BLDG TECH 5: CONCRETE

Question 1

A material, which, when mixed with water or other liquid substance, will form temporarily a plastic paste then after a short period of time, will harden or set to a rigid mass

Answer 1

CEMENT

Question 2

what are the main component materials of cement?

Answer 2

CALCIUM CARBONATE
SILICA
ALUMINA

Question 3

A hydraulic cement made by burning a mixture of clay and limestone in a rotary and pulverizing the resulting clinker into a fine powder

Answer 3

PORTLAND CEMENT

Question 4

Who patented Portland cement?

Answer 4

JOSEPH ASPDIN

Question 5

what component of Portland cement is responsible for the hardening or early gain in strength of cement?

Answer 5

TRICALCIUM SILICATE (C3S)

Question 6

what component of Portland cement is responsible for the aging or long term gain strength of cement?

Answer 6

DICALCIUM SILICATE (C2S)

Question 7

what component of Portland cement contributes to the initial setting of cement?

Answer 7

TRICALCIUM ALUMINATE (C3A)

Question 8

what component of Portland cement contributes to the process of cement manufacturing by allowing lower clinkering temperatures?

Answer 8

TETRACALCIUM ALUMINOFERRITE (C4AFe)

Question 9

[Determine ASTM]

Standard Specifications for Portland Cement

Answer 9

ASTM C150

Question 10

What type of Portland cement is for general use when special properties are not required?

Answer 10

TYPE 1: ORDINARY PORTLAND CEMENT, OPC (NORMAL)

Question 11

What type of Portland cement is for generating less heat and at slower rate during the hydration process?

Answer 11

TYPE 2: MODIFIED PORTLAND CEMENT (MODERATE)

Question 12

What type of Portland cement is for use where high strength is desired at early periods, usually within a week or less?

Answer 12

TYPE 3: HIGH EARLY STRENGTH CEMENT (EXTRA RAPID HARDENING CEMENT)

Question 13

What type of Portland cement is for use where low heat of hydration is desired, and develops strength at a much lower rate than Type 1?

Answer 13

TYPE 4: LOW HEAT CEMENT

Question 14

What type of Portland cement is for use when high resistance to sulfate action is desired?

Answer 14

TYPE 5: SULFATE RESISTANT CEMENT

Question 15

An interground mixture of Portland cement clinker and granulated blast furnace slag

Answer 15

TYPE IS, PORTLAND BLAST FURNACE SLAG CEMENT

Question 16

An interground mixture of Portland cement clinker and pozzolan, which has high resistance to various chemical attacks on concrete compared with ordinary Portland cement, used in marine structures such as bridges, piers, dams, and mass concrete works

Answer 16

TYPE IP, PORTLAND POZZOLAN CEMENT

Question 17

cement that uses selected raw material so that the finished product will be white rather than gray, primarily used for aesthetic purposes in decorative concrete and mortar

Answer 17

WHITE PORTLAND CEMENT

Question 18

Fine particles of ash recovered from waste gases of a solid fuel furnace, a cementitious material which can be used to replace cements in amounts of up to 20% to reduce permeability

Answer 18

FLYASH

Question 19

the chemical reaction that takes place when Portland cement and water are mixed together

Answer 19

HYDRATION

Question 20

What do you call the reaction when cement is mixed with water to form a fluid paste, the mixture will eventually become stiff and then hard?

Answer 20

SETTING

Question 21

What do you call the stiffening of a concrete mixture with little evidence of significant heat generation?

Answer 21

FALSE SET

Question 22

Refers to the heat generated when water and cement chemically reacts

Answer 22

HEAT OF HYDRATION

Question 23

An artificial, stone-like building material made by mixing cement and various mineral aggregates with sufficient water to cause the cement to set and bind the entire mass

Answer 23

CONCRETE

Question 24

concrete in which steel reinforcement is embedded in such a manner that two materials act together in resisting forces

Answer 24

REINFORCED CONCRETE / BETON ARME / FERROCONCRETE

Question 25

Concrete having no reinforcement, or reinforced only for drying shrinkage or thermal stresses

Answer 25

PLAIN CONCRETE

Question 26

concrete which is deposited in the place where it is required to harden as part of the structure, as opposed to precast concrete

Answer 26

CAST-IN-PLACE CONCRETE / CAST IN-SITU / IN-SITU CONCRETE

Question 27

What class of concrete proportioning is used for concrete subjected to post-tensioning on pre-tensioning, dams, and similar uses?

Answer 27

CLASS AAA

Question 28

what is the concrete component ratio of Class AAA (cement: sand: gravel) with a compressive strength of 4,500 psi?

