Concrete has been used for thousands of years, assisting man in creating amazing things throughout history, including architecture, infrastructure and more.
It’s made up of 3 basic components:
Water + Aggregate (rock/sand/gravel) + Portland cement = CONCRETE
Concrete in history:
- 3000 BC – Egyptian Pyramids:
The Egyptians were using early forms of concrete over 5000 years ago to build pyramids. They mixed mud and straw to form bricks and used gypsum and lime to make mortars.
- 300 BC – 476 AD-Roman Architecture:
The ancient Romans used a material that is remarkably close to modern cement to build many of their architectural marvels, such as the Colosseum, and the Pantheon. The Romans also used animal products in their cement as an early form of admixtures.
- 1824 – Portland Cement invented:
The invention of Portland Cement is credited to an Englishman named Joseph Aspdin, a material he produced by firing finely-ground clay and limestone until the limestone was calcined. He called it Portland Cement because the concrete made from it looked like Portland stone, a widely-used building stone in England.
- 1836 – Strength Testing:
The first test of tensile and compressive strength took place in Germany.
- 1930 – Air Entraining Agents:
Air en-training agents were used for the first time in cement to resist against damage from freezing and thawing.
- 1970’s Fibre reinforcement:
Fibre reinforcement was introduced as a way to strengthen concrete.
With the assistance of concrete, man has been able to push boundaries in the development of construction.
Unfortunately (or fortunately in some cases!) – nothing lasts forever. Just as reassuring as that fact is, it’s also incredibly depressing. You, the people you love, your home, your world – it’ll all be gone one day. Even concrete!
A common pest to us in conservation and the construction industry on a whole is “Concrete Cancer” aka “Alkali-silica reaction” – is caused when the steel reinforcing beams within a concrete slab begins to rust.
Common causes of Concrete Cancer:
- Poor waterproofing
- Salt-water chlorides for buildings near the sea
- Building defects
- Poor quality concrete and insufficient concrete cover
- Movement of the earth under the build leading to cracks
- Crazing and cracking concrete (concrete spalling)
- Rust stains which seem to leak out from within the concrete
- Bubbling (also called Plating) of concrete render
- Leaks which appear in overhead concrete surfaces
The dangers of:
- Concrete cancer, especially on the outside of a building, not only looks terrible, but it is potentially dangerous too. Over time, and with increased exposure to the elements, untreated pieces of concrete may fall from your structure. The risk is it falling and damaging property, or even worse, hitting a person walking below.
While the term hints at how severe this type of damage is, it is possible to fix Concrete Cancer in some cases. Depending on the cause, the engineer may recommend different solutions:
1. Polymer modified repair system solution:
For situations where concrete carbonation and low concrete cover are the issue, the engineer might recommend using a polymer modified repair system. This option removes the concrete around the reinforcing bars and cleans the steel, before applying both the steel primer, and a polymer modified material. They might also apply an anti-carbonation protective coating to the whole concrete surface. Sometimes the experts might recommend using additional reinforcing steel anodes before new concrete is applied, or the steel might be replaced in severe cases.
2. Electrochemical treatment option:
If it’s a case of chloride contamination in a building near the ocean, you might need to have specialist repair work done to treat the concrete cancer. This can include electrochemical treatment, such as cathodic protection.
3. Simple replacement method:
If it’s a case with less severe damage, you might be able to remove the damaged concrete, clean and replace the rusted, exposed steel, and fill in the cracks.
Engineers highly recommend waterproofing the area to stop it from happening. Waterproofing concrete is essential to prevent water from corroding the steel beams. This minimises the risk of future water damage, and prevents harsh chemicals contaminating the concrete from entering through pores. This is an important preventative because poor waterproofing, or worse, no waterproofing, could undo all the repair work on your building.
The services we provide for you at
Roof Tiling, Steeplejacks and Lightning Protection, Roof Drainage, Lead Protection, Roof Features.
Stone, Brick, Cast Stone, Terracotta, Sculpture, Statuary, Bronze Statuary.
Painting & Decorating, Plasterwork, Tiling, Timber Flooring.
Services & Treatment
Protection and Remedial Treatment, Paint Finishes, Mortars & Renders, Pointing, Paint Removal, Masonry Cleaning, Structural Repairs, Epoxy Resin Repairs.
Metal, Wood & Glass
Fine Joinery, Wood Carving, Windows and Doors, Secondary Glazing, Metalwork.
Whats on this month?
Thanks to Building Conservation for proving us with these Key Dates and Events not to be missed in January.
Incorporated in 2006, Aura Conservation have existed for over twelve successful years. We have a sound and experienced management team. We can assist you in any of your conservation needs and have a body of long standing and experienced tradesmen we can call on with specialist knowledge of the conservation world. Along with prudent financial management, we have a sound financial foundation that will see us prosper in the coming years.
You can contact us at:
Dunham House, 181 Wellington Road North, Stockport, Cheshire, SK4 2PB. Tel. 0161 442 9850 Fax. 0161 432 8478