Construction Materials & Testing CE 122 PDF

CONSTRUCTION MATERIALS & TESTING CE 122 ENGR. MANUEL A. RANGEL JR. Faculty INTRODUCTION WOODGROVE Engr. Manuel A. Rangel BANK 2 FACTORS TO CONSIDER IN SELECTING CONSTRUCTION MATERIALS A....

CONSTRUCTION MATERIALS & TESTING CE 122 ENGR. MANUEL A. RANGEL JR. Faculty INTRODUCTION WOODGROVE Engr. Manuel A. Rangel BANK 2 FACTORS TO CONSIDER IN SELECTING CONSTRUCTION MATERIALS A. Economic Factors – affecting the material selection process are not limited to the cost of the material. Factors that need to be considered include: a. Availability and cost of raw materials b. Manufacturing cost c. Transportation d. Placing/ installation e. Maintenance WOODGROVE BANK FACTORS TO CONSIDER IN SELECTING CONSTRUCTION MATERIALS B. Mechanical Properties – describes the response of the material to the external load. It is important to take into consideration: a. Loading conditions Static Dynamic b. Stress-strain relations c. Elastic behavior d. Elastoplastic behavior e. Viscoelastic behavior d. Temperature and time effects e. Failure and safety WOODGROVE BANK FACTORS TO CONSIDER IN SELECTING CONSTRUCTION MATERIALS C. Physical Properties – are characteristics of a material that is taken into consideration for its intended use. There are several physical properties of a material, but those of greatest concern to a materials engineer include: a. Density and unit weight b. Thermal expansion c. Surface characteristics WOODGROVE BANK FACTORS TO CONSIDER IN SELECTING CONSTRUCTION MATERIALS D. Production / Construction Considerations Production considerations include the availability of the material and the ability to fabricate the material into desired shapes and required specifications. Construction considerations address all factors related to the ability to fabricate and erect the structure on site. WOODGROVE BANK FACTORS TO CONSIDER IN SELECTING CONSTRUCTION MATERIALS E. Aesthetic Characteristics – refer to the appearance of the material WOODGROVE BANK PROPERTIES OF CONSTRUCTION MATERIALS WOODGROVE Engr. Manuel A. Rangel BANK 8 PHYSICAL PROPERTIES Physical properties are characteristics of a material that can be observed or measured without changing the composition of the substance. WOODGROVE BANK PHYSICAL PROPERTIES A. DENSITY(ρ) – the mass of a unit volume of homogeneous material denoted by where M = mass (g, kg, lbs) V = volume (cu.cm, cu.m, cu.ft, cu.in) WOODGROVE BANK PHYSICAL PROPERTIES Density of some building materials WOODGROVE BANK PHYSICAL PROPERTIES Types of density: 1. Bulk density, ρb – is the ratio of material mass to the total volume of material including spaces. WOODGROVE BANK PHYSICAL PROPERTIES Bulk density of some materials WOODGROVE BANK PHYSICAL PROPERTIES Types of density: 2. solid density, ρs – is the ratio of the mass of solid material to the volume of solid material without any space WOODGROVE BANK PHYSICAL PROPERTIES Relative density, d – is the ratio of the density of the material with pure water at 4°C Density index, (ρo) is the ratio of bulk density to density. Indicates the degree to which the volume of a material is filled with solid matter. ρo for all building materials is less than 1.0 WOODGROVE BANK PHYSICAL PROPERTIES B. Specific weight (γ) – or unit weight is the weight per unit volume. Used to determine the weight of a structure designed to carry certain loads while remaining intact and remaining within limits regarding deformation. WOODGROVE BANK PHYSICAL PROPERTIES C. Specific gravity, (Gs) of solid particles of a material is the ratio of weight/mass of a given volume to the weight/mass of an equal volume of water at 4°C. WOODGROVE BANK PHYSICAL PROPERTIES True or Absolute specific gravity (Ga) – specific gravity obtained if both the permeable and impermeable voids are excluded for determining the true volume of solids. Apparent or mass specific gravity (Gm) – ratio of mass density of fine grained material to the mass density of water. If both the permeable and impermeable voids are included to determine the true volume of solids, the specific gravity is called apparent specific gravity. WOODGROVE BANK PHYSICAL PROPERTIES D. Porosity, (n) the degree to which the volume of the material is interspersed with pores and expressed as a ratio of the volume of the spaces in the material to the overall volume. WOODGROVE BANK PHYSICAL PROPERTIES E. Voids ratio, (e) ratio of volume of voids to the volume of solids WOODGROVE BANK PHYSICAL PROPERTIES F. Water absorption, w.a. – ability of the material to absorb and retain water. Expressed as percentage in weight or of volume of dry material or by water- absorption ratio. a. Specific absorption of quality refers to the percentage of the absorbed water to the dry mass when the material absorbs water to saturation when s = 1 WOODGROVE BANK PHYSICAL PROPERTIES F. Water absorption, w b. Specific absorption of volume refers to the percentage of the absorbed water’s volume to the material’s natural volume when the material absorbs water to saturation WOODGROVE BANK PHYSICAL PROPERTIES G. Weathering Resistance, ability of a material to endure alternate wet & dry conditions for a long period without considerable deformation and loss of mechanical strength WOODGROVE BANK PHYSICAL PROPERTIES H. Water permeability, – capacity of a material to allow water to penetrate under pressure. Materials like glass, steel and bitumen are impervious. WOODGROVE BANK PHYSICAL PROPERTIES I. Hygroscopicity – property of material to absorb water vapour from air. It depends on the relative humidity, porosity, air temperature etc. J. Fire resistance – the ability of a material to resist the action of high temperature without any appreciable deformation and substantial loss of strength. K. Refractoriness – the ability of a material to withstand prolonged action of high temperature without melting or losing shape. L. Chemical resistance – the ability of a material to withstand the action of acids, alkalis, sea water & gases. M. Durability – ability of material to resist the combined effects of atmospheric and WOODGROVE other factors. BANK MECHANICAL PROPERTIES Mechanical properties describe a material’s behavior under loads or forces, such as tension, compression, bending, and torsion. These properties describe how a material responds to mechanical stress and provide important information about its strength, hardness, ductility, and toughness WOODGROVE BANK MECHANICAL PROPERTIES A. Strength – the greatest stress that a substance can bear under external forces (loads) without destruction. It is the ability to resist failure under the action of stresses caused by loads: compression, tension, bending, shear, impact etc. WOODGROVE BANK MECHANICAL PROPERTIES B. Elasticity – the property of a substance to deform with external forces and return to its original shape when the stress is removed. WOODGROVE BANK MECHANICAL PROPERTIES C. Plasticity – describes the deformation of a material undergoing nonreversible changes of shape in response to external forces WOODGROVE BANK MECHANICAL PROPERTIES D. Brittleness – describes the property of a material that fractures when subjected to stress but has a little tendency to deform before rupture. Generally, the brittle metals have high compressive strength but low in tensile strength. WOODGROVE BANK MECHANICAL PROPERTIES E. Toughness – impacted or vibrated by stress, material is able to absorb much energy and deform greatly without rupture, which is known as toughness, also called impact toughness Opposite condition of brittleness WOODGROVE BANK MECHANICAL PROPERTIES F. Hardness – refers to the property of a material to resist pressing-in or scratch of a sharp object. Hardness indicates the degree of hardness of a material that can be imparted particularly steel by the process of hardening. WOODGROVE BANK THANK YOU