Slide 1In This Unit…Slide 3Slide 4Slide 5Slide 6Compressive and tensile stresses in building componentsTensile and compressive stresses in a suspension bridgeSlide 9Modes of transfer of solar heat through a brick cavity wallThermal Resistance (R-value)Thermal ResistanceInsulating MaterialsSlide 14Questions about InsulationInsulation in floor over crawl spaceInsulating materialsSlide 18Unfaced fiberglassFaced fiberglassGranular InsulationBoards: perlite & expanded polystyreneInsulating concrete formworkPlacing insulating concreteSlide 25Lecture 3: Properties of MaterialsKamalesh Panthi, Ph.D.Department of Construction ManagementEast Carolina UniversityCMGT 2210 - Construction & Civil MaterialsIn This Unit…Properties of MaterialsStructural PropertiesThermal PropertiesAir and Water Vapor Flow PropertiesFire Related PropertiesAcoustical PropertiesLoad Resistance – The Structural Properties of MaterialsSmall spans in stonebrittle material, weak in tensionDiscovery of arch made longer spans in stone possibleStresses in a cableCompressive and tensile stresses in building componentsTensile and compressive stresses in a suspension bridgeThermal Properties of MaterialsModes of transfer of solar heat through a brick cavity wallThermal Resistance (R-value)How well a material resists heat flow depends on:Thickness of Material (L)Type of MaterialWhen L increases R increases, i.e., R  LBut R also depends on material type, i.e. their resistivity, Therefore, Thermal Resistance (R)=  LThermal Resistance•A material with a high R-value resists the flow of heat, and is called a thermal insulator.•A material with a low R-value allows heat to flow through it easily, and is called a thermal conductor.Insulating MaterialsCalculating R-Value R = L (thermal resistance X thickness)If the  value of concrete is 0.15, what is the R-value of a 6 inch concrete wall?R = (0.15)(6) = .9 If the  value of fiberglass insulation is 3.5, what is the R-value of 6 inch thick blanket of fiberglass insulation?R = (3.5)(6) = 21Questions about Insulation•Where to insulate?•Building envelope•How much insulation to use?•Varies with•Climate (heating degree days, cooling degree days)•Economics (return on investment)•Energy codeInsulation in floor over crawl spaceInsulating materials Fibrous Granular FoamedFibrous Insulation - thermal resistivity due to air contained between fibers Types Mineral fiber derived from glass (fiberglass) natural rock (rock wool) slag (slag wool) Cellulose derived from recycled newspaper, wood and sugarcane Forms Batts Blankets  Semi-rigid boardsUnfaced fiberglassFaced fiberglassGranular Insulation Expanded perlite (glassy volcanic rock) Expanded vermiculite (mica) Expanded polystyrene (combustible polymer)Boards: perlite & expanded polystyreneInsulating concrete formworkPlacing insulating concreteFoamed insulation: Foamed in