PRE-STRESSED CONCRETE POST-TENSIONING MAIN COMPONENTS

- FORM OF CONCRETE WHERE INITIAL

COMPRESSION IS GIVEN IN THE
CONCRETE BEFORE APPLYING THE
EXTERNAL LOAD SO THAT STRESS
FROM EXTERNAL LOADS IS
COUNTERACTED IN THE DESIRED ANCHOR
WAY DURING THE SERVICE PERIOD. - HOLDS THE TENSIONED CABLE.
- INITIAL COMPRESSION IS o VARYING AT TWO ENDS.
INTRODUCED BY HIGH-STRENGTH
STEEL WIRE OR ALLOWS OR CALLED
TENDONS LOCATED IN THE
CONCRETE SECTION.
- SMALL SECTIONS ARE TO BE
CONSTRUCTED.
DUCTS

- DIFFERENT TYPES OF DUCTS:

STEEL USED IN PRESTRESSED CONCRETE o TYPE OF MATERIAL USED FOR
- STEEL USED FOR PRESTRESSING CONSTRUCTION
MAY BE IN THE FORM OF WIRE OR ▪ STEEL
TENDONDS THAT CAN BE GROUPED ▪ CORRUGATED PIPES
TO FORM CABLES. - THE TENDONDS ARE RUNS IN THESE
- SOLID BARS DUCTS AND THEY SHOULD BE PLACE
- WIRE DIAMETER TYPICALLY RANGES AS SPECIFIED IN THE TENDON
FROM 3-7mm LAYOUT.
o CAN BE:
o ROUND
o CRIMPED
o INDENTED

TENDONS
PRE-TENSIONING
- MAJOR COMPONENT OF THE
- PRESTRESSES A CONCRETE MEMBER PRESTRESSING AND POST-TENSION.
BY STRETCHING THE REINFORCING - DEPENDING ON THE LOADS TO BE
TENDONS BEFORE THE CONCRETE IS APPLIED ON THE TENDONS IN POST
CAST. TENSION SLABS.

POST-TENSIONING UNBONDED POST-TENSIONING

- THE PRESTRESSING OF A CONCRETE - CONSISTS OF SINGLE (MONO)
MEMBER BY TENSIONING THE STRANDS OR THREADED BARS THAT
REINFORCING TENDONS AFTER THE REMAIN UNBONDED TO THE
CONCRETE HAS SET. SURROUNDING CONCRETE GIVING
- TEND TO SHORTEN OVER TIME DUE THEM THE FREEDOM TO MOVE
TO ELASTIC COMPRESSION, LOCALLY RELATIVE TO THE
SHRINKAGE, AND CREEP. STRUCTURAL MEMBER.
o STRANDS ARE COATED WITH
SPECIFIALLY FORMULATED
GREASE WITH AN OUTER
LAYER OF SEAMLESS PLASTIC
BONDED POST-TENSIONING

- COMPRISES TENDONS FROM ONE TO

MULTIPLE STRANDS (MULTISTRAND)
OR BARS.
- PRESTRESSING STEEL IS ENCASED
IN A CORRUGATED METAL OR
PLASTIC DUCT.
- AFTER THE TENDON IS STRESSED, METAL DECKING
CEMENTITIOUS GROUT IS INJECTED
INTO THE DUCT TO BOND IT TO THE
SURROUNDING CONCRETE. PRE-ENGINEERED BUILDING
o THE GROUT CREATES AN - PEB ARE THE BUILDINGS WHICH ARE
ALKALINE ENVIRONMENT ENGINEERED AT A FACTORY AND
WHICH PROVIDES CORROSION ASSEMBLED AT SITE.
PROTECTION FOR THE - STEEL STRUCTURES.
PRESTRESSING STEEL. - BUILT-UP SECTIONS ARE FABRICATED
AT THE FACTORY TO EXACT SIZE,
TRANSPORTED TO SITE AND
ASSEMBLED AT SITE WITH BOLTED
CONNECTIONS
- GENERALLY USED TO BUILD
BONDED POST-TENSIONING INDUSTRIAL BUILDINGS, METRO
STATIONS, WAREHOUSES, ETC.

