• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.120-121
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• 2017

Generally, slump of plain concrete slab is about 120~150mm and slump loss is easy to occur. So, water is added to concrete because this method is convenient for Placing. In order to solve this problem, performance evaluation of concrete using improvement type PC admixture was carried out. Target slump is 210mm and compressive strength is 18MPa. As a result, slump reference value was satisfied 60 minutes after placing and 7-day compressive strength was 21~25MPa.

• Journal of the Korea Institute of Building Construction
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• v.17 no.5
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• pp.445-451
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• 2017

Because of the supply-demand problem of aggregate, recently, the construction sites using 100% crushed sand are increasing and the use of low quality aggregate such as farmland sand is increasing too. When the low quality aggregate is used, the various quality defect of concrete such as the strength reduction, the increase of shrinkage and bleeding can be occurred. Therefore, in this study, the performance improvement PC admixture was developed to minimize the quality defect of plain concrete of basement parking area, when the low quality aggregate was used at the plain concrete of basement parking area. The slump loss to elapsed time test, the compressive strength test, the bleeding test and the drying shrinkage test were carried out.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.263-270
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• 2011

In this study, the performance of Poly-Naphthalene Sulfonate (PNS) type-admixture used widely in South Korea and Polycarboxilic type-admixture(i.e., WF2000) developed in the J company of the domestic, for precast concrete products produced in the factories, was evaluated. With the 20% reduced usage of WF2000 compared to PNS type-admixture, workability was considerably improved due to high water-reducing ratio, accelerating effect of concrete setting and accelerant dispersant action, which the product has, under the high temperature. In addition, the development of initial and long-term strengths of PHC plies was predominant. For WF2000, it is also possible to correspond with the change of original materials and environmental conditions since the control of water-reducing and supporting forces is feasible. Accordingly, it was noted that WF2000 is superior for deterioration of production & workability and bad casting problems in summer and the solution of initial strength reduction problem due to the delay of setting in winter.