i-manager's Journal on Structural Engineering (JSTE)


Volume 6 Issue 3 September - November 2017

Research Paper

Study on Adhesion and Bonding PerformanceBetween Bamboo and Concrete

Lokendra Kaushal* , Madan Chandra Maurya**
Kaushal, L., and Maurya, M.C. (2017). Study on Adhesion and Bonding Performance Between Bamboo and Concrete. i-manager’s Journal on Structural Engineering, 6(3), 1-7. https://doi.org/10.26634/jste.6.3.13719

Abstract

Bamboo used as reinforcement in concrete structure is expected to be the best replacement in place of steel reinforcement, since steel is non-renewable and a highly polluting construction material. The bonding and adhesion property is the main concern for the bamboo used as reinforcement in structural purpose. The main aim of this research work was to analyze the adhesion property and bond strength between Concrete and Bamboo strips. To examine the adhesion reinforcement in concrete generally the Bond test (Pull-out test) is conducted in the laboratory. For performing the pull out test the bamboo culms were dried, cut into 19-20 mm wide, 1000 mm long strips. Length of bamboo bar embedded in the concrete cylinder was 150 mm from the top surface of concrete cylinder. There were total 12 concrete cylindrical samples of dimension (150 mm diameter X 300 mm deep) casted in the laboratory and treated with some following special treatment agent to increase the bond strength value between concrete and bamboo.

Research Paper

P-Delta Effect on Multi-Storey Buildings

A.N.Pattar* , S.M. Muranal**
Pattar, A.N., and Muranal, S.M. (2017). P-Delta Effect on Multi-Storey Buildings. i-manager’s Journal on Structural Engineering, 6(3), 8-18. https://doi.org/10.26634/jste.6.3.13721

Abstract

The buildings are prone to deform laterally from original position with an eccentricity during an earthquake. When building structures are subjected to seismic loading causing the structure to deform, the resulting eccentricity of the total gravity load due to inclined axes of structure causes the extra moments at the base. The presence of infill, bracing and number of storeys may affect the additional displacement due to P-Delta. In the present study, the design parameters of buildings which are affected by P-Delta, such as lateral displacement, base shear, and moment at the base-columns are discussed. The non-iterative P-Delta analysis is adopted to determine the P-Delta effect for symmetric rectangular regular plan structures. It has been reported that, the bare frame Reinforced Concrete (RC) structures more than 20 stories are required to be analysed and designed for P-Delta effect. The P-Delta effect significantly controlled by the braced systems and masonry infill structures.

Research Paper

Experimental Investigation on Use of Optical Fibers inManufacturing of Light Transmitting Concrete

B. Yamini Nirmal* , K. Nehemiya**
* P.G. Scholar, DMS SVH College of Engineering, Andra Pradesh, India.
** Assistant Professor, Department of Civil Engineering, DMS SVH College of Engineering, Andra Pradesh, India.
Nirmal, B.Y., and Nehemiya, K. (2017). Experimental Investigation on Use of Optical Fibers in Manufacturing of Light Transmitting Concrete. i-manager’s Journal on Structural Engineering, 6(3), 19-25. https://doi.org/10.26634/jste.6.3.13726

Abstract

Light transmitting concrete is one of the fiber reinforced concretes, which is used for aesthetic application by incorporating the optical fibers in concrete. Optical fibers are one which helps for transmission of light through fibers. In this paper, the work is divided into two phases. In first phase, study of compressive strength and later in second phase study on flexural behaviour were carried out. Light transmitting masonry blocks were prepared of size 200 mm x 100 mm x 100 mm, and plastic optical fibers of diameter 0.38 mm were used. Fibers are inserted into the mortar bricks in order to investigate the amount of light transmitting potential and also to determine the strength parameter, i.e., compressive strength. Different percentages of fibers, such as 2% and 4% with different configurations were prepared. From this, the optimum fiber percentage and optimum fiber number along with location is determined and it can be used to observe the flexural behaviour in Prisms of standard size 50 cm x 10 cm x 10 cm and later beams were casted of size 130 cm x 18 cm x 20 cm with mesh, fiber alone, and a combination of both mesh and fiber, and the test results, i.e., Load vs. deflection (Load carrying capacity) were compared with that of regular or conventional concrete beams.

