Ready Mix Concrete Vs Site Mix Concrete
There are mainly two types of concrete used in construction i.e site mix concrete and ready mix concrete. In this article, we will briefly discuss the difference between ready mix concrete vs site mix concrete.
What Is Concrete?
Concrete is a composite material used in buildings that are made up of a hard, chemically inert particle component known as aggregate (sand and gravel) that is cemented together by cement and water. Concrete is one of the most commonly used construction materials.
Fine aggregates and coarse aggregates are both inert materials, whereas water and cement are active materials. Cement is a typical primary binding agent in concrete.
There are many different types of cement in the market that can be used depending on the need. Lime can also be substituted for cement. It has, however, gone out of favor in recent years.
The construction industry employs two types of concrete: Ready-mixed concrete and site-mixed concrete, which will be further discussed.
Properties Of Concrete
- Concrete has high compressive strength.
- It is not easily rusted.
- It hardens over time once it has reached sufficient strength after placement.
- Although concrete is weak in tension, steel can be used in areas where tensile loads must be resisted. Furthermore, its coefficient of thermal expansion is comparable to that of steel. As a result, unneeded tension is minimized.
- Because of its strong surface, it can also withstand abrasion.
- Cement concrete can also be used to build fire-resistant structures.
- When compared to steel construction, it is much more cost-effective.
What Is The Need For A Good Concrete Mix?
A proper concrete mix lays the groundwork for a strong and stable infrastructure. It entails a streamlined preparation procedure in which a mixture of components generates the necessary durability and strength for the concrete structure.
It is difficult to create a better concrete mix because each ingredient in the mix has specific qualities. All components must first be examined to identify their physical attributes. Another consideration is the current project location’s bearing capacity.
Key Characteristics Of Concrete
A good concrete mix is similar to a good chef’s recipe. Other cementitious materials or chemical admixtures are used in addition to the three main concrete components (cement, aggregates, and water).
Several concrete mixes typically trap air by incorporating air-entraining cement or admixtures. Chemical components in concrete mixtures should also be employed to delay, accelerate, or increase manageability.
Concrete mixes can use chemical components to reduce the amount of water used, enhance strength, and change the qualities of the concrete.
As a result, selecting the appropriate concrete mix is a vital process that must take into account both placement requirements and costs while offering an integral product. The following are the characteristics of a concrete mix:
Water Cement Ratio
The W/C ratio of the concrete mix establishes the ratio and relationship between the weight of water and the weight of cement added to the mix. These properties are proportional to the mix strength and have a direct and linear relationship. The more the water-cement ratio, the more workability and less the strength.
A concrete mix must also account for heat that is unconfined during chemical processes. As a result, it will fade away at a rapid rate without causing shrinkage or cracking.
Grade of Concrete
The grade of concrete chosen depends on its intended use.
Size of Aggregates
Before use, all aggregates should be quality scaled. Aggregates are an important component of every mix, and their selection is based on the physical attributes necessary for the design.
The workability of a concrete mix is a quality that identifies the mix’s ability to consolidate and be properly placed. As a result, it is possible to complete a product without any segregation.
This feature identifies the slump and mobility of concrete mixes. The slump is commonly used to measure this. The greater the slump values, the larger and more manageable the mobility will be.
A good concrete mix will undoubtedly give concrete that can withstand intense weather conditions and repeated changes without showing indications of degradation.
The more resistant concrete is to environmental variations such as drying, wetting, freezing, and heating, the more durable it is.
Concrete mixtures can also be classified according to their intended use, such as radiation protection, counterweights, resistance, and insulation. Density is the most common and one of the most important properties of a concrete mix.
What Is Site Mix Concrete?
Site mix concrete refers to concrete that is batched and mixed on-site. Site mix concrete is also known as on-site concrete or manual mix concrete. As the name implies, site-mixed concrete is volumetric concrete that is prepared on the construction site.
To achieve the appropriate strength, concrete components are combined in precise proportions. This method necessitates the use of formulas to determine the amount of ingredients and processes required to achieve the desired consistency.
To avoid any quality concerns in the concrete, workers must be precise and careful with the material’s proportions.
