ABSTRACT
The most comprehensive study of th i s type was carried out by Kay (3) on concretes to be considered for use in the hydraulic pressing of slabs. He investigated t r i a l mixes at three l e v e l s of A/C r a t i o , three l e v e l s of percentage fines, and five l e v e l s of W/C r a t i o , that i s , 45 t r i a l mixes, and also obtained r e s u l t s on production mixes. Two assessments of s u i t a b i l i t y were made, one on a too wet to too dry scale as judged by an experienced press operator, and the other on a scale of judgement of the finished product in terms of edge and surface defects. The r e s u l t was the diagram shown in Figure which i l l u s t r a t e s quite c l e a r l y the s u i t a b i l i t y band for the process. Further, Kay was also able to estimate that n = 1.94 rps and k = 1.7 ±0.3 Nms. These figures were
0.5 1.5 2'° 2'5 h ( N o b ) Fig.7. Kay's r e s u l t s , showing s u i t a b i l i t y band for hydraulic pressing process.
