written 5.8 years ago by |
Concreting operation includes:
i. Batching
ii. Mixing
iii. Transportation
iv. Placing
v. Compaction
vi. Curing
vii. Finishing
Batching:
The process of measuring different concrete materials such as cement, coarse aggregate, sand, water for the making of concrete is known as batching. Batching can be done in two different ways.
*1. Volume Batching
- Weight Batching.*
In volume batching the measurements of concrete materials are taken by volume & On the other hand the measurements are taken by weight in weight batching.
Mixing
The process of mixing various ingredients of concrete (cement, sand and water) in a specified proportion is termed as mixing. The quality and strength of concrete depends upon proper thorough mixing and uniform colour of concrete. Methods of Mixing
1. Manual Mixing (Hand Mixing) 2. Mechanical Mixing (Machine Mixing)
Transportation
When the mixing is done properly the freshly made concrete is then transported to the construction site, this process is known as transportation. After that, the concrete is correctly placed on the formworks. Concrete can be transported to the site location in two ways
1. Manual Transportation. 2. Mechanical Transportation.
Placing:
When the concrete is brought to the construction site, it is placed in formwork that defines its final position and shape. This process is known as placing of concrete.
Compaction
Compaction is the process in which the air bubbles are eliminated from the freshly placed concrete. It is required to increase the ultimate strength of concrete by enhancing the bond with reinforcement.
Methods of compaction:
a) Hand Compaction
i. Rodding
ii. Ramming
iii. Tamping
b) Compaction by vibrators
i) Needle or Poker vibrator
ii) Screed board vibrator
iii) Form vibrator
iv) Platform vibrator
v) Table vibrator
vi) Vibratory roller
Finishing
Finishing operation is the last operation in making concrete. It is the process to get a uniform, levelled and smooth concrete surface and also good in appearance Operations for Finishing • Screeding • Floating • Trowelling:
Curing
Curing may be defined as the operation of maintaining humidity and temperature of freshly placed concrete during some definite period following placing, or finishing to assure satisfactory hydration of the cement and proper hardening of the concrete. Or Curing may be defined as the process of keeping the concrete moist and warm enough so that the complete hydration of the cement can take place
Method of Curing: - i. Water curing iii. Application of heat ii. Membrane curing iv. Miscellaneous methods