Advantages Of Site Mix Concrete
1. In terms of scheduled concrete works, a small quantity of batch can be required and produced.
2. The design can be rather optimized per strength result, and project managers can do value engineering to save money.
3. There are no order quantity restrictions.
4. It is not essential to rely on outside organizations to accomplish concrete works.
5. Site-Mix concrete is approximately 20% less expensive than ready-mix concrete.
Disadvantages Of Site Mix Concrete
1. More storage space is necessary for materials.
2. It is necessary to take care of site logistics.
3. Wastage of old materials, as well as periodic reconciliation, must be monitored regularly.
4 On-site qualified personnel should supervise concrete manufacturing.
What Is Ready Mix Concrete?
Ready-mix concrete is manufactured in a plant and delivered to the project site in an unhardened, plastic state that is ready for use. Ready-mix concrete is sold by volume, which is often measured in cubic meters.
Concrete ensures greater long-term sustainability and durability. Because skilled laborers perform the process, the resulting blend is of higher quality and more exact.
Advantages Of Ready Mix Concrete
1. A centralized concrete batching plant is built, from which concrete may be conveniently delivered to multiple sites.
2. A higher quality of concrete is generated because the ingredients are batched and mixed precisely.
3. Furthermore, the consistency of concrete quality may be accurately maintained.
4. Better concrete quality increases building speed while decreasing maintenance expenses.
5. It has the potential to alleviate the problem of mixing concrete on narrow roads. The factory can be located in remote industrial locations, and ready-to-place concrete is transported to the job site.
6. The space taken up by the materials kept on the site is freed up.
7. RMC does not necessitate the hiring or purchase of concrete preparation machinery.
8. Because concrete mixers are mainly noisy, there is less noise and dust pollution on the job site.
9. The labour involved in the manufacture of the concrete is also eliminated.
10. In comparison to the site, basic resources are not wasted as much in the factory.
11. When using RMC, modern construction techniques can be easily utilized.
12. RMC is very effective for mass concreting and construction work in narrow locations.
Disadvantages Of Ready Mix Concrete
1. It is important to make sure that the main road and access roads to the site are not obstructed.
2. In the case of RMC, travel time from the facility to the site is critical. Material batching is done in the central facility. However, the mixing takes place while the truck is in motion. If the time is not carefully calculated and handled, the concrete will not be adequately mixed when it arrives at the job site.
3. When compared to on-site concrete, more careful planning is required because the mixed concrete ready for placement arrives at the site, and delays in placement may result in the concrete hardening before placement.
4. Concrete setting may occur if there is traffic on the route. The unpredictability of traffic may pose a concern for RMC transportation.
5. Both concrete types are viable in construction projects, however depending on the needs of the project, one may have substantial advantages over the other.
The table below summarises a quick comparison and some of the benefits and drawbacks between ready mix concrete vs site mix concrete:
Ready Mix Concrete Vs Site Mix Concrete
|Factors Under Consideration
|Site Mix Concrete
|Ready Mix Concrete
|Slower procedure as a result of several processes and setting time.
|It is delivered ready to use and takes less time.
|To manufacture concrete on-site, a weight batch mixer is required.
|Needs no equipment at the construction site.
|Has to be done manually.
|It is computerized.
|Selection Of materials
|The client is responsible for this.
|RMC supplier is responsible.
|Should be mixed at the exact point of use, to avoid contamination.
|Within a project, it is possible to deliver to many places.
|Low rise structure.
|High rise structure.
|To store and maintain materials such as cement and aggregates, a controlled storage facility is required.
|There is no need for additional raw material storage space.
|Some materials are wasted during storage and mixing.
|Material wastages at the site are minimal.
|Continuous supervision is for consistency among batches. Because of inconsistency, the time for setting may vary.
|Quality that is obtained is consistent as a result of an automated and controlled environment.
|More man-hours are required to prepare concrete on the job site.
|Only skilled workers are needed to pour and compact the concrete.
|Materials must be estimated independently, and purchases must be arranged separately.
|Concrete can be considered as a single item.
|It is difficult to mix large amounts of concrete on-site.
|Large amounts of concrete can be delivered.
|All materials and mixing equipment must be transported to the building site.
|If the batching facility is located a long distance away from the construction site, the concrete will require retardants and other admixtures to keep it from setting. Transportation costs will rise, and there may be quality issues.
Despite its increased cost, ready-mix concrete is often preferable for many jobs. When concrete is manufactured in a factory environment, it has greater quality and less fluctuation between batches.
Another important factor is the project’s location: transportation requirements influence which type of concrete is best suited for a project. Ready-mix concrete is typically recommended for large projects requiring a huge volume of material.
Site mixing, on the other hand, is a preferable alternative for minor projects and renovations with a small concrete volume.