The world of building materials is complex, especially for architects just starting out in their careers. If you\u2019re trying to get a handle on some new products, you might be running up against some terms and properties that you haven\u2019t dealt with before.<\/p>\n
This list of material properties, building off one compiled by The Constructor<\/a>, is a cheat sheet for many physical concepts that you might not be used to thinking about. As you search for materials on Architizer<\/a>, you may run into these terms when talking to manufacturers, and it\u2019ll make your life a lot easier if you\u2019re comfortable with what they\u2019re talking about. When you hear mentions of \u201ccreep,\u201d \u201cspecific heat\u201d or even \u201chygroscopicity\u201d(!) in relation to building materials, referencing this list will help you make well-informed decisions for your projects.<\/p>\n Mechanical properties describe how a material reacts to an applied force. These properties change depending on temperature, the form a material is taking and how the force is applied. For example, wood has higher impact strength when the impact is applied parallel to the grain. Many of these properties are most significant in structural members.<\/p>\n Strength<\/b><\/p>\n The strength of a material essentially is its ability to not break under stress. Breaking, or \u2018failure,\u2019 can be sudden and catastrophic, like glass shattering, or it can be gradual like a wooden roof beam sagging under snow. Loads may be compressive like the pressure pushing down on a column; they may be tensile like the weight of a hanging lamp on a wire; or they may be bending like the weight of a cantilever on a beam. This might be Structures 101, but a material may be very strong in one aspect and very weak in another. Spider silk has incredible tensile strength but virtually no compressive or bending strength.<\/p>\n Hardness<\/b><\/p>\n Hardness is determined by how easily a material can be scratched. Harder materials will scratch a softer material without being damaged; this is essentially why we can drive hard nails through soft wood but not metal. Hardness can be important in choosing between different varieties of concrete or other aggregates. Hardness is measured according to the Mohs scale.<\/p>\n Mohs scale; image via the National Park Service<\/a><\/i><\/p>\n Elasticity<\/b><\/p>\n Elasticity generally is the ability of a material to regain its shape after a stress has been applied to it, but it\u2019s also a measurement of how much a material will temporarily deform relative to how much stress is applied. Concrete doesn\u2019t change much, and it\u2019s inelastic. Steel, relatively, changes a lot and is more elastic.<\/p>\n Plasticity<\/b><\/p>\n Plasticity is elasticity\u2019s cousin. Whereas elasticity measures how much a material will temporarily deform, plasticity measures how much force it takes to make a material permanently deform without breaking. A plastic material will bend and stay in that shape, whereas an elastic material will bend and go back to its original shape. Again, something to pay attention to in structural members.<\/p>\n Brittleness<\/b><\/p>\n Brittle materials will not bend at all and will just break when a force is applied. Glass is very brittle, and different cladding materials, like ceramic tile or fiber cement, may be brittle. More brittle materials aren\u2019t necessarily worse than less brittle materials as long as the material is strong enough to withstand typical forces.<\/p>\n Bike handlebar fatigue testing, via MaterialsScience2000<\/a><\/i><\/p>\n Fatigue<\/b><\/p>\n Fatigue is the feeling you get while studying for your AREs. Just kidding! Architecture humor \u2026 A material that fails after repeated loads gets fatigue. A column that can withstand 100 earthquakes but will snap on the 101st is showing fatigue.<\/p>\n Impact Strength<\/b><\/p>\n How much a material can withstand an impact. Important for anything that needs to withstand a blast or may have significant environmental threats like broken tree limbs falling.<\/p>\n Abrasion Resistance<\/b><\/p>\n Abrasion is caused by two materials rubbing up against each other. This is important on pavers and anything that will see heavy traffic.<\/p>\n Creep<\/b><\/p>\n Creep is more or less what it sounds like. It\u2019s the slow movement of a material over time. Foundations can creep if they are in an unstable place. TLC can creep<\/a>, given the opportunity.<\/p>\n Bulk Density<\/b><\/p>\n Mass per volume of the material in its natural state including any pores or voids. If you think of terra-cotta brick, which naturally has air pockets, the bulk density tells you how much a stack of bricks will weigh, as opposed to how much a mound of solid terra-cotta with no bubbles would weigh.