• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.465-468
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• 2008

This study investigated the best condition when mixed sand with a river and crushed sand was used though the experiment for the properties of the concrete corresponding to the control of fine aggregate ratio to apply the mixed sand and properties of the fine aggregate at the ready-mixed concrete factory on Yeongnam and Honam. The physical properties of Yeongnam and Honam is satisfied with KS F 2526 and KS F 2527 except fineness modulus and passing amount of 8mm sieve. And, the mixed sand above two types which were incongruent to use individually was being used at each factory, and it was managed in accordance with KS. The flowabillity of the mixture proportion of concrete which was estimated by method of unit volume weight according to the fine aggregate ratio at each factory on Yeongnam and Honam was higher than existing mixture proportion. It was analyzed that the residual water due to decline of the surface area caused by reducing fine aggregate ratio was increased relatively. Accordingly, it was considered that the effect on the economic mixture proportion and improvement of durability might be possible.

• Economic and Environmental Geology
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• v.38 no.3 s.172
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• pp.319-334
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• 2005

Some of old fluvial sediments are originally composed of fine and silty-clay grains with sands or some of them have been segregated by weathering as a result of the influence of groundwater fluctuations. For this reason, some of old fluvial sediments are not suitable for using as fine aggregates. Furthermore, the old fluvial aggregates with comparatively good quality have been exploited for a long time and quality of most remainders have been significantly poor. Though many old fluvial aggregates do not satisfy the quality controls(QC) standards such as KS F2526 and KS F 2527, they must be utilized to various usage suitable far different quality categories. Thus, we try to make constant efforts to utilize aggregates of all qualities. This study shows that physical properties of old fluvial aggregates are both controlled by source rocks and also related to old fluvial environment.