Answer 28

1: 1: 2

Question 29

what is the concrete component ratio of Class AA (cement: sand: gravel) with a compressive strength of 4,000 psi?

Answer 29

1: 1/2: 3

Question 30

what is the concrete component ratio of Class A (cement: sand: gravel) with a compressive strength of 3,500 psi?

Answer 30

1: 2: 4

Question 31

what is the concrete component ratio of Class B (cement: sand: gravel) with a compressive strength of 3,000 psi?

Answer 31

1: 2 1/2: 5

Question 32

what is the concrete component ratio of Class C (cement: sand: gravel) with a compressive strength of 2,500 psi?

Answer 32

1: 3: 6

Question 33

what is the concrete component ratio of Class D (cement: sand: gravel) with a compressive strength of 2,000 psi?

Answer 33

1: 3 1/2: 7

Question 34

What class of concrete proportioning is used for concrete under water structures, retaining walls, and elevator shear walls?

Answer 34

CLASS AA

Question 35

What class of concrete proportioning is used for standard mixtures used for reinforced floor slabs, beams, columns, arches, machine/engine foundation and building foundation?

Answer 35

CLASS A

Question 36

What class of concrete proportioning is used for medium mixture used for slabs on fill, retaining wall, load-bearing wall or 100mm CHB, abutment piers, building wall and sidewalk?

Answer 36

CLASS B

Question 37

What class of concrete proportioning is used for lean mixture for stone masonry and filling, parapet walls, concrete plant boxes?

Answer 37

CLASS C

Question 38

What class of concrete proportioning is used for footpath, walkway, plantboxes, and lean concrete?

Answer 38

CLASS D

Question 39

For mortar mixture, what is the proportioning (cement:sand) of Class AA?

Answer 39

1:1

Question 40

For mortar mixture, what is the proportioning (cement:sand) of Class A?

Answer 40

1:2

Question 41

For mortar mixture, what is the proportioning (cement:sand) of Class B

Answer 41

1:3

Question 42

For mortar mixture, what is the proportioning (cement:sand) of Class C?

Answer 42

1:4

Question 43

For mortar mixture, what is the proportioning (cement:sand) of Class D?

Answer 43

1:5

Question 44

What concrete finish is when coloring agents are added to mixture which may be trowelled, sandblasted, tooled, stamped, etc?

Answer 44

INTEGRALLY PIGMENTED

Question 45

What concrete finish is a rough finish used on horizontal surfaces not exposed to weather, wear or view, and for base course of floors to receive cementitious toppings?

Answer 45

SCREEDED TROWELLED

Question 46

What concrete finish is a moderately rough finish for horizontal surfaces where slip resistance is required and appearance is a consideration?

Answer 46

SWIRL

Question 47

What concrete finish is a light-to-heavy rough finish for horizontal finishes where slip resistance and appearance is a consideration?

Answer 47

BROOMED

Question 48

What concrete finish is a medium-to-heavy texture for large surfaces, such as roadway pavements where slip resistance is required and appearance is of secondary importance?

Answer 48

BURLAP DRAG

Question 49

What is a finish coat of pigmented white cement is applied by throwing it vigorously over screeded-and-broomed for better bonding?

Answer 49

TRAVERTINE FINISH

Question 50

What concrete finish is similar in appearance to travertine, produced by scattering rock salt over a trowelled surface and then dissolving the salt after the concrete has hardened?

Answer 50

ROCK SALT

Question 51

What concrete finish is when selected aggregate is embedded in the fresh concrete after it has been placed and screeded exposed by removing the surface layer of cement paste by brush and water?

Answer 51

WASHOUT FINISH-HORIZONTAL SURFACES

Question 52

What concrete finish is when horizontal surfaces crushed stone, most commonly marble aggregate in concrete toppings over concrete base slab?

Answer 52

EXPOSED AGGREGATE

Question 53

What concrete finish is when vertical surfaces - aggregate may be embedded into precast concrete panels - during casting when in horizontal position - using the same procedure for horizontal surfaces, or may be exposed by sandblasting?

Answer 53

EXPOSED AGGREGATE

Question 54

What concrete finish is when a forum material - boards or panels such as plywood - may be used to impart a surface texture to concrete?

Answer 54

FORMBOARD

Question 55

What concrete finish is when plastic - thermoplastic or synthetic rubber sheets formed in a variety of patterns and/or textures are attached to the inside faces of formwork?

Answer 55

FORMLINERS

Question 56

What concrete finish is when plaster of Paris, glass fiber - sculptured surfaces are obtained by placing concrete over or against formwork?

