| Title |
Temperature History and Strength Development of Concrete Depending onColumn Size and Form Type Subjected to Cold Weather |
| Authors |
Han Cheon-Goo ; KIm Seoung-Soo ; Lim Choon-Goun ; Kim Jong-Baek |
| Keywords |
Cold Weather Concreting ; Bubble Board ; Insulating Form ; Temperature History ; Frost Damage at Early Age |
| Abstract |
The objective of the paper is to discuss an effective surface insulation curing method of column concrete when placed under cold weather condition in response to varying their column sizes and form types. In this test, the temperature profiles and strength development of the specimens are examined. According to the test results, it was clear that the temperature of specimens tended to decrease to below 0℃ more quickly as the section size of specimens was smaller, thus the specimen bigger than the size of 200×200mm maintained the temperature above 0℃ considerably, which can protect concrete from frost damage at early age. This is due to the heat keeping capacity of larger specimens, although there was no insulation curing methods prepared. In addition, using the metal and plywood form on the specimens sharply dropped the temperature to the below 0℃ before 24 hours as soon as they moved into the cold condition of a curing chamber. However the use of the bubble board and insulating form on the specimens did not result in a temperature drop of concrete below 0℃ at any part of specimens, and after around 36~48 hours, temperature of concrete was even back to rise again by their increased hydration heat. Importantly, the maturity of concrete using the bubble board and insulation form indicated more than 50°D?D, which satisfied minimum maturity, 40°D?D, for protection from the frost damage, proposed by Koh. Moreover, the compressive strength of concrete using the bubble board and insulating form had the largest values, compared to those of other types of forms. |