Ready-Mix concrete has become a pioneering product in the world of construction. Almost all modern structures require concrete. Schools, hospitals, homes, highways, bridges, flyovers, etc., use concrete to come into existence. Hence, the robustness and rigidity of structures depending on the quality and type of concrete used.

Ready-Mix Concrete has become the first choice in developed countries to build structures. Its usage in Bangladesh is also getting popular in recent years. If you plan to use concrete in your next project, you must know how to estimate and order Ready-Mix Concrete in Bangladesh. Ordering the right amount of concrete is a critical task as it will ensure less wastage and more efficiency in work. It can help your budget as well as protect the environment. Furthermore, there are some things you should take notice of before placing your next order.

How to Estimate Concrete Before Ordering

Ready-Mix Concrete is sold by volume to customers. Mixer trucks carry the product to the job sites per customers’ requirements. Before ordering Ready-Mix Concrete, discuss with your contractor how much you require. Otherwise, ordering too much or too little can disrupt the workflow.

Concrete estimation involves measuring and doing the math to figure out the amount. Here is a comprehensive guide to help you determine the amount of concrete you may require for a project.

Estimating the Amount of Concrete

In order to estimate the amount, you need to determine the following measurements.

• Fixing how thick you want the concrete to be
• Measuring the length and width of the area where you want to pour concrete
• Multiply the length and width to determine the square footage
• Convert the thickness of desired concrete from inches or centimeters to feet
• Multiply the thickness in feet with the square footage to determine the volume in cubic feet
• Convert the cubic feet to a cubic meter by multiplying 0.028

Here is an example to understand it better for a 10′ by 10′ concrete patio:

1.   10 x 10 = 100 sqft
2.   4 / 12 = .33 (Converting thickness to feet)
3.   100 x .33 = 33 cubic feet
4.   33 x .028 = 0.934 cubic meter

Generally, you need to determine the volume of the concrete you need to place. Then convert the measurement into a cubic meter or cubic yard to place your order.

If you plan to order Ready-Mix Concrete from a manufacturer, ask them about the minimum order value they are willing to deliver. Sometimes manufacturers do not deliver under a certain amount. Hence, it would help if you worked with bagged concrete or site-mixed concrete for smaller projects like pouring small slabs for sidewalks or patios, setting posts for fences or mailboxes, making repairs to foundation walls, walkways, or stairs, pouring small curbs, steps, or ramps, and footing for decks, pergolas, walls, and more.

On the other hand, if you plan to order a large quantity, you are good to go. Read-Mix Concrete is excellent for large patios, driveways, foundation slabs for a house, parking lots or commercial buildings, and sidewalks. There are also several benefits of using Ready-Mix Concrete to construct pool decks and modern buildings are incorporating these.

Your supplier will ask you how many cubic meters or yards of concrete they need to deliver. Many manufacturers will have a minimum order of 1 cubic meter and charge shortage fees when ordering partial batches. A standard mixer truck can carry around 7 – 8 cubic meters of Ready-Mix Concrete. Thus, estimate the amount accurately to avoid discrepancies. If your project requires more concrete, multiple trucks will be necessary.

Source: Concrete Network

Tips for Estimating Concrete Amount in Different Scenarios

Thickness Measurement

As a rule of thumb, add ¼” to the thickness of your concrete slab. It assumes that the job is evenly graded to the proper depth, and the grade is also well-compacted. When inspecting if one spot is 4″, some areas are 4.5″ to 5’’-the most optimum solution for both scenarios is to fix the grade.

Odd Shapes

Not every portion will be easy to calculate. Sometimes you will not find proper rectangular shapes to measure the square footage. But when encountering odd shapes, simply convert them into rectangles to estimate the required concrete.

Estimating the Amount of Concrete Needed for Footings

Footings do not follow the drawings accurately. Sometimes in rocky soils, the footings collapse when more enormous rocks are excavated. For example, a 12″ x 12″ footing may break on one side due to excavation or rain. Hence, check various spots on the footing to get an average size. A 12″ x 12″ footing may need to be calculated as a 12″ x 16″ footing to account for the odd shape. However, it will vary depending on the actual conditions you are working with. So, discuss with your contractor before placing an order.

Estimating Concrete Steps

Steps seem like a tricky task to estimate. However, following two simple tips to measure it accurately.

• Use the slab calculator to determine the Ready-Mix Concrete needed for the porch surface
• Use the footing calculator to determine the sides of the porch and the steps

Additional Tips

A perfectly placed order of Ready-Mix concrete will finish the job with a small amount left over. Never order the exact amount of concrete you require for a job. Because some amount of concrete will count as wastage due to spillage, transportation issues, and many more, a good rule of thumb is to order 5% extra for a task requirement.

If you order 20 cubic meters of concrete and get a leftover of 1 cubic meter, it is counted as a reasonable estimation or a good order. But it is not a good order if you are one cubic meter short. Remember, reordering smaller amounts will cost you extra and can hamper the quality of the project.

Extra costs of coming up short with concrete can include the following scenarios:

• Overtime payment for the crew.
• A short load charge from the nearby Ready-Mix Concrete supplier.
• A cold joint can occur if it is too late to pour down the second batch of concrete on top of the previous one. A cold joint weakens the concrete bond.

For accurately estimating the amount of concrete, try to remember the following tips:

• Use the discussed calculation methods to measure the amount.
• Figure out depths, widths, and lengths as they are built on the site. Do not order based on the plan of the project.
• Always order a bit extra to account for the loss.