Answer 56

FORMLINERS

Question 57

What concrete finish is when concrete is cast over a bed of crushed stone or gravel aggregate against a polyethylene sheet between them to prevent bonding?

Answer 57

DIMPLED

Question 58

What concrete finish employs aluminum tools to imprint various patterns in freshly placed horizontal concrete surfaces?

Answer 58

STAMPED

Question 59

What concrete finish is used to create textured patterns through the use of templates?

Answer 59

SANDBLAST AND GROUND

Question 60

What concrete finish is when hardened concrete may be tooled, bushhammered or point tooled to remove the smooth outer layer or hardened cement paste and reveal the tough textured aggregate below?

Answer 60

BUSHHAMMERED

Question 61

Any concrete which is transported through a hose or pipe by means of a pump

Answer 61

PUMPED CONCRETE (PUMPCRETE)

Question 62

Concrete production system which is delivered to the job site ready for placement

Answer 62

READY MIX

Question 63

what concrete production system is when concrete is mixed in a stationary mixer at the producer's yard and delivered to the job site in a transit mixer?

Answer 63

CENTRAL MIX

Question 64

what concrete production system is when concrete is completely mixed in a truck?

Answer 64

TRANSIT MIX CONCRETE

Question 65

what concrete production system is a combination of central mix and transit mix?

Answer 65

SHRINK MIXED CONCRETE

Question 66

the process of providing gentle motion in mixed concrete just sufficient to prevent segregation of materials and loss of plasticity

Answer 66

AGITATION

Question 67

Any substance other than cement, water, or aggregate, added to a concrete or mortar mix to alter its properties or those of the hardened product

Answer 67

ADMIXTURE / ADDITIVES

Question 68

An admixture that disperses entrained air in concrete or a mortar mix to increase workability, improve resistance to cracking induced by freeze-thaw cycles or the scaling caused by deicing chemicals

Answer 68

AIR ENTRAINING AGENT

Question 69

Hastens the setting and strength development of a concrete, mortar, or plaster mix

Answer 69

ACCELERATOR

Question 70

slows the setting of concrete, mortar, or plaster mix in order to allow more time for placing and working the mix

Answer 70

RETARDER / DECELERATOR

Question 71

what admixture is used for reducing surface tension of the mixing water in a concrete mix thereby facilitating the wetting and penetrating action of water?

Answer 71

SURFACE-ACTIVE AGENT/SURFACTANT

Question 72

What admixture reduces the amount of mixing water required for the desired workability, lowering water-cement ratio generally results in increased length?

Answer 72

WATER REDUCING AGENT/SUPERPLASTICIZERS

Question 73

What admixture is a pigment or dye added to a concrete mix to alter or control its color?

Answer 73

COLORING AGENT

Question 74

what admixture causes cement particles to separate by imparting like electrostatic charge, it prevents bleeding of water to the surface of concrete?

Answer 74

DISPERSAL AGENT

Question 75

What admixture improves denseness of concrete surface which are subjected to rolling live loads and impact?

Answer 75

CONCRETE HARDENER

Question 76

What admixture renders concrete more impermeable?

Answer 76

CONCRETE WATERPROOF

Question 77

What admixture improves bond between two concrete surfaces?

Answer 77

BONDING AGENT

Question 78

What admixture prevents cement paste from bonding to the surface and inhibits the setting of cement paste?

Answer 78

SET INHIBITING AGENT

Question 79

What admixture prevents the evaporation of water from concrete and allow it to be retained for hydration?

Answer 79

SURFACE SEALING AGENT

Question 80

What admixture causes a slight expansion in plastic concrete or mortar and thus reduces or eliminates voids caused by settlement?

Answer 80

GAS FORMING AGENT

Question 81

What admixture is an abrasive material used as topping to prevent slippery surfaces?

Answer 81

NON-SKID SURFACE AGENT

Question 82

What admixture is sometimes used in structures where it is desirable to avoid high temperature or in structures exposed to seawater or water containing sulfates?

