CDC 3e251 Set-a Vol. 3

All of the mentioned defects in security fencing require maintenance. Loose or broken strands of barbed wire can compromise the effectiveness of the fence as a deterrent. Bent or missing posts can weaken the structure and make it easier for intruders to breach the fence. Missing sections of top rail can also reduce the overall security and stability of the fence. Therefore, all these defects need to be addressed through regular maintenance to ensure the security of the fenced area.

Corrugations in flexible pavement usually occur at points where traffic brakes and accelerates. This is because the repeated application of brakes and acceleration causes the pavement to experience varying levels of stress and strain, leading to the formation of corrugations. These corrugations can disrupt the smoothness of the road surface and create an uncomfortable driving experience for vehicles.

Large cracks in pavement are repaired the same way as potholes. Both potholes and large cracks require similar repair methods, such as filling the damaged area with asphalt or other suitable materials. The repair process involves cleaning the area, applying a patching material, and compacting it to create a smooth and durable surface. By treating large cracks in a similar manner as potholes, the integrity and safety of the pavement can be restored effectively.

Maintenance on security fencing should be done as needed. This means that maintenance should be performed whenever there is a need for it, such as when there are damages, wear and tear, or any other issues that may compromise the security of the fencing. It is important to regularly inspect the fencing and address any maintenance requirements promptly to ensure its effectiveness in providing security.

When spreading bituminous materials by hand, it is important to prevent segregation. Segregation refers to the separation of the different components of the material, such as the aggregates and the binder. This can lead to an inconsistent mixture, with areas that have a higher concentration of binder and areas that have a higher concentration of aggregates. This can result in a weaker and less durable pavement. To prevent segregation, it is necessary to ensure that the materials are properly mixed and evenly distributed during the spreading process.

A bituminous paver uses less spreading time compared to a motor grader. This means that it can complete the paving process more quickly, saving time and increasing efficiency. This advantage is beneficial in construction projects where time is a critical factor. By using less spreading time, the bituminous paver allows for faster completion of the paving process, enabling the construction team to move on to other tasks sooner.

Large cracks in pavement are repaired the same way as potholes because both require similar repair techniques and materials. Both potholes and large cracks result in structural damage to the pavement, and repairing them involves filling the gaps with a suitable material, such as asphalt or concrete. The repair process for both involves cleaning the area, preparing the surface, and then filling the gap with the appropriate material. By treating large cracks in the same way as potholes, the pavement can be restored and made safe for vehicles and pedestrians.

Bituminous surfaces must be constructed on surfaces that are reasonably dry and free from caked mud or dust. This is because caked mud or dust can prevent proper adhesion between the bituminous material and the underlying surface, resulting in a weak and unstable pavement. Additionally, caked mud or dust can also lead to uneven compaction, which can affect the overall durability and smoothness of the pavement. Therefore, it is important to ensure that the surface is clean and free from any caked mud or dust before constructing a bituminous surface.

Alligator cracks are interconnected and form a series of connecting blocks that resemble chicken wire. These cracks are typically found in asphalt pavement and are caused by a combination of factors such as heavy traffic loads, aging, and poor maintenance. The cracks resemble the skin of an alligator, hence the name.

During an inspection of flexible pavements, it is important to determine the cause for the failure. This is because understanding the underlying reasons for the pavement's failure will help in developing an effective repair strategy. By identifying the cause, such as poor construction, inadequate drainage, or heavy traffic loads, appropriate measures can be taken to address the issue and prevent future failures. Determining the cause for the failure is therefore crucial in ensuring the longevity and functionality of the pavement.

The rolling operation for pavement repair using hot-mix should begin immediately after the material is placed. This is because rolling helps to compact the material and ensure that it is evenly distributed and tightly packed. By starting the rolling operation immediately, the material can be properly compacted while it is still hot and pliable, leading to a more durable and stable pavement surface. Waiting for the material to cool or aerate may result in a less effective compaction process and potentially compromise the quality of the repair.

A load of hot mix asphalt should have a dome shape in the bed of a dump truck. This is because the dome shape allows for proper distribution and compaction of the asphalt when it is dumped onto the desired surface. A dome shape ensures that the asphalt is evenly spread and compacted, resulting in a smooth and even surface once it is laid. This shape also helps to prevent any potential damage or spillage during transportation.

