Flexural Strength
All the beams will be tested in ‘Universal Testing Machine’
under two point loading to obtain the Flexural strength of
the beams. Flexural strength of beam specimens are made as
soon as practicable after removal from curing pond.
Mark the distance 50mm of supporting rollers on each side
of the specimen and mark the distance 133.33mm of loading
roller from the supporting rollers. Then 2 point loading is
applied continuously, uniformly and without shock. The rate
loading is 180kg/Minute continuously. The load is increased
until the specimen fails and record max load carried by the
each specimen during the test. Also note the type of failure
and appearance of cracks. The following formula were used
depending upon distance of line of fracture(a) from nearest
support.
i. Flexural Strength =Pl/bd2
When ‘a’>13.3cm
ii. Flexural Strength =3Pa/bd2
When ‘a’ 11cm.
Where P= Average applied load, d= Depth of specimen, b=
Breadth of specimen, a= Cracking distance from nearest
support, l = Length of specimen.
As compared to 2% coconut fibre 1% & 3% coconut fibre
has given the lesser tensile value. Flexural strength is
increased up to 32% for 75 aspect ratio & 47% for 125
aspect ratio with 1% fibre. Flexural strength is increased up
to 45% for 75 aspect ratio & 50% for 125 aspect ratio with
2% fibre. Flexural strength is increased up to 34% for 75
aspect ratio & 31% for 125 aspect ratio with 3% fibre. As
compared to 2% coconut fibre 1% & 3% coconut fibre has
give the lesser Tensile value.