Enhancement of Physio-Mechanical Properties of Concrete Using Steel, PPF, SYF Fibers and their Feasibility for Road Construction

Abstract

Plain concrete has two major deficiencies, Aghuy y low tensile strength and a low strain at fracture. The tensile strength of concrete is very low because plain concrete normally contains numerous micro cracks. It is the rapid propagation of these micro cracks under applied stress that is responsible for the low tensile strength of the material, eventually leading to brittle fracture of concrete. In past attempts have been made to impart improvements in tensile properties of concrete members by way of using conventional reinforced steel bars and also by applying restraining techniques. Although both methods provide tensile strength to concrete members, they how ever do not increase inherent tensile strength to concrete itself. It has been found that the addition of small closely spaced and uniformly dispersed fibers to concrete would act as crack arresters and would substantially improve its static and dynamic properties. This type of concrete is known as "Fiber Reinforced Concrete" (F.R.C.) This paper gives experimental investigation of steel, polypropylene and synthetic fiber in a glance. 24 cubes and 16 beams of M-40 grade concrete have been casted for different volumes of fiber based on literature survey. These specimens have been tested for compressive and flexural strength in laboratory based on the procedure given in codes. The results are analyzed and final conclusion is drawn. Based on conclusion, the fiber percentage is selected with considering technical and economical aspects which is 0.3% polypropylene fibers. Two slabs having dimensions 1m X 1mX 0.25m, one with 0.3% polypropylene fiber and another with normal concrete of M-40 grade have been cast. These slabs have been observed for the crack behavior after 28 days curing to come to final conclusion of the work done.