WHY DRYCRETE™ Moisture Stop?
The following explains how DRYCRETE™ Moisture Stop, an engineered silicate in a colloidal base, differs from other popular hardeners and sealers on the market - which consists primarily of sodium, magnesium, potassium, and lithium silicate blends.
DRYCRETE™ Moisture Stop is a unique proprietary formulation, which is proven to penetrate up to 100 mm, and in some cases as much as 150 mm into concrete – a far greater depth than other silicate products.
All silicate based products do not perform equally even though they are making similar claims. How can you tell which one to believe?
Silicates are plentiful in nature, constituting the greater number of minerals which compose the crust of the Earth. They are compounds containing silicon (next to oxygen, Earth’s most abundant element) with oxygen and a metal. Man-made silicates are used for a wide variety of purposes, from glass making to water treatment, while the major ingredients of Portland cement are silicates. Silicate materials are used as hardening and dust-proofing agents, while decreasing permeability. The decreased in permeability is attributed to the ability of water soluble silicates to contact and react with certain common ingredients which are always found inside Portland cement concrete, such as hydroxide materials, soluble calcium compounds or free and unused alkalis, and form insoluble precipitates. This allows the silicate to densify and harden the concrete surface, while decreasing permeability with a single application.
Silicate products react with the ever present calcium hydroxide residue immediately upon contact with the concrete’s surface. This generates a crystalline precipitate gel, which consists of variable-sized pores. The uneven pore sizes limit the useful life of the gel as water migrates through the larger pores, and eventually erodes the gel. The effectiveness of the applied silicate depends on the volume of water vapor emissions and its driving force passing through the concrete. Most silicates have a reputed effective lifespan of at least 5 years or more.
About DRYCRETE™ Moisture Stop
DRYCRETE™ Moisture Stop penetrates deep into concrete and forms precipitate, a gel-like compound, in the capillary voids upon contact with the always present free unused alkalis. It is successful in overcoming moisture problems and offers a permanent treatment against moisture vapor emissions and resulting damage to the concrete mass.
DRYCRETE™ Moisture Stop is a unique precision-blended colloidal liquid, which provides superior performance when compared to other silicates. The precipitate density creates microscopic pore networks of exact uniform-size porosity. As DRYCRETE™ Moisture Stop gel is formed, it causes polymer cross linking and branching, encouraging polymer particle and strand connection. This creates very strong polymer chains, providing extra strength and durability to become permanent and insoluble.
DRYCRETE™ Moisture Stop gel-like membrane does not expand further under hard freeze conditions, thereby causing freeze-thaw cycle damage, as does gel compounds of similar products. Other silicate products usually form shallower and weaker linked short chain gel polymer compounds. Although they hold up for an appreciable length of time, they are less effective overall, and will need to be re-applied periodically.
DRYCRETE™ Moisture Stop is the only silicate to offer a PERMANENT integral waterproofing solution.
DRYCRETE BENEFITS & OPTIONS
DRYCRETE versus H2S & Other ACIDS
An effective barrier against acid intrusion
DRYCRETE eliminates, or at least significantly retard, hydrogen sulphide (H2S) and other acids precipitated deterioration of concrete.
DRYCRETE, once applied, immediately penetrates past the concrete surface to permeate its matrix. As it does so, a portion of this unique solution becomes chemically absorbed by the cement gel or paste (Calcium Silicate Hydrate or C-S-H), becoming a residual part of this paste component, causing it to immediately become significantly more acid and chemical resistant.
DRYCRETE further permeates into the concrete's interior, and reacts with free alkali (not affecting bound alkali) and immediately transforms from a low solids solution to a 100% solids insoluble mass within the concrete's interior, occupying its accessible pore spaces. This chemical transformation produces a colloidal gel, not generating heat or internal pressure, providing increased density and additional bonding strength to the concrete.
DRYCRETE produced colloidal gel mass is made up of distinct spherically-shaped particles which are made up of microscopic spine-shaped pore networks containing pores smaller than a molecule of free water (moisture). This permits the treated concrete to breathe as needed, but does not allow water or free moisture passage, except in greatly-diminished volume vapor form. Water / free moisture (including acids) present in concrete prior to a treatment, becomes chemically tied up in, and even participates in the formation of the colloidal gel mass rendering these liquids harmless to the concrete.
DRYCRETE permeates to concrete's interior, rendering the cement paste significantly more acid resistant, and the colloidal gel barrier is created just beneath the surface porosity, where most of the concrete's free alkali normally lays. This prevents acid-producing agents entry into the concrete's interior from the treated surface.
DRYCRETE is recommended for use as a protective barrier in the preservation of concrete subjected to exposure or potential exposure to hydrogen sulphide gas or other acid-producing agents.
DRYCRETE when utilized in new construction, serves as a primary concrete integral protecting barrier and should a topical coating / liner of choice eventually fail, it will continue to protect the integral mass of the concrete structure. This same concept applies when rehabilitation plans call for the use of sacrificial cementitious material liners.
What are Colloidal Silicas?
Colloidal silicas are a suspension of fine amorphous, nonporous, and typically spherical silica particles in a liquid phase.
Usually they are suspended in an aqueous phase that is stabilized electrostatically. Colloidal silicas exhibit particle densities in the range of 2.1 to 2.3 g/cm3.
Most colloidal silicas are prepared as monodisperse suspensions with particle sizes ranging from approximately 30 to 100 nm in diameter. Polydisperse suspensions can also be synthesized and have roughly the same limits in particle size. Smaller particles are difficult to stabilize while particles much greater than 150 nanometers are subject to sedimentation.
