PRIORITY TERMS Construction and Concrete Finishing: Key Terms and Scaffold Safety

A membrane, coating, or sealer used in concealed locations to prevent water from entering a building.

Waterproofing

The natural material located along the horizontal alignment of the pavement and serves as the foundation of the pavement structure.

Subgrade

The tendency of dry materials used in making quality concrete to settle to the bottom and displace the mixing water to the surface.

Bleeding

Consists of material of a superior quality to that which is generally used for subgrade construction.

Subbase Course

The process of treating soils to improve their engineering properties.

Stabilization

The surface of newly placed concrete is struck off by moving a straightedge back and forth with a sawlike motion across the top of the forms and screeds.

Screeding

This course usually consists of granular materials such as crushed stone, crushed or uncrushed slag, crushed or uncrushed gravel, and sand.

Base Course

The bringing of a concrete surface to true grade with enough mortar to produce the desired finish.

Leveling

Consists of a mixture of mineral aggregates and asphalt.

Surface Course

Rounds off the formed edge of a slab to prevent chipping or damage when all bleed water and water sheen have left the surface.

Edging

Usually single applications of asphalt material that may or may not contain aggregates.

Seal Coats

A thin application of emulsified asphalt, usually with no aggregates added.

Fog seal

Immediately following or during edging, inserts are placed in concrete slabs to control cracking in the concrete as a result of shrinkage.

Jointing

May be done when the water sheen has disappeared and the concrete will support the weight of the finisher.

Floating

A uniformly mixed combination of a slow-setting asphalt emulsion, fine aggregate, mineral filler, and water.

Slurry Seal

Obtained by spraying asphalt, immediately covering it with aggregates, and then rolling the aggregates into the asphalt.

Aggregate Seals

Obtained by spraying asphalt binder materials onto nonasphalt base courses.

Prime Coats

A thin layer of asphalt material sprayed over an old pavement to facilitate the bonding of the old pavement and a new course.

Tack Coat

Is done on slabs that are to be left exposed or to receive thin finishes, such as resilient flooring, carpet, tile, or paint.

Troweling

A shortened form for superior performing asphalt pavements.

Superpave

A method to slightly roughen steel-troweled concrete surfaces to produce a nonslip surface.

Broom Finishing

The process by which a vehicle in one traffic stream joins another traffic stream moving in the same direction.

Merging

The breaking away of the hardened concrete surface of a slab to a depth of about 1/6 to 3/16 in. (1.6 to 4.8 mm).

Scaling

The occurrence of numerous fine hair cracks in the surface of a newly hardened slab due to surface shrinkage.

Crazing

The process by which a vehicle in a traffic stream leaves that traffic stream.

Diverging

The appearance of a powdery material on the surface of a newly hardened concrete slab.

Dusting

The process by which a vehicle first merges into a stream of traffic, obliquely crosses that stream, and then merges into a second stream.

Weaving

The strength and watertightness of concrete improve with age as long as conditions are favorable for continued hydration of its portland cement.

Hydration

The headway in a major stream, evaluated by a vehicle driver in a minor stream who wishes to merge into the major stream.

Gap

Made by building a large section of form supported on deep steel trusses, which can be lifted by crane and positioned without dismantling.

Flying Forms

The difference between the time a vehicle that merges into a main traffic stream reaches a point and the time a vehicle in the main stream reaches the same point.

Time lag

A method of continuously moving a form for vertical structures upward on jacks as new concrete is placed on top of the old.

Slip forming

Usually a bituminous coating applied to prevent materials from absorbing adjacent moisture.

Dampproofing

The difference, at an instant of time, between the distance a merging vehicle is away from a reference point in the area of merge and the distance a vehicle in the main stream is away from the same point.

Space lag

Must be repeated beginning at least at every fifth post on scaffolds whose length is greater than their height.

Longitudinal bracing on scaffolds

Timber/bamboo scaffold shall be limited to a height of ___________ from the ground or base; for over 6 meters height, steel scaffolds shall be used.

6 meters

Must be installed from the base of the end posts upward to the opposite end posts on scaffolds whose length is less than their height.

Longitudinal bracing installation

All site fabricated/conventional supported scaffolds exceeding _________ meters in height or a working load of _____ kg/m2 shall be designed and inspected by the structural engineer and approved by the appropriate authority.

6, 150

A _______________ equipment shall be used when working in a height of 2 meters and above;

Fall protection

A male worker shall not lift, carry or move any load over _______ kg and female workers over _______ kg.

25,50

Safe covered walkway construction shall be constructed over the sidewalk for use by pedestrians in a building construction work less than _________ from a sidewalk or public road.

2.3 m

Each platform unit shall be installed so that the space between adjacent units and the space between the platform and the uprights is no more than _____ inch wide.

1

Scaffolds standing for _______ months shall not be used until damaged members are replaced and the whole structure returned to its original strength.

four

Each scaffold platform and walkway shall be at least _____ inches wide.

18

All demolition operations of building or other structure over ________ meters high shall be under supervision of a competent person.

6

Each end of a platform, unless cleated or otherwise restrained by hooks equivalent means, shall extand over the centerline of its support at least ________ inches.

6

No person except the workers who are directly engaged in the demolition shall enter a demolition area to within a distance equal to _________ times the height of the structure being demolished.

1.5

Each end of a platform _______ feet or less in length shall not extend over its support more than _______ inches unless designed to support employees and/or materials.

10, 12

The demolition area where work is done by mechanical devices shall be barricaded for a minimum distance of ________ times the height of the structure.

1.5

On scaffolds where platforms are overlapped to create a long platform, the overlap shall occur only over supports, and shall not be less than _________ inches.

12

No holes shall be drilled within ________ meters of a hole containing explosives or blasting agents.

3.3

Supported scaffolds and their components shall be capable of supporting without failure at least _________ times the maximum intended load.

four

No holes shall be drilled within __________ meters of a hole being loaded with explosives or blasting agents.

6.6

Lumber with _______ nail holes aligned crosswise or _________ nail holes along its length shall not be used as horizontal load bearing member of scaffolds.

2, 4

A scaffold platform shall not project beyond its end support to a distance exceeding ________ times the thickness of the plank.

4

Slope of runway or ramp shall not exceed _________.

2 in 3

Always maintain the base width to height ratio of ________ during erection for stability.

1:4

Scaffolds over _______ meters shall be designed by a structural engineer and shall be erected, installed and dismantled by TESDA certified erectors.

6

When hooked-on ladder is used, a rest platform with a minimum width of __________ shall be provided every _______ m in height.

60 cm (2 ft), 4

Ladders used for access shall protrude at least ______ meters above the landing place.

1

When manual force is used to move the scaffold, it must be applied as close to the base as practicable, but not more than _______ above the supporting surface.

1.2 m (4 ft)

All casters must be secured to frame legs or screw jacks with pins, bolt & nut, and other secured means. Weight of tower should not exceed the capacity of the casters and should be designed to support ______ times the maximum intended load.

4

The distance between the ladders of the scaffold is less than __________ .

3 m (10 ft)

For work height of 10 meters, workers are required to use ___________ equipment.

Fall arrest

The finishing of standard-weight concrete slabs proceeds through several steps defined order.

Screeding

Leveling

Edging

Jointing

Floating

Troweling

Broom finishing or other surface texturing