Effect Of Fibers On The Water Permeability Of Concrete Under Direct Tensile Loading

Durability of concrete has always been a matter of concern for all researchers and structural engineers around the globe.The depletion of durability is due to the structural cracks which the concrete members go through during the lifespan.Due to these various hazardous chemicals,gases and other dangerous substances trespass in concrete which results in the deterioration of concrete leading to minor and major cracks.These cracks must be monitored.Fibers have been immerged lately as the ultimate solution of this problem to minimize the cracking of concrete specimens.Therefore,a new setup was designed to analyze the water permeability of fiber reinforced concrete and to monitor the cracking point under the direct tensile loading state.Fibers of different dosage was used to understand the effect of fibers on water permeability and tensile strength of concrete specimens.The main content of this research was as follows:Firstly,the workability and air content of concrete was investigated.It was observed that higher fiber dosage decreased the workability and increased the air content.Secondly,the compressive strength and tensile loading was analyzed and it was observed that compressive strength increased marginally while the effect of fiber on tensile strength was substantial.At the upper fiber dosages,the cracking load was improved clearly and the improvement was gradual for different fiber dosages.For a fiber dosage of more than 1%(78kg/m~3)multiple cracking was witnessed.During the tensile loading the self-designed setup was used to analyze the real-time water permeability of concrete.The fibers played a key role to minimize the water permeability.The permeability of concrete decreased upon increasing fiber dosage.Steel fibers 1.25%containing 97.5kg of steel fibers showed minimum permeability.The designed water permeability setup worked efficiently during the course of experiments which validates its usage in future experimental works.Concrete cracks were tried to monitor using smart concrete concept.The setup was inspired by four probe method.The cracking point and the effect of water along the crack zone of the specimens was successfully monitored using the setup.This setup can be used as an alternative to the expensive embedded and exterior crack monitoring sensors in structural members like bridges and high rising buildings.Surface geometry of cracked specimens were studied using surface parameters of cracked concrete specimens after tensile tests.The surface roughness and Tortuosity was evaluated using a self-designed setup.Results showed that fibers helped in increasing surface roughness and decreased the tortuosity.The results showed the effectiveness of the designed setup.