The LCPC BOX: a cheap and simple technique for yield stress measurements of SCC

This paper deals with two simple and cheap techniques to quantify the workability of Self Compacting Concrete (SCC). The first one is the standard slump flow test. It is demonstrated that, although the slump flow test is a good quality control empirical test, it is not correlated to the yield stress of the tested material as the thickness of the sample at flow stoppage is of the same order as the size of the largest particles. The second test, the LCPC box, is an alternative new test developed at LCPC. It fulfills all the conditions needed to correlate the measured empirical value to the yield stress of the SCC tested. The analysis, the description and the protocol of this new test are described in this paper.