Doctor of Concrete—Self-healing - The Issues and Discussion of Modern Concrete Science - page 150

Fig. 12.5 Numerical display of press machine

The author arrived at their laboratory and had seen that concrete which was
placed at the second time had already connected with concrete which was placed at
the

first time. However, as aggregates employed in the former and latter concrete
were different, the linkage place was obvious (as shown in Fig. 12.6 ). After testing,
strength had met designed strength of C40 concrete, but the specimen ruptured from
the linkage place again. There were white precipitates on fractured surface,
as shown in Fig. 12.7 .
The author asked tester to tie the destroyed specimen up again by iron wire and
put in into curing pool for curing for purpose of con rming whether they could

bond together again or not. It is found that they bonded together after 28 days, as
shown in Fig. 10.8 . The strength is 32 MPa via testing on press machine, which
reach requirement of C30 concrete. Yet, the specimen ruptured from linkage place
once again, as shown in Figs. 12.8 and 12.9 .
In 2006, after pouring by spring rain for several days in the next year, floor of

Hohhot Airport which was constructed in winter leaked water seriously. In August
of the same year, having been poured by heavy rain for a couple of days, the

oor
did not leak any more accidentally (as shown in Fig. 12.11 ). However, trace of the

first leakage still existed (Fig. 12.10 ).
In order to verify feasibility of applying self-healing in engineering, together
with engineers of Xi Qing, Ye Shao-fu, Yuan Xiao-juan, et al., the author had
seized the condition that self-healing phenomenon was continuously discovered in
Hohhot and conducted multiple experiments on self-healing phenomenon repeat-
edly in airport construction site laboratory.