Sakrete Maximizer

[edsiajb]

I'm making preparations to pour my hearth. I'm trying to decide between regular Sakrete and Sakrete Maximizer.

Since Maximizer utilizes an "air entrained" aggregate (expanded shale) and is lighter weight, it would seem that it would be less thermally conductive. Does anyone know this for sure? And has anyone used Maximizer for the hearth because of these properties?

[stonecutter]

Re: Sakrete Maximizer

I'm making preparations to pour my hearth. I'm trying to decide between regular Sakrete and Sakrete Maximizer.

Since Maximizer utilizes an "air entrained" aggregate (expanded shale) and is lighter weight, it would seem that it would be less thermally conductive. Does anyone know this for sure? And has anyone used Maximizer for the hearth because of these properties?

Probably not, since any heat transfer through the insulation is minimal. If your structural slab is getting hot, you've got problems. Use either one.

[edsiajb]

Re: Sakrete Maximizer

Probably not, since any heat transfer through the insulation is minimal. If your structural slab is getting hot, you've got problems. Use either one.

Thanks! I should have mentioned that my insulating layer will be 4" thick 5:1 vermiculite/portland cement. So there will be little or no transfer of heat through this 4" layer to the hearth?

[david s]

Re: Sakrete Maximizer

Any aggregate containing air will be weaker which in turn will make the concrete slab weaker and you then have to factor this into your design. You can make it stronger by making it thicker, but then you're back to square one.

[edsiajb]

Re: Sakrete Maximizer

Any aggregate containing air will be weaker which in turn will make the concrete slab weaker and you then have to factor this into your design. You can make it stronger by making it thicker, but then you're back to square one.

Thanks. I would think the same thing, but this Maximizer product is actually the strongest Sakrete I can buy - at least from a PSI perspective. Maximizer is rated at 5500 PSI while the regular product is rated at 3500 PSI.

[Tscarborough]

Re: Sakrete Maximizer

Maximizer uses expanded shale aggregate, so it is both lightweight and stronger than normal 3/8" pea gravel concrete mix.

Since it does uses that particular aggregate, it is subject to a flash set while mixing. The expanded shale aggregate is very dry (oven dried) and highly absorbent, so I recommend adding all of the recommended water to 3/4 of the bag, mixing, then adding the last dry component after it is thoroughly mixed.

[edsiajb]

Re: Sakrete Maximizer

Maximizer uses expanded shale aggregate, so it is both lightweight and stronger than normal 3/8" pea gravel concrete mix.

Since it does uses that particular aggregate, it is subject to a flash set while mixing. The expanded shale aggregate is very dry (oven dried) and highly absorbent, so I recommend adding all of the recommended water to 3/4 of the bag, mixing, then adding the last dry component after it is thoroughly mixed.

Wow...thank you for this vital information. It sounds like it could ruin my mixer!

[stonecutter]

Re: Sakrete Maximizer

Wow...thank you for this vital information. It sounds like it could ruin my mixer!

No, it just means you have less time to work with it. Use cold water too...hot water from the hose will accelerate the set.

[Tscarborough]

Re: Sakrete Maximizer

It is not normally an issue in power mixers, just when you are mixing by hand. Still do it the same way I said. You will see the effect if it happens, the surface of the mix glazes over and gets shiny. In a power mixer, it breaks itself up, but if you mix as I suggested, you will not see it.

All cementious mixes suffer from flash set to one extent or another. In power mixing, it is not a concern, but when hand mixing concrete or cement based mixes, it is very easy to add too much water when it flash sets, then you have soup once you mix it some more.

[Tscarborough]

Re: Sakrete Maximizer

Stonecutter is right about the hose. I normally fill a couple five gallon buckets and pour from them into the mixer, it is easier to gauge how much you are putting in and it stays cool.

[david s]

Re: Sakrete Maximizer

"Maximizer uses expanded shale aggregate" That sounds like LECA (lightweight expanded clay aggregate) which is good stuff, but expensive. How is the Maximiser for price?

[Tscarborough]

Re: Sakrete Maximizer

Almost 2x.

[david s]

Re: Sakrete Maximizer

Almost 2x.

Is that 2x LECA, or 2x standard aggregate?

[Tscarborough]

Re: Sakrete Maximizer

Regular 4000 psi concrete mix, .6 CuFt 80# bag - $3.70 (this is real concrete mix, not big box fence post garbage).

5500 psi Maximizer, 1 CuFt 80# bag - $6.75

[edsiajb]

Re: Sakrete Maximizer

For my area, the entire hearth will cost about $15 more using the Maximizer.