COMPONENTS:

1. PRIMARY FRAME
a. ASSEMBLY OF BUILT-UP I-
SHAPED STEEL MEMBERS
UN-BONDED POST-TENSIONING b. FRAMING CONSISTS TRUSSES
OR CASTELLATED BEAMS

COMPOSITE CONSTRUCTION
2. SECONDARY STRUCTURAL
- TWO OR MORE MATERIALS WITH ELEMENTS
DIFFERENT PHYSICAL OR CHEMICAL a. COLD FORMED MEMBERS
PROPERTIES ARE COMBINED TO b. CAN BE SHAPED LIKE Z, C, ETC.
CRETE A STRONGER AND MORE c. KNOWN AS PURLINS
EFFICIENT STRUCTURE.
- GOAL: TO LEVERAGE THE
STRENGTHS OF EACH MATERIAL 3. ROOF AND WALL PANELS
WHILE MITIGATING THEIR INDIVIDUAL a. TIN SHADES & CURTAIN WALLS
WEAKNESSES. MADE OF GLASS & ROLL-
- CONCRETE IS GOOD IN FORMED STEEL SHEETS
COMPRESSION USUALLY COMES IN THIS
- STEEL IS GOOD IN TENSION CATEGORY.
o WHEN TWO MATERIALS WORK
TOGETHER (CONCRETE AND
STEEL), THEIR STRENGTHS
CAN BE EXPLOITED TO RESULT
IN A HIGHLY EFFICIENT AND
LIGHTWEIGHT DESIGN.
 4. SANDWICH PANELS
a. MADE OF THREE LAYERS IN
WHICH A NON-ALUMINUM
CORE IS INSERTED WITH TWO
ALUMINUM SHEETS.
5. OTHER ACCESSORIES
a. MEZZANINE FLOORS
b. BOLTS BRACED FRAMES
c. INSULATION

LATERAL SYSTEM

1. RIGID FRAMING (MOMENT FRAMES)

a. BEAM-TO-COLUMN CHEVRON BRACING
CONNECTIONS IN A FRAME ARE
SUFFICIENTLY RIGID TO
MAINTAIN THE ORIGINAL 2. BRACED FRAMING
ANGLES BETWEEN a. CROSS-BRACING
INTERSECTING MEMBERS i. MAKE THE MOST OF
b. CONSIDERED A MOMENT- STEEL’S STRENGTH IN
RESISTING (RIGID) FRAME. TENSION TO
c. MOMENT-RESISTING FRAMES EFFICIENTLY USE SMALL
COMPRISE THE: STRUCTURAL SHAPES.
i. BEAMS ii. IF TENSION-ONLY
ii. COLUMNS CROSS-BRACED
iii. RIGID CONNECTIONS SYSTEM EXPERIENCES
BETWEEN THEM HORIZONTAL FORCE
FROM WIND OR SEISMIC
EVENT, THEN ONLY ONE
LEG OF THE CROSS-
BRACE WILL PROVIDE
RESISTANCE
b. CHEVRON BRACING
(CONCENTRIC)
i. TYPICALLY CONNECT
RIGID FRAME BUILDING ELEVATION CHEVRON BRACE
ELEMENTS TO
ASSOCIATED BEAMS
AND COLUMNS.
ii. THE MEMBERS CAN BE
EITHER WELDED OR
BOLTED TOGETHER –
DEPENDING ON
MOMENT RESISTING FRAMES PROCESSES AT THE
STEEL FABRICATION
SHOP OR AESTHETIC
CONSIDERATIONS

SHEAR WALL FRAMES

 3. ECCENTRIC BRACING
a. VERY SIMILAR TO CHEVRON-
BRACED FRAMES
b. THE GENERAL CONFIGURATION
IS A ROTATED K SHAPE WITH
THE BRACE CONNECTED TO A
COLUMN AND A BEAM/GIRDER COMPOSITE DECKING
AT THE LEVEL ABOVE.
c. BRACE MEMBERS INTERSECT - SERVES AS TENSILE
AT THE SAME POINT IN A REINFORCEMENT FOR THE
CHEVRON-BRACED FRAME CONCRETE SLAB TO WHICH IT IS
BONDED WITH EMBOSSED RIB
PATTERNS

