Constituents and Properties of Building Materials with respect to Climate

Building Materials and Sciences AR 103Constituents and Properties of Building Materials with respect to Climate part 2By Anupama Chawla

What are the properties required for Building Materials?For a material to be considered for building purposes, it should have the following properties:Physical PropertiesMechanical PropertiesChemical PropertiesElectrical PropertiesMagnetic PropertiesThermal Properties

Physical PropertiesThese are the properties required to estimate the quality and condition of the material without any external force. Bulk densityPorosityDurabilityDensityDensity indexSpecific gravityFire resistanceFrost resistanceWeathering resistanceSpalling resistenceWater absorptionWater permeabilityHygroscopicityCoefficient of softeningRefractoriness

Physical PropertiesBulk density is the ratio of mass to the volume of the material in its natural state that is including voids and pores. It is expressed in kg/m3. Bulk density influences the mechanical properties of materials like strength, heat and conductivity etc.Porosity gives the volume of the material occupied by pores. It is the ratio of volume of pores to the volume of material. Porosity influences many properties like thermal conductivity, strength, bulk density, durability etc.The property of a material to withstand against the combined action of atmospheric and other factors is known as durability of material. If the material is more durable, it will be useful for longer life.Density is the ratio of mass of the material to its volume in homogeneous state. Almost all the physical properties of materials are influenced by its density values.

Ratio of bulk density of material to its density is termed as density index. Hence it gives the volume of solid matter in the material. In nature, fully dense material is not available so, density index is always less than 1 for any building material.

Physical PropertiesSpecific gravity is the ratio of mass of given substance to the mass of water at 4oC for the equal volumes. Fire Resistance: The ability to withstand against fire without changing its shape and other properties. Fire resistance of a material is tested by the combined actions of water and fire. Fireproof materials should provide more safety in case of fire.

Frost resistance: The ability of a material to resist freezing or thawing is called frost resistance. It is depends upon the density and bulk density of material. Denser materials will have more frost resistance. Moist material have low frost resistance and they lose their strength in freezing and become brittle. Weathering resistance: The property of a material to withstand against all atmospheric actions without losing its strength and shape. Weathering effects the durability of material. For example corrosion occurs in iron due to weathering. To resist this paint layer is provided.The ability of a material to undergo certain number of cycles of sharp temperature variations without failing is known as spalling resistance. It is the dependent of coefficient of linear expansion.

Physical PropertiesThe capacity of a material to absorb and retain water in it is known as water absorption. It is expressed in % of weight of dry material. It depends up on the size, shape and number of pores of material.The ability of a material to permit water through it is called water permeability. Dense materials like glass metals etc. are called impervious materials which cannot allow water through it.

Hygroscopicity is the property of a material to absorb water vapor from the air. It depends on the relative humidity, porosity, air temperature etc.Coefficient of softening of a material is the ration of compressive strength of a saturated material to its compressive strength in dry state. It affects the strength of water absorbent materials like soil.Refractoriness: The property of a material which cannot melts or lose its shape at prolonged high temperatures (1580oC or more).Example: fire clay is high refractory material.

Mechanical PropertiesMechanical properties of the materials are found out by applying external forces on them. These are very important properties which are responsible for behavior of a material in its job. The mechanical properties are:StrengthHardnessElasticityPlasticityBrittlenessFatigueImpact strengthAbrasion resistanceCreep

Mechanical propertiesThe capacity of a material to resist failure caused by loads acting on it is called as strength. The load may be compressive, tensile or bending. It is determined by dividing the ultimate load taken by the material with its cross sectional area.Hardness:The property of a materials to resist scratching by a harder body. MOHS scale is used to determine the hardness of a materials.The capacity of a material to regain its initial shape and size after removal of load is known as elasticity and the material is called as elastic material. Ideally elastic materials obey Hookes law in which stress is directly proportional to strain. Which gives modulus of elasticity as the ratio of unit stress to unit deformation. Higher the value of modulus of elasticity lower the deformations.Plasticity: When the load is applied on the material, if it will undergo permanent deformation without cracking and retain this shape after the removal of load then it is said to be plastic material and this property is called as plasticity. E.g. steelWhen the material is subjected to load, if it fails suddenly without causing any deformation then it is called brittle material and this property is called as brittleness. E.g concrete