Bleeding in flexible pavement normally occurs in hot weather. This is because high temperatures cause the bitumen in the asphalt binder to soften and become more viscous. As a result, the bitumen can exude to the surface of the pavement, creating a shiny, black, and sticky film known as bleeding. This can reduce skid resistance, cause vehicles to track the bitumen onto other surfaces, and lead to rutting and deformation of the pavement. Hot weather conditions exacerbate the problem by increasing the likelihood of bitumen becoming fluid and flowing to the surface.

There are three ways used to grade asphalt cement. However, without further context, it is unclear what these three ways are specifically.

Asphalt cements are graded based on their performance grade, which refers to their ability to withstand different temperature ranges and traffic loads. This grading system helps engineers and contractors select the appropriate asphalt for specific applications, ensuring that the pavement will perform well and last longer. Grading based on volatility, setting rate, or evaporation rate is not commonly used in the industry.

A squeegee is used to force sealing material into the cracks in flexible pavement. It is a tool with a rubber blade that is used to spread and push the sealing material into the cracks, ensuring a tight seal. The rubber blade of the squeegee helps to evenly distribute the sealing material and press it into the cracks, preventing any gaps or air pockets. This ensures that the cracks are properly sealed and helps to extend the lifespan of the pavement.

The area of a square is calculated by multiplying the length of one side by itself. In this case, the square measures 22 feet by 22 feet, so the area would be 22 feet multiplied by 22 feet, which equals 484 square feet.

Flexible pavements should be inspected in spring and fall because these seasons represent significant changes in weather conditions. In spring, the pavement may have experienced damage from freezing and thawing during the winter, and it is important to assess any potential issues. In fall, the pavement may have endured heavy traffic and weather conditions during the summer, making it crucial to evaluate its condition before the winter season. Inspecting the pavement during these seasons allows for timely identification of any necessary repairs or maintenance to ensure its longevity and safety.

Blade-spreading operations involve the use of a blade to spread bituminous materials. This process often leads to poor edges because the blade may not be able to evenly distribute the material along the edges, resulting in uneven and irregular edges.

Poor construction methods can be a cause of depressions in flexible pavements. This could include improper compaction of the pavement layers, inadequate thickness of the layers, or incorrect placement of the materials. These construction deficiencies can result in weak spots or unevenness in the pavement, leading to depressions over time.

SS-S-1401 is the correct answer because it is a type of sealer that can be used satisfactorily with most types of asphalt pavements. The other options, SS-S-1614, SS-S-00020, and SS-S-00095, may not be as suitable for use with various types of asphalt pavements.

When removing defective flexible pavement, it is necessary to remove the base course materials until reaching firm dry material. This ensures that any damaged or compromised sections of the base are completely removed, allowing for proper repairs or replacement to be made. Removing until reaching firm dry material ensures a solid foundation for the new pavement to be laid, ensuring its longevity and stability.

Mixing asphalt cement with kerosene produces medium-curing cutbacks. Kerosene is a commonly used diluent for asphalt cement, which helps to reduce its viscosity and improve workability. The addition of kerosene allows the asphalt cement to be applied at lower temperatures, making it easier to handle and spread. This mixture is known as a medium-curing cutback, as it has a moderate rate of curing or hardening.

When the grade is excessive, it means that the slope or incline of the surface is too steep. In such conditions, operating the steel-wheeled roller with the tiller wheel forward can provide better stability and control. The tiller wheel helps to prevent the roller from sliding or losing traction on the steep grade, allowing for more effective compaction of the asphalt.

A gauge is a measurement of the thickness or diameter of a wire. In this case, the question is asking about the type of tie wire that should be used to secure the fence fabric to the line posts. The correct answer is 9 gauge because it is the most suitable thickness for this purpose. A 9 gauge tie wire would provide enough strength and durability to securely hold the fence fabric in place.

Slippage cracks in flexible pavement are caused by a lack of bond between the surface layer and the course beneath. This lack of bond can occur due to factors such as poor quality materials, inadequate compaction, or excessive traffic loads. Slippage cracks typically occur parallel to the pavement's centerline and are characterized by a smooth and polished appearance. They can lead to further pavement deterioration if left untreated, making proper repair and maintenance crucial to ensure the longevity and safety of the pavement.

