BSEH Secondary NSQF Construction flashcards

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

Minimum site PPE

Hard hat, safety footwear, high-visibility vest and eye protection are the baseline on an active site; hearing and respiratory protection are added for noisy or dusty tasks.

Fall protection threshold

Work at heights of 1.8 m or more requires guardrails or a full-body harness with lanyard anchored above shoulder level, plus inspected scaffolds with toe boards.

Excavation shoring rule

Excavations deeper than 1.5 m need shoring, benching or sloping, with spoil and plant kept at least 1 m clear of the edge and a ladder provided for access.

RCD on portable tools

Portable electrical tools on site should be double-insulated or supplied through a residual current device that trips on earth leakage, with cables kept off wet ground.

Silica dust control

Cutting, grinding and drilling concrete releases respirable crystalline silica causing silicosis; control by wet cutting, on-tool extraction and at least FFP2/N95 respiratory protection.

Noise action level

The action level is 85 dB(A) averaged over an 8-hour shift; each 3 dB increase roughly doubles sound intensity, so exposure time must be halved for each 3 dB rise.

Cement dermatitis cause

Wet cement is strongly alkaline, around pH 12 to 13, causing irritant and allergic contact dermatitis; gloves, barrier cream and washing facilities are the controls.

Waste segregation on site

Separate waste into recyclable, inert, hazardous and organic streams at source; hazardous items such as paint and solvent need recorded disposal, and burning waste is prohibited.

OPC setting times

Ordinary Portland cement has an initial setting time of at least 30 minutes and a final setting time not exceeding 600 minutes; grades 33, 43 and 53 denote 28-day strength in MPa.

Nominal concrete mixes

Volume proportions 1:3:6 give M10, 1:2:4 give M15 and 1:1.5:3 give M20; lower water-cement ratio raises strength and durability when concrete is fully compacted.

Fine versus coarse aggregate

Fine aggregate passes the 4.75 mm sieve and coarse aggregate is retained on it; well-graded combined aggregate reduces voids, water demand and segregation in concrete.

First-class brick properties

First-class burnt clay bricks are table-moulded, well burnt, uniform in colour, give a clear ringing sound when struck and absorb not more than about 20 percent water by weight.

Try square and spirit level

A try square checks that a corner is 90 degrees, while a spirit level checks level and plumb using a bubble in a curved vial; both are checked before each use.

Rip versus crosscut saw

A rip saw has chisel-shaped teeth and cuts along the grain, while a crosscut saw has knife-shaped teeth and cuts across the grain; set and sharpening control the kerf.

Hammer action drilling

Hammer action drilling is selected for masonry and concrete, rotary-only drilling for metal and wood; the bit type and rotation speed are matched to the material being drilled.

Concrete vibrator use

Insert the vibrator vertically at regular spacing, withdraw it slowly, and avoid over-vibration that causes segregation; never use the vibrator to spread or push concrete.

Drawing line conventions

Continuous thick lines show visible outlines, dashed lines show hidden edges, chain-dotted lines mark centre and grid lines, and thin lines carry dimensions and extension lines.

Plan and section defined

A plan is a horizontal cut about 1 m above floor level viewed downward; a section is a vertical cut showing heights, construction layers and levels of the building.

Title block contents

Every drawing sheet carries a title block with project name, drawing title and number, scale, date, revision status and the names of the person who drew and checked it.

Building drawing scales

Typical scales are 1:100 for plans, 1:50 for enlarged plans, 1:20 or 1:10 for construction details and 1:200 or 1:500 for site plans; the scale is always stated.

Masonry measurement rule

Brick masonry is measured in cubic metres as length times height times thickness, deducting openings above the specified area threshold and deducting lintels and beams.

Plaster measurement rule

Plaster is measured in square metres of finished surface, deducting openings larger than 0.5 square metres and adding jambs, soffits and reveals, with thickness and mix stated.

Rebar unit weight formula

The unit weight of a steel bar is d squared divided by 162 kilograms per metre, where d is the bar diameter in millimetres; total weight is bar count times length times unit weight.

Rate analysis meaning

Rate analysis derives the unit rate of a work item from material, labour, plant, overheads and contractor profit; the estimate is quantity times rate plus contingency and taxes.

English versus Flemish bond

English bond alternates whole header courses with whole stretcher courses and is strongest; Flemish bond alternates header and stretcher bricks within every course.

Slump test purpose

The slump test measures concrete workability; a true slump of about 25 to 75 mm suits normal reinforced concrete, while shear or collapse slump indicates an excessively wet mix.

Concrete curing period

Concrete must be kept damp for at least 7 days, and 10 to 14 days for harsh exposure, because curing supports strength gain and reduces shrinkage cracking and surface permeability.

Mortise and tenon joint

A mortise and tenon joint cuts a projecting tenon on one member into a matching mortise hole in the other, giving a strong interlocking frame joint used in doors and windows.

Timber seasoning purpose

Seasoning lowers timber moisture content towards equilibrium with service conditions, reducing shrinkage, warping, splitting and decay while improving strength and paint adhesion.

Soil versus waste pipe

A soil pipe carries foul water from water closets, a waste pipe carries sullage from sinks and basins, and a vent pipe equalises pressure to protect trap water seals.

Trap water seal

Every sanitary fixture needs a water seal trap of 50 to 100 mm, such as a P-trap, that blocks sewer gas; the vent stack prevents siphonage from emptying the seal.

Earthing conductor colour

The earth conductor is green or green-yellow and must never be used as a neutral; all metal enclosures need earth continuity, and earth resistance is tested periodically.