Mechanical propertiesIf a material is subjected to repeated loads, then the failure occurs at some point which is lower than the failure point caused by steady loads. This behavior is known as fatigue.If a material is subjected to sudden loads and it will undergo some deformation without causing rupture is known as its impact strength. It designates the toughness of material.The loss of material due to rubbing of particles while working is called abrasion. The abrasion resistance for a material makes it durable and provided long life.Creep the deformation caused by constant loads for long periods. It is time dependent and occurs at very slow rate. It is almost negligible in normal conditions. But at high temperature conditions creep occur rapidly.

Chemical PropertiesThe properties of materials against the chemical actions or chemical combinations are termed as chemical properties. And they areChemical resistance: The ability of a construction materials to resist the effects by chemicals like acids, salts and alkalis is known as chemical resistance. Underground installations, constructions near sea etc. should be built with great chemical resistance.Corrosion resistance: Formation of rust (iron oxide) in metals, when they are subjected to atmosphere is called as corrosion. So, the metals should be corrosive resistant. To increase the corrosion resistance proper measures should be considered. Otherwise it will damage the whole structure.

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Electrical and Magnetic propertiesElectrical Properties of Building MaterialsThe properties of a material to conduct or to resist electricity through them are electrical properties of material. For example, wood have great electric resistance and stainless steel is a good conductor of electricity.Magnetic Properties of Building MaterialsThe magnetic properties of materials like permeability, hysteresis etc. are required in the case of generators etc. iron is magnetic material and aluminum is non-magnetic material.

Thermal PropertiesThermal capacity: Thermal capacity is the property of a material to absorb heat and it is required to design proper ventilation. It influences the thermal stability of walls. It is expressed in J/NoC Thermal conductivity: The amount of heat transferred through unit area of specimen with unit thickness in unit time is termed as thermal conductivity. It is measured in kelvins. It depends on material structure, porosity, density and moisture content. High porous materials, moist materials have more thermal conductivity.Thermal resistivity: It is the ability to resist heat conduction. And it is the reciprocal of thermal conductivity. When it is multiplied by thickness of material it gives thermal resistance. Thermal resistivity of soil varies from 30 to 5000C-cm/W.Specific heat: Specific heat is the quantity of heat required to heat 1 N of material by 1oC. Specific heat is useful when we use the material in high temperature areas

1. Brush/thatchThatching grass is a waxy organic material that is packed to a density of approximately 35 kg/m2 throughout the roof. Thatch is not fire proof, as any other combustible material. However people living in thatch roof homes are more aware of the fire risk. Also, Thatch roofs occasionally do harbour insects. Thatch will last far longer in a climate that is either hot and dry or cool and damp. Should the climate be hot (30 degrees plus) and high humidity, the conditions for fungal growth is good and leads to deterioration of the roof in a far shorter time.

Weathering resistance- NoSpalling resistence - yesWater absorption- YesWater permeability- NoHygroscopicity- yes Insulating- yesBad conductor of heat

Strength- noHardness -noElasticity-noPlasticity-noBrittleness-no Susceptible to birds

Material Used in Tropical and Temperate climates

2. Ice/ SnowAn unusual property of ice frozen at atmospheric pressure is that the solid is approximately 8.3% less dense than liquid water. Thedensityof ice is 0.9167 g/cm3at 0C,whereas water has a density of 0.9998 g/cm at the same temperature. Liquid water is densest, essentially 1.00 g/cm, at 4C. Volume of ice is less than that of water. Hence ice floats on water!

