What goes into concrete? - Concrete is a mixture of sharp sand (fine aggregate), gravel (coarse aggregate) and cement. This mixture can be used for anything from house foundations to foundations for a garden wall of concreting in fencing posts, due to the many applications that this mixture can be put to there are different ratios at which the materials can be mixed
General Purpose Concrete Mix -
Here we concentrate on a general purpose concrete mix suitable for garden paths, fence posts, and shallow retaining wall foundations in all a general purpose domestic concrete mix. This concrete mix is a medium strength mix called a C20 mix. This means it will attain a strength equivalent to withstanding a compression of 20 Newton’s per square mm after 28 days. A stronger concrete mix is required for house foundations concrete.
Stronger Concrete Mix -
If a stronger mix is required, this can be called a C35Pmix, the mix is 1 cement, 1 gravel and 2 sharp sand, or 1 cement to 3 ready mixed aggregate.
Material Prices -
If you click on any of the icons on this page you will establish costs for materials such as sand, cement and ballast, as well as hire charges for cement mixers and transformers all at great prices and delivered to you for free. Bulk bags of ballast (sharp sand and gravel) can be bought ready mixed, or delivered loose on a tipper lorry if you require a larger quantity and have the room to tip it. Ballast is also called ½ inch to dust in the West Country.
|For Handy and Bulk 1 ton Balast bags prices with free delivery |
Click here >
|For 25kg cement bag prices with free delivery |
Click here >
|For 25kg bags of ballast & sand with free delivery |
Click here >
Water is a very important part of the mix and the volume of water used can dictate the strength of the finished mix. Where all materials sand etc are dry the ratio of water to cement should be 0.55. If one bag 25kg of cement is required for the mix if you times 25 x 0.55 it gives you 13.75kg which equates to 13.75 liters of water. In the real world sand and aggregate already contain high levels of water so caution is required when mixing to ensure to mixture does not become to sloppy, when shovelled up the mix should almost be self supporting
The correct mix -
When we come to mix the concrete there are a few things to take into consideration. It is important to get the right volumes for your mix and while ballast will heap up on your shovel, cement will slide off giving inaccurate volumes for the mix. To avoid this problem use a bucket to ensure 1no cement to 6no of ballast.
|Using a mixer -|
Mixing by hand is difficult and should be avoided if possible unless mixing a very small amount of concrete, it is difficult to get an even mix of cement and this will result in weakened concrete.
For great rates on cement mixer hire with free delivery and collection. Click here >