegate the realization of plasterboard that is used for the construction of partition walls and controsofitti.

Tufo

In the form of blocks, is mainly used to construct the partitions in place of the perforated bricks.

Slate

It is the ideal material to be cut into thin slabs, flat and lightweight, waterproof and very resistant to weathering. For this is typically used for roofing, for roofs, as well as for outdoor paving and the realization of stairs and steps.

Ceramic materials

In construction, the ceramic is often used for the cover, for tiles (for both walls and floor) and for the realization of health, ie, sinks, toilets, bidets, sinks and shower trays.

Metallic materials

Are often used for the construction of load-bearing structures, such as in skyscrapers, or for lining the walls of some buildings. The most widely used metal in construction is steel. Although aluminum is widely used, as lighter and less liable to corrosion due to atmospheric agents. Another material used is brass. They are often also used noble metals such as silver, gold and chromium, which often go to decorate the facades of buildings. Copper is also a certain usefulness in the construction industry, often for the construction of gutters.

Steel

The steel has an extraordinary mechanical strength and great flexibility, even if it is easily dischargeable, so not particularly durable when used in outside. It is mainly used to achieve load-bearing frames and for the realization of reinforced concrete.

Malta

It is composed of a mixture of binder, such as lime or cement, water and sand, which is a fine aggregate. It is therefore a mixture characterized by highly variable properties due to the nature of the components that comprise it. In the construction sector is used as a binding material in the construction of foundations, walls, screeds and plasters.

Concrete

Even the concrete is a composite material, which arises from the union of a material inert said, as may be gravel, sand or crushed stone, and a binding material such as cement. Often is used in its form 'armed', ie with a real steel armor inserted inside. The concrete then combines the high compressive strength of concrete with large flexural strength of steel.

The part of the concrete which is to cover the steel core is also called concrete cover, and can be of different thicknesses that vary according to factors related to the corrosion of the internal steel; corrosion in fact may be due to a decrease of the structural performance of the same reinforced concrete. In the phase of use of reinforced concrete are used special needle vibrators that serve to eliminate any air bubbles that may remain trapped within the concrete, causing a consequent weakening of the same structure.

Among the advantages of this material can undoubtedly cite its longevity, the ability to harden in different shapes and, last but not least, the ease of transport.

Its main use is the foundation and building structures, such as beams and pillars.

Bricks

They are produced from clay cotta, cement and sometimes a mix of sand and cement. Because of their great resistance to fire are often used in place of wood in the creation of partitions.

Polymeric materials

Otherwise also known as plastics, are used mainly for the creation of water pipes, rolling shutters and often the tanks.

Polystyrene

Also known by the name of the polystyrene is used in the creation of 'coats'. It is also an excellent acoustic and thermal insulation, and has the advantages of being light and above all economic.

Glass

It is perhaps the most fragile materials, and is used in thin sheets for the assembly of the windows. Its biggest advantage is to allow the passage of light in the various environments of a building, at the same time isolating it from rain, wind and snow. It is often used as decoration, such as the mosaic windows we see primarily in the windows of churches.

At times between a glass plate and the other can leave a gap that allows a good sound insulation as well as heat. This type of technique is also called rear view camera. Always with the glass may also build some real brick that can be employed for the construction of walls: the vetrocemento, in fact, allows the passage of light, without compromising the privacy of a given environment.

 

Innovative materials for the construction industry

Are defined as ceramics, metal alloys or polymers that are designed and tailored to meet specific construction needs. More than for their birth relatively recently, these materials differ from others for their extraordinary functionalization: often for their realization, in fact, their very chemical and physical structure is modified to allow elevation of performance.

Origin

These materials 'advanced' often arise from the characteristics and continuous innovation thrusts its other technology areas, such as areas aeronautical, automotive or biomedical. These areas are characterized by the search for materials with even better performance, which are essential for the creation of systems and products with maximum efficiency. Since building a sector in which innovation penetrates much more slowly, both from a standpoint of industrial architecture, these materials in order to enter into common usage should be subject to specific processes that adapt them to new conditions 'use and they may experience performance. Other obstacles to their diffusion can be technical difficulties in employment and the absence of specific rules that govern its use.

Developments

The recent achievements in the field of chemistry have significantly changed the relationship between humans and the different materials from which it is surrounded, allowing it to intervene even at the molecular level on the atomic compositions, up to the creation of new materials called 'managed to complexity'. These new products are the impurities and anistropie become strengths, specially created to get certain benefits.

The composition of matter of an object gives way to its potential performance, radically changing the way in which man has always been compared to the world around him: the latest generation of materials can not be classified according to the 'old' proper parameters for Because of their innovative potential and their often unpredictable behavior.