Jukkasjrvi Hotel, SwedenThe village Jukkasjrvi, is famous worldwide for its amazing Ice Hotel, which is constructed entirely from ice and snow since 1990 and situated in harmony with its context. The Ice Hotel represents every year an impressive example ofrevolutionary architecture. What is interesting and really hard to believe is that the hotel is built every year in December and melts in April with about four months life-long only. The ice is used as the main building material, which is brought from the nearby Torne River.

Strength- yesHardness -yesElasticity-noPlasticity-noBrittleness-yes Susceptible to heatDensity=480 kg/m3

Material used in Polar regions

3. MudMud bricks consist of clay, water, and binding material such as rice husks or straw. The advantages of mud brick include its low-cost and great thermal behavior.Disadvantages include: mud brick may tend to erode under rain impact; absorption of water causes swelling of mud brick, while evaporation of water from the mud brick gives rise to shrinkage and cracking; and mud brick is a relatively fragile material, which cannot resist earthquake hazardsDensity=1520 kg/m3 (packed earth)Weathering resistance- NoSpalling resistence - yesWater absorption- YesWater permeability-yesHygroscopicity- yes Insulating- yesBad conductor of heat- yesStrength- yesHardness -yesElasticity-noPlasticity-noBrittleness-yes

Wattle and daub

COB construction

Rammed earth

Adobe BlocksSusceptible to TermitesMaterial Used in Hot and Humid Climates

4. Stone/ RockRock (mineral), naturally occurring solid material consisting of one or more minerals. Minerals are solid, naturally occurring chemical elements or compounds that are homogenous, meaning they have a definite chemical composition and a very regular arrangement of atoms. Rocks are everywhere, in the ground, forming mountains, and at the bottom of the oceans. Earths outer layer, or crust, is made mostly of rock. Some common rocks include granite and basalt.

MaterialDensity (kg/m3)Steel7800 7900Brick2500 -2800Granite2600 2900

Weathering resistance- yesSpalling resistence - yesWater absorption- YesWater permeability- NoHygroscopicity- no Insulating- yesBad conductor of heat- yesStrength- yesHardness -yesElasticity-noPlasticity-noBrittleness-yes

Material can be used in any climatic zone

5. Wood/ TimberWood is the oldest material used by humans for construction after stone. Despite its complex chemical nature, wood has excellent properties which lend themselves to human use.Following are its properties:Specific gravity= 0.3 to 0.9Exceptionally strong relative to its weightA good heat and electrical insulator;of increasing importanceIt is a renewable and biodegradable resourceDensity=0.16 (Balsa) to 0.9 (teak) kg/m3 Swelling and shrinking takes placeSusceptible to Moisture, fungi, Insects, Ants

Weathering resistance- NoSpalling resistence - yesWater absorption- YesWater permeability- YesHygroscopicity- yes Insulating- yesBad conductor of heat- yesNot fire resistantStrength- yesHardness -yesElasticity-noPlasticity-noBrittleness-yesTensile strength of wood with 0,6/cm3 specific gravity is 100 N/mm2

Material can be used in Hot/Cold and Dry regions

Metropol Parasol Spain, Architect Jrgen MayerWood used-birch

6 . SandSand is loose particles of hard broken rock, it comprises of grains from disintegrated rock. The diameter of grains ranges between 0.06 and 2.0mm in size and varies in shades of brown and orange in colour. Most sand is made of quartz, which is largely silicon oxide. Following are its types:Pit/Coarse sand (badarpur)River sandCrushed stone sandDensity=1600 kg/m3

Weathering resistance- NoSpalling resistence - yesWater absorption- noWater permeability- YesHygroscopicity- no Insulating- yesBad conductor of heat- noNot used by itselfStrength- noHardness -noElasticity-yesPlasticity-yesBrittleness-no

7. BrickBricks are usually laid flat and are usually bonded forming a structure to increase its stability and strength.There are several types of bricks used many of them being about eight inches long and four inches thick.Common Burnt Clay BricksSand Lime Bricks (Calcium Silicate Bricks)Engineering BricksConcreteBricksFly ash Clay BricksDensity=1920 kg/m3