Answer 82

POZZOLANIC ADMIXTURE

Question 83

[Determine ASTM] Specifications for Blended Hydraulic cement

Answer 83

ASTM C595

Question 84

Consisting of sand having particle size smaller than 1/4 in (6.4 mm) and shall pass through a 3/8 in (9.5mm) sieve

Answer 84

FINE AGGREGATE

Question 85

consisting of crushed stones, gravel, or blast furnace slag having a particle size larger than 1/4 in (4.4mm) and retained on a No.4 (4.8mm) sieve

Answer 85

COARSE AGGREGATE

Question 86

A strong lightweight aggregate obtained by the exfoliation of clay or shale

Answer 86

EXPANDED CLAY/EXPANDED SHALE

Question 87

A strong lightweight aggregate obtained by the exfoliation of slate

Answer 87

EXPANDED SLATE

Question 88

A volcanic glass expanded by heat to form lightweight aggregate and as loose-fill thermal insulation

Answer 88

PERLITE/PEARLITE

Question 89

Mica expanded by heat into very light, worm like threads, used as nonstructural lightweight aggregate and as loose-fill insulation

Answer 89

VERMICULITE

Question 90

consists of the skeleton of tiny aquatic plants called diatoms which can be heated to melting point and used as a cinderlike, lightweight aggregate

Answer 90

DIATOMITE

Question 91

Consists of fine material particles produced by the burning of coal, useful in Portland cement concrete as a substitute for cement

Answer 91

FLY ASH

Question 92

used as aggregates fused into lumps by combustion of coal and are not softer ashes formed by lower temperature combustion

Answer 92

CINDER

Question 93

[Determine ASTM] Specifications for Concrete Aggregates

Answer 93

ASTM C33

Question 94

[Determine ASTM] Specifications for Lightweight Aggregates for Structural Concrete

Answer 94

ASTM C330

Question 95

A system of steel bars, strands or wires for absorbing tensile, shearing and sometimes compressive stresses in a concrete number or structure

Answer 95

REINFORCEMENT

Question 96

A reinforcing bar hot-rolled with surface deformations to develop a greater bond with concrete

Answer 96

DEFORMED BAR

Question 97

What are the standard hooks of reinforcing bars according to industry standards?

Answer 97

180° bend plus 4 db extension (but not less than 65mm at free end of bar 90° bend plus 12 db extension, at free end of bar

Question 98

What is the standard stirrup & tie hooks for 16mm bar and smaller?

Answer 98

90° bend plus 6db extension at free end of bar

Question 99

What is the standard stirrup & tie hooks for 20mm and 25mm bar?

Answer 99

90° bend plus 12db extension at free end of bar

Question 100

What is the standard stirrup & tie hooks for 25mm and smaller?

Answer 100

135° bend plus 6db extension at free end of bar

Question 102

What bar diameter shall not be bundled in beams?

Answer 102

larger than 32mm

Question 103

A test for determining the compressive strength of a concrete batch, using a hydraulic press to measure the maximum load a test cylinder can support

Answer 103

COMPRESSION STRENGTH TEST

Question 104

What is the size of a test cylinder cast from a represented batch and cured in a laboratory or in the field under controlled conditions?

Answer 104

152mm dia x 305mm length 6in dia x 12in length

Question 105

What concrete defect is characterized by the formation of hollow bumps of different sizes on concrete due to entrapped air under finished concrete surface?

Answer 105

BLISTERING

Question 106

What concrete defect is characterized by regular or irregular thin, large, shallow, or deep crevice running in any direction on concrete mass?

Answer 106

CRACKING

Question 107

What concrete defect is characterized by a patterned cracking or map cracking of closely spaced shallow cracks with uneven form?

Answer 107

CRAZING

Question 108

What concrete defect is characterized by the distortion of concrete surface either upward or downward esp. seen on the edges of the surface and usually occurs in SOGs?

Answer 108

CURLING

Question 109

What concrete defect is similar to blistering where top surface gets separated from underlying concrete?

Answer 109

DELAMINATION

Question 110

What concrete defect is characterized by the formation of fine and loose powdered concrete on concrete surface due to degradation of concrete?

Answer 110

DUSTING/CHALKING

Question 111

What concrete defect is characterized by the formation of deposits of salts on a concrete surface, generally whitish in color due to the presence of soluble salts in water used in mixing concrete?

Answer 111

EFFLORESCENCE

Question 112

What concrete defect results in flaking?

Answer 112

SCALING/SPALLING

Question 113

What concrete defect is caused by excessive vibration or agitation of concrete mix or presence of air entrapped in mix due to improper finishing?

Answer 113

BLISTERING

Question 114

What concrete defect is caused by over-reinforcement, under-reinforcement, improper design mix, insufficient curing, omission of expansion and contraction joints, use of high slump concrete mix, and unsuitable grade?

Answer 114

CRACKING

Question 115

What concrete defect is caused by rapid hardening of top surface of concrete due to high temperature or when concrete matrix contains excess water or due to insufficient curing?

