In basements, bathrooms, reservoirs, tanks, tunnels, culverts, and civil-defense concrete/mortar structures, specifiers are often stuck because "surface membranes debond, wet substrates are hard to treat, capillaries and micro-voids are not fully blocked, and rigid impermeability that lasts with the substrate are difficult to achieve together". External sheets and film coatings rely on surface barrier; with standing water, dampness, or micro-movement they blister and peel. Ordinary hydrophobic agents reduce surface water but rarely form insoluble gel inside for rigid plugging. Penetrating inorganic silicate (DPS-type) enters capillaries and reacts with alkali, yet pure silicate systems still need adjustment for organosilicone synergy, low-viscosity application, and specific cement compatibility. With underground, water-storage, and traffic-tunnel projects demanding "wet applicable, inward penetration, capillary plugging, densification, rigid non-peeling film", finding an "aqueous polysiloxane, strongly alkaline, low-viscosity, diffusible, alkali-reactive insoluble gel, rigid seal" building impermeability agent has become a key concrete-protection issue. Addressing this, Anhui IOTA Silicone Oil Co., Ltd. officially launches Organosilicone Building Sealant Impermeability Waterproofing Agent IOTA 2900A. Characterized by "polysiloxane aqueous solution; colorless, odorless, non-flammable water-soluble solution; pH 13±1; density at 20℃ >1.100 g/cm³; viscosity at 25℃ 1.05±0.5 c.s; good penetration and diffusion into concrete/mortar, reaction with substrate alkali to form water-insoluble gel that blocks internal voids, closes capillary channels, increases substrate density, and builds a waterproof layer; rigid sealant; for basements, bathrooms, reservoirs, tanks, tunnels, culverts, civil-defense; suitable/required for humid-environment application; 50kg plastic drum or customized; cool dry sealed storage; 6-month shelf life; non-hazardous", backed by "low-viscosity polysiloxane penetration + alkaline activation + alkali-triggered gel plugging", it serves as the "dam-building choice" for rigid building impermeability, achieving the leap from "surface film peels, dry-substrate-only" to "silicone seeps, alkali gels, wet-base internal dam". System Positioning: Aqueous Polysiloxane Penetrating Gel vs. Sheet/Film, Pure Hydrophobe, Pure Silicate DPS IOTA 2900A belongs to aqueous polysiloxane penetrating reactive rigid impermeability agent, distinct from sheet membranes, pure silicone hydrophobes, and pure alkali-silicate DPS. Sheets and films make an external barrier but fail at interfaces under dampness, micro-movement, and micro-cracks; pure hydrophobes lower surface water contact yet seldom build insoluble gel inside for rigid plugging; pure silicate DPS forms calcium-silicate gel with calcium alkali but involves less organosilicone low-surface-energy synergy. IOTA 2900A uses low-viscosity, strongly alkaline, diffusible polysiloxane aqueous system to travel inside concrete/mortar, react with substrate alkali into insoluble gel, block voids and capillaries, and densify—without building an independent surface film—so it fits damp, back-side, and underground conditions. Molecular Architecture: Low-Viscosity Aqueous Polysiloxane + Alkaline Carrier + Alkali-Triggered Gel The core design of IOTA 2900A comes from an aqueous polysiloxane penetrating-reactive system:

• Penetrating Polysiloxane Skeleton: Polysiloxane in water-soluble/water-dispersible form supplies low-surface-energy siloxane species; low viscosity (25℃ 1.05±0.5 c.s) favors diffusion along concrete capillary networks; siloxane chains modify pore walls with water repellency and physical filling, supporting reduced water migration together with reaction products.
• Alkaline Aqueous Carrier: The pH 13±1 alkaline water phase keeps siliceous components dispersed and activates the substrate alkali environment; strong alkalinity promotes condensation/gelation between siliceous species and cement hydration products or pore-liquid alkali (exact silicon species by COA, no formula assumed).
• Alkali-Triggered Insoluble Gel: After penetration, it reacts with substrate alkali (such as calcium hydroxide from cement hydration and free pore alkali) to form water-insoluble gel; the gel deposits in internal voids and capillary channels, converting "physical penetration" into "chemical plugging" and building an impermeable layer not subject to whole-film detachment.
• Low-Density High-Diffusion: Density at 20℃ >1.100 g/cm³ with near-aqueous composition allows spray, brush, roll, or pressure injection into damp mortar pores; low viscosity reduces surface filming and increases inward migration, matching the "rigid seal without independent surface film" positioning.