Weathering resistance- YesSpalling resistence - yesWater absorption- yesWater permeability- YesHygroscopicity- yes Insulating- yesBad conductor of heat- yesWeak in tensionHigh compressive strengthStrength- yesHardness -yesElasticity-noPlasticity-noBrittleness-noDurability-yes

Compressive /Crushing strength of bricks (Indian Made) are very variable, and may vary from 30 kg/sq.cm to 150 kg/sq. cm for hand-made burnt bricks, while Crushing strength of heavy duty bricks machine pressed (also called engineering bricks) may have compressive strength as high as450kg/sq. cm, and even 500 kg/sq. cm. The minimum crushing / compressive strengths of burnt bricks tested flat-wise prescribed are:(i)Common building bricks35 kg/sq. cm,(ii)Second class bricks70 kg/sq. cm,(iii) First class bricks 105 kg/sq. cm.(iv)Crushing strength of bricks not less than 140 kg/sq. cm are graded as AA class.Material Used in Temperate, Hot and Dry regions

8. CementCement is a fine, gray powder that is used as a construction binding material.When mixed with water, cement reacts chemically and becomes hard and strong. Cement is categorized as either hydraulic or nonhydraulic, depending on how it mixes with water..Cement is made by combining silicon, aluminum, iron, calcium and other chemicals in a controlled mixture. Other materials added to the mixture include chalk, clay, slate and limestone. When combined, the ingredients form a hard substance that is ground into cement. Density=1506 kg/m3

Weathering resistance- NoSpalling resistence - yesWater absorption- yesWater permeability- noHygroscopicity- yes Insulating- yesBad conductor of heat- yesHigh compressive strengthStrength- yesHardness -yesElasticity-noPlasticity-noBrittleness-noDurability-yes

9. ConcreteConcreteis acompositebuilding material made from the combination ofaggregateand a binder such ascement. The most common form of concrete is Portland cement concrete, which consists of mineral aggregate (generallygravelandsand),portland cementandwater.After mixing, the cementhydratesand eventually hardens into a stone-like material. When used in the generic sense, this is the material referred to by the term "concrete".Density=2370 kg/m3Corrosion resistantBinds rapidly with steel, weak in tensionTendency to shrink due to loss of waterIts formed on site and its qualities depend on the people handling it

Weathering resistance- NoSpalling resistence - yesWater absorption- yesWater permeability- yesHygroscopicity- yes Insulating- yesBad conductor of heat- yesHigh compressive strengthStrength- yesHardness -yesElasticity-noPlasticity-yesBrittleness-yesDurability-yes

Oscar Niemeyer, Brasilia Cathedral

10. MetalThink of the greatest structures of the 19th centurythe Eiffel Tower, the Capitol, the Statue of Libertyand you'll be thinking ofiron.Combined with varying (but tiny) amounts of carbon, iron makes a much stronger material calledsteel, used in a huge range of human-made objects, from cutlery towarships, skyscrapers, and space rockets.Density=7208 kg/m3Malleable into shapesConducts electricity and heatTendency to react with moisture in air causing rustStainless steel is an alloy of iron, nickel and chromium

Weathering resistance- yesSpalling resistence - noWater absorption- noWater permeability- noHygroscopicity- no Insulating- noBad conductor of heat- noHigh compressive strengthStrength- yesHardness -yesElasticity-noPlasticity-yesBrittleness-noDurability-yesStructural steel members, such asI-beams, have highsecond moments of area, which allow them to be very stiff in respect to their cross-sectional area.

