A Study Case on how concrete waterproofing technology can be a construction cycle accelerator, a money-saving factor and a solution for labor shortage

Xypex offers labor-saving waterproofing and repair products for all types of structures, both above-ground and underground. Underground concrete infrastructure benefits from Xypex protection incorporated into the mix design for structures such as commercial and residential foundations; utility vaults that keep water out and protect valuable equipment; water and wastewater structures built to prevent ingress and egress of liquids; tunnel linings; elevator pits; marine structures, and so much more. Depending on the project’s complexity, specifying Xypex in the mix can save days or even weeks of labor on the jobsite.

Integrating Xypex in the concrete mix provides other advantages as well:

• Upfront Cost Savings. Here’s an example comparing the cost of surface waterproofing on a finished foundation versus incorporating Xypex into the concrete mix: A contractor in Salt Lake City, Utah, recently calculated that it would cost about $10,000 in labor and materials to install 37 sq. yd. of blind-side waterproofing to a basement foundation, compared with a cost of $1,700 by using Xypex Admix C-500 in the concrete mix before pouring the foundation. $8,300 in savings.
• Lifecycle Cost Savings. Once incorporated into the concrete matrix, Xypex crystalline technology becomes part of the structure, providing long-lasting leak prevention and self-healing action for small cracks. This extends the structure's life, reduces expensive maintenance and increases cost savings over the structure's lifetime.
• Risk reduction. Since no extra workers are required to install concrete treated with Xypex, the risk of worker injury is reduced, improving jobsite safety.
• No additional material is needed. Xypex eliminates the chance of punctures and tears that plague surface-applied coating materials and reduces their effectiveness.
• Reduces scheduling hassles and headaches. No separate installation crew is required for Xypex-treated concrete.
• The ultimate protection. Xypex provides both positive and negative water resistance, unlike coatings or membranes.
• Crack repair. Xypex-treated concrete is self-healing. Cracks in the concrete up to 0.5 mm. are automatically repaired.
• Resists harsh environments. Xypex-treated concrete resists harsh chemicals and mitigates the attack of chlorides, sulfates, and carbonation and alkali-aggregate reaction effects.

With an aging workforce and increasing demand, the construction industry will need to attract an additional 650,000 skilled workers in the near future, according to Associated Builders and Contractors. And that’s just in the U.S. alone. In Canada, job vacancies in the construction trades increased 158% in 2019-2020, according to Statistics Canada, and have not yet recovered. In the EU and many other countries worldwide, construction labor will continue to be a challenge in the future. Wherever labor can be reduced, contractors and project owners will benefit. Xypex scientists understand that and continue to refine and improve Xypex products to support efficient construction methods.

While modular construction has been around since the 1970s, it has grown steadily in recent years due to various factors. The increasing use of BIM 3D modelling, construction speed, jobsite safety, and less environmental jobsite impact are among the factors that have launched a new era in modular construction, as stakeholders continue to find ways to move labor to offsite facilities like precast concrete plants.

Crystalline waterproofing is uniquely positioned to contribute to modular building in three important ways: savings in time, labor and costs for contractors and project owners. Incorporating Xypex crystalline waterproofing into the concrete mix versus installing membranes or spray-applying coatings on the jobsite leads to considerable savings. Based on a study done in the United States, crystalline waterproofing costs $19 per square meter, compared with $135 for PVC membrane and $170 for spray-applied membranes.

The installation rate for these waterproofing technologies was also dramatically different, with crystalline waterproofing requiring no installation time since it is added directly to the concrete mix versus a typical installation rate for PVC membranes of 85 square meters per shift and 250 square meters per shift for spray-applied membranes.

