WATERPROOFING Importance of Filling Cracks, Joints & Voids

WATERPROOFING Importance of Filling Cracks

Samir Surlaker
Samir Surlaker, Director, Assess Build Chem Private Limited discusses some new joint treatments and injection systems in waterproofing.

It is a myth that waterproofing treatments can be carried out by application of single material on new concrete or existing treatments. There cannot be a single material that is right for every structure. Most of the failures in waterproofing are on account of this misconception. The only way to ensure reliable treatment is by considering the waterproofing treatment as a system. A System for Waterproofing can be defined as a combination of materials, preparation of specifications, application techniques designed by taking into considerations the requirement of the client or homeowner, which would provide efficient, reliable and long-term protection to concrete structures with minimum maintenance costs.

Waterproofing should never begin with a specific material in mind. The properties of material needed, are to be stated and then the material is to be selected as per the merit. To combat the different entry modes of water into concrete, a combined system of treatments is therefore necessary. To waterproof a structure completely, one has to address the 3 primary routes of entry into the structure, viz.
  • Pores, Capillaries and Voids in the concrete
  • Joints and Transitions
  • Cracks in the concrete cover
These can be achieved by use of:
  • Admixtures and additives to reduce the porosity and capillarity in the concrete
  • Treatment of joints, transitions and cracks using suitable coatings with reinforcement, flashing tapes and expansion joint tapes
  • The cover concrete is to be protected by appropriate surface barrier coatings
Many a times, due to age and deterioration, the effect of these treatments begin to fade, and water enters the living / usable space. It is at this time remedial waterproofing comes into play. The aim of this remedial waterproofing is to minimize the voids in the structural element [walls (basement or rooms), slab (ceiling or basement) or other structural elements. Normally a combination of this re-densification of the structural elements and joint treatment will solve most water ingress problems.

WATERPROOFING Importance of Filling CracksFigure 1: Selection of Injection / Impregnation Materials based on Crack Width

Waterproofing using Injections Types and its Applications
Injection Technologies have long been used to treat waterproofing issues. In Brief, Table 1 below gives an idea of the type of Injection materials available and the conditions these materials can be used under. The areas of application of the suitable filling materials and filling methods depend mainly on the intended application goal, the crack width, crack movement, and dampness of the cracks/crack edges/crack flanks and voids. Usually three different injection systems/methodologies are specialized to solve critical waterproofing problems:

Table 1: Materials and Crack / Void Property they can be used to Address
Crack Void Property / Materials Cement Based Epoxy PU Acrylic Gels Coatings
Surface Crack + ++     ++
Deep Crack   ++ ++ ++  
Load Transfer ++ ++ +    
Water Stoppage     ++ ++  
Moving     ++ ++ +
Non-Moving ++ ++      
Water Bearing / Damp +   ++ ++  
Dry ++ ++ ++    
+: Suitable;  ++: Most Suitable; Blank: Not Suitable
  • Grid Injection [Crack treatment or creation of a waterproof layer from the negative side]
  • Water Bar Injection/Expansion Joint Treatments/Transitions
  • Injection Hoses
WATERPROOFING Importance of Filling CracksFigure 2: Flow-Chart for Decision Making on Repair of Cracks [Ref.: Dr. V.K. Raina, Raina’s Concrete Bridge Practice: Construction, Maintenance and Rehabilitation (Second Edition)]
Selection of materials based on crack width is shown in table 1 and figure 1. Figure 2 gives a brief flowchart for Injection Strategies.

Positive Waterproofing from Negative Side, Grid Injections Low Viscosity Pus or Low Viscosity Acrylic/Methacrylate Gels
Water penetration is often caused by bad concrete compaction, honey combing or defective seals. Sometimes an interconnected void system also allows water to pass through the element and causes leakages. Grid injection is an application technique, developed from the standard crack injection process. This method is more useful where a true source of leakage is not easily traceable and a complete water stopping solution is required.

Normally if the injection is to be performed into the element, (around a cracks) a combination of polyurethanes is generally used. For very low water ingress or dampness a low foaming polyurethane (PU) can be used in isolation. In case of heavy ingress or water under pressure, a high foaming PU is used as a primary injection to stop the heavy flow, followed by a non-foaming low viscosity structural PU.

WATERPROOFING Importance of Filling Cracks

Low viscosity Acrylic/Methacrylate gels are used specifically for curtain grouting beyond the structure into the soil, when a waterproofing injection into the element is not possible or successful, due to technical, or economic reasons. The gelling of the substrate adjacent to the structure or the injection of gels into gaps in the structure creates a sealing layer, which provides a secondary waterproofing for structural components. These materials can also be used to increase the bearing capacity of soils for foundations or abutment walls. The schematic for the injection is shown in figure 3 and the practical process is shown in figure 4. The advantages of using these materials include:
  • Sealing without digging
  • Long-term tested, Systems
  • Waterproof up to 12 bars
  • High chemical resistance
  • Adjustable to soil conditions
Thus, no water can reach the leakage affected elements anymore and they have a chance to dry out fully. For a curtain injection first of all a grid of packers has to be set up. The grid should cover the highest assumed level of ground water. The distance of 30cm in-between the packers is just an average.

