8.2s KNOW CONSTRUCTION MATERIALS & THEIR PROPERTIES Flashcards
S1 - EFFECTIVE STRUCTURAL BUILDING MATERIALS COMPRISE OF
- Stiffness w Elasticity
* Resist Dimensional Instability due to Humidity & Temp.
S2 - QUALITIES OF WOOD AS A STRUCTURAL MATERIAL
• SMALL • RENEWABLE • FLEXIBLE
• LIGHT • EXPOSED TIMBER
* GOOD IN COMPRESSION & TENSION
S3 - QUALITIES OF CONCRETE AS A STRUCTURAL MATERIAL
• FREEDOM OF FORM • NATURALLY FIRE PROTECTED
• EXPOSED STRUCTURE • INEXPENSIVE
* GOOD IN COMPRESSION - MUST BE PAIRED WITH STEEL REINFORCING FOR TENSION
S4 - QUALITIES OF STEEL AS A STRUCTURAL MATERIAL
- REPETITIOUS MODULAR • LONG SPANS
* LIGHT • STIFF & ELASTIC
S5 - WHAT IS CONCRETE MIX COMPRISED OF?
+ CEMENT (PORTLAND)
+ WATER
+AGGREGATE
S6 - WHAT KIND OF CEMENT IS PORTLAND CEMENT AND HOW IS IT MADE
• HYDRAULIC CEMENT
1 - BURN CLAY & LIMESTONE IN A KILN
2 - PULVERIZE INTO FINE POWDER
S7 - 5 TYPES OF CONCRETE
TYPE I - NORMAL TYPE II - MODERATE PORT. CEMENT TYPE III - CURES FASTER (COLD WEATHER) TYPE IV - LOW HEAT TYPE V - SULFATE RESISTANCE (salty acidic soil)
S9 - CONCRETE MIX CONTAINS __-__% AGGREGATE.
60-80%
THIS IS KEY TO •FR •STRENGTH •WEIGHT
S10 - SIZE OF FINE & COARSE AGGREGATE. WHAT IS APPROPRIATE DEPTH & THICKNESS FOR SLAB & WALLS RESPECTIVELY?
FINE: sand < 6mm COARSE: (Abram's Law) must be <1/3 slab depth must be <1/2 wall thickness
S11 - RELATIONSHIP OF WATER-CEMENT RATIO TO STRENGTH + IDEAL RANGE:
- Compressive strength inversely proportional to ratio of water to cement.
- IDEAL RANGE .45-.60
S12 - LIGHTWEIGHT CONCRETE MADE WITH _______ OR ___________.
EXPANDED SHALE OR SLATE AGGREGATE
S13 - INSULATING CONCRETE MADE WITH _________
PERLITE AGGREGATE OR FOAM AGENT.
S14 - Describe the advantages of WOOD as a structural material. (6)
\+ strong \+ durable \+ light \+ rigid & flexible \+ easy to work w \+ renewable
S15 - What are the 2 major classes of wood?
*do NOT describe hardness 1 - SOFTWOOD = used for construction • predominantly evergreen • pine/fir 2 - HARDWOOD = used for finishing • predom. broad leaf flowering trees • Cherry/Oak/Maple
S16 Wood is great in tension and compression, but the grain should be considered. Describe the strength of wood cut:
1 - Parallel to the grain
2 - Perpendicular to the grain
1 - Parallel = BEST for tension and compression
(1/3 stronger in compression)
2 - Perp = best for shear strength
(allowable force = 1/5-1/2 that of parallel)