Tension wire should be used with fences without top rail because it helps to provide stability and prevent sagging of the fence. Without a top rail, the fence may not have enough support to withstand external forces such as wind or pressure, which could cause it to become loose or collapse. Tension wire is typically installed at the bottom of the fence and helps to keep the bottom line taut, ensuring that the fence remains secure and upright.

A fence made of concertina or razor wire is commonly known as a Type C fence. This type of fence is designed to enhance security and deter unauthorized access. Concertina wire consists of sharp blades or barbs that are tightly wound together, making it difficult for intruders to climb over or cut through the fence. Razor wire, on the other hand, has sharp, razor-like edges that can cause injury to anyone attempting to breach the fence. Therefore, Type C is the correct answer.

The correct answer is "What the post is used for." When determining the footings for fence posts, it is important to consider the purpose of the post. Different types of posts, such as corner posts or gate posts, may require deeper or larger footings to provide adequate stability and support. Additionally, the type of soil and environmental conditions in the area where the post is being placed may also influence the footing requirements. Therefore, understanding the intended use of the post is crucial in determining the appropriate footings.

Bituminous construction should be suspended when the temperature drops below 50 degrees. This is because bituminous materials, such as asphalt, become less workable and more brittle at lower temperatures. Below 50 degrees, the asphalt may not adhere properly, leading to poor compaction and reduced durability of the pavement. Additionally, colder temperatures can affect the curing process, resulting in a weaker and less stable surface. Therefore, it is crucial to halt bituminous construction below 50 degrees to ensure the quality and longevity of the pavement.

Central plant mix is the most widely used type of flexible pavement construction. This method involves mixing the aggregate and asphalt binder at a central plant before transporting it to the construction site. This allows for better control over the mixing process and ensures consistent quality of the pavement. Central plant mix is preferred for its durability, flexibility, and ease of construction, making it a popular choice for road construction projects.

Asphalt emulsion can be used with damp aggregate because it is a mixture of asphalt cement, water, and an emulsifying agent. The emulsifying agent allows the asphalt to mix with water, creating a stable emulsion. This makes it suitable for use with damp aggregate, as it can effectively coat and bind the aggregate particles even in the presence of moisture. Road tar, road tar cutback, and asphalt cement are not specifically designed to be used with damp aggregate and may not provide the same level of performance in such conditions.

To convert tons to metric tons, you need to divide the given value by 1.1023. Therefore, when you convert 120.25 tons of hot mix asphalt to metric tons, the correct answer is 109.09 mt.

Emulsions are the best materials to use as primecoats because they are environmentally friendly. Emulsions are made by mixing asphalt and water, which reduces the amount of volatile organic compounds (VOCs) released into the air compared to other materials like tars and cutbacks. Emulsions also have good adhesion properties, allowing them to bond well with the underlying pavement surface. Additionally, emulsions are easy to apply and can be sprayed onto the surface, resulting in a smooth and uniform coating. Overall, emulsions provide an effective and environmentally conscious solution for primecoats.

Finish rolling is done solely to improve the surface. This process involves using a heavy roller to compact and smooth the surface of a material, such as asphalt or concrete. By applying pressure and rolling over the surface, any irregularities or imperfections are leveled out, resulting in a smoother and more even surface. This improves the overall quality and appearance of the surface, making it more suitable for its intended use.

A crayon is the best item to mark defective flexible pavement because it is made of wax and has a thick, opaque consistency that allows for clear and visible marking on the pavement surface. Chalk and pencil may not be as effective as they can easily get smudged or washed away, while a straightedge is used for measuring and not for marking. Therefore, a crayon is the most suitable choice for this task.

The correct answer is 2 inch mesh openings. This means that the fence's fabric should have mesh openings that are 2 inches in size. This is important because the mesh openings determine the size of the gaps in the fence, which can affect its effectiveness in keeping things in or out. Smaller mesh openings provide a tighter barrier and prevent smaller objects or animals from passing through. Therefore, a fence with 2 inch mesh openings would be more secure and suitable for the intended purpose.

