ABSTRACT
Abstrac t Yiel d stres s measurement s wer e conducte d o n a variet y o f concret e mixe s t o evaluat e th e influenc e o f th e fres h concret e structur e o n yiel d stres s an d pos - sibilit y o f yiel d stres s predictio n whe n compositio n i s known . Th e measurement s wer e carrie d ou t usin g rotationa l viscomete r wit h van e typ e impeller . Fo r unifor m descriptio n o f three-phas e structur e o f fres h concret e thre e parameter s charac - terisin g th e structur e o f aggregate , cemen t past e on d concret e mi x compose d o f the m wer e proposed . Th e objective s o f th e stud y wer e relationship s betwee n yiel d stres s valu e an d propose d parameter s o f th e structure . I t wa s foun d tha t i n th e absenc e o f norma l stresse s th e yiel d stres s o f fres h concret e result s fro m capillar y cohesio n an d varie s i n broa d limit s dependin g o n th e ratio : liqui d dis - persin g phas e volum e /soli d dispersed phas e surfac e area . Thi s relationshi p ha s ver y distinc t maximu m correspondin g t o th e constan t valu e o f th e cemen t past e volume / aggregat e void s volum e ratio . A matematica l mode l o f thi s relationshi p is given . Keywords : Fres h Concrete , Rheology , Yiel d Stress , Structur e Parameters , Measurements .