<\/p>\n Density<\/b><\/p>\n Pure density is a measure of the mass of a solid block of a material as though it included no air pockets. For nonporous materials, the bulk density and pure density are the same.<\/p>\n Specific Gravity<\/b><\/p>\n This is more of a physics term, but if you see it somewhere, it\u2019s a way to measure density. A higher number means a denser material (steel\u2019s specific gravity is 7.82, and aluminum\u2019s is 2.72). It\u2019s technically measured by comparing the density of the substance to the density of water at 4 degrees Celsius.<\/p>\n Porosity<\/b><\/p>\n Porosity is a measurement of the ratio of the volume of the pores to the volume of the solids in a material. A brick with a lot of holes will have a higher porosity, as will coarse sand that doesn\u2019t tightly pack.<\/p>\n Water Absorption<\/b><\/p>\n Water absorption is the ability of a material to absorb and retain water, as opposed to \u2026<\/p>\n Water Permeability<\/b><\/p>\n \u2026 Water permeability, which is the ability for water to pass through a material, which is different than \u2026<\/p>\n Hygroscopicity<\/b><\/p>\n \u2026 Hygroscopicity is the ability of a material to absorb water from the air.<\/p>\n Coefficient of Softening<\/b><\/p>\n Continuing the water theme, the coefficient of softening is \u201cthe ratio of compressive strength of a saturated material to its compressive strength in dry state.\u201d This is particularly important for foundations or any material with a high water-absorption potential.<\/p>\n Fire resistance testing; image via ACImalta<\/a><\/i><\/p>\n Fire Resistance <\/b><\/p>\n In order to be fire-resistant, materials have to be able to keep their strength and shape in flames and also water so they won\u2019t collapse when they get sprayed with a fire hose.<\/p>\n Frost Resistance<\/b><\/p>\n Freezing can tear apart boulders, to say nothing of vulnerable building components. Frost-resistant materials are dry and dense.<\/p>\n Weathering Resistance<\/b><\/p>\n Exterior materials have to be able to resist the corrosive effects of wind, rain and whatever other environmental force may wear at a building\u2019s outside.<\/p>\n Spalling Resistance<\/b><\/p>\n Spalling is, according to The Constructor, \u201cthe ability of a material to undergo a certain number of cycles of sharp temperature variations without failing.\u201d<\/p>\n Refractoriness<\/b><\/p>\n Unlike spalling resistance, which is the ability to withstand repeated temperature fluctuations, refractoriness is the ability to withstand prolonged exposure to temperatures over 1,580 degrees Celsius.<\/p>\n Salt corrosion on aluminum structural elements; image via ATMG<\/a><\/i><\/p>\n Chemical and Corrosion Resistance<\/b><\/p>\n Rust is the most common kind of corrosion, but structures near the ocean are also subject to corrosion from salt spray that can blow relatively far inland.<\/p>\n Specific Heat<\/b><\/p>\n Specific heat is how much energy it takes to raise a specific mass of a substance (1 Newton, if you\u2019re into the physics) 1 degree Celsius. This sounds similar to \u2026<\/p>\n Thermal Capacity<\/b><\/p>\n \u2026 Thermal capacity, which is how much energy it takes to change the temperature of a variable amount of a substance. So, to clarify, all brick has the same specific heat, but 1 ton of brick has a higher thermal capacity than one pound of brick. The thermal capacity of a product is important in determining how much the temperature of a building will fluctuate.<\/p>\n Thermal Conductivity and Resistivity<\/b><\/p>\n These two properties are the opposite of each other. Highly conductive materials have low resistance and vice versa. Conductivity is represented by the letter U and resistance by the letter R. These properties are important for windows, insulation and anything else that could potentially transmit heat between inside and out.<\/p>\n Architects: Want to have your project featured? Showcase your work by uploading projects to Architizer<\/a>\u00a0and sign up for our\u00a0inspirational newsletters<\/a>.<\/em><\/p>\u00a0<\/span><\/p>\n","protected":false},"excerpt":{"rendered":" Don\u2019t know much about building materials? Learn some concepts on this list.<\/p>\n","protected":false},"author":16,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"architizer_featured_type":"projects","architizer_featured_image":"2177647","_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[7,2],"tags":[28701],"architizer_project":[],"architizer_brand":[],"architizer_firm":[],"architizer_product":[],"class_list":["post-13271","post","type-post","status-publish","format-standard","hentry","category-materials","category-practice","tag-young-architect-guide"],"acf":[],"yoast_head":"\nMechanical Properties<\/h2>\n
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Physical Properties<\/h2>\n
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Chemical and Thermal Properties<\/h2>\n
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