4 Grouping and Types of Concrete in Indonesia

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4 Grouping and Types of Concrete in Indonesia

Concrete is composed of three main components, namely cement, water and aggregates. And if needed it will be added auxiliary material (admixture) to change certain properties of the concrete. The properties of concrete in a state that is still fresh and after hardening can show considerable differences. Depending on the type, quality and comparisons of the mixed materials used. Grouping of concrete basically develops from time to time, and adjusts to the needs of each country or agency concerned.

Based on unit weight (SNI 03-2847-2002)

Lightweight concrete : unit weight <1,900 kg / m³

Normal concrete : unit weight 2,200 kg / m³ - 2,500 kg / m³

Concrete weight : unit weight> 2,500 kg / m³

SNI does not classify heavy concrete, but in general concrete with a unit weight above 2,500 kg / m³ is categorized as heavy concrete, although some apply a value of 3,200 kg / m³ as a heavy concrete lower limit Concrete whose unit weight is between the above categories is generally not effective comparison of its own weight and strength, although there is no prohibition to make concrete with a unit weight between 1,900 kg / m³ - 2,200 kg / m³

1. BASED ON CONCRETE QUALITY

(SNI 03-6468-2000, ACI 318, ACI 363R-92) from cylindrical test objects (dia. 15 cm, height 30 cm)

1. Low quality concrete (low strength concrete): fc '<20 MPa
2. Medium quality concrete (medium strength concrete): fc '= 21 MPa - 40 MPa
3. High strength concrete: fc '> 41 MPa

2. BASED ON SERVICE

1. Conventional concrete, is a normal concrete that does not experience Prestressed pre-service stress
2. Pre-stressed concrete is concrete which is given pre-service stress at the time of manufacture, with a pre-stressing system
3. Post-tensioned concrete, is concrete which is given pre-service stress at the time of manufacture, with a post-tensioning system.

Pre-service stress delivery is generally designed to provide opposing forces with service style, so that when the reinforced concrete construction bears the load, it practically reduces the workload. This type or group concrete must be designed, implemented and supervised by experienced consultants and specialist contractors

3. BASED ON THE ENVIRONMENT

Concrete in special environments is generally grouped based on conditions that threaten the resistance of reinforced concrete construction:

1. concrete in a corrosive environment, because of the influence of sulfate, chloride, alkali salts, etc.
2. concrete in a non-corrosive wet environment
3. concrete in the environment exposed to weather
4. concrete in an environment protected from weather

in general, treatment, materials or design and implementation requirements are required specifically for the environment that have the potential to threaten the durability or durability of construction

4. BASED ON MAKING

From the way it is made, concrete is generally grouped:

1. In-site cast concrete, which is casted concrete in place, with mold or reference installed in the location of structural elements in buildings or buildings or infrastructure
2. Pre-cast concrete, which is concrete casted at a special manufacturing location, and then transported and assembled to be installed in the location of structural elements in buildings or buildings or infrastructure.