Division 3: Concrete Flashcards
One of the oldest manufactured building materials used as a mortar and plaster by early civilizations
Lime
The process of mixing quicklime with water is absorbed and heat is energetically evolved
Slaking or hydration
This may be used one half hour after being made into a putty
Special finishing hydrated lime
A type of lime which will set under water is
Hydraulic lime
The densest and hardest gypsum that can be applied with a trowel
Keene’s cement
Made by mixing slaked lime with pozzolana which hardened under the water
Cement
Who rediscovered hydraulic cement?
Smeaton, 1756
Who invented and patented portland cement
Aspdin
Obtained by finely pulverizing clinker produced by calcining to incipient fusion an intimate and proportioned mixture of argillaceous and calcareous materials
Portland cement
Components of portland cement
Tricalcium silicate 1/2 volume
Dicalcium silicate 1/4
Tricalcium aluminate 1/10 volume
Yeha
Each bag of portland cement holds
1 cu. ft weighs 94 lbs
Type of portland cement used when early removal of formwork is desired or in cold-weather construction
High early strength
Type of portland cement used in construction of massive concrete structures
Low heat: sulfate resisting
Quick setting cement
Alumina cement
Prepared mixtures of portland cement
Masonry cements
Cements made of natural raw materials
Natural cements
Type of cement made of lime mortar and pozzolanic material
Pozzolanic cement
Type of cement made of lime mortar and pozzolanic material
Pozzolanic cement
Storage of cement should be stored in shed with a wood floor raised about __ from the ground
12”
Piles should be limited to ___ sacks in height
12
The proportioned mixture of cement m, aggregate and water, which when properly proportioned is at first a plastic mass which can be cast or molded into predetermined size or shape
Concrete
Good quality concrete is obtained through
Careful selection of mayerial Correct proportioning Thorough mixing Careful transporting and placing Proper curing or protection of the concrete
measuring the consistency of a concrete mix
Slump test
The amount of water used per bag of cement
Water-cement ratio
Size of slump test metal cone
Bottom-8”
Top-4”
Height-12”
Consistency slump of reinforced foundation, walls and footings
Max and min
125mm(5”)
50mm(2”)
Consistency slump of plain footings, caissons and substructure walls
Max and min
100mm(4”)
25mm(1”)
Consistency slump of slabs, beams, thin reinforced walls & bldg columns
Max and min
150mm(6”)
75mm(3”)
The most widely used test for concrete compressive test
Compressive test
To test existing concrete structures by drawing out a core cylinder
Concrete Core test
The strength of a workable concrete mix depends upon the _______
Water-cement ratio
Economy of the mix depends upon the proper proportioning of
Fine and course aggregates
Methods of proportioning concrete includes:
Proportioning by arbitrary proportions.
By water-ratio and slump test.
By water-ratio, slump and fineness modulus.
Class AA
1:1.5:3
For concrete under water;retaining walls
Class A
1:2:4
For slabs, beams, columns, arches walls of 4” thk
Class B
1:2.5:5
Walls thicker than 4”, footings, steps, reinforced concrete slabs on fill
Class C
1:3:6
For plant boxes and non critical structures