building construction Flashcards
Bogue’s compound
C3S, C2S, C3A, C4AF
cement basic compounds
lime (Cao) : 60-67% silica(SiO2): 17-25% Alumina(Al2O3): 3-8% Iron oxide)(Fe2O3):0.5 -6% Magnesia(MgO) : 0.1- 4% Sulphur Trioxide(SO3): 1-3% Soda and potash (Na2O +K2O) : 0.5 -1.3%
water permissible impurities for concreting
organic-200mg/l inorganic - 3000 sulphates(So3) - 400 chlorides -2000 for plane - 500 for RCC suspended matter- 2000 PH - 4.5 to 8.5 values from IS 3025
consistency of cement
measuring instrument and consistency limits
Vicats apparatus
300g plunger ,50 mm length, 10 mm dia
mould h=40, D=80
plunger should penetrate 30-35 mm deep
initial setting time for OPC and low heat
and test setup
30 min - OPC
60 min - low heat
water =0.85p
1mm square needle 33~35mm penetration
final setting time
and test setup
needle cant leave a mark on solid surface
time > 10 hrs
soundness of cement tested by
Le Chateier’s method
autoclave test
both are good for lime soundness
compressive stregth test of cement grade
33 grade cement
16 mpa -3 days
22 mpa- 7 days
33 mpa- 28 days
tensile strenght limit of OPC
2 Mpa -3 day
2.5 Mpa -7 Days
Sieve test of cement
90 micron sieve residue
OPC -10% residue
Rapid- 5%
PPC - 5%
heat of hydration for low heat portland cement
7 days -66 cal/g
28 days - 75 cal/g
what is shallow foundation
Depth less then width
what are compaction piles
piles driven in granular soil to increase bearing capacity of that soil
Timber piles
D = 300-500 mm
L < 20.D
P < 200 Kn
c-c spacing ~ 900 mm
screw piles
D = 150~300 mm
for soft clay and loose sand
disc piles
disc connected to base of hollow cast iron pipe
D.disk = 0.6 ~ 1.2 m
caissons
water tight structure for excavation and construction of foundation
Box , open, Pneumatic caisson
what are shoring structures
temporary structures required to support unsafe structure
underpinning of structure
supports provided underneath the existing structure without disturbing its stability
sill member in building
to support window or door
LINTEL
what is jamb and reveal
vertical member in side of a door
width 76~114 mm
reveal- outer part of the jamb vivible in door or window openings
or exposed vertical surface left on the sides of opening after door or window frames has fitted in position
cornice of building
horizontal moulding projection (usually made by POP)
blocking course and Frieze in building
- a course of stone provided immediately above the cornice
- a course of stone provided immediately below the cornice
stone masonry and its types
https: //civilseek.com/stone-masonry/
https: //www.aboutcivil.org/Stone-Mortars.html
http: //constructionanddesign.blogspot.com/2017/01/stone-masonry-and-types.html