ities for human motion 
ition measurement. Bio- 
using linear array CCD 
Asian Institute of Tech- 
ber, S.X., Robinson, M., 
round inspection of ob- 
netrics V", Vol. 3174, 
| - 282. 
International Archives of Photogrammetry and Remote Sensing. Vol. XXXII, Part 5. Hakodate 1998 
DISCUSSION ON THE RELATION BETWEEN THE INTERNAL TRANSFORMATION OF CONSTRUCTION AND 
SURFACE TEMPERATURE JOINTLY USING THE THERMAL IMAGE AND HEAT BALANCE MODEL 
Yukio AKAMATSU and Masahiro SETOJIMA 
Department of Research & Development 
Kokusai Kogyo Co., Ltd. 
2 Rokubancho, Chiyoda-ku, Tokyo, 102-0085 
E-mail:yakamatu@kkc.co.jp 
JAPAN | 
Yoshizumi YASUDA 
Department of Information and Computer Science 
University of Chiba 
1-33 Yayoi-cho, Inage-ku, Chiba, 263-0022 
JAPAN 
Commission V, Working Group I 
KEY WORDS : thermal image, heat balance model, non-destructive investigation, construction diagnosis, internal 
transformation 
ABSTRACT 
Many of civil engineering constructions have superficial and internal transformation along with the elapse of time. 
High attention is gathered on the investigation method using thermal image as it allows effective investigation by 
non-destructive and non-contact methods. In the application of this method, it is necessary to know in advance what 
kind of time serial changes in temperature the construction surface may show under specific conditions 
In this study, we made thermal image observation and empirically discussed the relation between the 
environmental change and construction surface temperature. Also, we studied the heat balance model to predict the 
time serial temperature change of structure under the outdoor environment. 
As a result of this study, we were able to clarify that the environmental changes such as in the atmospheric 
temperature and solar insolation would exert great influence on the surface temperature of construction which had 
a internal transformation. We were also able to construct a heat balance model which can predict with fairly high 
accuracy the temperature change of construction reflecting these environmental conditions. 
1. INTRODUCTION 
Many of civil engineering constructions have superficial 
and internal transformation due to the deterioration 
along with the elapse of time. Especially, in the case of 
concrete bridge, there is an apprehension that the 
surface layer concrete may exfoliate because of the 
corrosion of internal reinforcement bars. High attention 
is gathered on the investigation method using thermal 
image for the diagnosis of exfoliation locations as it 
allows effective investigation by non-destructive and 
non-contact methods. 
This method places focus on the fact that the existence 
of internal exfoliation gives an influence on the 
apparent thermal capacity of surface layer of 
construction and, in turn, on the surface temperature of 
the construction, and judges the existence and situation 
of the exfoliation by measuring the temperature 
distribution of construction surface. On the other hand, 
the surface temperature of construction is influenced to 
large extent by the environmental conditions such as 
insolation and atmospheric temperature in addition to 
the existence of exfoliation. In the application of this 
method, therefore, it is necessary to know in advance 
what kind of changes in temperature and what kind of 
time serial change the construction surface may show 
under specific conditions. 
One of the methods for this purpose is to measure the 
surface temperature of a construction or test structure 
which has deformation by some means, and accumulate 
the data of time serial changes under various conditions. 
In the past researches, however, the studies were 
concentrated mainly on the test structures, and the 
adequate studies have not been made on the time serial 
changes of actual outdoor structures under the various 
conditions. Another method is to make a model of 
thermal balance at the surface and inside of 
construction, and to determine time serial temperature 
change under the various conditions by theoretical 
calculation. However, since there were problems in 
structure of model and setting of parameter in the past 
studies, it is not likely to have accurately identified the 
actual time serial temperature change. 
In this study, we made thermal image observation on 
the slab and rail of bridge having an internal exfoliation, 
and empirically discussed the relation between the 
environmental change of outdoor and time serial change 
of construction surface temperature. Also, we studied 
the heat balance model which is necessary to accurately 
predict the time serial temperature change of structure 
under the outdoor environment.