Water was leaking out of this lake because it was flowing under the spillway instead of over it. Polyurethane grout injection was used to remedy the situation. Holes were drilled on the face deep enough to reach the backside of the spillway. Mechanical packers were then placed in the hole. The installed packers are now an injection port to hook up to the grout pump, which pumps the polyurethane to the back side of the spillway. The grout used was Hyperflex, a moisture activated polyurethane. Once in contact with the water, it foams to fill the voids and seal the leak paths. Hyperflex is NSF/ANSI/CAN 61 approved for contact with potable water and is manufactured by SealGuard, Inc. The grouting was performed by Sub-Technical, Inc.
This elevator shaft was leaking groundwater in between the floor and the first course of concrete filled block walls. Although this shaft has a drainage system, it needed to be dry to pass the final building inspection. To stop the unwanted inflow, polyurethane grout was injected to seal the leak paths. The grout used was Hyperflex and was injected by a pump and mechanical packers. Hyperflex is a single component, pre catalyzed, moisture activated polyurethane that is NSF/ANSI/CAN 61 approved for contact with potable water. Hyperflex is manufactured by SealGuard, and the grouting was performed by Sub-Technical, Inc.
A view of the tail seal brushes on a tunnel boring machine. In this situation, the tail seal brushes needed replaced and there was water flowing through seams in the tunnel segments. To control the heavy flow of water, polyurethane grout was injected around the leaks. The grout used was SealGuard II, which is manufactured by SealGuard, Inc. SealGuard II is a dual component, fast reacting material that can be easily applied with a dual component caulking gun. The grouting was performed by Sub-Technical, Inc.
Water intrusion can cause serious structural damage to buildings, leading to costly repairs and potential safety hazards. That’s why selecting an effective water sealing solution is crucial for any construction project.
Precast concrete structures have low permeability rates, which means they can effectively prevent water intrusion and provide reliable and durable sealing. Moreover, they are a sustainable choice for environmentally conscious builders as they can be constructed from recycled materials.
This article will discuss precast concrete water sealing methods, including joint sealing, using hydrophobic admixtures, and surface coating.
Precast Concrete Sealing Methods
Several methods are available to ensure reliable and effective water sealing. Each has its advantages and disadvantages, and the choice of method typically depends on various factors. These include the structure’s location, the type of water exposure, and the desired lifespan of the sealing system.
Here are some of the most popular precast concrete sealing methods:
Joint Sealing
Joint sealing involves filling and sealing the gaps between two adjacent precast concrete elements using specialized sealants. It is a popular sealing method due to its effectiveness and durability. The sealant’s flexibility also allows for the elements’ natural movement due to changes in temperature and humidity without compromising the water seal.
Using Hydrophobic Admixtures
Hydrophobic admixtures are designed to make the concrete itself water-resistant. They are often added to the concrete mixture during the batching process, and they work by reducing the water’s surface tension. They also provide a permanent, water-resistant barrier integral to the concrete. This means that there is no need for additional waterproofing materials or coatings.
Surface Coating
Surface coating entails applying a waterproof layer to the surface of the concrete. The coating functions as a barrier, keeping water out and preventing structural damage. This method creates a long-lasting, water-resistant shield that can tolerate harsh environmental conditions. Most coatings are also easy to apply and be customized to meet the project’s specific requirements.
Waterstopping
Waterstops are specifically designed materials to be placed at joints or seams in concrete structures to prevent water from penetrating them. They are highly dependable and are often utilized in underground construction such as tunnels, basements, and swimming pools. They can also give long-term protection against water penetration and are available in various materials, including rubber, PVC, and metal.
Injection Grouting
Injection grouting is a widely used method for sealing cracks and voids in precast concrete structures, making it an effective water sealing technique. The process involves drilling holes at the site of the damage and injecting grout material under high pressure into the opening. Various grout materials — such as cement-based mixtures, polyurethane foam, or epoxy resin — may be used depending on the project’s needs.