Answer 115

CRAZING

Question 116

What concrete defect is caused by differences in moisture content or temperature between slab and slab substrate esp. when the top surface dries and cools off before the bottom does and then begins to shrink?

Answer 116

CURLING

Question 117

What concrete defect is caused by the hardening of the top layer before hardening of underlying concrete, placing new concrete on old concrete Iayers without proper surface preparation, and poor bonding between old and new concrete?

Answer 117

DELAMINATION

Question 118

What concrete defect is caused by excessive amount of water during mixing process wherein the fine particles of cement migrate toward the surface?

Answer 118

DUSTING/CHALKING

Question 119

What concrete defect is caused by soluble salts migrating towards the surface by hydrostatic pressure during concrete setting?

Answer 119

EFFLORESCENCE

Question 121

What concrete defect is caused by water penetration through concrete surface, resulting in corrosion of steel reinforcement and causing separation of steel & concrete, use of non-air entraining concrete mix, and in adequate curing and use of low strength concrete?

Answer 121

SCALING/SPALLING

Question 122

What is the minimum thickness of tied column?

Answer 122

200mm

Question 123

What is the minimum covering of ties of tied columns?

Answer 123

not less than 40mm not less than 1.5 times the max size of coarse aggregate

Question 124

What is the minimum number of bars for tied columns?

Answer 124

4-16mm dia

Question 125

What is the lateral de spacing for tied columns?

Answer 125

not more than 16 bar dia not more than 48 tie dia not more than the least dimension of column

Question 126

What is a concrete column with spiral reinforcement enclosing a circular core reinforced with vertical bars?

Answer 126

SPIRAL COLUMN

Question 127

what is the minimum diameter for spiral columns?

Answer 127

250mm

Question 128

what is the minimum diameter of spiral ties for spiral columns?

Answer 128

10mm dia

Question 129

What is the spacing of spiral ties for spiral columns?

Answer 129

25mm - 75mm not less than 1.5 times the size of coarse aggregate 1/6 core dia

Question 130

What is the minimum number of bars for spiral columns?

Answer 130

6-16mm dia

Question 131

what is the clear distance between longitudinal bars of spiral columns?

Answer 131

not less than 1.5 times bar dia not less than 1.5 times max size of coarse aggregate

Question 132

A column with a structural steel encased in a concrete of at least 7cm thick reinforced with wire mesh surrounding the column at a distance of 3 cm inside the outer surface of the concrete covering

Answer 132

COMBINED COLUMN

Question 133

A fabricated post made of steel provided with a plain flat steel ban or plate which holds girder, girl, or beam. The steel pipe is sometimes filled with concrete for additional strength and protection from rust or corrosion

Answer 133

LALLY COLUMN

Question 134

What is the concrete covering from face to the reinforcing steel?

Answer 134

40mm

Question 135

what is the clearance of slab reinforcement from the bottom?

Answer 135

200mm

Question 136

what is the clearance of slab reinforcement from the top of slab?

Answer 136

150mm

Question 137

where should you locate your reinforcing bars for 0.10m thk concrete walls?

Answer 137

AT THE CENTER

Question 138

How long is the setting time of concrete?

Answer 138

2hrs

Question 139

How long is the curing time of concrete to achieve full strength?

Answer 139

28 days

Question 140

How long is the curing time for type 3 concrete (high early strength)?

Answer 140

5-7 days

Question 141

How long is the lifespan of concrete?

Answer 141

50 yrs

Question 142

How many cubic meters is a truckload of ready mix concrete?

Answer 142

5-9 cu.m

Question 143

How many cubic meters is a one truck load of G1 gravel using a standard 10-wheeler dump truck?

Answer 143

20.00 cu.m

Question 144

When should you remove homework for side of beams and columns?

Answer 144

48 hrs

Question 145

When should you remove from work for slab or Soffit (props left under)?

Answer 145

3 days

Question 146

What do you call aggregates that pass through a 3-in sieve but is retained on a No. 4 sieve?

Answer 146

GRAVEL

Question 147

What do you call aggregates pass through a No. 200 sieve?

Answer 147

SILT-CLAY

Question 148

What do you call aggregates that pass through No.4 sieve but is retained on a No. 10 sieve?

Answer 148

COARSE SAND

Question 149

What do you call aggregates that pass through No. 40 sieve but is retained on a No. 200 sieve?

Answer 149

FINE SAND

Question 150

How many days can you remove the forms used for the footing?

Answer 150

24 hrs

Question 151

After concrete pouring for the slab, how soon can you step on it?

Answer 151

24 hrs

Question 152

When should you remove from works for beam soffits (props left under)?

Answer 152

7 days