Treating Failed Expansion Joints/Water-bar Injection
This is a special injection application used when joint treatments in an RCC Structure fail. Water-bars are used to seal joints in moving structures against pressurized water. However, the concrete often proves to be defective in the area of the water-bar because of inadequate compaction. Water-stop Injections effectively address this defect. The materials used here are flexible methacrylate/Acrylic Gel Injections. This schematic is shown in figure 5.

Re-injectable hoses
Other critical areas with regard to the water tightness of a building or structure are expansion joints that are not sealed with water bars. Inserting injection pipes provides the possibility of sealing expansion joints effectively at a later date. The material used for such cases must display excellent flow properties. Figure 6 shows the Injection Hose System.

WATERPROOFING Importance of Filling Cracks

Injection is a proven method of sealing against pressurized water in structural renovations. The grouting of injection hoses also provides the benefit of using the advantages of injection technology in new construction specifically for the sealing of construction joints. New generation injection hoses can be injected several times, have been used successfully for construction joint sealing for many years.

They can be injected with microfine cements, acrylate gels or urethane resins. In contrast to passive sealing systems such as conventional water stops, which only seal by so-called circumference extension, active systems such as injection hoses and injection grouts can be used to strengthen possible weak points in the concrete caused by cracks or badly compacted concrete.

Conclusions
The technologies highlighted in the article are a first step to stopping water leakages completely. The injection treatment is usually followed by treating the transition with flashing or expansion joint tapes. This is finally protected by a coating system to enhance the durability of the waterproofing system as a whole.

In conclusion, it is important to know and identify the water ingress avenues expected in the building structure. This will help us in identifying the system that can withstand these loads over time and provide a reliable seal against water ingress into living spaces. The consequences of water/dampness entering the living space is multifold and can impact health, safety, fire-worthiness, structural durability, aesthetics as well as can destroy property. These issues need to be addressed by the waterproofing system, to improve living conditions and safety. Of course, the combination of materials, detailing and application will finally determine the success of the waterproofing system.
NBM&CW April 2020
Fabric Reinforced Cementitious Matrix: Structural Strengthening Systems

Fabric Reinforced Cementitious Matrix: Structural Strengthening Systems

The need for structural strengthening in aging infrastructures is rapidly escalating across various sectors, encompassing buildings, industrial structures, bridges, dams, ports, and other important structures. This demand extends

Read more ...

Assess Build Chem: Long-Lasting Solutions for Basement Waterproofing

Assess Build Chem: Long-Lasting Solutions for Basement Waterproofing

Assess Build Chem provides effective and long-lasting protection for buildings with its innovative products and solutions for deep/large basement waterproofing. Basement waterproofing is a crucial aspect of building construction, especially in

Read more ...

Dam Rehabilitation With Cutoff Wall for Seepage Control

Dam Rehabilitation With Cutoff Wall for Seepage Control

As storm damage becomes more severe and has occurred more frequently in recent years, addressing the needs to repair essential infrastructure and dam rehabilitation is also becoming more common. However, deep foundation experts and others

Read more ...

JOGANI Reinforcement: Alkali Resistant ARACC Coated Waterproofing Mesh

JOGANI Reinforcement: Alkali Resistant ARACC Coated Waterproofing Mesh

Jogani Impex is considered an industry leader in providing international grade Alkali Resistant ARACC Coated waterproofing mesh, which enhances the waterproofing systems and solutions in all types of buildings and structures, while saving money

Read more ...

Assess Build Chem’s Deep & Large Basement Waterproofing Solutions

Assess Build Chem’s Deep & Large Basement Waterproofing Solutions

Assess Build Chem, a leading provider of construction chemicals, is ensuring long-term protection of buildings with its innovative waterproofing solutions that include a 5-step waterproofing method for deep and large basements. Sunny Surlaker, Head

Read more ...

Agrani: Waterproofing, Retrofitting, Civil Work & Interior Fit Outs

Agrani: Waterproofing, Retrofitting, Civil Work & Interior Fit Outs

By adhering to the highest industry standards, Agrani Group has gained a reputation for delivering solutions waterproofing, retrofitting, civil work & interior fit outs that surpass client expectations, avers Ramendra Bahadur Sinha

Read more ...

FAIRMATE's FAIRFLO CRYSTALLINE: Waterproofing Admixture for Concrete

FAIRMATE's FAIRFLO CRYSTALLINE: Waterproofing Admixture for Concrete

FAIRMATE is catering to the Speciality Construction Chemical Industry by manufacturing a complete range of construction chemicals like FAIRFLO CRYSTALLINE - Waterproofing Admixture for Concrete, along with cost-effective solutions and world-class

Read more ...