BBR stands for Bending Beam Rheometer, which is a type of equipment used to measure binder properties at low temperatures. The BBR applies a controlled stress to a small beam of asphalt binder, and measures the resulting strain. This allows for the determination of the binder's stiffness and its ability to resist cracking at low temperatures. The BBR test is commonly used in the asphalt industry to evaluate the performance of binders in cold weather conditions.

A completed flexible pavement patch should be level with the surrounding area or slightly elevated to ensure proper drainage and prevent water accumulation. A 1/8 inch elevation above the surrounding area allows for adequate water runoff without causing any significant disruption to the pavement surface.

Steel-wheeled rollers are heavy construction equipment used for compacting surfaces. The maximum speed of these rollers should not exceed 3 mph because higher speeds can cause instability and reduce the effectiveness of the compaction process. Slower speeds allow for better control and ensure that the roller can properly compact the material without causing any damage.

When repairing defective flexible pavement, it is recommended to place and compact the base course materials in 2-3 inch layers. This allows for better compaction and ensures a stable and durable base for the pavement. Placing the materials in thinner layers also allows for easier control and adjustment of the base course thickness, preventing any potential issues or inconsistencies in the pavement structure.

The final step in the preparation of a hole for flexible pavement repair is to apply a tack coat to the vertical faces. This is done to ensure proper adhesion and bonding between the existing pavement and the new repair material. The tack coat acts as a bonding agent, allowing the repair material to adhere firmly to the vertical faces of the hole. This helps to prevent any separation or delamination between the existing pavement and the repair material, ensuring a durable and long-lasting repair.

Fog seal should be used to seal hairline cracks in flexible pavements. Fog seal is a thin layer of asphalt emulsion that is sprayed onto the surface of the pavement. It helps to seal the cracks and prevent water infiltration, which can cause further damage to the pavement. Fog seal also rejuvenates the pavement by restoring the asphalt's flexibility and preventing oxidation. It is a cost-effective and efficient method for maintaining and extending the life of flexible pavements.

During the intermediate rolling, it is recommended to make at least 3 coverages with the pneumatic-tired roller. This is because multiple coverages help to evenly compact the material and achieve the desired density. By making at least 3 coverages, the roller can effectively distribute the compaction effort and ensure that the entire surface is properly compacted. This helps to improve the strength and stability of the material being compacted.

Edge cracks in pavement are typically caused by a lack of side or shoulder support. When the edges of a pavement are not properly supported, they become more susceptible to cracking due to the stress and pressure exerted on them. Without adequate support, the edges of the pavement may experience movement, shifting, or deformation, leading to the formation of cracks. Therefore, the lack of side or shoulder support exacerbates the development and progression of edge cracks in pavements.

When installing a security fence, line posts should be placed at a maximum distance of 10 feet apart. This spacing ensures that the fence remains stable and secure, preventing any potential breaches or damage. Placing the line posts too far apart may result in the fence sagging or becoming weak, compromising its effectiveness as a security measure. Therefore, a maximum distance of 10 feet is recommended to maintain the structural integrity of the fence.

SS-1 is recommended for tack-coats.

Dual-type road shoulders exist along narrow pavements, inside curves, and at intersections. This type of road shoulder is designed to accommodate different types of vehicles and provide additional space for turning and maneuvering. It typically consists of a combination of materials such as earth and bituminous or soil-aggregate, which provide stability and durability. Dual-type road shoulders are essential for ensuring the safety and smooth flow of traffic in these specific areas.

Fog seal is a type of surface treatment that is used to seal surface voids in new asphalt plant mixes. It involves spraying a thin layer of asphalt emulsion onto the surface of the asphalt, which helps to fill in any small cracks or voids and prevent water infiltration. This treatment also helps to rejuvenate the asphalt, improve its appearance, and extend its lifespan.

Steel-wheeled rollers are the best option for breakdown rolling because they provide better compaction and stability compared to the other options. The weight of the steel wheels helps to apply more pressure on the surface being rolled, resulting in better compaction of the soil or pavement. The steel wheels also offer better traction, allowing the roller to move smoothly and evenly over the surface. This ensures that the material is properly compacted and any air voids are eliminated, creating a strong and stable base.