Grouting of suspension bridge cables.

Solutions

Expert Solution

The oldest and most common protection against corrosion is the use of grout. Cables are fitted in ducts that will be filled with grout (therefore isolating the cables from the external environment).

The main disadvantages of this method:

* Difficulty to fill the duct uniformly with grout "

Since the ducts are holding the grout, they should well protected against corrosion and external factors

* The heavy weight of the grout will reduce the effective tension that a cable can provide

* Due to its low tensile strength, the stiff grout (usually cement grout), not being able to follow the deformation of the cables will crack. The uncovered areas of the cable will lead to weakness points (by being exposed to the atmosphere)

These are done by pumping and vaccum injection method

Usually, cement grout is injected after the cable is under dead Ioad stresses because cement grout is the cheapest filling material and also has good corrosion protection characteristics.

Pumping:

The standard method for placing grout in a tendon duct is by pumping. The pumps used for grouting are typically screw or auger type pumps. The mixed grout is discharged into a hopper, which feeds the pump directly. The pump is connected to the duct inlet pipe with a hose and valve. The air and water are pushed out of the duct as the grout displaces it.

Vacuum injection

it is the specified technique for filling voids after initial grouting. It can also be used for the initial grouting but the sealing of an entire tendon is more problematic than sealing a small void. The vacuum injection method requires the duct system to be sealed. The air is drawn out of the void by a vacuum pump. A calibrated meter then measures the volume of air drawn back into the void as the vacuum is released. The final step is to re-establish the vacuum and inject the measured volume of grout into the evacuated void.

Ally Wells answered 7 months ago

Next > < Previous

Related Solutions

Grouting of suspension bridge cables.

Vancouver Inc. invests in a new piece of equipment, the Suspension Bridge, costing $140,000 on January...

Vancouver Inc. invests in a new piece of equipment, the Suspension Bridge, costing $140,000 on January 1, 2021. It intends to operate the equipment for five years when the scrap value will be zero. Expected net cash flows from the project are $15,000 in the first and second years and $25,000 for the last three years. The discount rate is 14 per cent and the rate of corporation tax is 35 per cent. Calculate the project’s post-tax NPV

The state government of Perak has recently announced the building of a suspension bridge between Pulau...

The state government of Perak has recently announced the building of a suspension bridge between Pulau Pangkor and Peninsular Malaysia. The construction cost of the bridge is estimated at RM100 million and this 4-lane bridge will take approximately 3 years to complete. This infrastructure project is expected to encounter many technical challenges and require the involvement of various parties, particularly engineers of different disciplines and expertise. Predict engineering-related ethical issues that may possibly occur during the construction of the suspension...

A producer of steel cables wants to know whether the steel cables it produces have an...

A producer of steel cables wants to know whether the steel cables it produces have an average breaking strength of 5000 pounds. An average breaking strength of less than 5000 pounds would not be adequate, and to produce steel cables with an average breaking strength in excess of 5000 pounds would unnecessarily increase production costs. the producer collects a random sample of steel cable pieces. the breaking strength for each of these cable pieces is recorded in the file p09_03.xlsx...

How does the electromagnetic suspension and electrodynamic suspension works on the maglev train?

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m2. The mixture will not be used unless experimental evidence indicates conclusively that the strength specification has been met. Suppose compressive strength for specimens of this mixture is normally distributed with σ = 66. Let μ denote the true average compressive strength. (b) Let X denote the sample average compressive strength for n = 14 randomly selected...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m2. The mixture will not be used unless experimental evidence indicates conclusively that the strength specification has been met. Suppose compressive strength for specimens of this mixture is normally distributed with σ = 56. Let μ denote the true average compressive strength Let Xdenote the sample average compressive strength for n = 10 randomly selected specimens. Consider...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m2. The mixture will not be used unless experimental evidence indicates conclusively that the strength specification has been met. Suppose compressive strength for specimens of this mixture is normally distributed with σ = 70. Let μ denote the true average compressive strength. (a) What are the appropriate null and alternative hypotheses? H0: μ = 1300 Ha: μ...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have...

A mixture of pulverized fuel ash and Portland cement to be used for grouting should have a compressive strength of more than 1300 KN/m2. The mixture will not be used unless experimental evidence indicates conclusively that the strength specification has been met. Suppose compressive strength for specimens of this mixture is normally distributed with σ = 66. Let μ denote the true average compressive strength. (a) What are the appropriate null and alternative hypotheses? H0: μ = 1300 Ha: μ...

A Wobbling Bridge

On June 10, 2000, the Millennium Bridge, a new footbridge over the River Thames in London, England, was opened to the public. However, after only two days, it had to be closed to traffic for safety reasons. On the opening day, in fact, so many people were crossing it at the same time that unexpected sideways oscillations of the bridge were observed. Further investigations indicated that the oscillation was caused by lateral forces produced by the synchronization of steps taken...

Subjects