TRANSPORTATION OF READY MIXED CONCRETE

The fresh concrete that has been produced in the ready mixed concrete facilities should not lose homogenousity while being transported to construction site; its features should not be affected especially by the weather conditions such as heat, cold and humidity.  

The ready mixed concrete is transported by the specially produced trucks called transmixers to the place of dumping. The fresh concrete is shuffled during transportation at a low speed rotation of the mixer vessel (approximately 1 - 4 rotations / minute) and taken to the construction site without hardening.  

The mixer vessels have a capacity to carry 7 - 8 - 10 - 12 m³ of concrete. Besides there are smaller vessels with 4 - 6 m³ capacity to transport special project Shotcrete and grout concretes. According to concrete standards concrete that is carried in the transmixers vessels should not occupy over 80 % of the vessel capacity.  

The transportation period of concrete is maximum 2 hours or a total of 300 rotations. This period may be extended by using anti-hardening additives and similar precautions or shortened by taking into consideration other limitations after the consent of the parties.   

The transportation type and transportation distance of the fresh concrete must be taken into consideration when the blending ratios are designed.  

HOW TO ACCEPT READY MIXED CONCRETE

İThe producer is obliged to present to the customer at each concrete load (transmixers) delivery a computer printout, a printed document or hand written transportation and delivery document that has at least the following information.
( TS EN 206 - 1 / APRIL 2002 )

• Title of the ready mixed concrete facility,
• Serial number of the transportation and delivery document,
• Loading date and time,
• Plate number or the introductory information of the transmixer,
• Name of the recipient,
• Name and place of the construction site,
• Details or references of the contract (code number, order number, etc.),
• Volume of concrete in m³,
• Statement of conformity with the contracts and EN 206 - 1,  
• Name and sign of the certification body, if any,
• Time of arrival of the concrete to the construction site,
• Starting time of dumping,
• Dumping completion time.  

In addition, the following detailed information should take place in the transportation and delivery document.  

a.For designed concrete:

• Class of resistance,
• Environmental effect limits,
• Class of chloride content,
• Class of density and targeted value,
• Limit values of the concrete mixture ratios, it specified,
• Type of chemical additive and mineral additive, if specified,
• Special features if required,
• The largest reference grain size of the aggregate,
• Class of density or the defined target value for light or heavy concrete.

b. For the defined concrete:

• Detailed information related to composition of concrete, amount of cement, type of additive if any, etc.,
• Ratio of water / cement, class of density or target value as specified,
• The largest reference grain size of the aggregate.  

According to the standards the information given for defined concrete should be in harmony with the standard clauses.