11. PlasticsPlasticis the generic name for a family of synthetic materials derived frompetrochemicals. It is often product of two or more components.There are many families of plastics and polymers being used in construction industry. Examples of plastics used in building are:AcrylicCompositesExpanded PolystyrenePolycarbonatePolyethylenePolypropylenePolyvinyl ChlorideDensity of poly urethane=24-29 kg/m3Malleable into shapesDo not rot or corrodeConducts electricity and heatLightweight and easy to installLow conductor of heat and bad conductor of electricity

Weathering resistance- yesSpalling resistence - noWater absorption- noWater permeability- noHygroscopicity- no Insulating- yesBad conductor of heat- no

Strength- yesHardness -yesElasticity-yesPlasticity-noBrittleness-yesDurability-yes

12. PaperPaperis a thin material produced by pressing together moistfibresofcellulosepulp derived fromwood,ragsorgrasses, and drying them into flexible sheets. It is a versatile material with many uses, includingwriting,printing, packaging,cleaning, and a number of industrial and construction processes. Shigeru Ban collaborated with German architect/engineer Frei Otto (another one of Ban's main influences) on an even more daring and highly visible long-span structure for theJapan Pavilion Expo 2000 Hannover. Addressing the Expo theme "Man, Nature, Technology" by using materials that could be easily reused or recycled after the five-month exhibition period, Ban and Otto developed a lattice-like structure of paper tubes more than 35 meters long that were erected in the horizontal position and then jacked up into the resulting billowy form. A secondary wood-arch structure above the tubes held the roof membrane and provided secondary support for the tubes.Density =250-1500 kg/m3

Weathering resistance- noSpalling resistence - noWater absorption- yes Water permeability- yesHygroscopicity- yes Insulating- noBad conductor of heat- yes

Strength- yesHardness -yesElasticity-noPlasticity-yesBrittleness-noJapan Pavilion Expo 2000 Hannover, Shigeru Ban

13.FoamSheet foam is found in many different varieties, and each has different properties that will make one more appropriate than another in a certain situation. In construction, sheet foam is widely used as a convenient and effective form of insulation. LAST-A-FOAMR-9300 CONSTRUCTION FOAM BLOCK INSULATIONThe R-9300 Structural Continuous Insulation Series is a high-density rigid cellular polyurethane block designed to support structural loads while insulating buildings. Cellular polyurethane is a natural insulator, and formulated in these high-density blocks, it provides the strength to support large compressive loads with little deflection. At the same time, it offers economical, code-required continuous insulation that reduces loads on cooling equipment for lower energy costs.Density = 300-640 kg/m3

Weathering resistance- yesSpalling resistence - yesWater absorption- noWater permeability- noHygroscopicity- no Insulating- yesBad conductor of heat- yes High compressive strength

Strength- noHardness -noElasticity-yesPlasticity-yesBrittleness-yes

Foam sheetsFoam blocks

14.Ceramic TileAtileis a manufactured piece of hard-wearing material such asceramic,stone, metal, or evenglass, generally used for covering roofs, floors, walls, showers, or other objects such as tabletops.. Resistance to Abrasion:It specifies the resistance of the tile to mechanical damage resulting from the impact of the abrasive factor. Grade 0 to grade 5.Freeze Resistance: the ceramic tiles, which are to be laid out at places exposed to the impact of negative temperatures, should have the declared freeze-resistanceThermal shock , Chemical resistance and Stain resistant tiles Density = 2790-3000 kg/m3

Weathering resistance- yesSpalling resistence - yesWater absorption- noWater permeability- noHygroscopicity- no Insulating- yesBad conductor of heat- yes High compressive strength

Strength- yesHardness -yesElasticity-noPlasticity-noBrittleness-yes

Faade-Dome of the Rock, Jerusalem

15. FabricFabric structuresare tensilestructuresin which a membrane is 'stretched' to form a three-dimensional surface that can be used to create aroof, shading, or decorative component. Sometimes described as 'modern tents',fabric structuresuse very little material compared to other forms of construction, and are typically translucent, but they provide littlethermal massor insulationand can have a shorter lifespan than some othermaterials.Unlike conventionalroofingsystems,fabric structurescan cover very large areas with no supportingcolumns. This makes them particularly suitable for buildings such as sports faculties, auditoriums, shopping centres, transport interchanges and so on.The concept was implemented on a large scale byDavid H. Geigerwith the United States pavilion atExpo '70inOsaka, Japanin 1970 . It is usuallydome-shaped, since this shape creates the greatestvolumefor the least amount of material. To maintain structural integrity, the structure must be pressurized such that the internalpressureequals or exceeds any external pressure being applied to the structure (i.e.windpressure). The structure does not have to be airtight to retain structural integrityas long as the pressurization system that supplies internal pressure replaces any air leakage, the structure will remain stable.Density= 2.6-6 g/cm3

