How Does Aggregate Size Impact Concrete Strength?

When it comes to concrete, the size of the aggregate used in the mix can have a significant impact on its strength and durability. Larger coarse-grained aggregate can result in higher compressive strengths than smaller coarse-grained aggregate. Cook observed that the difference in compressive strengths due to aggregate size is increasing with a decreasing water-cement ratio and an increasing test age. Smaller coarse-grained aggregate also increases the flexural strength of concrete.

The increase in the granular composition of the aggregate increases the efficiency in the use of cement in concretes working in compression. At the same time, there is a reduction in deformation and an increase in Young's modulus and unit weight of concrete. The tensile strength of concrete is severely affected by the increase in aggregate size. The interfacial transition zone reduces concrete strength by producing weaker sections and microcracks.

When the right mix is selected, concrete suppliers can create the desired final concrete product with ease. By increasing the maximum grain size to 120—180 mm, the reduction in tensile strength is 30 to 50% compared to concretes with a maximum aggregate size of 20 mm. When designing concretes with given strength and deformation properties, aggregate roughness is one of the most important technological parameters important. Dzhavakhidze, “The Effect of Technological Factors on Concrete Fracture Strength, Stroitel'stvo i Arkhitektura, Tbilisi, No. As the aggregate size decreases, the mixture requires more water to suspend the particles and create a viable solution.

Coarse-aggregate mixes tend to stay in the 1% absorption range when mixed with the right amount of moisture to set the concrete. In addition, parts can segregate during the drying and curing process, leaving weak spots throughout the concrete. The ability to select the right type of concrete aggregate every time starts with learning how properties affect the final mix. An experienced concrete professional can use your project evaluation to identify the best shape and size of concrete aggregate for each phase of construction. As a result, most aggregate shapes and sizes offer high durability for a wide range of structures and other projects.

Here I will discuss how coarse-grained aggregate sizes affect various properties of concrete, such as its compressive strength, workability, etc. Larger concrete aggregate pieces in the mix can range from small, smooth chunks to large, jagged chunks.