Studies on Permeability of Self-Healing Built-In Bacteria Concrete
Srinivasa Reddy V1, Jyothi Kumar K S2, Seshagiri Rao M V3, Sasikala Ch4
1Srinivasa Reddy V, Department of Civil Engineering, JNTUH College of Engineering, Hyderabad (Telangana), India.
2K.S Jyothi Kumar, Department of Civil Engineering, JNTUH College of Engineering, Hyderabad (Telangana), India.
3M.V. Seshagiri Rao, Department of Civil Engineering, JNTUH College of Engineering, Hyderabad (Telangana), India.
4Ch Sasikala, Centre for Environment, JNTU Hyderabad (Telangana), India.
Manuscript received on 21 January 2013 | Revised Manuscript received on 28 January 2013 | Manuscript published on 30 January 2013 | PP: 119-125 | Volume-1 Issue-6, January 2013 | Retrieval Number: F0450021613/2013©BEIESP
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© The Authors. Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)
Abstract: Permeability is the most crucial internal factor in concrete durability. The durability of a concrete is closely related to its permeability. The permeability dictates the rate at which aggressive agents can penetrate to attack the concrete and the steel reinforcement. Water penetrability is defined as the degree to which a material permits the transport gases, liquids or ionic species through it. Water can be harmful for concrete, because of its ability to leach calcium hydroxide from the cement paste, to carry harmful dissolved species such as chlorides or acids into the concrete, to form ice in large pores in the paste, and to cause leaching of compounds from the concrete. Water absorption, sorptivity and water permeability measurement are some methods to determine the water penetrability of concrete. A triaxial cell permeability apparatus and method for determining water permeability of concrete are presented in this paper. This method utilizes Darcy’s Law for steady flow so as to relate water permeability to the rate of water flow under a pressure head. The major drawbacks commonly encountered in triaxial cell permeability apparatus are addressed by evaluating the water permeability as per as per German standard DIN 1048(Part 5):1991 specifications and MORT&H (Ministry of Road Transport & Highways) 4th Revision specifications. Test results indicated that bacterial concrete is highly impermeable than normal concrete. Permeability measurement techniques and durability modeling are based on the Darcy equation for permeability based on measurement of flow rate, and the Valetta equation for permeability based on measurement of penetration depth and time. Bacteria built-in concrete works on the phenomenon of microbiologically induced calcite precipitation. Calcite crystals formed, due to microbial activities of bacteria Bacillus subtilus JC3, seals the cracks and pores in concrete and enhances the strength and durability of concrete by making concrete impermeable to transport different fluids or gases, like water, chlorides, sulfates or oxygen
Keywords: Water Permeability, Durability, Bacterial Concrete, DIN 1048, IS 3085:196.
Scope of the Article: Concrete Engineering