Experimental Investigation on Combined Effect of SBR and Steel Fiber on Properties of Concrete

Concrete is the most widely used construction material having desirable properties like high compressive strength, stiffness and durability under usual environmental condition. Also concrete is brittle and weak in tension. Plain concrete has low tensile strength and a low strain at fracture. These shortcomings have been overcome by reinforcing concrete. The properties of ordinary cement concrete are generally improved to a great extent by latex modification. Hardened cement paste mainly has an agglomerated structure of calcium silicate hydrated and calcium hydroxide bound together by the weaker forces, and therefore, micro cracks occur easily in the paste under stress. This leads to poor tensile strength and fracture toughness of ordinary cement mortar and concrete. In the present work, experimental test are carried out to calculate compression strength on cube, flexural strength on beam, spilt tensile strength on cylinder and pull out test on cube with embedded steel bar. Casting of the specimen is done in laboratory using 15% polymer (styrene butadiene rubber) with 1% to 10% of the hooked end steel fiber. The 16 mm diameter bars are used in the pull out test. All the test on hardened concrete is carried out as per the IS code of the respective test, Specimen to be casted. It is observed that by contras in the polymer modified concrete micro cracks are bridged by the polymer film on membranes which prevent cracks propagation and simultaneously a strong cement hydrate- aggregate bond is developed. As per result flexural strength and bond strength of concrete is increased with the addition of steel fiber and constant percentage of polymer.