Slenderness effects in prestressed concrete columns (original) (raw)

Yearnings of a Reinforced Concrete Structure

2009

Portland cement based concrete is today the most widely used material of construction. Concrete has attained this preeminent position because of many useful properties it is endowed with. Among these properties are the relative ease of formability, rigidity on setting and curing, and the great ability to resist compressive forces (generally in the range of 20-80 MPa and in special cases up to 280 MPa). Concrete is, however, weak in its resistance to tensile forces, flexural tension, shear and torque. It tends to be brittle in nature. These weaknesses are overcome with the addition of reinforcing bars (rebars) of steel in the case of reinforced concrete and high strength steel wires or cables in the case of prestressed concrete. With its weaknesses overcome and its positive properties retained, beautiful concrete structures have given expression to man’s imagination and sense of elegance. The utility and elegance as well as the durability of concrete structures, built during the firs...

Second-order analysis of prestressed concrete columns

2019

The use of prestressed concrete columns has been quite rare in Finland, mainly for reason of a lack of national design regulations and guidelines. To promote their use, the Confederation of Finnish Construction Industries initiated a research project on precast prestressed concrete columns, in connection with an extensive research programme at Tampere University examining slender concrete structures. A displacement-based calculation model developed earlier in the programme for reinforced concrete columns and piles was developed further for evaluating the buckling of slender prestressed columns. The researchers applied this model to compare structural behaviour between prestressed and reinforced columns of the same dimensions and concrete strength and to evaluate the structure’s suitability for test specimens for a later, experimental stage of research. The prestressed cross section cracked only after quite considerable bending. With simultaneous compressive force to the top of the c...