Xypex crystalline waterproofing products are comprised of portland cement, fine-treated silica sand and proprietary chemicals. This waterproofing system takes advantage of the chemical nature of concrete. It uses it to achieve waterproof concrete and concrete that can heal itself when hairline shrinkage cracks develop. Crystalline waterproofing reacts with moisture and the byproducts of cement hydration such as calcium hydroxide, other soluble mineral salts and un-hydrated or partially hydrated cement particles within the concrete substrate to form mineral-based dendritic crystalline structures that are insoluble in water. The formation of the crystals in the concrete pores, cracks and other voids is an ongoing, gradual process, requiring several days to a couple of weeks for the crystals to reach maturity.

The barrier effect from crystalline waterproofing inherently improves the durability and performance of concrete structures, lowers maintenance costs and extends the lifespan by protecting against the effects of water ingress and aggressive chemicals such as chlorides and sulfates.

Xypex’s Crystalline waterproofing works the same in all applications, whether incorporated into new concrete as an admixture, applied to the concrete surface as a slurry coating for repairs, or applied as a waterproofing treatment. These project profiles from around the world illustrate the range of ways that Xypex products save labor, reduce costs, and enhance any concrete project with unmatched waterproofing technology that lasts for the life of the concrete.

DEEP FOUNDATIONS

Amos Rex
Helsinki, Finland

Like a buried treasure, the multi-domed ceiling of the underground Amos Rex art museum pushes up from below Helsinki’s Lasipalatsi Plaza to create an interactive outdoor playscape. Opened in 2018, the museum features five mounds of varying sizes on the plaza, each equipped with large portholes that offer a glimpse of the artistic treasures below and provide abundant natural light to illuminate more than 2,200 m2 (23,680 ft2) of gallery space in the museum.

Because much of the museum is underground, the designers required absolute moisture resistance in the concrete foundation and walls. At a depth of 14 meters (45 ft), the foundation would be at least seven meters below the average water table for that area and under constant hydrostatic pressure.

The design team considered many waterproofing options, including membranes, coatings, and concrete additives. After exploring all the scenarios, the design team selected Xypex Admix C-1000 NF based on its track record of success with similar deep-foundation projects worldwide.

Project engineers consulted with Xypex Technical Services to determine the optimal dosing for Admix C-1000 NF at various depths of the foundation. The lowest and most hydrostatically susceptible structures – footings, slabs and elevator pit – received the highest dose at 5 kg/m3. The concrete walls of the lower level (storage area) were dosed at 4 kg/m3, and the gallery level walls (just below ground level) were dosed at 3 kg/m3.

With the museum quickly gaining international popularity, the design team and Amos Rex patrons can rest assured, knowing that the deep foundation of their iconic space is protected from the elements by Xypex Crystalline Technology.

409 + 499 Illinois
San Francisco, California, USA

Designers knew they would have considerable waterproofing challenges in the planning stages for a new office space called 409 + 499 Illinois. The complex would feature two six-story towers constructed over a three-level subterranean parking garage in San Francisco underground area. The 409 + 499 campus is adjacent to a filled-in shipping channel from the early 20th century that presented a water infiltration conduit from the bay to the garage.

With an exceptionally high water table at 3.8 m (8 ft) below grade and the likelihood of a saltwater attack, developers faced a far greater concrete waterproofing and protection issue than usual. Aware of the reliable performance of Xypex Crystalline Technology in resisting both extreme hydrostatic pressure and saltwater attack, project engineers and designers specified Xypex Admix C-1000 NF to waterproof and protect the below-grade slabs and perimeter walls.

The project’s ready-mix supplier blended Xypex Admix into the concrete during batching and worked closely with Xypex Technical Services to orchestrate a 15-hour, problem-free continuous pour of more than 7,200 m3 (8,000 yd3) of Xypex-enhanced concrete to ensure a foundation that would perform and endure under pressure.

Studio City Casino
Macau, China

Studio City Macau is built on the reclaimed land of Cotai, a 5.2 km2 (2.0 square mile) landmass created by combining the islands of Coloane and Taipa into one continuous strip. Known as one of Asia's most popular travel and shopping destinations, the Cotai area features Las Vegas-style casinos and world-renowned brands sold in designer boutiques. Because of its proximity to the ocean, a significant concern in constructing the Studio City Casino was the chloride content of the high-water table.

