Concrete is well-known around the world for its strength and durability, affordability, recyclable nature and more. A mixture of concrete in its simplest form includes water, cement and aggregates. Since these materials are easily located almost anywhere in the world, many countries are able to produce their own at a low cost.
Whether you’re using pre-mixed concrete or you’re making it yourself, one thing that must be considered is the concrete strength. Not every concrete mixture is created equal.
But how do you know you’re mixing the perfect batch? Or if you’re going the premix route, you might want to consider ways to strengthen the mixture for your project.
H2 – Concrete strength properties
Concrete strength can be measured in a few different ways. Let’s explore them below.
- Compressive strength
This is the most popular method of measuring the strength of a concrete mixture. Compressive strength is measured in pounds per square inch (psi). It measures the ability of the concrete mix to withstand loads that will reduce the size of the concrete.
- Tensile strength
This measures the ability of the concrete to withstand tension without cracking. Traditional concrete usually has a much lower tensile strength than compressive strength.
- Flexural strength
This is an indirect method of measuring the tensile strength of concrete. It is defined as the ability of an unreinforced concrete slab to resist bending.
H2 – Factors affecting concrete strength
There are a number of factors that affect the strength of your concrete mixture. Let’s explore them below:
- Water/cement ratio
This measures the ratio of water to cement in your concrete mixture. A lower water to cement ratio results in a stronger mixture, but it is more difficult to run with. A higher water to cement ratio results in a runnier mix which is easier to manipulate. The strongest concrete is that which contains a good mix of both.
- Proportion of materials
The basic things that are used to create a concrete mix include cement, aggregates and water. The amount of each one used helps to determine the overall strength of the mixture. For example, a mixture containing mostly cement will be runny and easy to pour. But this mixture would crack very easily. On the other hand, too little cement will result in rough and porous concrete.
- Mixing time
The time you take to mix the concrete helps to determine its strength. Finding the optimal time can be difficult, as it varies based on a number of factors: the type of mixture being used, the speed of the mixture, and the components used in the mixture.
Generally, the strength of the mixture increases the longer you mix. But mixing for too long will cause the water to evaporate from the mixture.
H2 – UHPC vs Traditional Concrete
While concrete is well-known as a strong and affordable material, the strength varies from batch to batch. Many different factors determine the ultimate strength of each batch. Newer concrete technologies have emerged to produce stronger mixtures than traditional batches.
This new technology is called Ultra High Performance Concrete (UHPC).