High-Quality Sealing Products From SealGuard
SealGuard II, HyperFlex, and X-Seal from SealGuard are highly effective sealing products to prevent water from penetrating concrete structures. These products are applied in their oil-like raw form, and each has a unique way of sealing precast concrete. SealGuard II is a polyurethane-based grout that reacts with a catalyst to expand and form a foam-like substance.
HyperFlex and X-Seal are hydrophilic polyurethane-based grouts ideal for precast concrete sealing applications. They work by reacting with water to expand and form a foam, filling the gaps and voids between the segments. The foam created by these grouts has excellent adhesion properties and can effectively prevent water infiltration.
Partner With SealGuard for Exceptional Sealing Solutions
SealGuard is a leading polyurethane grouting material manufacturer for water management, sealing, and adhesion of precast concrete sections and other constructions! Our products are of the highest quality and effectiveness, making them ideal for various sealing applications. Contact us today to learn more about our products and services!
Manholes are essential to any urban infrastructure, providing access to underground utilities such as water, sewage, and electrical systems. However, they can deteriorate, crack, or collapse over time due to constant exposure to heavy traffic, weather conditions, and corrosive materials. These failures can cause accidents, traffic disruptions, and even sewer backups, resulting in significant damage and costs.
Effective manhole repair and maintenance can mitigate the high costs and significant disruptions of system failures. By adopting appropriate repair methods, utility chambers can last longer and avoid potential issues down the line. This article will discuss the key aspects of manhole repair, such as the different methods available and best practices.
How Do Manhole Systems Work?
Manhole systems have a vertical chamber or shaft from the surface to the underground utility network. Their upper portion is protected by a durable cover that can be removed when repairs are necessary. Furthermore, their purpose is to enable workers to enter the underground network, examine and clean the pipelines, and perform repairs or enhancements.
In addition to providing access for maintenance and repairs, utility holes also serve other functions in managing urban water systems. For example, they act as entry points for testing and monitoring the quality of water and sewer systems. This is essential for ensuring the water supply is safe for human consumption.
Different Methods for Manhole Repair
Various factors, including natural wear and tear, environmental conditions, and poor installation, can cause utility hole failures. Listed below are the different repair methods:
Structural Lining
Structural lining creates a new interior wall within the existing structure. It involves cleaning and preparing the interior surface of the utility hole, then applying a specialized material to the walls. This creates a smooth, durable lining that can restore the structural integrity of the manhole and prevent further deterioration.
Cementitious Grouting
Cementitious grouting injects a cement-based grout into the voids and cracks in the structure. The grout material is typically made of cement, sand, water, and additives to improve the mixture’s flow, strength, and durability. This is an effective and relatively inexpensive method for repairing utility holes with minor to moderate damage, such as cracks or voids.
Epoxy Injection
The epoxy injection uses epoxy resin to fill the cracks, voids, and other structural defects. The material is typically a two-part system consisting of a resin and hardener mixed before injection. This process can seal leaking joints or prevent water infiltration into the hole. However, it may not be suitable for severe damage or structural issues that require more extensive repairs.
Polyurethane Foam Injection
Polyurethane foam injection utilizes a two-component polyurethane foam to repair the voids and gaps in the structure. The foam is a mixture of a polyol component and an isocyanate component combined at the time of injection. It can fill gaps around pipes and other penetrations in the structure, preventing water infiltration and improving the stability of the utility hole.
Best Practices for Repair and Maintenance
Maintaining and repairing manholes are essential for ensuring underground utility networks’ safe and efficient operation. Here are some of the best practices and strategies to keep in mind:
Regular Inspections and Maintenance
Regular inspections and maintenance are critical for identifying and addressing issues in utility holes before they become major problems. This includes visually inspecting manhole covers, frames, and surrounding areas to check for signs of wear, damage, or deterioration.
Utilization of High-Quality Materials
Using high-quality materials and equipment is crucial for ensuring the effectiveness and longevity of manhole repairs. This encompasses selecting materials compatible with the conditions and requirements of the utility hole, like temperature, moisture, and chemical exposure.
