Multi Span Steel Walking Bridge Small Military Steel Bridges 10 Meters Length

Multi-span Steel Bridge/small Military Steel Bridges

Corrosion is a significant concern for bridge structures, especially those made of steel or reinforced concrete. Early detection of corrosion is crucial to prevent structural failures and extend the service life of the bridge. Here are some common signs of bridge corrosion to look out for:

1. **Rust and Discoloration**
- **Appearance**: Rust is a reddish-brown substance that forms on the surface of steel. Discoloration can also indicate the presence of corrosion.
- **Locations**: Rust is commonly found on exposed steel components, such as beams, girders, and fasteners.
- **Significance**: Rust is a clear indication of active corrosion. If left untreated, it can weaken the steel and compromise the structural integrity of the bridge.

2. **Pitting and Surface Irregularities**
- **Appearance**: Pitting corrosion appears as small, often deep holes or cavities on the surface of the steel. Surface irregularities can also indicate localized corrosion.
- **Locations**: Pitting is common in areas where water can pool or where protective coatings have been damaged.
- **Significance**: Pitting can significantly reduce the cross-sectional area of steel components, leading to a loss of strength and potential failure.

3. **Cracking and Spalling in Concrete**
- **Appearance**: Cracks in concrete can be visible on the surface and may vary in size and depth. Spalling is the breaking away of concrete, often revealing the underlying reinforcement.
- **Locations**: Cracks and spalling are common in areas subjected to freeze-thaw cycles, chloride ingress (e.g., from de-icing salts), or carbonation.
- **Significance**: Cracks can allow moisture and corrosive agents to penetrate the concrete, leading to corrosion of the reinforcing steel. Spalling indicates advanced corrosion and potential structural weakness.

4. **Efflorescence**
- **Appearance**: Efflorescence appears as a white, powdery deposit on the surface of concrete or masonry. It is caused by the crystallization of salts.
- **Locations**: Efflorescence is often seen on the surface of concrete structures, especially in areas exposed to moisture.
- **Significance**: While efflorescence itself is not harmful, it can indicate the presence of moisture and salts, which can lead to corrosion of embedded steel.

5. **Delamination**
- **Appearance**: Delamination is the separation of layers within the concrete or between the concrete and the reinforcing steel. It can be detected by a hollow sound when the surface is tapped.
- **Locations**: Delamination is common in areas where the concrete has been exposed to moisture or where the reinforcing steel has corroded.
- **Significance**: Delamination can reduce the load-bearing capacity of the concrete and lead to structural failure if not addressed.

6. **Corrosion of Fasteners and Connections**
- **Appearance**: Corrosion of bolts, nuts, and other fasteners can be visible as rust or pitting. Connections may also show signs of wear or loosening.
- **Locations**: Fasteners and connections are particularly susceptible to corrosion due to their exposure to the elements and frequent handling.
- **Significance**: Corroded fasteners can weaken the connections between bridge components, leading to structural instability.

7. **Coating Degradation**
- **Appearance**: Degradation of protective coatings can be seen as peeling, blistering, or chalking of the paint or galvanized coating.
- **Locations**: Coating degradation is common in areas exposed to harsh environmental conditions, such as UV radiation, salt spray, or chemical exposure.
- **Significance**: Degraded coatings can expose the underlying steel to corrosive agents, leading to accelerated corrosion.

Conclusion
Regular inspection and monitoring are essential to detect these signs of corrosion early. Timely maintenance, such as repairing cracks, applying protective coatings, and replacing corroded components, can significantly extend the service life of bridges and ensure their safety.

Specifications:

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CB200 Truss Press Limited Table
NO.	Internal Force	Structure Form
		Not Reinforced Model				Reinforced Model
		SS	DS	TS	QS	SSR	DSR	TSR	QSR
200	Standard Truss Moment(kN.m)	1034.3	2027.2	2978.8	3930.3	2165.4	4244.2	6236.4	8228.6
200	Standard Truss Shear (kN)	222.1	435.3	639.6	843.9	222.1	435.3	639.6	843.9
201	High Bending Truss Moment(kN.m)	1593.2	3122.8	4585.5	6054.3	3335.8	6538.2	9607.1	12676.1
202	High Bending Truss Shear(kN)	348	696	1044	1392	348	696	1044	1392
203	Shear Force of Super High Shear Truss(kN)	509.8	999.2	1468.2	1937.2	509.8	999.2	1468.2	1937.2

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CB200 Table of Geometric Characteristics of Truss Bridge(Half Bridge)
Structure	Geometric Characteristics
	Geometric Characteristics	Chord Area(cm2)	Section Properties(cm3)	Moment of Inertia(cm4)
ss	SS	25.48	5437	580174
	SSR	50.96	10875	1160348
DS	DS	50.96	10875	1160348
	DSR1	76.44	16312	1740522
	DSR2	101.92	21750	2320696
TS	TS	76.44	16312	1740522
	TSR2	127.4	27185	2900870
	TSR3	152.88	32625	3481044
QS	QS	101.92	21750	2320696
	QSR3	178.36	38059	4061218
	QSR4	203.84	43500	4641392

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CB321(100) Truss Press Limited Table
No.	Lnternal Force	Structure Form
		Not Reinforced Model				Reinforced Model
		SS	DS	TS	DDR	SSR	DSR	TSR	DDR
321(100)	Standard Truss Moment(kN.m)	788.2	1576.4	2246.4	3265.4	1687.5	3375	4809.4	6750
321(100)	Standard Truss Shear (kN)	245.2	490.5	698.9	490.5	245.2	490.5	698.9	490.5
321 (100) Table of geometric characteristics of truss bridge(Half bridge)
Type No.	Geometric Characteristics	Structure Form
		Not Reinforced Model				Reinforced Model
		SS	DS	TS	DDR	SSR	DSR	TSR	DDR
321(100)	Section properties(cm3)	3578.5	7157.1	10735.6	14817.9	7699.1	15398.3	23097.4	30641.7
321(100)	Moment of inertia(cm4)	250497.2	500994.4	751491.6	2148588.8	577434.4	1154868.8	1732303.2	4596255.2

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Advantage

Possessing the features of simple structure,
convenient transport, speedy erection
easy disassembling,
heavy loading capacity,
great stability and long fatigue life
being capable of an alternative span, loading capacity