Project engineers selected Xypex Admix because of its proven track record for resisting hydrostatic pressure and chloride attack. Xypex Admix was used to waterproof and protect more than 100,000 m3 (109,361 y3) of concrete in the basement slab and walls.

Because it is an integral waterproofing system, Xypex Admix enabled the contractors to forego using membranes, reducing construction costs and accelerating the construction schedule. The resulting time and money savings enabled the casino to open two months ahead of schedule. Due to the size and scope of this project, it took five ready-mix producers to supply the massive amount of concrete needed.

TUNNELS

Thames Tideway Hammersmith
London, England

Considered London’s new “super sewer,” the Thames Tideway Tunnel runs from Acton to Abbey Mills and is designed to prevent millions of tons of pollution from reaching the River Thames. As part of an innovative design package for the tunnel, the technical team selected Xypex as the sole waterproofing agent for the primary lining at the west section of the Hammersmith Connection Tunnel, which runs from Acton in West London to Fulham in South West London.

The original tunnel design called for a sprayed concrete primary liner and a cast-in-place secondary liner with a waterproof membrane between the two layers. The designer wanted a new approach and backed it up with testing. In pre-construction trials, the designers showed that Xypex Crystalline Technology would reduce the permeability of the concrete.

Working with a ready-mix company, the team showed how Xypex Crystalline Technology would behave within their particular mix design. In addition, the trial compared concrete treated with and without Xypex products to prove its water-tightness over standard tunnel construction methods. The results proved that adding Xypex Admix C-Series to the concrete mix provided the greatest protection against permeability.

Joint protection was a vital requirement of the stakeholders. In a 45-degree “day” test, the researchers took core samples through the joints in three axes to test for water permeability. Results confirmed that Xypex Crystalline Technology was superior. Trial results showed that the growth of the Xypex crystalline structure across the joint sealed beyond expectations.

The designer’s specification of the Xypex Admix C-Series meant that, after the successful trials, the stakeholders were satisfied enough not to include the application of a membrane in the Hammersmith Connection Tunnel.

Contractors incorporated Xypex into more than 100,000 kg (220,462 lbs.) of sprayed concrete and saved seven weeks on the tunnel construction and 11 weeks on the drop shaft.

As an additional benefit for sewer projects like this, concrete treated with Xypex self-heals cracks up to 0.5 mm and provides durability against many aggressive chemicals, including microbial-induced corrosion (MIC). Xypex handles chemical attacks in severe biochemical conditions such as sewage and wastewater treatment structures and eliminates the need for membrane applications or other post-construction waterproofing, saving contractors and project owners considerable time and labor expense.

Blacklick Creek Sanitary Interceptor Sewer Tunnel
Columbus, Ohio, USA

The rapidly growing city of Columbus, Ohio, needed to increase the capacity of its sewer line for its eastern suburbs. The project called for a 3.65 m (12 ft) outside diameter tunnel approximately 7,300 m (24,000 ft) in length with a depth of 12 m (40 ft) to 42 m (140 ft).

The segmentally lined tunnel was excavated using a tunnel boring machine (TBM) with a short section of the project constructed by open-cut sanitary sewers. The TBM tunnelled through varying glacial and alluvial materials, tills, boulders, sand, fill and shale.

This is a harsh environment, subject to microbial-induced corrosion. To protect the precast concrete tunnel segments, design engineers and contractor AECOM specified Xypex to improve the acid resistance of concrete and protect against sulphate attack. By incorporating the concrete waterproofing into the concrete mix, the contractors saved time, labor and costs on the jobsite because no additional spray-on applications or liners were needed. With the help of the Xypex Admix waterproofing solution, the project wrapped up 436 days ahead of schedule.

MARINE STRUCTURES

Cronulla Wharf – Chloride Diffusion Results
New South Wales, Australia

The Cronulla Marina is located within Gunnamatta Bay in New South Wales, Australia. The floating docks are subject to aerosol chlorides, and the top surfaces are within the splash zone. The conditions can be described as a severe marine environment.

