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Take in consideration engineering and economical considerations.
Steel bridges need more maintannce (painting) than concrete bridges
it depends on the situation if you want long span without middle supports and quick construction time go for steel bridge however if the budget is limited go for concrete bridge
Though Steel Spans last longer, rebuild able and long life than concrete spans but when span length allows, concrete spans are cheaper than steel spans. Concrete spans has reduced maintenance as compared to steel. Steel spans typically requires periodic painting and cleaning. Concrete is more flexible, allowing for the easy treatment of curved beams, including box girders which excel at withstanding torsion. For long spans, pre-stressed concrete is usually the most efficient choice. When both the initial cost and long term costs are added together, concrete is typically cheaper.
According to the United States National Bridge Inventory, the number of concrete bridges far outstrips the number of steel bridges.
Concrete is better but limited using, while steel is widely used specially for complicated case.
Concrete is cheaper upfront, but steel can be more economical in the long run. Not only outright cost is considered, but also durability, adaptability to the locale, and resistance to climate change
Well , it depends
1- the steel spans last longer then a concrete , concrete will last around to years.
2-concrete is cheaper upfront, but steel can be more economical in the long run. Not only outright cost is considered, but also durability, adaptability to the locale, and resistance to climate change.
3- steel bridges are rebuild able and maintainable and damage in steel structure is easy noticeable
Broadcaster Ted Failon makes a sensible conclusion from the many studies on traffic-causing buses on EDSA: compel the owners to merge. That way, the consortium will field the buses rationally. No bunching up at bus stops of nearly empty units, no racing on the road, no fighting for passengers. Drivers will be disciplined because unrushed; passengers will have sure rides; other motorists will be safer. No wasting of everybody’s time and fuel. Land transport authorities will be dealing with only one company for franchising, anti-pollution, and road safety. Colorum units easily will be detected.
The idea should work for jeepney operators too, if banded under one cooperative per route or town or district.
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What’s better, steel or concrete? The item came up during a recent Senate inquiry on the President’s bridge program (PBP).
A quick research on the Internet and interviews with government and private engineers and economists yielded common points. Concrete is cheaper upfront, but steel can be more economical in the long run. Not only outright cost is considered, but also durability, adaptability to the locale, and resistance to climate change:
• Steel spans last longer than concrete ones. Those built by eight mostly European firms under the PBP are rated for 80-100 years. Concrete has a maximum lifespan of only 40 years — or the soonest earthquake, typhoon, or raging flood. The bill comes up double to build two consecutive 40-year-lifespan bridges.
Opinion ( Article MRec ), pagematch: 1, sectionmatch: 1• Steel bridges are re-buildable. In 2008 the swollen river from Typhoon Frank washed away a newly built steel span in Alimodian, Iloilo. With no special tools, the townsfolk salvaged components of the bridge and reconstructed it themselves, calling the new span the “Love Bridge.” Only rubble remains from a collapsed concrete bridge. In this country that’s sixth most at risk from climate change (Maplecroft Report), storms knock down about 10,000 lineal meters of bridges each year. The Department of Public Works and Highways is turning more and more to steel technology.
• Damage to a steel structure is easily noticeable. It should surface after a thorough inspection post-calamity, with no special tools save for a good pair of eyes and a flashlight. Such damaged part can be repaired or replaced. In contrast, cracks in the inflexible concrete can compromise the structure and void the rated lifespan. Usually damage may not be perceptible, until it sags or collapses. Also hidden are poor workmanship, and substandard materials like undersized re-bars.
• Short steel bridges take only days to piece together; longer ones take weeks. The US transportation department’s Federal Highway Administration says so. This is because the modular steel parts are manufactured long beforehand. Shorter disruption of traffic and economic activity. Concrete can take months to years to construct and cure before use.
• Modular steel bridges follow the European standard. That is, they should withstand a rolling load of 60-80 tons, as heavy as the NATO main battle tanks (eg., the US M1 Abrams). Steel spans that have anti-skid coatings do not shrink.
• Most steel bridges are built using soft foreign loans. Such overseas development assistance (ODA) require 25 percent to be outright grant. Repayment is spread over a longer period. In contrast, concrete span constructors require 30- to 50-percent down payment, with progress billings thereafter. The structure is fully paid for before it can have time to generate revenues. Thus economists favor ODA-funded steel spans.
It will always boil down to money. Material prices will fluctuate all the time, then you need to evaluate the project cost if built by concrete or steel.
In my work we switch between both depending on the cost. We do not make estimation for the project twice but we have the knowledge of prices of each material to start with.
Also Steel structure is faster to build than concrete espicially if it is big project.
Good Luck
By engineering view it depends on a lot of issues to solve like span and height , but i go for combined system between RC and Steel :)
both materials work but material choice depends on types of moving loads and the seismic forces as well
in the comparison : of course ( concrete ) is better