These new materials in fact we often appear as heterogeneous and not always easily classified with the traditional criteria because the element that characterizes them is not derived from the properties of the material itself but from its original properties and alien, which contributes to increasing their contribution with informative speeches of different dimensional scales.

Today we can speak about a product on multiple levels, ranging to change its dimensional scale based on the property that we want to have. For example, an intervention at the atomic level can modify its general properties, the ones that stand out the three families of products polymeric, metallic and ceramic. Speaking instead on the spatial distribution of the atoms and the intensity of these ties can variarne the state of aggregation, for example, from solid, liquid and gaseous, and this occurs mainly in the case of the realization of new metal alloys or ceramic materials with specific performance very elevate.È the microstructure of a material, in fact, define the physical and mechanical properties, while it is the macrostructure that allows us to modify and functionality.

Characteristics and properties

Often these materials present an optimization of the properties with respect to the so-called common building materials to meet specific application needs. Their performances are often variable, controllable and selectable. Their physical and chemical characteristics can be modified to achieve ownership and innovative performance, which had never been attained, nor considered in the past years.

The fundamental difference with respect to the materials used traditionally, in fact, lies in performance; often common materials that are 'innovative' performance (eg in concrete) can be considered as advanced materials. Even specific production processes or synthesis of a given material can go to identify certain types of advanced material, as in the case of nanostructured materials, which arise from the coupling of nanoscale materials 2 or more.

 

 

Types of advanced material

There are two main categories: the fixed performance materials, characterized by the final properties that are selected and determined previously with special processes conformation chemical / physical and special processes of synthesis, and the materials defined 'smart', whose characteristics may change as response to external stimuli.

The performance materials fixed:

-       advanced structural materials: in this category the fiber reinforced composite materials, glass structured, the high performance concrete and metal foams or polymeric, are used in various applications requiring primarily a great versatility in terms of mechanical properties.

-       thermo-structural materials: are part of the flame retardant fibers and 'flame retardant', the advanced ceramic products or transparent, heat-resistant resins, foams, ceramics and ceramic light, with excellent mechanical and thermal properties.

-       material surface properties and interface: fall into this family, the materials used for wear-resistant coatings, thermal, catalytic and corrosion, but also self-cleaning glass, selective and low-emission, which when used as outer coating provides a high protection against the various atmospheric and environmental factors.

Two are the different categories of materials 'smart':

-       property changing materials: for example, the phase change materials (magneto-electrorheological, photo-thermo-elettrotropici), the photo-thermo-electrochromic materials, the phase change materials (photo-thermo-elettrotropici or magneto-electrorheological, ) and those of shape memory, which soon able to modify some of their properties as a response to any changes in climate, without it being necessary to an external intervention or a control system.

-       exchanging energy materials: fall into this category certain sensors or piezoelectric actuators, some photo-elettrochimicoluminescenti and OLED materials, but also organic materials that allow the photovoltaic conversion that can convert incoming energy into another type of energy exit following the first law of thermodynamics. Are often used as control systems or devices to produce energy.

In these classifications fall time course materials used in the building sector, such as fiber-reinforced composites that go to consolidate some or structures that are used for the creation of structures resistant but read. Some materials instead are experiencing right in the contemporary increase in demand, for example in the case of low-emission glass and selective that save energy, or sensors and special devices used in new applications of home automation. Other materials are however knowing a primarily experimental that still leaves a glimpse possible future applications of large capacity, as in the case of protective coatings nanostructured both protective that photocatalytic, photovoltaic elements of organic origin and materials of shape memory.

 

 

List of advanced materials

Ceramic materials

Investment research in the field of ceramics are all aimed at improving the properties of a material that has limits of performance data from the difficulty of processing and its extreme fragility. The studies and experiments in progress have as their objective the identification of one or more new materials that are able to marry the positive characteristics of ceramics, for example, the thermal inertia, the stability at the chemical level and hardness, with quality unpublished for this type of material, such as tenacity and easier processability. Thanks to its wide variety of products, such as concrete, glass and stone products, the ceramic industry is the one that concentrates the largest number of trials and the additional investment in research.

Concrete

The market is experiencing in our time the entry of innovative products such as high performance concrete type HPC and RP4C, who as a strength a great workability, excellent mechanical strength, volume stability, reduced tendency to crack, a elevation of the degree of permeability and especially un'incrementata curability even and especially in adverse weather and environmental conditions.

-       fiber-reinforced concretes: are special materials in which the bending strength is increased considerably by the inclusion in the mixture of special polymeric fibers.

-       concretes smart: contain within them of carbon fibers or of fiber optics that allow careful monitoring of the integrity of the structure itself through a passage of electricity;

-       translucent concrete: in which the density of the mixture decreases considerably thanks to the presence of a high quantity of reinforcing fibers.