The marina floats were cast in October 1994, employing a high-early-strength concrete design incorporating 530 kg (1,168 lbs.) of GP cement and 4.2 kg (9.3 lbs.) of Xypex Admix NF C-Series. The 100 mm (4 in) thick panels are pre-tensioned with wire strands and have foam flotation attached to the soffit. The wire strand steel reinforcing is only 40 mm (1.6 in) below the top surface of the concrete panel.

The top surfaces of the panels are a nominal 350 mm (13.8 in) above sea level. In 1998, four years after the floats were commissioned, a condition survey incorporating a visual inspection, chloride penetration and half-cell testing was commissioned. Testing for concrete durability, chloride permeability and performance life indicated that the performance of the Xypex treated concrete exceeded that of untreated concrete in high chloride environments.

The same research group replicated the testing protocol in May 2013 after 19 years of service. Testing included concrete sampling at various depths, with analysis of those samples for chloride content and half-cell equipotential mapping. The results again showed very low chloride diffusion coefficients and half-cell results which indicate passive or near passive conditions. Visual inspection of the float also revealed no rust spotting, staining, or cracking that would have suggested corrosion of the embedded steel. Key results from testing were:

• An expected time to corrosion of 129 years (after 19 years of service, meaning nearly 150 years expected time to corrosion from the time of commissioning).
• Chloride diffusion rates 92% lower than the initial test after an additional 15 years of exposure.
• The absence of any significant half-cell potential gradients. Given the shallow concrete cover and the severe environment, this real-life long-term test lends solid support to the test results showing Xypex’s ability to improve a concrete’s resistance to chloride ingress and corrosion.

Studies like this show that Xypex Crystalline Technology significantly extends the lifecycle of concrete structures. Xypex saves labor and time by incorporating waterproofing into the concrete batching rather than adding expensive spray-on coatings or liners at the jobsite. And, as this research shows, the savings continue for many years after installation.

Port Adelaide
Australia

Corrosion resistance, durability, extended service life and reduced maintenance costs were critical priorities for Flinders Ports in constructing the Berth 8 Outer Harbour Grain Wharf. The wharf is a concrete deck and beams on piles structures 228 m (748 ft) long, a roadway along the quay, deep rail support beams, and two 36 m (118 ft) wide access ramps.

One of South Australia’s critical ports is designed to berth Panamax and New Panamax vessels and will support a travelling ship-loader. To meet the Flinders Ports priorities, designers specified Xypex Admix C-1000 NF for the 4,500 m3 (4921 yd3) concrete needed for the wharf. While the specifications called for 50-year service life, the Xypex protection added when concrete batching would likely protect the concrete for much longer.

Xypex Admix C-1000 NF permanently seals the concrete and prevents the penetration of water and other liquids from any direction. Xypex Admix C-1000 NF is particularly suited to this wharf structure as its chemical composition slows the diffusion of chloride penetration, ensuring protection from the harsh marine environment. Pile plugs, pile caps, rear ramp support walls, wharf beams, the deck and ramps were all dosed with Xypex Admix C-1000 NF at a rate of 3.9 kg (8.6 lb) per meter.

Not only did the Xypex approach eliminate the need to add spray-on waterproofing or membranes at the site, but it also saved time, labor and maintenance costs for years to come by significantly extending the life of the concrete.

WASTEWATER TREATMENT PLANTS

Chatham Park Decentralized Wastewater Reclamation Facility
Pittsboro, North Carolina, USA

The Chatham Park Decentralized Water Recovery Center is one of the few treatment plants to use eco-engineering to clean wastewater and convert it into non-potable water. In developing the wastewater facility to complement the sustainability goals of Chatham Park, the engineering team turned to Xypex admixtures to protect the concrete for this high-profile $15 billion planned community in Pittsboro, NC.

