QUALITY ASPECTS OF CTD AND TMT REBARS

Abstract

The weakness in tension of both masonry and concrete is the principal limitation in their use for structural purpose. Therefore, concrete has no useful tensile Strength and limited in its structural use until the concept of steel reinforcement as developed. Reinforcement bar is use to resist tension in structural member whose height must be reduced for architectural reasons. CTD Rebars and TMT Rebars are the types of Reinforcement bars. The full form of CTD Rebars is Cold twisted deformed Reinforcement bars and TMT Rebars is Thermo-mechanically treated Reinforcement bars. The main difference is CTD Rebars are twisted after rolling where as TMT Rebars are not twisted and are thermo treated. The purpose is of the present investigation was to experimentally establish the differences in behavior between the CTD Rebars and TMT Rebars with special reference to gain in tensile strength, load-deflection graph, ductility and using it in beam to find out the ultimate load and midspan deflection. The experimental programme consists of CTD Rebars and TMT Rebars of 8, 10, 12, I 6, 20, 25 & 32mm diameter of each three specimen and tested the diameter of rebars by taking weight with calculation, ultimate tensile load by Universal testing machine and elongation by Dial gauge. The data recorded were diameter, ultimate tensile load and III elongation. Comparison studies were carried out for gain in diameter of Rebars, ultimate tensile load and elongation and relevant conclusion drawn from it. In another experimental programme consists of 24 beams of 1.80m length, 100mm width and 150mm depth were cast which using CTD Rebars and TMT Rebars of 8, 10 and 12mm diameter. The entire specimens were tested at 28 days curing after casting. The data recorded were load with midspan deflection and ultimate load. Comparison studies were carried out for gain in strength and midspan deflection and relevant conclusion drawn from it.