Abstract
To apply the limitation of amount of material passing standard sieve 75μm, micro particles, in aggregates as 1% for crashed coarse aggregate and 7% for crashed fine aggregate on limestone aggregate can be considered to be unreasonable by the following results from the study on the effect of micro particles in limestone aggregate on the properties for concrete.
(1) Micro particles in limestone aggregate produced from crushing and transportation is almost the same as a limestone powder additive for concrete.
(2) The micro particles increasing effects on loss of slump indirectly. It leads to loss of entrained air therefore it leads to loss of slump. A proper content of the micro particles in limestone crushed sand can be more than 10% to improve plasticity for concrete.
(3) The micro particles increasing leads to reduction of bleeding, acceleration of setting time, enhancement of strength.
(4) The micro particles increasing dose not deriver a harmful effect on drying shrinkage and durability to freezing and thawing.
