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RA. B Depaa ¹, T. Felix Kala ¹

Affiliations
1 Dr. MGR Educational and Research Institute University, Chennai - 600095, Tamil Nadu, IN

Abstract

The process of self-healing of concrete has been gaining momentum nowadays due to increased deterioration of concrete structures subjected to adverse environmental conditions. Admixtures like silica fume and ground granulated blast furnace slag is one of the self healing agents being experimented recently. The method of usage of Silica fume and ggbfs, the waste derivatives from coal and steel industries, strength and durability testing of these mixes for achieving the self healing property has been presented. The effects of self-healing on normal concrete by adding small amounts of GGBFS and silica fume to concrete is studied. For this purpose, silica fume is added to concrete at percent of 0%, 2.5%, 5%, 7.5%, 10%, 12.5% and cement has been replaced with GGBFS by 35% and 55% respectively. The adopted water binder ratio for silica fume and GGBFS mixes is 0.45. M30 mix design is being done as per the Indian Standard Code IS: 10262-1982. The specimens are first tested for compressive strength at 28 days, then 70% and 90% of the compressive load is applied to another set of specimens to generate microcracks for studying the durability properties of the specimens. The strength properties of concrete specimens made using silica fume and GGBFS are tested for compressive strength and the durability properties are studied using sorptivity index test. The pre loaded specimens are cured for 28 days and then compressive strength tests and sorptivity index measurements are being made at an interval of 14 days. The test results indicated that self healing property can be achieved using silica fume and GGBFS as mineral admixtures as well as the use of these pozzaalonic materials increased the compressive strength values also.

Keywords

Cementitious, Pre – Loading, Sorptivity, Self – Healing, Uniaxial

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S. Kavitha ¹, T. Felix Kala ¹

Affiliations
1 Dr. M. G. R Educational and Research Institute University, Chennai - 600095, Tamil Nadu, IN

Abstract

Background/Objectives: An attempt has been made in the present investigation to assess the outcome of bamboo fibers on strength behaviour of FRSCC. An innovative natural plant bamboo fiber, having numerous benefits such as economical, low density, environmental-friendly, sustainable and biodegradeble. Bamboo fibers extracted by using mechanical method was used in this study. Methods/Statistical Analysis: Proportion of mix of SCC has been arrived by trial and error method. Nine trial mixes were investigated totally, keeping w/c quotient constant for all mixes and variation parameter is percentage of weight fraction of (0.25, 0.5, 0.75,1 and 1.25 %) of bamboo fibers (l/d ratio = 40) of 4.9 mm length to the weight of cement. Finally, 18 cubes, 18 cylinders and 18 beams casted, out of which 15 are BFRSCC beams, 3 are control beams without fibers made with SCC. Findings, Applications/Improvements: The outcome of using bamboo fibers in the strength behavior in compression, split tensile and the flexural had studied. The maximum enhancement in compressive and split tensile strength for 28 days was observed to be 43.2 N/mm² and 6.9 N/mm², hence optimum fiber content is 1% for aspect ratio of 40. The addition of bamboo fibers also make concrete much resistive in flexure and for 28 days maximum improvement was resulted 8.1 N/mm², consequently addition of bamboo fiber content increases the flexural strength.

Keywords

Bamboo Fiber, Fiber Reinforced Concrete, Performance, Self-Compacting, Strength.

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S. Kavitha ¹, T. Felix Kala ¹

Affiliations
1 Dr. M. G. R. Educational and Research Institute University, Chennai - 600095, Tamil Nadu, IN

Abstract

Background/Objectives: The study investigates that alccofine and GGBS combination can be used in the SCC as the strength enhancer. SCC being a high performance concrete after the addition of alccofine, produces a high performance and high strength concrete. Methods/Statistical Analysis: Mix design for SCC can be carried out by Nan-Su method which is considered as a simple mix design and the dosage of super plasticizer will be determined by trial and error as substantial result of characteristics of fresh and hardened concrete and effect of alccofine (5%, 10%, 15% and 20% by volume) by keeping the GGBS percentage constant (30%) on rheological properties and strength properties were investigated. Findings Applications/Improvements: The improvement in behaviour of SCC is because of enhancement in union strength and pore refinement by GGBS. The outcome implies that the workability of SCC with 5% and 10% alccofine by volume of concrete leads to decline of other rheological properties given by codal provisions (EFNARC). In contrast, the improvement in properties of concrete like compressive strength from 36.6 to 42.9 N/mm², splitting tensile strength from 3.8 to 7.9 N/mm² and flexural strength from 4.9 to 8.3 N/mm² at 28 days was observed with increase in alccofine dosage. Finally the conclusion has been drawn that alccofine and GGBS combination can be used in the SCC as the strength enhancer.

Keywords

Alccofine, Ground Granulated Blast Furnace, High Performance Concrete, Placement of Cement, Strength Behavior.

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