The Water Recovery Center processes wastewater using organisms that consume nitrogen, phosphorus and other nutrients in the wastewater stream. It is an environment with potentially high levels of hydrogen sulfide and microbial-induced corrosion.

The engineers of record, McKim & Creed, specified using a high-build acid-resistant coating to protect the concrete. Bowen Engineering proposed Xypex Bio-San C500 admixture as an alternate to this coating because it contains Xypex’s antimicrobial crystalline technology. The Xypex approach protects the concrete from chemical attack, saves labor, and speeds construction by taking the concrete treatment offsite.

Xypex Bio-San C500 protects concrete from MIC by killing the acid-producing bacteria and breaking the biochemical chain of events that cause MIC. It also contains the proprietary Xypex Crystalline Technology that waterproofs concrete at the microscopic level, creating an internal water-stopping bond that blocks ingress and egress of water and other liquids.

Xypex Bio-San C500 provides superior protection and eliminates the long-term maintenance required by protective coatings. In other parts of the Water Recovery Center, such as the headworks and various tanks, the engineers specified Xypex Admix C-500 to provide watertight, chemically resistant concrete to protect installed liners from the negative-side hydrostatic push-off. Xypex products provide cost-effective, long-term protection and waterproofing to the concrete for this new piece of critical infrastructure in Pittsboro.

WATER TREATMENT PLANTS

Richland Creek WTP
Atlanta, Georgia, USA

Metro Atlanta’s new Paulding County Richland Creek Reservoir Water Supply Program includes a 123-ha (305-acre) reservoir and a water treatment plant to produce drinking water for 47,000 customers.

PC Construction, one of the key players in the $215 million project, built the water treatment plant and other project elements. When cracks were discovered in some water treatment plant structures during hydrostatic testing, expensive and time-consuming crack injection and patching were not required. The cracks healed themselves because all the concrete used in the water-holding structures had been treated with Xypex Admix C-500 crystalline waterproofing. Admix C-500 is added to the concrete at the time of batching and generates a non-soluble crystalline formation that fills and plugs pores in concrete, becoming a permanent, integral part of the structure.

This makes the concrete itself waterproof, preventing the ingress of water and other liquids from any direction for the life of the structure. Admix C-500 also provides chemical resistance properties that mitigate the attack of chlorides and sulfates and the effects of carbonation and alkali-aggregate reaction. Because Xypex Admix C-500 crystalline waterproofing was used in all water-holding structures in the Richland Creek plant, PC Construction achieved leak-free concrete without any additional cost or labor, and the water treatment plant will continue to operate uninterrupted, delivering up to 57 million litres (18 million gals) of clean water to its customers every day.

AQUARIUMS

Wonders of Wildlife
Springfield, Missouri, USA

The $300 million Wonders of Wildlife National Museum and Aquarium took ten years of planning and construction. The 32,516 m2 (350,000 ft2) nonprofit educational and conservation-themed attraction features 5.7 million litres (1.5 million gals) of fresh and saltwater tanks showcasing 35,000 fish, amphibians, reptiles, birds and mammals. To eliminate the additional labor required to spray-on waterproofing or install waterproof membranes, the design team specified approximately 15,400 kg (34,000 lbs) of Xypex Admix C-500 for the ready-mix concrete used in three of the largest aquariums. The Xypex solution saved construction time, jobsite labor and ensured watertight and corrosion-resistant structures long into the future.

Cleveland Aquarium
Ohio, USA

When local developer Jacobs Investments proposed to create the 6,053 m2 (70,000 ft2) Greater Cleveland Aquarium in the lower level of the vintage FirstEnergy Powerhouse on the west bank of the Cuyahoga River, it posed multiple engineering and logistical challenges.

One of the key concerns was how to protect the critical concrete bases and walls of the more than 40 separate aquarium tanks being built in the basement of the nearly 130-year-old building. Constructing the assortment of fresh and saltwater tanks would require 841 m3 (1,100 yd3) of ready-mix concrete. And every tank had to be waterproof, corrosion-resistant and crack-resistant.

