Frequently Asked Questions

Does CLEVA CRETE conform to the Australian Building Code and Standards Australia requirements for an admixture?

The Australian Building Code requires that the construction sector needs to arrest the moisture problem in concrete flooring prior to laying all floor covering types. CLEVA CRETE does this impeccably.

The Australian Standard AS1478.1-2000 requires that an approved admixture does not adversely affect the MPa, setting times and shrinkage of concrete. CLEVA CRETE has officially shown to meet all such requirements.

As a testament to CLEVA CRETE’s outstanding technology and performance, DIT is utilizing CLEVA CRETE on most major projects and has recommended our MVRA technology for the NATSPEC.

Are standard curing measures required when using CLEVA CRETE?
How does CLEVA CRETE affect the setting and curing time of the concrete?

CLEVA CRETE creates and adds more of the right type of calcium silicate hydrate. Additionally, it increases setting times by 13 to 17% on average depending on mix design. It is typical to see 7-to-10-day strengths after 48 hours from being poured. Also a few hours after the concrete has been batched and placed, there should be no moisture released out of the slab in the form of bleed water. Full curing time of the concrete usually occurs at the same time as normal, which is 28 days, as with any other concrete or control mixes. At this point there is typically no more than 4 to 11% increase.

How does CLEVA CRETE enable early laying of resilient flooring finishes?

This is achievable because the CLEVA CRETE 842 tech grabs the excess water in concrete while its still wet, the water that normally rises up in a form of bleed water, we capture the free water and turn it into a pure form of concrete, stopping capillary formation. No capillaries means no moisture vapour emanating out of the slab. This process is over in 72 hours so we comfortably recommend laying of resilient flooring after 14 days.

The only reason we don’t recommend laying flooring any earlier is because the pH level of the concrete slab requires 2 weeks to oxidise to reach the required pH level.

How does CLEVA CRETE affect the concrete slump and workability?
How does CLEVA CRETE affect concrete shrinkage?

CLEVA CRETE improves shrinkage rates anywhere from 17-32%. This is better than a typical Shrink Reducing Admixture (SRA).

CLEVA CRETE captures the free water and turns it into a pure C-S-H gel and as this gel does not evaporate, only the very top fractions of a millimeter of the concrete will dry out. This results in a concrete slab with heavily reduced shrinkage, and in most cases, no shrinkage cracking at all.

How does CLEVA CRETE improve concrete strength?

CLEVA CRETE admixtures enhance low permeability, strength and durability to the life of concrete. It works with the calcium hydroxide and the free water in concrete to produce additional calcium-silicate-hydrate (C-S-H) gel, the nano building block of concrete.

The resultant absence of capillaries in concrete and the production of extra gel produces a tough, durable, and dense concrete.

There is a typical gain of 13-17% increase in MPa during the setting stage (first 1 to 2 days) of concrete. Then, as the concrete cures through the 28-day process, strengths show a 4 to 11% increase in MPa overall and overtime.

What is the difference between CLEVA CRETE and crystalline growth admixtures?

Crystalline growth technology is reactive. It works by initially allowing all moisture to enter the concrete matrix via the capillaries. All crystal growth technology is rich in the presence of nano sized crystals which when hydrated grow and expand in an attempt to seal up these capillaries. By so doing, they slow down the permeability of moisture enough to create a drying effect.

On the other hand, CLEVA CRETE 842 is proactive. It captures the free water in the concrete while it’s still in its’ plastic stage and being placed turns that free water firstly into a C-S-H gel and then into a very pure (amorphous) style of concrete. The concrete now, hydrophobically, resists any moisture egress or ingress.

What is the difference between CLEVA CRETE and hydrophobic admixtures (eg. Caltite)?

Engineers know that hydrophobic type water-proofers like Caltite, work very well, but they also realise that their hydrophobicity causes additional problems in that it slows down or delays effective hydration of the cementitious materials in the concrete. Generally concrete strengths are compromised in some cases up to 35% less compressive strengths, requiring more cement (and cost) to compensate for this.

How does CLEVA CRETE affect the concrete design life?

All forensic concrete engineers have very different views on what causes catastrophic failure yet, will agree that by reducing the permeability of concrete, slowing ingress of chlorides, sulphides, moisture and oxidised materials, you will lengthen the design life of any concrete structure. The higher the impermeability of the concrete, the greater the longevity.

How effective is CLEVA CRETE in containment of radon gas on contaminated sites?

CLEVA CRETE technology has been successfully utilised over radon gas affected substrates all over the world for over 30 years. In fact, the most contaminated radioactive site in the world, the Fukushima Daiichi nuclear power plant, has used CLEVA CRETE technology to completely seal the contaminated site as it is so effective in controlling such hazardous radioactive emissions.

Who uses the CLEVA CRETE technology?

CLEVA CRETE 842 is currently being utilised by many Tier 1 and 2 construction companies for use on major commercial construction projects where the architects specify and demand a superior moisture vapour free concrete to control the moisture under flooring for the healthcare, aged care, education and public infrastructure. Engineers also specify us to ensure structural durability and longevity.

CLEVA CRETE – Partnering with you from the first pour to deliver superior waterproofing and durability within the concrete itself. Our innovative solutions save you time and reduce costs, ensuring sustainable project success.