Glass

Elicits a particular interest experimentation toward the creation of selective products that can change according to the radiation of the sun, to electrical impulses or to particular induced magnetic fields, such as the chromogenic glasses, which are divided into the following categories:

electrochromic glass: that are able to vary its transmittance due to a change in electrical voltage.

photochromic glasses: they are able to change their appearance when exposed to a light radiation.

thermochromic: when heated, their appearance changes.

LCD: when subjected to an electrical stimulus are capable of changing its transparency.

electrophoretic inside them, there are special particles 'suspended' in a gel content of organic origin in a film. As a response to an electrical stimulus, the particles change their arrangement and then vary the transparency of the glass itself.

Photoelectrochromic through the integration of technology with photochromic and photovoltaic, are special glasses that feeds on itself.

Stone products

Although these materials are objects of studies on innovation, especially to try to overcome the problem of their fragility. The aim of the research is in fact able to achieve:

-       stones fibro-reinforced: with a load resistance 10 times greater thanks to the interposition of carbon fiber.

-       rolled stones: matching the stone slab to thin sheets of glass or plastic you get extra protection against the elements.

Always in the field of ceramic products, the most recent directions of study and development are intended to create:

-       paints and ceramics that can boast very high insulating properties and reflective

-       ceramic foams that combine high insulating properties also a great strength.

Metallic materials

Also the field of metal products is experiencing great innovations, is realized, in fact, an increasing number of metal alloys which can boast an improvement in strength and processability, and therefore may be subject to processes with very high precision, very similar to those to which they are subjected, the thermoplastic polymers.

There are many, nowadays, the latest generation of metal products that have improved their potential and overcome their limitations: they are corrosion-resistant products, incredibly pliable, easy to work with and great adhesion to the wide variety of treatments that can undergo a superficial level.

Here are the most important:

-       light alloys and superalloys: born from studies carried out in the automotive and aviation industry to enhance the performance of a vehicle.

-       metal foams: available mainly nickel and aluminum, have a high level of lightness and stiffness combined with good properties of thermal and acoustic insulation.

-       steels composites: are produced both as 'sheets' or plates, which as said honeycomb panels that are 'coupled' physically termopalstici materials that are usually used for cladding facades or for the realization of panels, but also as a composite of fiber of metal, to be used for specific industrial applications.

-       microleghe metal of high performance are incredibly resistant to both rupture at high temperatures, thanks to special combinations of vanadium, molybdenum and copper. They find their best application in construction in areas prone to earthquakes.

-       shape memory alloys: particularly interesting for biomedical science, these special alloys can be modified in a reversible manner in response to changes in temperature.

-       metal fabrics: mainly used for applications outside the joint, where it can present very low or very high temperatures, such as aerospace missions, fibers are enriched with oxides of aluminum, silicon and boron. Some versions of these alloys are also used in the construction industry in the facade panels, but mainly for their aesthetic value.

Polymeric materials

Even the plastic polymers are the subject of studies and experiments, especially for the production of special films and technical textiles. The family of technical textiles is vast and includes a large number of products and materials, textiles and non-employed in many fields, from electrical to the automotive industry, from construction to aerospace to get up to the clothing industry and microfarmaceutico, for this is not always easy classification.

The architectural industry sees the use of special membranes produced with fabric covered with plastic resins that give the material a great resistance since the individual wires that make it up are extraordinarily strong, this resistance can, however, vary according to the type of fabric, such as those warp and weft, than rolled, sheets or films.

Today the textile materials employed in the building can be divided into two categories, based on the amount of polymers used for the realization of the fibers and the matrices:

-       multicomponent products: such as polyester fabrics and PVC, glass and PTFE and glass and silicone;

-       component products: products are even more modern, such as the fabric of expanded PTFE and ETFE plastic films and THV.

Due to their rapid spread across many industries, these products are subject to continual research and innovation aimed primarily at increasing their performance especially with regard to the resistance, insulating properties, the durability, efficiency and maintainability.

In particular, the plastic films, which are used for the creation of film photovoltaic which serve to produce electricity from renewable sources, are the subject of constant studies in order to increase the efficiency, which is currently at a level slightly lower than that of conventional cells photovoltaic.

The recent debates over the environment has brought to the fore the need to create plastics that have a lower environmental impact, which is why it was necessary to review all the phase and the production techniques of plastic polymers. Regarding the last stage of the life cycle of a polymeric product, however, they begin to get noticed projects of particular interest, involving the creation of biodegradable polymers, specially designed to degrade when they meet certain environmental situations, the reintegrandosi in natural organic cycles .

 

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Source:
Italian version of CercaGeometra.it

 

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