운반시간 지연에 의해 저하된 레미콘의 성능회복에 관한 기초적 연구 = A Fundamental Study on the Performance Restoration of Deteriorated Remicon by Delivery time Delaying

다국어 초록 (Multilingual Abstract)

In this paper, availability of deteriorated remicon due to delaying delivery time is discussed. According to test results, fluidity and air content of plain concrete exhibited a tendency to decline with a elapse of time. After 90 minutes since mixed, use of superplasticizer and AE admixture resulted in an increase in fluidity and air content. Adequate dosage of superplasticizer and AE adimixture is found to add with 0.4％ and 0.002％ respectively to restore the level of original slump and air content from loss one. Setting time of concrete exhibited an acceleration with an increase in leaving time of concrete. Compressive strength of plain concrete is enhanced with and increase of leaving time of concrete. Therefore, it is found that the use of superplasticizer with 0.4％ and AE admixture with 0.002％ has a desirable effect on restoring the deteriorated quality of concrete related to fluidity, air content and setting time without strength loss caused by delivery time delaying.