Concrete Volume Estimation

Concrete volume estimation and how to order it  are two topics that all civil engineers need to know about. These details may seem trivial but they can become a nightmare for young newly employed civil engineers. So let’s clarify it.

In most of countries, to order concrete mixture you need to request it by filling an official for containing some information about :

• Delivery address, time, and the name of company that orders it.
• The usage of concrete, is another important factor. Sometimes the producer can give you some suggestions or even correct your mistakes because at the end the day they are professional in this matter.
• The volume: you need o be able to estimate the amount of required concrete mixture. However there are some Apps and pieces of software to do it for you, it is highly recommended to calculate it manually. Here is a useful page that offers this service for free:

http://www.calculconversion.com/concrete-calculator.html

 

• The Class of the concrete which may be either normal or special class. Depending of the class of concrete, site engineers need to check some of concrete specifications at the time of arrival.

NORMAL CLASS CONCRETE	Strength: 20, 25, 32, 40 and 50 MPa at 28 days. slump at delivery time: 20–120 mm maximum size of coarse aggregate: 10, 14 or 20 mm
SPECIAL CLASS CONCRETE	This group includes any concrete with customized specifications. For example slump, lightweight aggregate, color pigments must be mentioned.

 

Tip 1 : Always check the slump of the mixture and take cubic samples in order to control and verify the quality of concrete production. In many cases, when truck mixer drivers stick in traffic jam they add water to the mixture to prevent its hardening. SO ALWAYS CHECK THE SLUMP OF EACH TRUCK MIXER.

Tip2 : Always order more than you have estimated. A 10 percent redundancy is completely reasonable due to concrete waste as well as shrinkage. Depending on the country, the increments may be different but is most regions the increments is 0.2-m3.

Tip 3 : time management plays a crucial role. The trucks must arrive in orders and within a time interval so that you have enough time to emplace the concrete before the arrival of the next truck.