Will a standard concrete truck be able to get access to where the concrete is to be placed? Do I require a mini mix, maxi or twin steer truck for the concrete delivery. If a fully loaded concrete truck is to be driven onto the property, will it cause damage to items such as driveways, paths, patios and services in the ground such as stormwater and sewer pipes? If so, will a smaller truck such as a mini-mix truck avoid the problem, or will it be better to pump the concrete from the street? Concrete trucks are not liable for any damages beyond the kerbside.
The simplest method of placing concrete is to be able to discharge the concrete directly into its final position from the concrete truck, ie placement by chute. If wheelbarrows will be used to transport the concrete from the truck to its final position, remember that 1 m3 of concrete weighs about 2400 kg. Using a conventional 50-litre-capacity wheelbarrow will take 15 trips and each wheelbarrow load will weigh about 160 kg. To make transporting the concrete easier, it is recommended to only half fill each wheelbarrow, even though it will double the number of trips.
Also, remember that the concrete truck has a 30 minutes to unload and after this point waiting time will be charged. Waiting time is charged at $2.00 per minute +GST.
If emptying the concrete truck using wheelbarrows make sure you plan to have the appropriate number of wheel barrows and people to push the barrows in order to avoid truck waiting time charges.
Concrete pumps can be used when it is required to place large volumes of concrete, when tight access becomes an issue and when you simply can't get enough guys to push wheelbarrows.
When handling and using wet concrete, avoid contact with the skin and wear suitable protective clothing and footwear. Concrete burns can be a serious health risk.
As a general rule for small projects, 10% extra concrete should be allowed for wastage when estimating the volume required. This allows for small errors in estimating and/or allows for concrete left in the hopper of a concrete pump. Concrete volumes should be carefully estimated from on-site measurements and not from drawings or plans. Variations in the slab thickness, deflection or movement of forms, over excavation, uneven or irregular ground levels, placement on uncompacted sand or fill and use for other minor items are all things that can not be assessed from drawings or plans. Concrete can be ordered in multiples of 0.2 m3, so when ordering the concrete the estimated quantity should be rounded up to the next 0.2 m3. For example, if it is estimated from measurement that 2.85 m3 is required for a garage floor slab, add an allowance for wastage (say 10% or 0.28 m3) giving a total of 3.13 m3, round up to the nearest 0.2 m3 and order 3.2 m3.
Remember when ordering concrete, it is far more economical to order a little extra and to send the excess back than to have to order a small additional quantity to finish the job. This will save you money in the long run.