concrete2014a-lecture6

Lecture 6 - ConcreteObjectives:-

1. To learn the different concrete categories2. To relate the concrete as per clauses in SMM23. To determine the various clauses applied to the

different elements of concrete

Outcomes:-4. Able to differentiate the different clauses used for

concrete measurement.5. Able to write down the dimensions clearly.

Concrete work

Concrete truck and mixer

Pouring of concrete.

Vibrating and leveling of concrete

Types of concrete

• Type A concrete is filled with 16mm diameter reinforcement bars and is known as reinforced concrete.

• Type B concrete is without any reinforcement bars and is known as mass concrete.

16mm reinforcement bar

A

B

Waterproof concrete

• For reinforced concrete roof the concrete used must be protected with waterproofing additives so that rainwater could not penetrate.

Rapid hardening concrete

• For construction of structure below water level, rapid hardening cement is used so that the concrete could harden in a shorter time

Foundation

Placing of concrete

• Different types of machines are used for placing of concrete depending on the available of space and the speed of placing.

Concrete beds laid to slope

• Concrete bed laid to slope must be separated into :-

• 1. Not exceeding 15 degree from horizontal.

• 2. Exceeding 15 degree.

Angle > 15 degree

No deduction shall be made for:-

• 1.Volume occupied by the reinforcement bars.

• If the volume of the concrete is 10m3 and the volume occupied by the bars is 1m3 the concrete volume is still 10m3.

Reinforcement bars

No deduction shall be made for:-

• If we have a concrete column whereby we need to place a mild steel pipe as a service pipe we need to find out the area of the pipe before we make any deduction.

Area not exceeding

0.05m2

Concrete column

Steel pipe

Structure of building

Column

Floor beam

Roof beam

Ground floor slab Ground beam

1st. Floor slab

Unit of measurement

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