| Title |
An Experimental Study on the Flowability and Strength Properties of Normal Strength - High Fluidity Concrete by Combination of Polycarboxylate Superplasticizer and Viscosity Modifying Admixtures |
| Authors |
공태웅(Kong, Tae-Woong) ; 이한승(Lee, Han-Seung) |
| DOI |
https://doi.org/10.5659/JAIK.2021.37.4.223 |
| Keywords |
High Fluidity; Normal Strength; Viscosity Modifying Admixture; Passing Ability; Filling Ability |
| Abstract |
High fluidity concrete has a high level of fluidity with the segregation resistance and the self-compacting property without the extra work for
compaction. Therefore this concrete represents high quality concrete with excellent workability and enables the easy production of heavily
reinforced concrete structures of complex geometry. Despite its obvious advantages, the high cost of high fluidity concrete prevents its wider
use. Also the application of typical high fluidity concrete is limited in the normal strength range (18~35 MPa) because of the uneconomical
strength development due to large amount of binder. It is required to design the formulation of an economical binders, proper materials and
mixtures for normal strength and high fluidity in order to expand the usability of such high fluidity concrete for general application. But if
the usage of binders is low in concrete, it is reduced the fluidity and segregation resistance due to the decrease in self-compacting reduction
by lack of viscosity. The aim of the study is to evaluate the fluidity and strength of high fluidity concrete for normal strength range using
the combination of polycarboxylate viscosity modifying admixture (P-VMA) and methyl cellulose viscosity modifying admixture (C-VMA). To
improve the fluidity of concrete, this paper investigated the effects of VMA on the slump flow, passing ability, self-compacting and
segregation resistance. In addition, the effect of VMA on compressive strength was investigated. The dosage of P-VMA and C-VMA in the
mixtures was 0.2%, 0.4%, 0.6% and 0.1%, 0.2%, 0.3% by weight of the total biders, respectively. As a result of this study it has been
found that addition of VMA to concrete improves its fluidity and segregation resistance by increasing the viscosity of concrete, but the
compressive strength decreased with increase of VMA. |