Compliance With Safety Standards and Regulations
Compliance with safety standards and regulations are essential for protecting the safety of workers and the public during repair and maintenance activities. This includes adhering to proper procedures for confined space entry, ventilation, and personal protective equipment.
Collaboration With Qualified Professionals and Contractors
Partnering with qualified professionals and contractors ensures the quality and effectiveness of utility hole repair and maintenance. This entails working with experienced engineers and technicians to assess the condition of manholes and develop appropriate repair strategies.
Experience High-Quality Sealing Solutions With SealGuard
SealGuard offers various high-quality repair products and solutions to help keep your manholes leak-free and your system running smoothly! Our products are known for their unmatched quality and effectiveness in protecting surfaces from damage. Moreover, our experts can guide you in selecting the right product for your application and recommend its effective use.
Contact us today to learn more about our products and services!
Water leaking around pipe intrusions can be stopped with polyurethane grout. In this instance, a hole was drilled at an angle to reach the annular space in-between the pipe and the concrete. SealGuard II, a dual component polyurethane grout, requires a static mixer to mix properly. The mixer gets inserted into the drilled hole, then the grout is injected by using a dual caulking gun. SealGuard II reacts within a few seconds, creating a rigid foam, which seals off the flow.
When water is encountered during directional drilling, the most common method to try and stop it is pumping concrete. However, if there is a large volume of water, the concrete simply washes away and doesn’t seal the leak. Concrete also shrinks as it dries, so new leak paths are formed. In this instance concrete was tried and did not work, so polyurethane grout was injected 150 feet into the problem area. The grout used to stop the water flow was Hyperflex, a moisture activated hydrophobic polyurethane that is NSF/ANSI/CAN 61 approved for contact with potable water. Hyperflex is manufactured by SealGuard, Inc. and grouting was performed by Sub-Technical, Inc.
The primary purpose of adding sealant to the joints of precast concrete is to establish an extra layer of protection between the blocks or segments. This will prevent water or dirt from entering a construction joint. Common structures requiring joint sealants are catch basins, culverts, manholes, sumps, and trenches.
Liquids take the joints of concrete structures as the primary route to the ground. Thus, failure to seal these gaps and spaces could result in detectable leaks or potential structural damage, especially if immediate action is not taken.
This article will discuss the advantages of joint sealants for precast concrete and the application process.
Advantages of Using Joint Sealants
The primary advantage of joint sealants is that they remain flexible and accommodate movement between precast concrete components. If used for floors, they will also support the movement and contraction of joints.
The following are the other benefits of joint sealants:
Ability to move with the concrete joint, extending the seal’s lifespan
Ability to enhance the visual appearance of concrete joints, increasing their appeal to architects and customers
Capability to adhere to precast concrete to ensure the joint remains permanently sealed
Fast and cost-effective application
Exceptional mechanical strength, chemical resistance, and durability
Simple to employ without the requirement for specialized equipment or instruction
How To Apply Sealants to Precast Concrete Joints
Joints in precast concrete must always be properly sealed; therefore, the correct application procedures must be followed. Here are five steps in correctly applying sealants:
Step 1: Preparing the Concrete Joint
Before applying the sealant, ensure the joint is completely dry and clear of dust, dirt, and release agents. To do so, you can thoroughly scrub the joint and its surroundings with a hard brush. If an excessive release agent is visible or you are sealing a concrete surface exposed to the elements, cleaning the covers with a pressure washer or cleaning solution may be required.
Step 2: Applying the Joint Sealant
SealGuard II, HyperFlex, and X-Seal are designed to seal concrete structures and prevent water from penetrating into them. These products are applied in their oil-like raw form. In particular, SealGuard II is a polyurethane-based grout that reacts with a catalyst to expand and form a foam-like substance. This foam fills in any gaps or cracks in the concrete and creates a watertight seal.
