Lecture 7 - Concrete

Objectives:-

1.To learn the units of measurement of concrete.2.To relate the measurement as per clauses in SMM23.To determine the classification of sizes for slabs.

Outcomes:-1.Able to differentiate the different clauses used for the measurement of concrete2.Able to write down the dimensions based on the drawings.

Unit of measurement

• Measurement to be in m3 or volume for all structural members.

Clause F3.3 Isolated foundation base

• 1. To identify the footing.

• 2. To include the number.

Foundation - Footing

Clause F3.4 - Casings

• 1. Concrete support to hand railing.

• 2. Measurement to include the number of support.

Steel railing

Concrete support

Clause F3.5 ground beams

• Concrete for ground beams must not be group with other members like stump and footings.

Ground beams

Stump

Footing

Clause F.3.6 Casing to steel ground beam

• Concrete casing is needed to provide protection to the steel beam.

Concrete casing

Steel beam

Clause F2,F3. 8 & 9 Beds and suspended slabs

• Measurement of slab shall be under the following categories:-

• A. Not exceeding 100mm.• B. 100mm to 150mm• C. 150mm to 300mm.• D. Exceeding 300mmGround floor slab

1st. Floor slab

Clause F.3.10 Troughed slab

• Slab of this shape must be separated and named as troughed slab.

• To state overall thickness.

A (overall thickness)

b

Coffered / troughed slab

Clause F.3.11 Upstand, kerbs

• These are smaller structures whereby the construction would be slower and more laborious.

Upstand

Kerb

Coping

Low wall

Clause F.3.12 Walls

• Reinforced concrete wall is a structure to prevent landslide or movement of earth to a lower level.

Retaining wall

Kicker

Hill

Clause F.3.12 Fascia and fins.

• These are beams are very thin in thickness and mainly served as decorative surface and sun shading.

• The construction of these beams is very difficult due to the thinness.

Fascia beam

Fins

Clause F.3.16 steps and staircases

• These structure is very difficult to construct due to the different sizes and drops.

Staircase

Steps

Clause F.3.17 Tops and cheeks of dormers

• As the construction of the small structure is in a very high level and involved very delicate job the cost could be high.

Dormers

Clause F.3.19 Machine bases

• The construction of plinth shall mean the support of a machine like a water pump or the water tank support.

Water tank

Concrete plinth

Concrete slab

Clause F.3.20 Filling to pockets.

• 1. Volume of void exceeding 0.10m3 to be measured in m3 and to state how many number.

• 2. Volume less than 0.10m3 to be enumerated irrespective of sizes.

R.C. slab with pockets of voids to be filled.

Clause F.4.2 Joints.

• Casting of large panel slabs shall be in panels and the joints could include waterstop, expansion or compression joints and be measured in meters.

R.C .slab cast in panels

A B

C D

Airport runway

• Construction of runway for planes must be strong and durable.

The concrete slab must be flexible to withstand the contraction and expansion.

Expansion joints

Clause F.7.3 Guniting

• It is a slope improvement system to prevent the slope from failing.

• The concrete is splayed to the surface of the slope and the measurement is in m2 stating the thickness.