Plain cement concrete is used to provide a rigid impervious bed to RCC in the foundation where the earth is soft and yielding. It can be used over brick flat soling or without brick flat soling.
The short name of plain cement concrete is PCC. It is also defined as Cement Concrete (CC) or Blinding Concrete.
In this post, I’ll share about plain cement concrete, its properties, and uses. I’ll also discuss how to produce and construct plain cement concrete.
What is Plain Cement Concrete?
When we say reinforced cement concrete, we know that there are reinforcements inside that concrete. when we don’t use any reinforcement inside the concrete, that is the plain cement concrete. It’s just a mix of concrete ingredients.
Properties of Plain Cement Concrete
The following are the most important properties of plain cement concrete:
- Compressive strength: 200 to 500 kilogram/square centimeter
- Tensile strength: 50 to 100 kilogram/square centimeter
- Density: 2200 to 2500 kilogram/cubic meter
- Durability: Excellent
Uses of Plain Cement Concrete
PCC is mainly used in footings, grade slabs, and concrete roads. The purpose of using it in footings is to provide firm, rigid, non-porous, impervious and leveled base for RCC footings.
We sometimes make brick flat soling below PCC if the base soil is soft and yielding.
Materials Used to Produce PCC
Cement: We generally use Portland cement as bonding material in PCC.
Fine Aggregate: Sand is used as fine aggregate. The FM of sand should be 1.2 to 1.5.
Coarse Aggregate: We normally use brick chips for producing PCC. Stone chips can also be used for this purpose. The size of the coarse aggregate is 20mm downgrade.
Water: Pure drinkable water should be used in PCC.
How to Produce and Construct PPC?
Use the following techniques to produce and construct plain cement concrete.
We normally use the following tools for producing Plain Cement Concrete-
- Wooden or Steel rammer
- Mixture machine (if any)
The thickness of PCC is normally 50mm over Brick Flat Soling (BFS). If you don’t use BFS below PCC then the thickness should be 75mm. When the PCC is used in car parking area then the thickness should be 75mm over BFS.
Ingredients Proportion of PCC:
The proportion of cement, sand and brick chips in foundation or basement is 1:3:6. But, when used in the car parking area, the proportion should be 1:2:4.
The Procedure of Manufacturing PCC:
If you want to use ready-mix concrete then you should skip this step. If you want to produce PCC by mixture machine then click “How to mix concrete by mixture machine”. If you don’t have a concrete mixture machine and want to mix concrete by hand read “how to mix concrete by hand”.
Placing and Compaction of PCC:
- Make sure brick soling/sand bed level for PCC is ok.
- Make formwork for PCC with wooden planks as per specified dimensions.
- Clean dust and foreign materials from concreting area.
- Spread polythene over the bed of PCC.
- Make level pillars of fresh concrete in the area at suitable intervals but not more than 2m c/c both ways.
- Place the concrete gently from one side. Use the mixed concrete within 45 minutes after the water is added.
- Use wooden rammer for compaction and finishing of PCC.
- Make the surface of PCC roughen for joining future work before the concrete becomes harden.
Curing of PCC:
After 24 hours of laying PCC, moist the concrete surface by flooding with water or by covering with moist gunny bags at least for seven days.
Checking and Inspection:
- Check the dimensions of formwork of PCC before mixing concrete.
- Check polythene sheet is laid over PCC bed.
- Check the concrete slump (maximum slump should be 75mm)
- Check the thickness and level of PCC before casting by putting steel pegs in concreting area or putting a level pillar of fresh concrete at a suitable distance.
- Check the finish level of PCC by thread fixing with nails in formwork.
- Inspect if the concrete is placing gently.