Designers chose Xypex Admix C-500 for all water-holding structures, providing integrated, lifetime waterproofing and chemical protection. Using Xypex Admix, C-500 saved installation time, cost less than coatings or membranes, and significantly reduced future maintenance or restoration.

Barbados Aquarium

The first commercial saltwater aquarium and the only park of its kind in the Eastern Caribbean, Ocean Park Aquarium in Barbados is a popular attraction on the island. In developing the 26 display tanks, the engineering team chose Xypex Admix C-1000 for long-term waterproofing, cost reduction, and labor and construction time savings. Added to the concrete mix, Xypex was used in all the seawater tanks, pump rooms and electrical stations.

Resistance to Positive and Negative Hydrostatic Pressure

Permeability of Concrete
U.S. Army Corps of Engineers CRD C48,
Aviles Engineering Corp., Houston, USA

Two concrete samples containing Xypex Admix and an untreated control sample were tested for water permeability. Both the treated and untreated samples were subjected to a pressure of 150 psi / 1.04 MPa (350 ft. / 106.7 m water head). Results showed moisture and permeated water throughout the untreated sample after 24 hours. The Xypex Admix samples, however, showed no leakage and water penetration of only 1.5 mm / 0.06 inches after 120 hours (5 days).

Water Permeability of Concrete
ACCI Water Permeability Test
Australia Centre of Construction and Innovation, University of New South Wales, Sydney, Australia

Concrete samples containing Xypex Admix NF at a dosage rate of 0.8% and 1.2% were tested for water permeability against control samples. All samples were subjected to a pressure of 10 bars (100 meters / 328 ft. water head) for two weeks. When water permeability coefficients were calculated, the Xypex Admix-treated concrete showed a significant reduction in water permeability by up to 93% at a dosage rate of 1.2%.

Protecting Concrete from Chlorides, Sulfates and Acidic Corrosion

Durability Assessment of Reinforced Concrete Structure Containing Xypex Admix Exposed to 19 Years of Severe Marine Environment
HB 84-2006, Sharp and Howells Pty. Ltd. Chemical Laboratories, Victoria, Australia

Lascelles Wharf serves as a bulk chemical and grain dock. In 1995, as part of an extensive maintenance program and to protect new precast concrete panels from the extremely harsh and aggressive marine environment, the concrete was dosed with Xypex Admix C-2000 NF at 1%. Scientists conducted tests to predict “initiation time to corrosion.” Extracted cores were tested for chloride content at incremental depths into the concrete. Chloride content profiles, concrete cover, surface chloride content, and chloride corrosion threshold were used in a model based on Fick’s 2nd law of diffusion to predict the residual service life of this structure. The average initiation time to corrosion for the Xypex-treated concrete was estimated at 164 years, whereas the structure had been designed for 50 years of service life. (See Lascelles Wharf Project Profile in this report.)

Measuring Loss of Surface Due to Sulphate Attack of Concrete Treated with Admix C-1000/C-1000 NF
CSN 73 1326, Betonconsult, Building Materials Testing Laboratory, Prague, Czech Republic

Concrete specimens treated with Xypex Admix C-1000 (at 1% and 2%) and Admix C-1000 NF (at 0.5% and 1%) were cast along with non-treated concrete specimens. The specimens were exposed to a highly concentrated sulfate solution (36,000 mg/l) for four months, and samples were periodically weighed to determine mass loss. The Xypex Admix treated samples recorded a mass loss between 5 and 50 g/m2 and showed no surface deterioration. At the same time, the non-treated specimens measured an average mass loss of 4,860 g/m2 with significant surface deterioration.

