There are many questions that must be answered before the order is even dispatched from the factory. It must be seen if a standard truck will be able to reach the construction site. Then, there is the choice of the truck type. It must also be foreseen if the movement of a fully-loaded truck will damage any property or service in the construction site. In case it will, a decision must be made between using a smaller truck and using concrete pumps. It is worth noting that the truck is not liable for any damages caused beyond the kerbside.
Working Safe with Concrete
If you think that concrete is just a harmless material like mud, you cannot be more wrong. Wet concrete is dangerous and can cause serious burns when in contact with the skin. Thus, to stay safe, it is strongly advised to use protective clothing and footwear when handling and using wet concrete.
When it comes to placement, it is a trade-off between time and efforts. Generally, wheelbarrows are used to transport concrete from truck to site. Since 1.00 m3 of concrete has a weight of 2400kg, it requires considerable efforts to carry it. If 50-litre concrete is transported at a time, it would need 15 trips and a load of 160 kg in each trip. Reducing the load would make it easier to carry, but increases the trips required. However, if it comes to a choice, the more efficient option would be to only fill half the wheelbarrows, even though it increases the time because it reduces the efforts and risk of spillage.
Apart from time and efforts, numerous other factors must be considered. As you might be aware, waiting time is a major issue. A concrete truck only has a waiting time of 30 minutes, which means that you only have 30 minutes to transport all the concrete from the truck to the construction site. Any additional waiting time beyond this would be charged at $2.00 per minutes, exclusive of GST.
If you are opting for wheelbarrows, ensure two things beforehand: that you have the necessary number of wheelbarrows, and that you have necessary people. Lack of either would only increase the waiting time, risking additional charges.
In cases like the amount of concrete is too much, when the exact site is difficult to access or when there aren’t enough wheelbarrows/people, it is prudent to go for concrete pumps.
Scope for wastage
Given the nature of concrete and how it is used, some wastage is inevitable. But as a smart customer, you should keep that wastage into account beforehand and order the quantity of concrete accordingly.
Generally, 10% concrete should be ordered extra for the various types of wastages. Measuring errors may require more concrete than anticipated, while some concrete may be waste inside concrete pumps. A host of other errors, like the variation in slab thickness, form deflection, over-excavation, irregular ground level or wrong placement on sand can all contribute in concrete wastage.
As a general rule, the final estimated quantity of concrete (including extra concrete) should always be rounded off to the nearest 0.2 m3. So, if you think that you would need 2.85 m3 for a domestic project and an additional 10% (or 2.85 m3) is added, the total amount of concrete would seem to be 3.13 m3. This amount should be rounded off to 3.2 m3, to be on the safer side.
In case you are wondering why, the reason is very simple: It is far more economical to order extra concrete, compared to ordering a small amount of concrete separately.