Bulk Aggregates for Sale – Important Factors to Consider for Concrete Mixes
Finding bulk aggregates for sale is not the problem; the problem is choosing the right materials for the particular construction project. First, let us have a look at what bulk aggregates entail. Aggregate is an inert filling material making up anything from 60 to 80% of concrete’s volume – and it can account for up to 85% of the concrete’s weight. The material determines the thermal, elastic, and dimensional-stability characteristics of the concrete. Both fine and coarse bulk aggregates are available for sale and when deciding which aggregate to choose, one has to consider the desired compressive strength of the concrete
When you are thus looking at the bulk aggregates currently for sale, consider the physical and mineral make-up of the material because this is important to determine the mixture required. In this regard, look at size gradation, texture, bulk weight, and moisture content. These, in addition to the ratio of cement to water, determine the workability, durability, and strength of the concrete.
The shape and texture of the aggregate influence the concrete in its fresh state more than when it has hardened. Rounded and smoother material used in the mix means a smoother and more workable concrete. Crushed stone provides improved bond properties but more cement is needed to ensure optimal workability of the concrete. Rounded and smoother sand provides for better workability. In essence, a rough surface makes for better bonding and thus an improvement in the strength of the concrete. A smoother surface means better workability but less bonding strength.
The grading of the material is also important, as it affects the paste required for optimal workability. The paste is the costly part of the concrete and the aim is to use less paste without compromising the strength and durability of the concrete. The amount of paste needed is determined by the void spaces that have to be filled in relation to the surface that has to be covered. Uniform aggregate particles mean more void space to fill and thus more cement required. Different sizes of particles mean more of the voids can be filled and less paste is needed, reducing the cost of the concrete mix. If more void spaces must be filled, the concrete becomes less workable. It is, therefore, important to achieve the right balance to ensure cost-effectiveness, workability, and strength.
We recommend making use of our bulk-supply and delivery services in Gauteng. We offer a wide range of aggregates for sale and can help you select the right inert filling materials that have the correct grading and shape.