شبكة التخطيط العمراني بسم الله الرحمن الرحيم
للكاتبين
Abdelaty, M. A. Ghazy, M. F. and Showaib, E. A.
Faculty of Engineering, Tanta University
ABSTRACT
In this paper, the effect of notch-size on the behavior of fibrous mortar beams in flexure is
experimentally investigated. Two types of fibers namely glass fibers and polypropylene fibers
are conducted. Identical single edge notched beams cast with glass fibers and polypropylene
fibers were prepared for testing. In addition, identical single edge notched beams cast with
plain mortar were prepared also and tested as reference specimens. A data acquisition system
capable of performing one thousand loops per second was used to continuously record load
and central deflection up till failure. The results were statistically analyzed from which the
notch- sensitivity effect on flexural strength, fracture toughness, fracture energy and
toughness were clearly determined. A decrease in the net flexural strength with the increase of
notch length was noticed only for short notches of plain mortar as well as for mixes
containing 1 % polypropylene fibers type. An increase on the net flexural strength was
recorded for higher notch lengths and for higher polypropylene fibers volume fraction. For
mixes containing glass fibers, an increase of the measured flexural strength was recorded at
all notch lengths.
For plain mortar mix, the fracture toughness KIC values were notch sensitive since the higher
the notch length the higher the fracture toughness values. Mixes containing fibers generally
were less notch sensitive materials although the slightly increase of the measured values at
higher notches.
The results of the fracture energy values indicated that the fracture energy was a notch
sensitive property for the investigated mixes. Moreover, toughness indices values of fibrous
mortar mixes were notch sensitive. The sensitivity degree depends on fiber type rather than
fiber volume fraction. Generally, the results indicated that notch size was found to be
significant of the evaluated properties