ECCENTRIC BRACING

PIN-JOINTED STEEL FRAMING

CELLULAR DECKING
- A STRUCTURAL FRAMEWORK
- MANUFACTURED BY WELDING A
CONSISTING OF SEVERAL MEMBERS
CORRUGATED SHEET TO A FLAT
JOINTED TOGETHER AT THEIR ENDS
STEEL SHEET – FORMING A SERIES
BY RIVETS OR BOLTS TO FORM
OF SPACES OR RACEWAYS FOR
REQUIRED SHAPE AND TO CARRY
ELECTRICAL AND COMMUNICATIONS
THE APPLIED EXTERNAL LOADS.
WIRINGS
- RULE OF THUMB FOR OVERALL
DEPTH: SPAN/24
OPEN WEB STEEL JOIST (OWSJ)

- LH LONG SPAN
- DLH DEEP LONGSPAN COLUMN
- CJ OPEN WEB COMPOSITE STEEL
JOIST
- K OPEN WEB STEEL JOIST
- KCS K-SERIES CONSTANT SHEAR

W-SHAPE ROUND PIPE

METAL DECKING

FORM DECKING RECTANGULAR WELDED PLATES

OR SQUARE TUBING
- SERVES AS PERMANENT FORMWORK
FOR A REINFORCED CONCRETE SLAB
CAN SUPPORT ITS LIVE LOAD.
 o INTERNAL AIR MUST BE
SUPPLIED CONSTANTLY AND
KEPT PRESSURE HIGH THAN
ATMOSPHERIC.

PNEUMATIC STRUCTURE: MATERIALS

TRIANGULAR GRID SQUARE GRID
- ISOTROPIC MATERIALS – THESE
SHOW THE SAME STRENGTH AND
STRETCH IN ALL DIRECTIONS:
o PLASTIC FILMS – PRIMARILY
PRODUCED FROM PVC,
POLYETHYLENE, POLYESTER,
POLYAMIDE, ETC.
o FABRICS – MADE OF GLASS
HEXAGONAL GRID
FIBERS WHICH ARE COATED IN
SPACE FRAME PVC, POLYETHYLENE,
POLYESTER, POLYURETHANE
- LONG-SPANNING THREE-
FILM
DIMENSIONAL PLATE STRUCTURE
o RUBBER MEMBRANE –
BASED ON THE RIGIDITY OF THE
LIGHTEST AND MOST FLEXIBLE
TRIANGLE AND COMPOSED OF
o METAL FOILS – POSSESS A
LINEAR ELEMENTS.
VERY HIGH GAS DIFFUSION
RESISTANCE AND HIGH
TENSILE STRENGTH
PNEUMATIC STRUCTURE ▪ PROBLEM: USE OF
- MEMBRANE STRUCTURE THAT METAL FOILS IS IN NEED
STABILIZED BY THE PRESSURE OF TO PRODUCE VERY
COMPRESSED AIR. EXACT CUTTING
- AIR-SUPPORTED STRUCTURES ARE PATTERNS.
SUPPORTED BY INTERNAL AIR
PRESSURE
o AIR PRESSURE WITH THIS - ANISTROPIC MATERIALS – THESE DO
BUBBLE IS SLIGHTLY NOT SHOW THE SAME STRENGTH
INCREASED ABOVE NORMAL AND STRETCHABILITY IN ALL
ATMOSPHERIC PRESSURE DIRECTIONS
o MAINTAINED BY o GRIDDED FABRIC – COARSE-
COMPRESSORS OR FANS WEAVE MADE OF ORGANIC
o DEVISED BY WALTER BIRD IN MATERIAL OR SYNTHETIC
THE LATE 1940s FIBERS
- FROM THE GREEK WORD PNEUMA o SYNTHETIC RUBBERS –
MEANING BREATHE OF AIR AS COMBINATION OF PLASTIC AND
MEMBERS GET MAINLY SUPPORTED RUBBER, THEY CAN TAKE
BY AIR BETTER WEAR OR TEAR.
o PLASTIC-LIKE WOVEN FABRICS
TYPES OF PNEUMATIC STRUCTURE – ITS ADVANTAGE IS THAT THEY
- AIR-INFLATED HAVE MORE OF TENSILE
o PRESSURIZED AIR IS SUPPLIED STRENGTH THAN NORMALLY
AND CONTAINED IN THE MANUFACTURED PLASTIC
VOLUME SHEETS
- AIR-SUPPORTED