CASE STUDY: Cemen Tech Stationary Mixer for Pre-Cast

What Was The Project?

The Cemen Tech SCD5-100 was recently and very successfully used for an infrastructure project to create pre-cast concrete segments for a tunnel lining.  The concrete panels were to be manufactured in their thousands over a period of nine months, therefore a solution had to be found to ensure the manufacture process was not only cost effective but also of high accuracy and consistency.

A Solution To Suit The Complexity Of The Project

Initially, our thoughts were to utilise a traditional mixing method of a series of large one tonne pan mixers manufactured by ANTEC, which for many years have been the most common solution in the refractory industry for mixing low cement castable products.  This solution would be too problematic for this specific project due to a high level of manufacturing crane movements needed to feed this machine with raw materials along with concerns of batch control, and hence, not the most viable solution.


A prime focus was to ensure 100% of the pre-cast blocks produced in the moulds would meet the concrete design criteria, as failures and defective products would not be accepted. Therefore, throughout the production process, the ability to monitor and control the ratio of raw ingredients of stone, cement and water was imperative, which is where the Cemen Tech Stationary Mixer was offered as the best solution.

stationary mixer

The Cemen Tech Stationary Mixer

Sand, stone and cement were delivered to the manufacturing plant in bulk and loaded into the Cemen Tech Stationary Mixer.  A conveying system was developed to move the moulds along to a finishing area where the tops were vibrated and screeded for curing.  The Cemen Tech Stationary Mixer is controlled and monitored using a small computer referred to as an AP2.  This computer allowed the production team to access information regarding the volume of concrete produced and the details of raw materials used via USB exported and printed data.

Initial trials provided the opportunity to adjust the mix design to accurately understand what settings to apply to each ingredient.  Once this was determined and set, changes were very rarely made to the stone gates, cement ratio or water flow.  Several moulds were produced in this initial testing phase to be cured, cored and analysed.

The Final Result

The use of the Cemen Tech Stationary Mixer removed the reliance on and subsequent frustration that comes with waiting at the job site for a subcontracted delivery of conventional ready-mix concrete.  The real advantage lay in the fact that casting of concrete was produced throughout the project as required, six days a week for a nine month period, with very minimal waste of materials and labour.

Return on investment was 6 months with 50 tonne of material used per week.  The project was completed 4 months ahead of a schedule that had been shortened after the project commenced by the major contractor by 3 months.  With the high level of accuracy and consistency provided by Antec’s solution of the Cemen Tech SCD5-100, there were only 5 panels out of the 80,000 produced that didn’t pass QA testing.