It can be disappointing to be left with extra concrete you have no use for and have paid for. But it is almost impossible to calculate 100% accurately what amount you might require for a project. So, having an extra amount of concrete is the cost of construction, which can save you a lot of trouble compared to coming up short.

You can also request your Ready-Mix Concrete supplier to visit your worksite. A representative may come to your place to discuss the amount of concrete you might require. Compare the figure with what you have calculated. Discuss the variance with the supplier to get a better estimation.

Discussing with the representative is valuable as it can help you check the margin of safety, identify issues you have not thought of before, and get information on any local conditions that may interrupt your workflow.                                                                                       

The Advantages of Using Volumetric Concrete Mixing

Ordering Ready-Mix Concrete is an efficient method that guarantees that you only pay for the amount you require. Experts suggest ordering based on volume as it is the most cost-effective method. A skilled technician can ensure the ratio of the mix is precisely calibrated according to your concrete mix design. Therefore, you are not only paying for the concrete but also for the expertise of a trained professional who can assist you in completing the task and maintaining a high work standard.

Ready-Mix Concrete Ordering Tips

After you have finalized your estimation for concrete, it is now time to place your order. However, it would help if you consider some crucial aspects before placing your order. You could be ordering the wrong mix design, which can bring unsafe results for your structure. Here is a list of essential aspects you should consider:

Strength

One of the essential factors of ordering Ready-Mix Concrete is knowing what compressive strength you require. Generally, compressive strength between 3500 – 4500 psi is enough for slabs, 3500 – 5000 psi for slabs on grade, and 3000 – 5000 psi is for beams, slabs, girders, columns, and walls. Pavement requires strength between 4000 – 5000 psi; for footings and walls, 2500 psi is enough. Outdoor home improvement can be made with compressive strength of 3500 – 4500 psi. So, place your order accordingly.

Aggregates

The size of aggregates must be specified before you order your Ready-Mix Concrete. Honeycombing can occur if you place a large coarse aggregate of concrete in a cross-section where there is a high steel ratio. A standard must specify the maximum size of the coarse aggregates as it depends on the spacing between reinforcement steel placed inside the formwork. As a rule of thumb, the aggregate size should not surpass 1/5th of the narrowest inside form dimension and should not be larger than 3/4th of the spacing between the rebars. Ensure your contractor speculates these criteria before placing the order for Ready-Mix Concrete.

The Slump of Ready-Mix Concrete

A slump refers to the consistency of the concrete. The slump value can change due to the job’s requirements like spacing between the reinforcement, the type of formwork, and the slope of the place. Here is a list to help you determine of slump value:

• A slump between 2 – 4 inches for RCC foundation work
• 1 – 4 inches for footings and caissons
• A slump between 3 – 6 inches for beams, columns, slabs, and RC walls
• 2 – 3 inches of a slump for pavements
• 1 – 3 inches for heavy mass concrete work

Source: Concrete Construction

Entrained Air in the Mix

Air-entrained concrete is ideal if it has the probability of being exposed to freezing temperatures in service or during construction. In Bangladesh, the weather does not get near-freezing temperatures, and non-air entrained concrete is good enough. Typical air content in the concrete depends on the size of the coarse aggregate, and the standard range is 4% – 5% of the concrete volume. The tolerance for this value is around 1.5%.

Ordering Criteria

Before placing your order, adhere to the following guidelines:

• If the batching plant is far from the job site, make sure to consult with the manufacturer’s representative to specify the need for admixtures. Transportation long distances can negatively impact the quality of the concrete
• Confirm the arrival time of the trucks, especially if you have ordered more than one. You must account for the traffic and narrow roads in cities like Dhaka and Chittagong. Ask your contractor to ensure enough space for the trucks to move into.
• Confirm the mode of pumping concrete.
• Air or non-air mix
• The purpose of the concrete
• Concrete mix design method

Sometimes manufacturers may ask you to provide a washout area after the trucks have finished delivering. This is to prevent the setting of concrete in the truck. After the trucks have finished pouring concrete, provide liquid detergents to clean the trucks.

Summary

Ready-Mix Concrete has several benefits over traditional site-mixed concrete, and consumers demand it. As a result, numerous Ready-Mix Manufacturers have emerged in the Bangladeshi concrete industry. However, make sure to find the most reliable Ready-Mix Concrete supplier in Bangladesh and order from the manufacturer that provides good quality concrete and has a batching plant near your worksite. If you follow the discussed tips to calculate the amount of concrete required, contractors cannot charge you more with unrealistic measurements. Furthermore, make sure to order the correct type of concrete that will suit your job’s requirements perfectly.

Frequently Asked Questions (FAQs)

How do I know what concrete to order?

Ans: Discuss with your contractor what kind of concrete you require for your construction project.

How much extra concrete should I order?

Ans: It will vary depending on the type of work and the amount. But ordering around 5% – 10% extra is safe to avoid any risks.

What to do with the remaining concrete?

Ans: You can ask the manufacturer to take it away with them or give it to any concrete recycling company.

What to do if I order less than what I need?

Ans: You must place an order as soon as possible to avoid cold joints. Order from the nearest batching plant to save time.

How to find the nearest Ready-Mix Concrete supplier?

Ans: You can search online to find the nearest Ready-Mix Concrete supplier in your location.