Yes, chlorine, especially in high concentrations or imbalanced pH, can damage concrete over time by causing surface erosion, discoloration, cracking, and speeding up corrosion of steel reinforcement (rebar) through chloride ion penetration, leading to "concrete cancer" and spalling. Proper maintenance, sealing, and balanced pool chemistry (pH 7.4-7.6) are crucial to prevent these issues, particularly in pools, decks, and water features.
The sulfuric acid dissolves the carbonates in the hardened cement paste (HCP), and also calcium hydroxide (portlandite: Ca(OH)2) and calcium silicate hydrate (CaO·SiO2·nH2O), and causes strength loss, as well as producing sulfates which are harmful to concrete.
Chlorides have little effect on hardened concrete but they increase the risk of reinforcement corrosion. Corrosion of the reinforcement will be initiated when the chloride ion concentration at the steel reaches the so called 'threshold level'.
On the other hand, Chlorine is an excellent choice for removing oil stains from concrete floors. To avoid long-term damage, chlorine is ideal if you plan to pressure wash your backyard floor or driveway on your own.
Will straight bleach harm concrete? Yes. Undiluted bleach can damage concrete by causing surface erosion, discoloration, and deterioration of sealers. It should never be applied full-strength on concrete surfaces.
Mix about 1/3 cup of bleach into a gallon of clean water in a plastic bucket or container. Apply the bleach solution using a nylon-bristled brush or broom. Scrub thoroughly. Leave the bleach solution on the concrete for about 10 minutes.
Some contractors use at least a little degreaser for most jobs, even to remove dirt, which can be somewhat oily. According to Hinckley, alkaline cleaners are also the preferred chemical for cleaning soot from concrete. Heavy rust stains can penetrate deeply into concrete, so they can be tough to remove completely.
This material is typically produced at a utility sluice pond site by dumping raw ash into the pond and allowing it to hydrate and harden into a working platform. Additional raw ash is placed on top of the platform in thin lifts, watered, compacted, and allowed to hydrate and harden.
Patio Cleaner, Swimming Pool Chlorine
Sodium Hypochlorite can be used for water purification, surface purification, bleaching, odour removal and water disinfection. It is widely regarded as the best patio cleaner chemical on the market.
Additionally, calcium chloride damages concrete through the formation of oxychloride. Oxychloride is formed between calcium chloride and water. This new compound creates destructive hydraulic pressures. Magnesium ions, supplied by magnesium chloride react with the C-S-H to produce M-S-H.
The 10-20-30-40 concrete rule is a rule of thumb for mix proportions by volume: roughly 10% cement, 20% water & air, 30% sand, and 40% gravel/stone, aiming to use as much cost-effective aggregate as possible while the cement paste binds it. This ratio creates a strong, well-graded mix where smaller particles fill gaps in larger ones, reducing void space and cement needs, making it economical and durable for general construction.
The electrochemical removal of chloride from concrete structures is accomplished by applying an anode and electrolyte to the concrete surface and passing direct current (DC) between the anode and the reinforcing steel, which acts as a cathode.
Concrete has been used as a strong, durable building material for thousands of years, dating back to many ancient concrete structures that are still standing to this day. Yet, it has one fundamental enemy it can't escape—water.
Rapid drying of the concrete, improper mix ratios, lack of reinforcement, and excess pressure can all be causes of concrete cracking. The important aspect of concrete cracking is determining if the crack is structural, surface, cosmetic, etc.
The "90-minute concrete rule" was a standard guideline (ASTM C94) requiring ready-mix concrete to be discharged from the truck within 90 minutes (1.5 hours) of mixing to ensure workability and quality, but this rule has been updated, allowing for custom time limits to be set by the purchaser and producer, acknowledging modern admixtures that extend working time, though the original principle of limiting time to maintain quality remains crucial.
Water damage to concrete considerably impacts its strength. When excess water penetrates the concrete grains, it causes them to spread apart and crack, consequently creating more space between the grains.
Cement is a binding powder, while concrete is the strong, finished construction material made by mixing cement with water, sand, and gravel (aggregates); think of cement as flour and concrete as the resulting bread, used for everything from foundations to roads. Cement itself hardens when mixed with water, but concrete gains immense strength and durability from the chemical reaction (hydration) of all its components, making it suitable for structural projects, unlike cement used alone, which cracks easily.
Don't use de-icers containing ammonium nitrate, ammonium sulfate, magnesium chloride, magnesium acetate, or magnesium nitrate. Don't use rock salt (sodium chloride) or calcium chloride. Read the instructions and disclaimers on any product purchased. They typically recommend not to use on “new concrete.”
How to Make Your Concrete Look New Again
Over time, regular exposure to chlorinated water can lead to the degradation of concrete surfaces, manifesting as discoloration, increased porosity, and surface weakening. This is due to chlorine's reactive nature with concrete's constituents, leading to a slow erosion of the material.
The 20/30/40 rule in concrete is a simple guideline for mix proportions, suggesting roughly 20% cementitious materials, 30% water + admixtures (for workability), and 40% aggregates (sand and gravel), providing a good balance for quality and economy. While often linked to a broader 10-20-30-40 rule (10% cement, 20% water/air, 30% sand, 40% gravel by volume), the 20/30/40 emphasizes the key component percentages for a practical mix, especially for achieving good strength and pumpability.
Measurement: After 24 hours, we take a humidity measurement. This process takes about five minutes per box. Results: Humidity measurements below 70% indicate that the concrete is dry enough to lay floor coverings.