Assessment and classification of performance mixers - Final report

The RILEM Technical Committee TC 150-ECM has been working for the past few years on the definition of concrete mixer efficiency. The commission is preparing a document that is expected to turn into an international recommendation. This article describes the technical information that will constitute the recommendation. At the beginning, it deals with the definition of terms that characterize mixing, mode and principle. It includes a description of the different parts of the mixer container, paddle, discharge system, etc. This information should contribute to a better understanding between the various parties in both economic and technical exchanges. Then, the influencing parameters are described. Next, the mixing cycle is defined. This part in particular sets forth what should. be counted as mixing time. While highly conventional, the mixing time is of very great technical importance for the implementation of concrete mixing plants. Following this, random sample analysis and mixing quality measurement are described. The final parts describe qualification procedures and, in particular, set the parameters used to characterize a mixer, the testing conditions and the performance criteria. Mixer efficiency is Judged according to three performance levels - ordinary mixers, performance mixers and high performance mixers.