Determinants of tensile stress of the concrete

Articles > Determinants of tensile stress of the concrete

Factors affecting the tensile strength of Concrete:

The strength of the concrete is the only purpose of conducting concrete work during construction. Concrete work is done due to its strength and durability. The strength of the concrete is dependent on two types of stresses: (i). Compressive Stress, (ii). Tensile Stress. The compressive stress prevents the concrete structure to compress and bent, while the tensile stress prevents the concrete structure from expansion and bending. Both of the strengths are interdependent in order to provide strength to the concrete. There are several interdependent as well independent factors which directly or indirectly influence the either of the stresses. In our previous article, factors influencing the compressive stress were explained in detail. This article is about the factors which influence the tensile stress of the concrete. Following are the determinants of the strength of the concrete:

Factors affecting the tensile strength of the concrete:

The tensile strength largely depends on the reinforced steel used in the concrete, however, the concrete itself has also a partial role in creating the tensile strength. In this article were are discussing in detail, the factors of compressive strength of the concrete material.

Bonding between reinforced material and concrete: The bonding of the reinforced material like steel and iron rods/cable and the concrete is the foremost factor, which influences the strength of concrete due to tensile stress in it. The bonding between concrete is dependent upon the round ring like lines on the steel and the quality of concrete material. The better the quality of concrete mixture is, the more will be the boding and adhesion between the steel rods/cable and the concrete will be.
Shape of the steel rods/cable: Generally the steel rebars (reinforced bars), are available with circular linings. The purpose of the linings on the rebars is to firmly withhold the steel rebars with in the concrete. In case if the steel rebars were smooth, the bonding between steel and concrete would be very weak. The round linings on the bars increase the tensile strength of the concrete.
Thickness of the steel: The thickness of steel rebars guarantees the tensile strength of the steel. The thicker steel rods as compared to the thinner rods and bars are more durable and strong and can bear heavier dead weight structure and applied load on it. The risk of breakage in structures with thin rods is more than that with a thicker rods.
Structure of steel structure/ Truss: The truss or the whole structure of reinforced material has very deep impact on the durability of the concrete structures. The large number of bars used in reinforced truss gives additional strength to the concrete structure. Concretes with fewer bars are vulnerable to the dead weight of the concrete as well as the external load applied on it.
Overall compressive stress: On one hand the role of reinforced material in the concrete is of pivotal importance, while on the other hand the overall compressive strength (which is totally dependent on the strength of concrete and its determinants) another factor which directly influence the tensile strength of the structure. If the compressive stress is higher, then weaker bars will also sustain, but if the compressive stress is weaker, then stronger and thicker rebars will also fail to sustain.
Access of corroding agents to the rebars: The access of the corroding agents like oxygen and other acidic compounds is possible through the pores in the structures of the concretes. If the concrete is impervious and non-porous the access of corroding agents to the rebars is not possible. In case of use of an inferior material in the concrete, the corroding agents penetrate the concrete structures and cause rusting on the rebars. Thus the rebars become weak due to rusting/ oxidation and corrosion.
Type of fine and coarse aggregates: If the fine and coarse aggregate are free of impurities, they cause strong bonding among the parts of the structure. The presence of the impurities in the concrete aggregate and sand, results in weak binding of the material. Quality of fine and coarse aggregate plays an important role in the durability and strength of the concrete caused by tensile stress.

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