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Reply to a discussion by G.H. Tattersall of “Study of fresh concrete flow curves”
CEMENT and CONCRETERESEARCH. Vol. I I , p. 489, 1981. Printed in the USA. 0008-8846/81/030489-01502.00/0 Copyright (c) 1981 Pergamon Press, Ltd.
REPLY TO A DISCUSSION BY G.H. TATTERSALL OF "STUDY OF FRESHCONCRETEFLOWCURVES"* Velimir Ukraincik Department of Concrete and Masonry Structures Building Institute of Zagreb, Zagreb Yugoslavia I appreciate the comments and information given by Dr. Tattersall about the part of my paper regarding the results from rotating hook viscometer. In reply, I would like to emphasize some data about the method of measurement and offer the following comments.
I)
The procedure of loading the bowl of the viscometer with fresh concrete applied in our experiments essentially d i f f e r s from the procedure described in Reference 3 of Dr. T a t t e r s a l l ' s discussion. Namely, after loading a certain mass of fresh concrete into the viscometer, f i r s t , the lower y i e l d point was measured, and after that the moments for six speeds from lowest to the highest were measured progressively. In this way in the course of measurements the concrete sample suffers volume changes followed by alteration in f r i c t i o n , granular i n t e r ference and occasionally capillary forces.
2)
Idealised diagrams suggested in Fig. 3 can well be seen in cases of cement paste or aggregate mixture flow curves respectively. Their shapes have indicated the s i m i l a r i t y with diagrams of most concrete mixtures. In our experiments, only medium and high workable mixtures with A/C r a t i o 4.5:1 have nearly s t r a i g h t lines.
3)
Fig. 4 is the sketch of possible intersection of flow lines and reverse sequence of y i e l d points in cases described in the paper on page 207. This is why Fig. 4 d i f f e r s from data given in Table I .
*CCR I__00, 203 (1980).
489
REPLY TO A DISCUSSION BY G.H. TATTERSALL OF "STUDY OF FRESHCONCRETEFLOWCURVES"* Velimir Ukraincik Department of Concrete and Masonry Structures Building Institute of Zagreb, Zagreb Yugoslavia I appreciate the comments and information given by Dr. Tattersall about the part of my paper regarding the results from rotating hook viscometer. In reply, I would like to emphasize some data about the method of measurement and offer the following comments.
I)
The procedure of loading the bowl of the viscometer with fresh concrete applied in our experiments essentially d i f f e r s from the procedure described in Reference 3 of Dr. T a t t e r s a l l ' s discussion. Namely, after loading a certain mass of fresh concrete into the viscometer, f i r s t , the lower y i e l d point was measured, and after that the moments for six speeds from lowest to the highest were measured progressively. In this way in the course of measurements the concrete sample suffers volume changes followed by alteration in f r i c t i o n , granular i n t e r ference and occasionally capillary forces.
2)
Idealised diagrams suggested in Fig. 3 can well be seen in cases of cement paste or aggregate mixture flow curves respectively. Their shapes have indicated the s i m i l a r i t y with diagrams of most concrete mixtures. In our experiments, only medium and high workable mixtures with A/C r a t i o 4.5:1 have nearly s t r a i g h t lines.
3)
Fig. 4 is the sketch of possible intersection of flow lines and reverse sequence of y i e l d points in cases described in the paper on page 207. This is why Fig. 4 d i f f e r s from data given in Table I .
*CCR I__00, 203 (1980).
489