Cast-iron Girders Research Articles

Flexural Tests of Full-Scale Cast Iron Girders Reinforced with CFRP Plates to Investigate the Benefits of the Strengthening

Abstract This paper presents the results of the flexural testing to destruction of two cast iron girders preserved during the demolition of a railway bridge in Scotland. The 151-year-old girders we...

The Selected Issues of Adaptation of 19th and 20th Century Post-Industrial Buildings in Łódź

The paper deals with selected technical problems related to the adaptation for new uses of the structure of existing post-industrial buildings from the turn of the 19th and 20th centuries. A major difficulty is the fact that the strength and geometric properties of cast-iron, steel, and masonry elements often differ significantly from the values characterizing contemporary materials. Due to uncertainty regarding the load-carrying capacity of historical structures, in many cases there is a need to carry out destructive tests of elements taken from the buildings. As the example of cast-iron girders in the former spinning mill of “I. Poznański” demonstrated, such tests can prove a significant margin of load-carrying capacity and confirm the possibility of adapting the structure to new purposes. The paper also presents examples of strengthening the existing wooden ceilings by joining with the reinforced concrete structure, which allowed the keeping of the original elements and an increase of the allowable load. Selected problems related to the assessment of historical masonry structures were also described. The discussed examples of structural failures showed that they often resulted from incorrect assessment of the strength of historical masonry elements as well as improperly conducted construction works.

Moment capacity of cast-iron beams exposed to fire

Cast-iron girders were used in many nineteenth century structures, especially in fireproof flooring systems (such as jack arches). Many such structures are still in use today and it is important that they fulfil the current requirements on fire resistance when there is a change of use. Cast iron has limited ductility so it is not possible for cast-iron beams to achieve total plasticity as for modern steel beams. Furthermore, cast iron has different mechanical properties in tension and compression and there is often a severe non-uniform temperature distribution in cast-iron beam sections. This paper presents the development of a simplified method to calculate the bending moment capacity of cast-iron beams in a jack arched system exposed to a standard ISO 834 fire. The method is based on an assumed strain distribution in the cross-section. A comparison of the results calculated using the simplified method with those using the fibre method, validated by Abaqus simulation results, indicates that the proposed simplified method is sufficiently accurate as the basis of a design method.

Train loading on bridges since Stephenson's Rocket

Railway locomotives increased in weight from less than 10 tons in 1825 to more than 100 tons by the 1930s. Originally loading on bridges was assumed as an average weight per unit length ignoring axle concentration and generous factors of safety were used to compensate for the absence of any dynamic allowance. After the Dee Bridge collapse of 1847 Board of Trade rules were imposed. The comparatively few bridge failures under train loading are summarised. After several failures of flawed cast-iron girders these were gradually replaced after 1891. There was no rigorous consideration of dynamic effects until the 1900s. Civil engineers had been rejecting heavier new locomotives without comparing hammer blow characteristics. Dynamic effects were eventually investigated for the Bridge Stress Committee Report of 1928. With the elimination of steam traction, loading as developed for Europe was introduced and is now adopted in the Eurocodes. Comparisons are made between early and modern loadings taking account of the effect of increasing speeds.

Train Loads on Bridges 1825 to 2010

Weights of railway locomotives increased from less than 10 tons in 1825 to more than 100 tons at the zenith of steam power in the 1930s. With the elimination of steam traction, wagon loading became more critical. Early bridges of timber and cast iron became unsuitable as loadings increased, but on secondary lines some early bridge types have survived. In the early years, the criterion for bridge loading was taken as the quotient of the weight of a vehicle divided by its length (an average tons per foot run), ignoring axle concentration. Generous factors of safety were used to compensate for the absence of any dynamic allowance. There were no formal rules until the Dee Bridge disaster of 1847 led to those of the Board of Trade. The comparatively few bridge failures under train loading are summarised. After several failures due to casting flaws culminating in the 1891 Norwood Junction collapse, cast iron girders were gradually replaced. There was no rigorous consideration of dynamic effects until the twentieth century. Civil engineers had been rejecting new locomotives with heavier axle loading without considering comparative hammer blow characteristics. Dynamic effects were investigated for the Bridge Stress Committee Report of 1928. With the elimination of steam traction in 1968, European standards (Eurocodes) have been introduced. Comparisons are made between early and modern loadings taking account of the effect of increasing speeds.

Repair of fractured cast iron bridge

This paper reports on the repair and reinstatement of fractured historic cast iron elements of the High Level Bridge in Newcastle upon Tyne, UK. As a part of a full structural refurbishment of this grade 1 listed structure, three cast-iron girders were extracted from the historic bridge and subjected to fatigue testing. This destructive testing was carried out under the condition imposed by English Heritage that the cross-girders could be reinstated with the least visual impact. To satisfy this requirement, the damaged elements were repaired using a refurbishment procedure employing strengthening with externally bonded fibre-reinforced polymer (FRP) plates and ‘cold' metal stitching with alloy inserts. The paper discusses the numerical analysis, structural modelling and the quality control measures adopted during construction for the repair of the girders. The fatigue testing will be presented in a separate paper.

Experiments on the strength of cast iron girders

Experiments on the strength of cast iron girders

Experiments on the strength of cast-iron girders

Experiments on the strength of cast-iron girders