| Title |
A Study on the Estimation of Unit Water Content of Fresh Concrete Using Heat Drying Method by Micro Wave |
| Authors |
Han Cheon-Goo ; Jeon Chung-Keun ; Kim Kwang-Seo ; Kim Young-Deuk |
| Keywords |
Micro Wave ; Heat Drying Method ; Unit Water Content ; Fresh Concrete ; Mixing Factors ; Aggregate Factors |
| Abstract |
This paper is intended to investigate the influence of mixing and aggregate factors on the estimation of unit water content of concrete by heat drying method using micro wave. According to the results, as for mixing factors, estimated unit water content is a little smaller than mixture unit water content below 200kg/m3, but larger than mixture unit water content above 200kg/m3. As the replacing ratio of mineral admixture increases, the difference between estimated and mixture unit water content becomes small. As the amount of AE agent increases, estimated unit water content is smaller than mixture unit water content, so precaution for that should be taken. Estimated unit water content with the kinds of aggregate is larger in order of basalt, lime stone and granite aggregate. Also in the case of recycled aggregate, unit water content is estimated favorably in the range of ±5 kg/m3 in comparison with mixture unit water content, and it is found that if material segregation by fine aggregate ratio occurs, a error for estimation increases. Since estimated unit water content is smaller by 3kg/m3 than mixture unit water content due to a defect of absolute drying, correction for that is ne |