Article

Bending Characteristics of ReinforcedConcrete Beams

Sai Sandeep Uppala* , T. Muralidhara Rao**, K. N. V. Chandrasekhar***
* GET, Shapoorji Pallonji Construction Limited, Hyderabad, India.
** Professor & Head, Department of Civil Engineering, CVR College of Engineering, Hyderabad, India.
*** Assistant Professor, Department of Civil Engineering, CVR College of Engineering, Hyderabad, India.
Sandeep, U.S., Rao, T.M., and Chandrasekhar, KNV. (2017). Bending Characteristics of Reinforced Concrete Beams. i-manager’s Journal on Structural Engineering, 6(3), 26-36. https://doi.org/10.26634/jste.6.3.13729

Abstract

To avoid sudden and brittle failure of bending members, the Indian Standard Code prescribed limits on the minimum and maximum values of longitudinal reinforcement ratios. In the present paper, a computer program in C-language is developed for moment-curvature relationship of the reinforced concrete beams with minimum percentage of steel. The moment-curvature relationship helps in understanding the strength characteristics, flexural behaviour, and ductility characteristics of RC beams under flexure. The influence of grade of concrete, grade of steel, percentage of tension steel, and geometric parameters like depth of the beam section on the moment-curvature relation of reinforced beams is studied. Based on the Moment-curvature diagrams, it is found that the first crack moment and the ultimate moment of concrete increases with increase in the grade of concrete due to the increase in the interfacial toughness. The energy absorption capacity and curvature ductility of the concrete is found to be decreasing with the increase in the compressive of the concrete and percentage of steel due to the increase in brittleness of the concrete.

Research Paper

Healing of Micro-Cracks in Fly Ash Cement Composite using NaOH and Na2SiO3 Solution

Shaswata Mukherjee* , Saroj Mandal**, U. B. Adhikari***
* Research Scholar, Department of Civil Engineering, Jadavpur University, Kolkata, India.
** Professor, Department of Civil Engineering, Jadavpur University, Kolkata, India.
*** Retd. Scientific Officer, Central Glass and Ceramic Research Institute, Kolkata, India.
Mukherjee, S., Mandal, S., and Adhikari, U.B. (2017). Healing of Micro-Cracks in Fly Ash Cement Composite using NaOH and Na2SiO3 Solution. i-manager’s Journal on Structural Engineering, 6(3), 37-45. https://doi.org/10.26634/jste.6.3.13733

Abstract

Microstructural properties of autonomically healed 0, 20, 40, and 60% OPC replaced by fly ash in cementitious composites are reported in this paper. Artificial micro-cracks were generated on cementitious cube specimens by the applications of compressive loads. NaOH (10-M) and Na SiO solution were used as healing agent. The cracked 2 3 O specimens were either injected or submerged in the chemical solution, followed by heat curing at 60 C for 48 hours. Self-healing in terms of recovery of properties were observed in UPV measurement and compressive strength study. Specimens containing 40% fly ash content mortar specimens showed better recovery of UPV and compressive strength. For limitation and better control of some analytical testing like TGA (Thermogravimetric Analysis), FTIR (Fourier-Transform Infrared Spectroscopy), XRD (X-ray Diffraction), SEM-EDAX (Scanning Electron Microscope with Energy Dispersive X-ray Analysis) were done in paste mixes rather than mortar mixes. Sodium calcite and sodium aluminate phases were found at the crack zone after submerging and injection of the NaOH (10 M) and Na SiO solution in 40% fly ash content paste 2 3 mix. FTIR analysis shows higher degree of geo-polymerization after submerging. TGA confirms higher mass loss for mix without any fly ash for both submerged and injected specimens. SEM reveals that the microstructure is more homogeneous in submerged specimens.