| Title |
Influence of Experimental Factors on the Rebound Value of P Type Schmidt Hammer |
| Authors |
Han. Cheon-Goo ; Lee. Yong-Sung ; Kim. Ki-Jeong |
| Keywords |
P Type Schmidt Hammer ; Pressure ; Thickness of Specimen ; Humidity ; Restrike ; Strike Position |
| Abstract |
This study is intended to search for how the influencing factors have effect on the rebound value of P type schmidt hammer as a part of a study on quality control of concrete by P type schmidt hammer. According to the results, as the influence of pressure, the rebound value of P type schmidt hammer increases with increase of pressure below 2.5MPa, but it shows the invariable value above 2.5MPa. As the specimen decreases in thickness, the rebound value also decreases, and so thickness of specimen needs to be more than 120mm under the condition of this experiment. As the specimen grows dry, the rebound value increases, but after drying for 15 hours, it becomes constant without increase of rebound value. As the number of strike increases, the rebound value increases, and so it is thought that restrike should not be done. The rebound value decreases by 30% at a side of specimen, but it becomes almost constant at the position over 25mm from a side. Comparing the rebound value of upper part with that of the lower part, the former shows the lower rebound value than the latter. |