Colloidal silicas are most often prepared in a multi-step process where an alkali-silicate solution is partially neutralized, leading to the formation of silica nuclei. The subunits of colloidal silica particles are typically in the range of 1 to 5 nm. Whether or not these subunits are joined together depends on the conditions of polymerization. Initial acidification of a water-glass (sodium silicate) solution yields Si(OH)4.
If the pH is reduced below 7 or if salt is added, then the units tend to fuse together in chains. These products are often called silica gels. If the pH is kept slightly on the alkaline side of neutral, then the subunits stay separated, and they gradually grow. These products are often called precipitated silica or silica sols. Hydrogen ions from the surface of colloidal silica tend to dissociate in aqueous solution, yielding a high negative charge. Substitution of some of the Si atoms by Al is known increase the negative colloidal charge, especially when it is evaluated at pH below the neutral point. Because of the very small size, the surface area of colloidal silica is very high.
The colloidal suspension is stabilized by pH adjustment and then concentrated, usually by evaporation. The maximum concentration obtainable depends on the on particle size. For example, 50 nm particles can be concentrated to greater than 50 wt% solids while 10 nm particles can only be concentrated to approximately 30 wt% solids before the suspension becomes too unstable.
- In papermaking colloidal silica is used as a drainage aid. It increases the amount of cationic starch that can be retained in the paper. Cationic starch is added as sizing agent to increase the dry strength of the paper.
- High temperature binders
- Investment casting - used in moulds
- An abrasive - for polishing silicon wafers
- Carbonless paper
- Moisture Absorbent
- It increases the bulk & taped density of powder & granules also
- It is also be used in Lubrication of Tablet
- Stabilizing and rigidizing refractory ceramic fiber (fiberfrax) blankets
- Abrasion-resistant coatings
- Increasing friction - used to coat waxed floors, textile fibers and railway tracks to promote traction
- Antisoiling – fills micropores to prevent take up of dirt and other particles into textiles
- Surfactant – used for flocculating, coagulating, dispersing, stabilizing etc.
- Liquid silicon dioxide (colloidal silica) is used as a wine and juice fining agent.
- Colloidal silica is used in concrete densifiers and polished concrete.
- In manufacturing Quantum dots, small semi-conductors used in various scientific research settings.
Ref - AMORPHOUS
In condensed matter physics, an amorphous (from the Greek a, without, morphé, shape, form) or non-crystalline solid is a solid that lacks the long-range order characteristic of a crystal.
Easy to Apply
- Permanent moisture control over the lifetime of the concrete substrate
- Does not alter surface tension or profile.
- Does not interfere with adhesion of adhesives, coatings or sealers
- Deep, internal penetration within the capillary voids of the concrete matrix
- Alkali chemical bonding and reactivity
- Infinite particle size and polymer chains result in excellent depth and strength of resulting gel barrier
- Unique formulation of a composite, engineered hydro-silicate in a colloidal base
- Excellent resistance to acid deterioration
- Significant resistance to organic and synthetic oils, including motor oil and hydraulic fluid.
- Field proven performance for over 20 years.
UNIQUE PROPERTIES SUMMARY
DRYCRETE Products are user-friendly, environmentally safe, non-flammable, penetrating liquid which is non-toxic, with zero VOC. DRYCRETE Products readily penetrates deep into concrete, that subsequently form an insoluble unique 100% solids contaminant barrier, as it reacts with un-hydrated cement (free alkali) within the concrete slab. This 100% solids integral contaminant barrier contains its very own microscopic pore network, uniquely, and effectively, mimicking the pouring of concrete within concrete. DRYCRETE Products can be applied on concrete against water flow (hydrostatic pressure leakage) to permanently reduce moisture vapor emissions to a negligible level.
PROPRIETARY ADVANTAGES OF DRYCRETE MOISTURE STOP
- Integrally waterproofs concrete, including internal migration.
- An effective and immediate halt to contaminant ingress.
- Significantly and immediately increases concrete's density.
- Increases and reinforces concrete's compression and flexural strengths.
- Diminishes permeability by as much as 97%.
- Protects against acid and calcium chloride contamination and damage.
- Virtually eliminates water or gas vapor emissions.
- Effectively halts & prevents alkali-silicate reactions (ASR).
- Eliminates dusting potential for new or old concrete.
- Provides significant additional surface abrasion resistance.
- Provides increased surface bond quality.
- Does not alter traction quality.
DRYCRETE Products do not adversely affect concrete's visual appearance, physical characteristics, surface traction quality, or surface bond quality, which means they can effectively be used to enhance any Portland cement concrete installation, whether traffic-bearing or not.
CONCRETE CURING ANALOGY
The curing of concrete is probably the most important step in the development of high quality concrete. The placement of an appropriate mix must be followed in a timely manner, by curing in a suitable environment during the early stages of strong initial hydration, generally as soon as is practical following the surface finish.
Curing is a term given the procedures used to promote optimum hydration of plastic, or semi-plastic Portland cement concrete, during its early development of strength. Curing normally consists of temperature control and moisture movement in or out of newly-placed concrete. The moisture movement ultimately affects the concrete’s strength, permeability, and durability.
The conventional accepted objective in concrete curing, is to retain as much of the original mix water inside newly-placed concrete. The more water retained, the longer the initial accelerated hydration process within the concrete mass. This increased hydration process subsequently produces larger volume of Calcium Silicate Hydrate (C-S-H) or hydration product, significantly improving finished concrete quality. This is especially true when mix water pockets or capillaries are filled to their fullest possible extent by products of hydration. However, in most concrete placement, jobsite active curing stops long before the maximum possible hydration has taken place.
The general consensus is that no practical curing method can perform as well as water ponding. However, water curing requires continual monitoring of curing progression. Curing time varies greatly, based on many factors such as temperature, humidity, degree of concrete protection, admixtures used and more. The net result of these variances makes water ponding labor intensive and costly.