Batter Boards, Concrete, & Masonry Flashcards
Calculating a Diagonal
3,4,5 or a2 + b2=c2 (pythag)
Calculating decimals into inches
multiply first by 12 (fractions of a ft) and take whole number as your inches, then multiply remaining decimals by 16 (fractions of an inch) to get your fractions of an inch
Batter Board considerations
- Building site
- fundation
- substructure
- superstructure
Building Site considerations
- Drainage
- Slope
- Soil Stabilization
- Tactical emplacement
- CDRs desire
Batter Boards
Temporary framework used to assist in locating corners when laying out a foundation
Batter Board Steps
- temporary markers
- batter boards
- level
- string line
- adj. string line
- adj. markers (Plumb bob)
Squaring Methods
- 3,4,5
- Carpenters Square
- Diagonal method (most accurate)
Concrete Composition
-Mixture of aggregates, sand, portland cement, water and often controlled amounts of entrained air and held together by a hardened state.
-hydration causes concrete to harden
desired temp of concrete is 73 degrees
Aggregates and sand need to be…
clean, durable, free of chemicals and free of any coating
Max size of coarse aggregate
should not exceed 1/5 of the diameter of a wall or structure
- should not exceed 1/3 slab thickness
- should not exceed 3/4 of the clear space between reinforcing bars
Types of Portland Cement
1- normal or portland - takes 28 days to cure 2- modified - takes 45 days to cure 3- high early - takes 7 days to cure 4- low heat - takes 90 days to cure 5- sulfate resistant- 60 days to cure
Calcium Chloride
Accelerates the curing process, adds strength gain by 2%
Shipping
1 bag = 94 lbs = 1 ft3 of loose measurement
1 barrel = 376 lbs = 4 bags
“Warehouse pack”
sacked cement in storage packed too tightly store off ground and cover to prevent
Types of Concrete
Reinforced
Prestressed
Precast
Light weight
Desirable properties of quality concrete
Plastic state
- readily moldable
- changes shape slowly
- workable
- uniform
Construction Joints
Expands and contracts w/ moisture and temp changes
Control Joints
Cuts made to control where the concrete cracks when curing
Expansion joint
Pre formed, pre molded elastic resilient material, oil filled, approx 1/4” to 1/2” thick as wide as concrete is thick
Slump test
pour concrete into cone, remove cone, measure drop
-to figure out how much water is in a concrete mix
Hand mixing sequence
1 part portland cement
2 parts sand
3 parts gravel
3/2s rule (Estimating Material)
PV = Volume x # of structures LF = PV x 1.05 or 1.10 depending of PV LV = LFx 1.5 Bags = 1/6 x LV Ft3 Sand = 2/6 x LV Ft3 Gravel = 3/6 x LV #of bags x 8 = gals of water
Forms
Hold concrete until it sets
Elements of Wooden Forms (WALLS)
- sheathing
- studs
- wales
- strong backs
- braces
- shoe plates
- spreaders
- tie wires
Elements of Wooden Forms (column)
- sheathing
- batten
- yokes
- bracing
Masonry definition
To build a structure from any building materials that consist of units held together with mortar
Concrete Block
- 35-45 lbs
- nominal dimensions 8”x8”x16”
- actual dimensions 7.5/8”x7.5/8”x15.5/8”
- allows for 3/8” mortar joint
Cinder Block
25-35 lbs
non load bearing
Factors affecting Bond strength:
- Type of mortar, M,S,N,O
- quality
- workability or plasticity
- water retention
- surface texture of the mortar bed
- quality of workmanship
Desirable Properties of mortar
- plasticity
- water retentivity
- strength and durability
Mortar is produced in two methods
- Portland cement
- Masonry cement
- main difference Portland cement does not contain masonry lime.
Types of Sand
- Manufactured
- Natural
- Sand must be in a damp and loose condition
Control joints (masonry)
- breaks masonry work into panels
- used to prevent extensive cracking
- rule of thumb = no greater than 25’ no thicker than 1/2”
Wall Intersections
Do not intersect, join w/ control joint
Estimate Masonry Material
- Linear feet x Height x #of structure x 1.125 = # of block
- # of block/100 x 3 = bags of masonry cement
- # of bags/ 8 = tons of sand
- # of bags x 8 = gals of water
