TRANSACTIONS OF THE JAPANESE SOCIETY OF IRRIGATION, DRAINAGE AND RECLAMATION ENGINEERING, Volume 167, Page 55-64 (1993)

A Method for Preventing Thermal Cracking in a Concrete Box Culvert Wall

Masato KUNITAKE*, Hidehiko OGATA**, Takao NAKAZAWA ***, Kenzou TAGUTI****, Tadashi KODAMA*****, Hiroshi YAMASHITA*****, Kazuto KIRIYAMA*****, Yoshiaki, TAGUTI*****, and Tadayoshi KIKUMURA******

*Faculty of Agriculture, Miyazaki University
**Graduate School of Agriculture. Miyazaki University
***Faculty of Engineering, Miyazaki University
****Kokudo kaihatu Consultant Co.
*****Department of Agriculture, Miyazaki Prefecture
****** Ready-Mined Concrete Association of Miyazaki

Abstract

　Although a lot of measures to control or prevent concrete cracks due to temperature changes are available at present, for economic reason or something, no special measures have been adopted for wall-structures whose thickness is relatively small. One of the causes of temperature cracking is that there is a sharp drop in the greatest internal temperature over a definitely pre-scribed time interval. Shortly after the maximum temperature of concrete deposited in the form of box culverts because of its exothermic reaction, thermal insulation was secured by tightly covering it with tarpaulin, and then it was thermally cured by burning a briquete inside them so that it might be kept warm to smoothly reduce the drop. As a result, no temperature cracking was found around them. The results of concrete temperature measurement with a thermocouple and of the three-dimensional finite element analysis of transient heat conduction have proved that the insulation is valid.