Fiber, When Is Useful? - The Issues and Discussion of Modern Concrete Science - page 84

fiber-reinforced con-
crete was 1 MPa higher that ordinary concrete averagely when cementitious material
reached 430 kg. Discreteness of experimental data is large and regularity is poor (it
described in detail in the article of Appendix A:

The experimental result was that flexural strength of steel

problems and misunderstanding on
study and application of fiber reinforced concrete currently in China ), but the

concrete can basically meet the requirements of construction. As we held great
enthusiasm about applying the new technology of steel fiber in airport engineering,

construction experiments were conducted at once. During construction, lot of dif-

fiber tip emitting
concrete surface, and the experimental engineering had been accomplished wholly.
Going through suf

ficulties were overcome, such as mixing, fiber clustering, and

cient discussion on experimental results, all technicians

basically held a negative attitude on application of steel fiber. Main conclusions are

in three aspects: improvement on flexural strength is not signi cant; it is

① ②

different for construction; and engineering costs are basically doubled.

The results reminded me of experiment of applying shot steel

③

fiber-reinforced

concrete in slope supporting, which was conducted by Third Of ce of Chinese

Railway First Group in Qinghuangdao section of Jin-Qin Railway in 1986. It
directly in

fiber in Chinese military and
civil airport engineering. When someone proposed to do the same experiment
again, it would be opposed by engineers who join in the previous experiment,
certainly including me.
The third experiment was conducted at the end of 2003 at a military airport in
Ningbo. As for unsatisfactory effect of steel

uenced adoption and application of steel

ber was recommended
by someone. Five engineers, including the author, Han Ming-cang, Xu Zhong-huai,
etc., had undertook the task due to tribute and enthusiasm to new material and new
technology. The experiment had lasted for a year from beginning to end. It is
recognized by academia that main effect of polyester

fiber, polyester

fiber is avoiding plastic
shrinkage crack from happening [ 2 ], so we were eager to get this result. However,
experimental result showed that polyester fiber rarely had practical effect, which

made us feel rather disappointed.
The author and Han Ming-cang summarized the several experimental results and
wrote an article named

problems and misunderstanding on study and application of
fiber reinforced concrete currently in China. It was published on vol. 8 of Concrete,

a magazine mainly edited by Mr. Liu Ji-liang who was prestigious in China con-
crete scienti c and technological circles.

ection of the article was unexpected. More than ten discussional and
deliberate telephones were received by the author, including professors, engineering
technicians at construction

Re

fiber manufactured enterprise.
Several controversial articles were also published at the same year on Concrete.
In short, there is little argument on experimental result of steel

field, and bosses of

fiber while for

polyester fiber. A professor from Inner Mongolian University of Technology (his

name remained unknown until now) was quite agitated because his result of
experimental on polyester fiber was opposite to us. A letter to the author wrote by

Professor Qin Wei-zu of Tsinghua University was published on Concrete in
December of 2004. In the letter, he shared his viewpoint about adoption of

ber