Liquid glass to concrete: proportions and water resistance

Weightage liquid glass into concrete — one of the most affordable ways to make the structure denser, faster in setting and more resistant to water and corrosive media. We are talking about an aqueous solution of sodium silicate (sodium liquid glass), which is injected directly into the cement-sand mixture or used as an impregnation of the finished surface. ETIZ produces sodium liquid glass — universal concentrate for construction, waterproofing and work with concrete.

Why add liquid glass to concrete

Sodium silicate in contact with cement slurry reacts with hydration products and forms insoluble silicate compounds that fill the pores and capillaries of concrete stone. Due to this, several effects are achieved at once.

• Water resistant and water resistant. Filling the capillaries cuts off the paths of moisture movement, reduces water absorption — concrete "pulls" water less and resists its pressure better.
• Setting acceleration. Liquid glass acts as an accelerator: the solution loses mobility faster and gains primary strength earlier. This is convenient for emergency terminations, work on water inflow, winter concreting.
• Chemical stability The dense silicate structure is better resistant to weak acids and aggressive solutions — this is how acid-resistant concrete is obtained for industrial floors and tanks.
• Dedusting and hardening of the surface. When used as an impregnation, liquid glass binds dust and hardens the top layer of screed and concrete floor.

You can choose a concentrate for a specific task in the catalog liquid glass ETHYZ: the sodium composition is suitable for both concrete additives and membrane waterproofing.

Proportions of liquid glass into concrete: landmarks

There is no single "iron" recipe — the proportion depends on the task, the brand of cement, the moisture content of the aggregates and the required setting time. Therefore, all values below are given tentatively, check according to the instructions of ETIZ and the specific task. General rule: when entering into concrete, liquid glass is taken as a small fraction of the cement weight, and not "by eye" with a bucket for kneading.

Practical procedure: liquid glass is first dissolved in hardening water, and then a cement-sand mixture is closed with this water — this is how the additive is distributed evenly, without lumps and local "instantaneous" setings. Knead in small portions, because the mixture with silicate loses mobility much faster than usual.

Typical Characteristics of Sodium Liquid Glass

Numerical characteristics should be taken from the product data sheet. As a reference, typical of sodium liquid glass landmarks: silicate module of the order 2,6–3,4, order density 1.4 g/cm³. The exact values are in the ETHYZ passport. Sodium liquid glass is standardized according to GOST 13078 (without giving specific numerical points here).

How Liquid Glass Affects Water Resistance

The main mechanism is the compaction of the structure. Ordinary concrete is permeated with a network of capillaries, through which moisture rises and penetrates deep. Silicate neoplasms "seal" these channels, therefore:

• capillary suction and general water absorption are reduced;
• increased resistance to pressure water in basements, pits, tanks;
• increased resistance to alternating moisture-drying.

At the same time, it is important to understand: liquid glass gives water resistance "from the inside of the concrete body" when entering the kneading and "film" protection when coating the surface. For critical waterproofing, the coating layer is usually combined with the total density of concrete and protected from mechanical damage — in its pure form, the silicate film is brittle.

Cons and risk of overdose

The main mistake of beginners is "pour more to be sure". With liquid glass, this does not work: exceeding the dosage speeds up the setting so much that the mixture becomes unstackable, and the final concrete strength may decrease. Excess silicate makes the stone more brittle and prone to efflorescence.

• Overdose reduces strength. The optimum is the minimum sufficient share, not the maximum.
• Very short working time. The mixture sets quickly — prepare small portions and work quickly, in small areas.
• Brittleness of the clean film. The exposed silicate layer without protection may crack.
• Safety precautions. Alkaline solution — a number of tasks require gloves and eye protection.

A reasonable approach is to make a trial batch with the selected dosage, evaluate the setting time and workability, and only then scale it to the entire volume. The range and packaging of concentrate (cans of 5 liters weighing 7 kg and 10 liters weighing 14 kg) is convenient to choose in the section Liquid glass on the ETIZ website.

Application Brief

In addition to entering into concrete, sodium liquid glass ETIZ is used for membrane waterproofing of foundations, basements, cellars, pools and wells, as a primer-impregnation of floors, fire-retardant and antiseptic treatment of wood, silicate glue and a component of refractory putties for furnaces. That is, one universal concentrate covers a whole range of construction and repair tasks.

FAQs

How much liquid glass should be added to the concrete?

There is no exact universal figure: the share is taken approximately as a small part of the cement mass, and is specified according to the ETIZ instruction and a specific task. For water resistance, units of percent are sufficient, for emergency acceleration of setting, the proportion is increased. Always make a trial mix: liquid glass dramatically speeds up the set, and an overdose reduces the final strength of the concrete.

How to properly introduce the liquid glass into the solution?

First, dissolve the liquid glass in the tempering water, and then with this water seal the cement-sand mixture — so the additive will be distributed evenly, without lumps and local instant curing. Knead in small portions and stack quickly, in small sections, because the mixture with silicate loses mobility noticeably faster than usual.

Does liquid glass increase the water resistance of concrete?

Yes. Sodium silicate forms insoluble compounds that fill the pores and capillaries of concrete stone, reducing water absorption and capillary suction. This increases pressure water resistance in basements, pits and tanks. When coating the surface, a film is formed that cuts off moisture, but for critical waterproofing, it is usually combined with the total density of concrete and protected from damage.

What is the danger of an overdose of liquid glass?

Excess silicate accelerates setting so much that the mixture becomes unstackable, and the final strength of the concrete may decrease. The stone becomes more fragile, efflorescence is possible. Therefore, focus on the minimum sufficient dose, not the maximum, and check it on the trial mix before working with the full volume.

What liquid glass does ETHYZ produce — sodium or potassium?

ETHYZ produces sodium liquid glass — an aqueous solution of sodium silicate from quartz sand and soda. This is a universal composition for construction, waterproofing and work with concrete. Potassium glass is another product (more often for paints and flame retardants) and is not positioned in this line. Typical module and density are indicated in the product data sheet; packing — cans of 5 l (7 kg) and 10 l (14 kg).