RBSE SS Voc Construction flashcards

34 cards. Read the term and the definition here. The deck at the top of this page is optional.

First class brick

A burnt clay brick with sharp edges, water absorption less than 20% by weight, and compressive strength of at least 10.5 N/mm², used for superior masonry work.

Initial setting time of cement

The time from adding water to the point when cement paste begins to lose plasticity; for ordinary Portland cement it must not be less than 30 minutes.

Concrete grade M20

Concrete with characteristic cube compressive strength of 20 N/mm² at 28 days, used for normal reinforced concrete work and tested on 150 mm cubes.

Water-cement ratio

The ratio of water to cement by weight in a concrete mix; lower values increase strength and durability, while excess water causes bleeding and shrinkage cracks.

English bond

A brick masonry bond with alternating courses of headers and stretchers, producing strong walls with no continuous vertical joints; used for walls one brick or thicker.

Damp-proof course

A continuous layer of waterproof material, such as cement mortar with waterproofing compound or bitumen felt, laid at plinth level to stop moisture rising into walls.

Staircase rise and tread

Rise is the vertical height of one step and tread is the horizontal going; typical values are rise 150-190 mm and tread 250-300 mm for comfortable use.

Concrete cover

The thickness of concrete between the reinforcement and the outer surface, protecting steel from corrosion and fire; typical values are 40 mm for footings and 20 mm for slabs.

Scale 1:100

A drawing scale where one unit on the drawing represents 100 units on the ground, so 1 cm on paper equals 1 m in reality; common for building plans.

Hidden line

A dashed line on a technical drawing used to show edges or features that are not visible from the viewing direction, such as embedded reinforcement or concealed openings.

Bar bending schedule

A table listing each reinforcement bar's mark, diameter, shape, number, cutting length, and weight, used for fabrication, checking, and payment in reinforced concrete work.

Section drawing

A drawing showing the internal details of a building or component as if cut by an imaginary plane, with cut surfaces hatched to indicate materials.

Plinth area estimate

A preliminary cost estimate calculated by multiplying the plinth area of a building by a standard plinth area rate per square metre for similar construction.

Centre-line method

An estimating method for walls where the total centre-line length is multiplied by breadth and depth; junction adjustments are made for wall thickness to avoid double counting.

Bill of quantities

A document listing items of work with descriptions, units, and quantities, used for tendering and item-rate contracts; rates are filled in by bidders to form the contract sum.

Rate analysis

The process of determining the unit rate of a construction item by summing material, labour, plant, overhead, and profit components per unit of work.

Whole circle bearing

A bearing measured clockwise from magnetic north through 360 degrees, used in compass surveying; it is converted to reduced bearing for calculations.

Height of instrument

In levelling, the reduced level of the line of sight of the instrument, calculated as the backsight reading added to the reduced level of the benchmark.

3-4-5 method

A setting-out technique for establishing a right angle on site by forming a triangle with sides in the ratio 3:4:5, where the angle opposite the 5-unit side is 90 degrees.

Contour line

A line on a map joining points of equal elevation above a datum; closely spaced contours indicate steep ground and widely spaced contours indicate gentle slopes.

Needle vibrator

An internal concrete vibrator with a flexible shaft and vibrating needle, used to compact reinforced concrete and remove air voids; over-vibration can cause segregation.

Sheep-foot roller

A compaction roller with projecting feet on its drum, suitable for cohesive soils such as clay; it kneads and compacts the soil in layers.

Safe working load

The maximum load that a crane, hoist, sling, or scaffold is designed to carry safely under normal operating conditions, marked on the equipment and never exceeded.

Plumb bob

A pointed weight suspended from a string, used to check verticality of walls, columns, and formwork by aligning the string with a reference mark.

Hierarchy of controls

The order of risk control measures from most to least effective: elimination, substitution, engineering controls, administrative controls, and personal protective equipment.

Excavation shoring

Temporary support such as timber or steel bracing used to prevent collapse of excavation sides, required for depths beyond about 1.2 to 1.5 metres depending on soil.

Silica dust hazard

Fine dust produced by cutting, grinding, or drilling concrete and stone; inhalation can cause silicosis, so wet cutting and dust masks are required.

Residual current device

A safety device that quickly disconnects an electrical circuit when it detects leakage current to earth, protecting workers from electric shock on site.

Vernier caliper least count

The smallest measurement a vernier caliper can read, typically 0.02 mm, calculated as the difference between one main scale division and one vernier scale division.

Tap drill size

The diameter of the hole drilled before tapping an internal thread, approximately equal to the nominal thread diameter minus the thread pitch.

Curing of concrete

Keeping concrete moist after placing to allow cement hydration; at least 7 days is required, and 14 days in hot weather, to achieve design strength and durability.

Break-even point

The level of sales or output at which total revenue equals total cost, calculated as fixed cost divided by the difference between selling price and variable cost per unit.

Retention money

A percentage, typically 5-10%, withheld from each payment to a contractor until completion, to ensure defects are rectified and obligations are met.

STAR interview method

A technique for answering interview questions by describing the Situation, Task, Action taken, and Result achieved, giving structured and evidence-based responses.