On the other hand, HyperFlex and X-Seal react with water to expand and form a foam. These products are typically used in precast concrete applications, where the segments are joined together to form a larger structure. Basically, the product is applied to the joint, and then water is added to activate the product. The foam then expands to fill any gaps.
Both processes eliminate the risk of the tar strip moving or deteriorating and ensure long-lasting, effective concrete sealing.
Choose SealGuard for the Best Sealing Solutions
Since 2004, SealGuard has been manufacturing polyurethane grouting materials for water management, sealing, and adhesion of precast concrete sections and other constructions. We currently offer SealGuard II, HyperFlex, and X-Seal — all of which are unparalleled in terms of quality and effectiveness!
When it comes to pre-cast concrete structures, durability and strength are essential. However, even the most robust structures can experience damage over time due to weathering, impacts, and other factors. Thus, it is vital to assess the damage and determine the most appropriate repair method to restore the structure to its original strength and stability.
One method to consider is pre-cast concrete crack injection. However, when repairing a structure, it’s vital to consider several key factors to ensure the procedure is done correctly.
1. Type of Damage
When assessing how to repair a pre-cast concrete structure, the first key consideration is the type of damage that the structure has sustained. This will help determine the appropriate repair method and materials needed.
Several types of damage can occur in pre-cast concrete structures, including:
Chipping: Chipping is typically caused by impacts or abrasion and occurs in areas with high foot or vehicle traffic. Depending on its severity, the repair method can range from applying a patching material to replacing the damaged section.
Spalling: This refers to larger pieces of concrete that break off the structure’s surface. It occurs due to freeze-thaw cycles, exposure to harsh chemicals, or age-related deterioration. Repair methods for spalling can include using a bonding agent on the damaged area or replacing the portion.
Cracks: These occur for several reasons, such as shrinkage, settlement, overloading, or exposure to extreme temperatures. The size and location of the damage will determine the appropriate repair method — injecting an epoxy filler, applying a bonding agent, or replacing it entirely.
2. Cause of Damage
It is crucial to know the underlying cause of the damage to ensure that the repair method addresses the root issue. Doing so allows you to prevent it from recurring and ensure the structure’s longevity. In addition, an accurate diagnosis will save you time and money in the long run by avoiding unnecessary costs and procedures.
3. Location of Damage
Damage in visible areas can be an eyesore and negatively impact the perception of your structure. As such, it’s important to consider the visual impact of the chosen repair method. Additionally, the location of the damage may impact the accessibility of the area, which can make the repair more challenging and time-consuming.
4. Age of the Structure
As pre-cast concrete structures age, they may require more extensive repairs than newer structures. The repair method must consider the wear and tear that older systems undergo and the potential for more advanced damage. Failing to consider the age of the structure can result in further damage, structural issues, and even safety hazards.
5. Condition of the Reinforcing Steel
The reinforcing steel in a pre-cast concrete structure provides additional strength but must be replaced if it’s corroded or damaged. Neglecting to consider the condition of the reinforcing steel can compromise the integrity of the repair and worsen the structure’s issue.
6. Local Building Codes
Local building codes may specify certain materials or repair methods that must be used to ensure the structure’s safety and compliance with regulations. Therefore, consulting and checking existing policies before undertaking any repair is crucial to ensure you’re using the right materials and methods. This will also help you avoid fines and sanctions from your community.
7. Structural Integrity
This aspect must be assessed to determine if the damage has compromised the strength or stability of the entire structure. More extensive repairs may be necessary if the damage has affected the foundation’s structural integrity. Ensuring that the building is structurally sound and safe is of utmost importance in these cases.
8. Environment
If the structure is located in a coastal environment, the repair method must consider the potential impact of saltwater corrosion. Failure to do so can lead to further damage or render repair works useless, wasting time and money.
9. Accessibility
Damage located in hard-to-reach areas can be a challenge to repair. In addition, special equipment or techniques may be needed, which can increase the cost and time required. Therefore, it’s important to consider the accessibility of the damage to plan the repair effectively.
