| Title |
A Study on Concrete Quality Properties in Hot Weather Circumstance a using Mock-up Test |
| Authors |
Lim Suk-Do ; Jung Sang-Jin ; Paik Min-Su ; Kim Seong-Deok |
| Keywords |
Hot Weather Concrete ; Quality Management ; Hot Weather Circumstance ; Curing Temperature ; Concrete Test |
| Abstract |
When concrete is manufactured and used for construction in a hot-weather environment, the increase in the concrete temperature due to the high air temperature may lead to a high hydration temperature and thermal expansion that may affect the long-term strength of the concrete. In this study, a Mock-up specimen of an actual post was introduced in terms of concrete casting and maintenance in a hot-weather or summer environment. This study reviewed and evaluated the effects of hot weather on concrete hydration temperature and strength, and compared the results with those in the standard seasons (spring and fall), during which the temperature is similar to the standard curing temperature of 20ºC. There was a slump loss as a flow characteristic as time passed, which indicated that transport and outside air temperature changes must be reviewed in a construction site. In hot weather, the strength of the specimen varied via the curing method, and the specimen achieved the desired strength on the 28th day. The core strength was high at the lower part of the specimen. With the passing of time, the strength in hot weather became similar to that in the standard period. As for the hydration temperature, the temperature rise was faster in the hot-weather period due to the effect of outside air. The maximum difference between the temperatures at the center and on the surface was 8-13ºC depending on the material and the desired strength. The temperature crack index was 1.1 at 24MPa in standard period, 1.2 at 24MPa in the hot-weather period, 1.3 at 40MPa in the standard period, and 1.7 at 40MPa in the hot-weather period. The probability of crack occurrence was lower when the desired strength was higher and the concrete was cast in the hot-weather period. |