Performance Leap: From "Surface Seal Peels" to "Internal Gel Builds the Dam" Introducing IOTA 2900A brings the following improvements:

• Inward Penetration: The low-viscosity aqueous system travels inside concrete/mortar rather than only covering the surface; useful for porous, low-strength, and old substrates (penetration depth by substrate porosity, temperature, and humidity trial; no figures supplied).
• Insoluble Gel Plugging: Reaction with substrate alkali forms insoluble gel that blocks internal voids and closes capillary channels, reducing pathways for water and corrosive media; compared with pure surface film, it is less prone to whole-area debonding from substrate micro-movement or dampness.
• Densification and Impermeability: Gel deposition increases local substrate density; it assists rigid impermeability for basement walls, slabs, tank liners, and tunnel micro-pores; it does not replace structural reinforcement—serious cracks follow structural repair.
• Wet-Applicable: Supplied data state suitability/requirement for humid environment, fitting basements, tunnels, and culverts that cannot be fully dried; it reduces rework caused by substrate moisture limits (standing water/ponding handled by site process).
• Rigid Non-Film: It forms a rigid sealed waterproof layer without relying on an independent elastic surface film; compatibility with subsequent mortar, protection layers, and selected coatings must be trialed to avoid cases where full surface closure would impair required breathability or overlay adhesion.

Application Penetration: From Basement to Civil-Defense Culvert IOTA 2900A covers concrete impermeability scenarios:

• Basement Slab/Wall: Damp-substrate and back-side application, corners and section changes for penetrating impermeability, reducing inward leakage after partial external membrane failure.
• Bathroom/Kitchen Retrofit: Mortar beds, pipe-penetration nodes, and floor-drain perimeters plug capillaries inward; combine with flexible joint sealing for rigid-flexible complement.
• Reservoir/Tank: Potable-water tanks require local hygiene approval; clear-water and process tanks use internal densification to reduce capillary seepage and leaching.
• Tunnel/Culvert: Initial-support seepage, secondary-lining micro-pores, and blind-drain surroundings treated under damp conditions; low-viscosity spray suits ventilation- and window-limited traffic tunnels.
• Civil Defense/Underground Works: Sealing, moisture control, and impermeability together; rigid gel plugging helps long idle-recovery; compatibility with defense-node materials by design trial.
• Pre-Treatment before Repair: Micro-void, honeycomb, and slight capillary sweating substrates receive penetration sealing before mortar/resin repair; wide, active, or settlement cracks are not treated by this product alone.

IOTA Technical Guide: Wet-Base Spray, Strong-Alkali Protection

• Substrate Preparation: Remove laitance, oil, mold-release, and loose material; assess cracks/honeycomb structurally—micro-capillary sweating uses penetration, while wide/active/settlement cracks use grouting or elastic sealing. Damp without free water is directly applicable; divert and drain standing water before application.
• Dilution and Application: Supplied data give no dilution ratio or dosage; determine by substrate porosity and target impermeability via trial; spray, roll, brush, or pressure-inject. Low viscosity (1.05±0.5 c.s) favors capillary self-diffusion; multiple thin passes are better than one heavy coat for inward penetration; highly porous substrates may need extra passes.
• Curing: The alkaline system continuously reacts with substrate alkali under humid conditions to form gel; keep substrate moist but not ponded during curing to favor diffusion (curing duration by temperature, substrate humidity, and design trial). Before mortar protection or coating, run small-area bond verification to avoid gel-layer effects on demanding interfaces.
• ⚠️ Taboo: pH 13±1 is strongly alkaline; use alkali-resistant gloves, goggles, long sleeves, and splash protection; rinse skin with water after contact, flush eyes with plenty of water and seek medical help. Do not mix directly with strong acid to avoid neutralization heat, breaking, or gas; avoid blind blending with incompatible cationic or polyvalent-metal additives that may flocculate. Non-flammable but ventilate; reseal 50kg plastic drum after use to prevent contamination. Non-hazardous, yet manage as alkaline chemical.
• Storage: 50kg plastic drum or customized; cool, dry, sealed storage; 6-month shelf life. Unlike IOTA 1318 (leather nonionic modified-silicone hydrophobic), IOTA 1325 (fabric cationic silicone-emulsion durable waterproof), IOTA 2900A is aqueous polysiloxane rigid concrete/mortar dam-builder—1318 for leather surface film, 1325 for fabric wash-durable film, 2900A for concrete internal alkali-gel plugging.

Industry Insight: The core value of penetrating reactive building impermeability agent lies in "low-viscosity aqueous for capillary depth, alkaline carrier for reaction activation, polysiloxane plus alkali-gel for insoluble plugging, rigid non-film for wet-base non-debonding". IOTA 2900A, with "polysiloxane aqueous solution, colorless odorless non-flammable, pH 13±1, density >1.100 at 20℃, 1.05±0.5 c.s at 25℃, penetration into concrete/mortar with alkali to insoluble gel, void/capillary blocking, rigid seal, humid application, 50kg plastic drum, 6 months, non-hazardous" hard parameters, fills the alkaline polysiloxane penetrating rigid node between sheet-membrane surface peeling, pure hydrophobe non-plugging, and pure silicate lack of siloxane synergy. For underground, water-conservancy, tunnel, and civil-defense applicators, it upgrades along the path of "sheet membrane → pure hydrophobic surface coat → polysiloxane alkali-gel internal dam", reducing wet-base debonding, capillary seepage, and repeated dampness recurrence while raising rigid-impermeability and substrate-life premium.