• C30/37 concrete cubes
• 36,000 mg/l sulphate solution, 4 months
• Mass loss for Xypex treated samples 5-50 g/m2
• Mass loss for control samples 4,860 g/m2
• Xypex sample achieved same sulphate resistance levels (3,000 - 6,000 mg/l) (EN 206)

Sulfuric Acid Resistance Test
Aviles Engineering Corporation, Houston, USA

Researchers tested concrete containing Xypex Admix at different dosage rates (including 3% specimens) against untreated control samples for sulfuric acid resistance. After immersion in the sulfuric acid, each sample was tested daily for weight loss until a weight loss of 50% or a definite response trend was obtained. The percentage weight loss of the samples containing Xypex Admix tested was significantly lower than the control samples.

Protecting Concrete from Microbiologically Induced Corrosion

Evaluation of Antimicrobial Effect of Xypex Bio-San C500 and Corrosion Rate
SO 22196 (Modified), McGrath Engineering Ltd, North Vancouver, B.C., Canada

Xypex Bio-San C500 was added to portland cement mortar at a 1% dosage rate and compared to untreated control samples to measure antimicrobial performance. Compared with the untreated samples, the Xypex-treated samples registered a substantial reduction in the sewer bacteria Thiobacillus Novellus / Starkeya novella, indicating a definite antimicrobial effect.

Concrete was cast in 100 x 200 mm (4 x 8 in) cylinders with both control and treated mixes. A wastewater facility with elevated H2S levels and substantial existing MIC corrosion damage was chosen. Test samples were suspended in the air space of the tank for ten years. Exposure trials showed that treated concrete had nine times less mass loss than control samples. After exposure of 10 years, the bacterial concentration on the treated samples was minimal, indicating continued antimicrobial action and efficacy.

Healing Cracks in Concrete

ASTM C1585 and ASTM C1202, Evaluation of Self-healing Capability of Self-compacting Concrete Made with Blast-furnace Slag Cement Activated by the Xypex Crystalline Catalyst
Instituto Tecnologico de Aeronautica, Sao Jose dos Campos, Brazil

Blast furnace slag and slag-modified portland concrete samples, treated with 2.5% Admix C-500, were evaluated for self-healing capabilities. Microcracks were induced by loading to 90% of ultimate compressive strength. Cracked samples were then immersed in water to trigger self-healing after 28, 56 and 84 days. Strength and ultra-sonic pulse velocity tests were used to determine mechanical recovery. Sorptivity and rapid chloride permeability tests measured water tightness recovery. Results substantiated the ability of Xypex Admix to trigger a self-healing reaction in cracked concrete.

Testing of Xypex Admix C-1000 NF Crack Healing Capabilities
CH Karnchang (Lao) Company Ltd., Xayaburi Laboratory, Ban Xieng Yeun, Vientiane, Laos

Before constructing a Mekong River dam, researchers conducted a test to substantiate the ability of Xypex Admix to self-heal static cracks up to 0.5 mm. Three large concrete slabs treated with Admix C-1000 NF at 0.8% were cast along with three control slabs.

After curing, a force was applied at the mid-point of each slab to create cracks, which measured an average of 0.5 mm in width. Water was ponded above the cracked area. Initially, all cracks leaked. At four days, all dripping ceased from the cracks in the Xypex-treated panels, while leaking continued through the cracks of the control slab until the end of the test period (25 days). SEM photographs showed significant crystalline growth throughout the cracks of the Admix treated slab.

The need to control costs, reduce skilled labor and meet construction timelines is a never-ending battle. Xypex aids contractors and project owners with those challenges by taking concrete waterproofing offsite to eliminate the additional time, cost and labor required to apply concrete coatings or waterproof membranes at the jobsite.

Xypex crystalline waterproofing technology provides superior moisture resistance, self-heals cracks and protects against aggressive chemicals such as H2S, chlorides and sulfates. Proven in thousands of projects in all environmental conditions worldwide, Xypex Crystalline Technology for waterproofing concrete has a long track record of success, backed by our knowledgeable distributor network, expert technical team, and a history of scientific research that dates to 1969.

Xypex products and services are available in over 90 countries. To find a Xypex representative near you and learn how our innovative products enhance all types of concrete, please visit xypex.com.