Weathering resistance- yesSpalling resistence - yesWater absorption- yesWater permeability- yesHygroscopicity- yes Insulating- yesBad conductor of heat- yes

Strength- noHardness -noElasticity-yesPlasticity-noBrittleness-no

United States pavilion - Osaka, Japan, Expo 70

16. GlassArchitectural glassis glass that is used as abuilding material. It is most typically used as transparentglazingmaterial in the building envelope, including windows in the external walls.Glassis also used for internal partitions and as an architectural feature. When used in buildings, glass is often of asafety type, which include reinforced, toughened and laminated glasses.Glass block, also known as glass brick, is an architectural element made fromglassused in areas where privacy or visual obscuration is desired while admitting light, such as underground parking garages, washrooms, and municipal swimming baths. Density= 2580 kg/m3

Weathering resistance- yesSpalling resistence - yesWater absorption- noWater permeability- noHygroscopicity- no Insulating- yesBad conductor of heat- yes Fire retardant- yesTransparent

Strength- noHardness -yesElasticity-noPlasticity-yesBrittleness-yes

17. GypcreteGypsum is a white to gray mineral found in the earths crust. It is chemically known as hydrous calcium sulfate (CaSO4.2H2O) which are obtained through mining from vast veins.Gypsum concreteis abuilding materialused as a floorunderlaymentused inwood-frameandconcreteconstruction forfire ratings, sound reduction,radiant heating, and floor leveling. It is a mixture ofgypsumplaster,Portland cement, andsand. The brand nameGyp-Crete, a Maxxon Corporation trademark, has come into general use as a term for gypsum concrete by construction professionals and architects.Rapidwall, using a mixture of gypsum plaster and 300mm plus fibreglass rovings, is used to make partition walls. Density= 1762 kg/m3

Weathering resistance- yesSpalling resistence - yesWater absorption- noWater permeability- noHygroscopicity- no Insulating- yesBad conductor of heat- yes Fire retardant- yesThermal insulation- yes Acoustic insulation- yes

Strength- yesHardness -yesElasticity-noPlasticity-yesBrittleness-yes

ThatchIceMudStoneWoodSandBrickCementConcreteMetal PlasticsPaperFoamCeramicsFabricGlassGypcreteeStrengthHardness ElasticityPlasticityBrittlenessWeather resistenceSpalling resistenceWater absorptionWater permeabilityHeat insulationFire retardentR value (m2K/W)0.260.180.70.0070.110.160.30.60.1170.0050.070.016.30.010.070.025Thermal conductivity (k) W/m deg K0.072.20.83.50.1720.70.91.28520.170.050.0351.20.040.80.68Acoustic

Bibliographyhttp://ebooks.narotama.ac.id/files/Building%20Materials%20in%20Civil%20Engineering/Chapter%202%20The%20Basic%20Properties%20of%20Building%20Materials.pdfhttps://www.slideshare.net/mohammadnaserrozy/physical-properties-of-building-materialshttp://www.nios.ac.in/media/documents/313courseE/L36A.pdfhttps://theconstructor.org/building/properties-of-building-materials.../14891/http://www.archinomy.com/case-studies/712/mud-architecture-construction-details-and-techhttps://www.designingbuildings.co.uk/wiki/Fabric_structures Sruthi G S; Mud Architecture; Research article published in International Journal of innovative research in Science, Engineering and Technology, Dec 2013