Load Carrying Capacity Of Columns Research Articles

Behavior of cement-stabilized rammed earth circular column under axial loading

Detailed study has been carried out on the load carrying capacity of cement stabilized rammed earth (CSRE) circular columns under axial compression. Tests on CSRE cylinders and columns were performed to determine the effects of concentric axial loading and slenderness ratio; and stress reduction factors were assessed. A comparative study was made between the ultimate compressive strength (σu) of columns determined using tangent modulus theory and experimental values. Furthermore, the validity of using masonry design rules for the design of CSRE columns was also assessed. The result shows that with increasing slenderness ratio the load carrying capacity of columns decreases. The ultimate compressive strength of column predicted by tangent modulus theory tend to converge with experimental values at higher slenderness ratio and the masonry codal predictions are observed to be un-conservative as compared to experimental reduction factors. Lastly, the characteristic strength determined for columns yields relatively higher safety factor and indicates that it is possible to construct a single storey load bearing houses when designed properly.

Effects of shape of transverse cross-section on the load carrying capacity of laminated glass columns

In this paper simplified expressions for the calculus of the load carrying capacity of glass columns having rectangular, tee (T) and cruciform (X) transverse cross-sections are proposed and verified against available experimental data. Members with T and X cross-sections are obtained by gluing single multilayered glass panels.The expressions derived take into account of the: shape of the transverse cross-section (rectangular, T, and, X sections); buckling phenomenon (flexural and torsional); failure in the glued sections; long time effects. Case of full connections and absence of connections are considered to determine the range of variation of expressions adopted. The comparison between the analytical and the experimental results highlights that in the case of columns or beam-like elements having rectangular cross-sections the flexural buckling resistance governs the load carrying capacity of columns, while in the case of glass columns with X and T cross-sections failure due to torsional buckling effects strongly limits the load carrying capacity of members, also penalized by the glued connection failure.

Influence of end plate splices on the load carrying capacity of columns

A column splice is part of the column and therefore must be designed for second order bending moments and shear forces in addition to the axial force. In this paper strength and stiffness requirements for column splices are derived on the basis of column stability considerations. A strength requirement for the column splice is suggested based on an imperfect column. A stiffness requirement is suggested by allowing a 5% reduction in the Euler buckling load of the column. In order to test the suggested design requirements for column splices, full scale experimental tests on spliced columns were carried out. Three different column splices were investigated. Columns without splices were tested for reference purposes. All tests were performed three times. It has been found that splices can have a negative influence on the load carrying capacity of slender columns.

A Study On Use Of Blended Ferrocement:A High Performance Material ForRepair/strengthening Of Brick Masonry Columns

The use of ferrocement, containing blended cement, to repair and enhance the strength of brick masonry columns of old buildings and structures showing distress has been investigated for use as a rehabilitation/strengthening material. Intensive experimental study has been carried out on plain brick masonry columns and brick masonry columns with single, double and triple layers of ferrocement, with/without the use of chemical bonding agents. Use of blended cements containing agricultural waste i.e. rice husk ash have not as yet been investigated at all for use in ferrocement. Blended cement containing 75% OPC and 25% rice husk ash has now been investigated for use in ferrocement. Ferrocement containing blended cement has been observed to substantially increase the load carrying capacity of brick masonry columns along with decreasing the strains by about 50%. Strength improvements of up to 160% in the load carrying capacity of columns with single layered ferrocement have been observed whilst about 100% strength improvements have been observed in columns with 2/3 layers of ferrocement applications. The slope of the stress-strain curve resembles typical curves characteristic of high strengths. The results of this study have been highly encouraging and the use of ferrocement with blended cement is recommended for the repair and rehabilitation/strengthening of brick masonry columns. The use of rice husk ash for blending with ordinary Portland cement produces a stronger, impermeable and durable material in addition to ease of in-situ application, reducing the disposal problem of this agricultural waste and reducing the costs of repairs.