Protect Your Structure With SealGuard’s Reliable Sealing Solutions!
SealGuard has been producing polyurethane grouting solutions for water management, sealing, and adhesion of pre-cast concrete sections and other structures since 2004. We offer SealGuard II, HyperFlex, and X-Seal — all of which are of the highest caliber and efficiency!
Manholes are an essential component of an area’s sewage system, serving as maintenance access points and providing structural support for the pipes. They are also crucial to the system’s proper operation, allowing for wastewater collection, transport, and treatment.
However, manholes can deteriorate and become damaged over time. The most common causes of manhole damage are corrosion, ground movement, and heavy traffic. These can result in leaks, blockages, and collapses, requiring costly repairs and posing safety risks to the public.
Manhole rehabilitation may appear daunting, but it can be accomplished efficiently and effectively with the right knowledge and resources. Using trenchless techniques enables efficient and cost-effective maintenance. This method involves repairing the utility hole from the inside.
Listed below are the steps to effective rehabilitation:
Step 1: Preparing the Substrate
Prepare the concrete and steel substrates so the restorative materials can adhere sufficiently. This will also ensure the repair’s success and extended durability. Next, remove loose and contaminated substrate material through pressure washing, grinding, or abrasive blasting.
Verify that the Concrete Surface Profile (CSP) is suitable for the application of repair mortars — per SSPC-SP12/NACE No. 6 — requiring a CSP equivalent to medium-grit sandpaper. Lastly, inspect the concrete’s pH level to confirm whether the surface is contaminant-free. If the pH is less than 10, contaminants are still present on the substrate, and additional actions may be required.
Step 2: Injecting the Grout Material
Injecting grout into a manhole is a rehabilitation step that aids in the repair and stabilization of the structure. In concrete structures, grout fills voids, cracks, and joints. It is also typically composed of cement, water, and different aggregates.
The trenchless procedure involves drilling holes through the concrete whenever cracks or leaks exist. Then, you should inject a low-viscosity, water-activated polyurethane grout that follows the path of the infiltrating water around the structure. The grout hardens in place and creates a tight seal between the underside and the soil.
The optimal grout material for a particular rehabilitation depends on the project’s conditions and requirements. Some examples include the following:
Epoxy grout
Polyurethane grout
Cement-based grout
Hybrid grout or multi-component grout
Step 3: Rehabilitating the Structure
Next, it’s time to address and repair the structural issues of a manhole, which may include cracks, holes, deformations, and corrosion of the steel reinforcement. The appropriate cementitious repair mortar will vary depending on the substrate, the service environment, and the coating.
One of the most popular repair materials that can be used is cementitious microsilica repair mortars. This mixture possesses superior strength, durability, flowability, adhesion, and impermeability. You can also use cementitious calcium aluminate repair mortars. They are distinguished for their rapid hardening, heat resistance, low shrinkage, and eco-friendly properties.
Step 4: Applying the Coatings and Linings
Applying corrosion-resistant coatings or linings to a manhole is an essential step in the rehabilitation process that prevents further deterioration and damage to the structure. Typically, these substances are applied to the walls and floor to create a barrier against water, chemicals, and other potentially damaging factors.
Here are the two types of semi-structural liners:
Freestanding Liners
A freestanding semi-structural liner is typically composed of a fiberglass-reinforced polymer (FRP) material that is durable, corrosion-resistant, and lightweight. Furthermore, it is designed to be self-supporting and can be used to repair structural defects like cracks and holes.
Bonded Liners
Unlike a freestanding semi-structural liner, a bonded liner is firmly attached or adhered to the existing structure. Therefore, it requires surface preparation of the current system and a proper installation and curing process to ensure effective adhesion.
Contact SealGuard for High-Quality Sealing Products and Solutions
Manhole rehabilitation can increase the sewer system’s overall flow capacity, prevent infiltration and exfiltration, and reduce the risk of collapse. It can also optimize the manhole’s condition to avoid further deterioration and extend its lifespan.
