Few construction materials are as important and versatile as concrete. As urban landscapes grow in size and complexity, the demand for durable, cost-effective and sustainable concrete solutions continues to be high.
Choosing the right type of concrete for your construction needs is slightly more complex than a one-size-fits-all solution.
Read this brief guide on what you need to know before choosing concrete.
You can estimate the volume of concrete needed for a particular element of construction using three dimensions.
Construction experts recommend multiplying the length by the width and the height (L x W x H). If you use feet as the standard measurement unit, the formula will give the volume of concrete in cubic feet.
Accordingly, standardize all measurements into common units before you begin calculations for the amount of concrete you will need.
There are concrete calculators available on the internet to help you determine the weight and volume of concrete needed for various construction projects.
When calculating the amount of concrete needed for a construction project, you need to prioritize a few factors such as the type of structure and the mixing design.
Different structures dictate the use of different types of concrete, in the way a high-rise building requires higher strength concrete and a pavement may warrant a different mix.
You also need to consider the proportions of cement, sand, aggregate and water. These additions will affect the volume, thus affecting how much concrete you need.
You may also need to mix slightly more concrete than is calculated to account for changes to the project, over-excavation and wastage.
Also, if your construction project requires reinforcement, the amount of steel used affects the total volume of concrete needed.
Extreme weather variations, such as hot weather, can change the curing process of concrete thus warranting some adjustments in your mix design.
Concrete features different strength properties, each of which adds different qualities to make them ideal for various use case scenarios. The different types of concrete strength include;
This is the most widely used and reliable way to measure concrete strength to evaluate how well a particular concrete mixture works. It gauges the concrete's resistance to loads that cause the material to contract in size.
Concrete cylinder specimens are broken in a specialized apparatus made to measure this kind of strength to determine the material's compressive strength. Pounds per square inch (psi) is the unit of measurement that is standard for this kind of strength.
Since it is the primary criterion for determining whether a particular concrete mixture will satisfy the requirements of a particular job, the significance of compressive strength cannot be understated.
The compressive strength of concrete is measured in pounds per square inch (psi). A greater psi indicates that a given concrete mixture is stronger, and thus more expensive. However, these tougher concretes are also more durable, which means they will last longer.
The appropriate concrete psi for a specific project is determined by a variety of factors, but the basic minimum for any project is often between 2,500 and 3,000 psi. Each concrete construction has a psi range that is typically acceptable.
Concrete footings and slabs on grade typically require 3,500 to 4,000 psi concrete. Traditional concrete walls and columns typically vary from 3,000 to 5,000 psi, whereas pavements require 4,000 to 5,000 psi.
Colder temperatures require a higher psi for concrete structures to endure more temperature fluctuation cycles.
To measure the psi, compressive strength is normally tested after seven days and again after 28 days. The seven-day test is used to determine early strength increases, and it can be performed as early as three days in some situations.
The ability of concrete to withstand breaking or cracking under tension is referred to as tensile strength. It has an impact on the size and frequency of cracks in concrete buildings. Tensile forces that surpass the tensile strength of the concrete cause cracks.
Compared to its compressive strength, traditional concrete has much lower tensile strength. This means that concrete constructions subjected to tensile stress must be reinforced with high-tensile strength materials, such as steel.
Because it is difficult to evaluate the tensile strength of concrete directly, indirect methods are used. Flexural strength and split tensile strength are the two most popular indirect approaches.
Another indirect metric of tensile strength is flexural strength. It is defined as the ability of an unreinforced concrete slab or beam to withstand bending failure. In other terms, it refers to the concrete's ability to withstand bending.
Flexural strength is typically between 10% and 15% of compressive strength, depending on the concrete mixture.
Flexural tests are extremely sensitive to the preparation, handling, and curing of concrete. Therefore, compressive strength test results are more commonly utilized for describing the strength of concrete since they are considered more dependable.
This refers to the water-to-cement ratio in the concrete mixture. A lower water-to-cement ratio results in stronger concrete, but it is also more difficult to work with.
To attain the desired strength while maintaining workability, the proper balance must be reached.
Traditional concrete is composed of water, cement, air, and a sand, gravel, and stone aggregate mixture. The proper mix of these elements is critical for increasing concrete strength.
A concrete mixture containing too much cement paste may be easy to pour, but it may crack and fail over time. In contrast, using insufficient cement paste results in rough and porous concrete.
The optimal mixing time is critical for the strength of concrete. While mixing time does boost strength to a degree, combining for too long might induce excess water evaporation and the development of fine particles inside the mix. As a result, the concrete becomes more difficult to work with and less robust.
The longer concrete remains moist, the stronger it will become. When curing concrete in excessively cold or hot temperatures, precautions must be taken to preserve the concrete.
By multiplying the length, width, and height of a planned structure, the volume of concrete required for construction can be determined. Before performing calculations, standardize the measurements you take.
Consider structural type, mix design, and weather to end up with the right amount and strength of concrete.
Water/cement ratio, quantities, mixing time, and curing procedures are all factors that influence concrete strength.
Longer exposure to moisture improves strength. A proper balance of these components promotes strength as well as workability.