Nippon Paint India: Paints, Construction Chemicals & Waterproofing

Nippon Paint India: Paints, Construction Chemicals & Waterproofing

In line with its global vision, Nippon Paint India is expanding its portfolio beyond the paint and coatings product range; it will now offer products and solutions under the broad categories: Dry mix, Repair and Maintenance, Construction Chemicals, and

Read more ...

Alkali-Aggregate Reaction in Concrete Structures & Preventive Measures

Alkali-Aggregate Reaction in Concrete Structures & Preventive Measures

When the alkali of cement reacts with the reactive constituents of aggregates, the reaction is deleterious though very slow, and the distress is exhibited when the volume inside the concrete is increased due to the formation of alkali-silica gel, causing the

Read more ...

Retrofitting for buildings: Enhance structure lifespan & efficiency

Retrofitting for buildings: Enhance structure lifespan & efficiency

Despite understanding the potential of retrofitting and its distinct and far-reaching advantages in making existing buildings green and sustainable, retrofitting continues to be undertaken on a very limited scale; hence, it needs to be promoted and made mandatory

Read more ...

Cause of Distress of an Old Building Through Advanced Analysis

Cause of Distress of an Old Building Through Advanced Analysis

The technical service life of a reinforced concrete building is the time in service when structural safety is unacceptable due to either material degradation or exceeding the load carrying capacity, or both. In which case, the repair strategy may be adopted

Read more ...

Value Engineering with MCI®-2019 Water Repellent for Concrete Repair

Value Engineering with MCI®-2019 Water Repellent for Concrete Repair

True value engineering saves money without reducing service life or affecting the quality of construction or materials. Ideally, it adds value to the project. MCI®-2019 Water Repellent is one such value engineering solution that can extend

Read more ...

Agrani Milestone Use Carbon Fiber Laminates to Strengthen Slab

Agrani Milestone Use Carbon Fiber Laminates to Strengthen Slab

Ramendra Bahadur Sinha, Managing Director, Agrani Milestone, explains the remedial measures and challenges faced during slab strengthening of a deflected slab at IIT. NBCC India Limited undertook the strengthening of a deflected slab at a G+2 storey IIT building

Read more ...

Waterproofing Challenges & Remedial Measures in High Rise Buildings

Waterproofing Challenges & Remedial Measures in High Rise Buildings

High-rise buildings need special attention when it comes to waterproofing as the challenges inherent in them are peculiar in nature. Unfortunately, there is a lack of knowledge on the remedies and products available in the market as water- proofers continue to

Read more ...

Importance of Waterproofing Structures

Importance of Waterproofing Structures

The longevity of structures depends on how much resistance the building element will offer to water ingress. Water leakage not only reduces the durability but also hampers the serviceability or usability of the structure; hence, a good waterproofing system will

Read more ...

Terrace Waterproofing Solutions for Energy-Efficient Buildings

Terrace Waterproofing Solutions for Energy-Efficient Buildings

Terrace waterproofing is particularly important and is considered a priority as the roof is always exposed to harsh climatic conditions and weather changes. Rajeev Gupta, Business Head, ECMAS Construction Chemicals Pvt. Ltd. An effective waterproofing solution

Read more ...

Structural Rehabilitation of Reinforced Concrete Structures

Structural Rehabilitation of Reinforced Concrete Structures

Cement concrete is one of the most important construction materials and is practically basic to present-day developments. It is strong enough mechanically, yet vulnerable to deterioration. It thus gets damaged and even fails. This deterioration may be due to the weathering

Read more ...

Thermax - HDPE-SBS Waterproofing System for Basement Waterproofing

Thermax - HDPE-SBS Waterproofing System for Basement Waterproofing

Gradual shift in lifestyle has driven the idea of modern construction towards developing underground spaces and buried structures to bring efficiency in use of space. However, the improved efficiency comes with an increase in challenges like infiltration

Read more ...

Waterproofing in Hilly Areas with Sub-Zero Temperatures

Waterproofing in Hilly Areas with Sub-Zero Temperatures

Industry experts Kunjan Popat, General Secretary, Waterproofing Association of India; Ramendra Bahadur Sinha, Managing Director, Agrani Enterprises, and MS Sudish, Director, SIWIN Institute of Waterproofing and Insulation, share the challenges

Read more ...

Dow Sealants for Sustainable Infrastructure

Dow Sealants for Sustainable Infrastructure

Durability is a key requirement for modern infrastructure projects – highways and roads, bridges, airports and airfields, walkways and plazas, parking structures and stadiums. Miles of concrete must

Read more ...

To get latest updates on whatsapp, Save +91 93545 87773 and send us a 'Saved' message
Click Here to Subscribe to Our eNewsletter.