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Reinforcing rebar is placed axially in the column to provide additional axial stiffness. Accounting for the additional stiffness of the steel, the nominal loading capacity P n for the column in terms of the maximum compressive stress of the concrete f c ' , the yield stress of the steel f y , the gross cross section area of the column A g , and ...
Rebar cages are normally tied together with wire, although spot welding of cages has been the norm in Europe for many years, and is becoming more common in the United States. High strength steels for prestressed concrete cannot be welded. [citation needed]
This is only the average stress, actual stress distribution is not uniform. In real world applications, this equation only gives an approximation and the maximum shear stress would be higher. Stress is not often equally distributed across a part so the shear strength would need to be higher to account for the estimate. [2]
It is required that the designer identifies the environmental exposure conditions and the expected degradation process, assessing the correct exposure class. Once this is defined, design code gives standard prescriptions for w/c ratio, the cement content, and the thickness of the concrete cover.
Rebar detailing is the discipline of preparing 'shop/placing' or 'fabrication' drawings or shop drawings of steel reinforcement for construction. Engineers prepare 'design drawings' that develop required strengths by applying rebar size, spacing, location, and lap of steel .
Engineers usually specify the required compressive strength of concrete, which is normally given as the 28-day compressive strength in megapascals (MPa) or pounds per square inch (psi). Twenty eight days is a long wait to determine if desired strengths are going to be obtained, so three-day and seven-day strengths can be useful to predict the ...
Conventionally the term concrete refers only to concrete that is reinforced with iron or steel. However, other materials are often used to reinforce concrete e.g. organic and inorganic fibres, composites in different forms.
However, measurement of the resistance between a rebar and a single probe at the concrete surface is sometimes done in conjunction with electrochemical measurements. Resistivity strongly affects corrosion rates and electrochemical measurements require an electrical connection to the rebar. It is convenient to make a resistance measurement with ...