Air entrainers

Belith AE air entrainment agents are formulated products to achieve stable constant air entrainment

Belith AE20N - formulated air entrainment agent for the entrainment of stable, homogeneous small particle air to improve workability, anti sedimentation or freeze thaw resistance properties of mortars.

Variations for higher volume air entrainment are available.

On Belith Air Entrainment Admixtures:

Quantity and distribution of air entrained in mortars depends on the nature of the air entraining agent, on the mortar composition and mortar preparation/application. The air entrainment agent must have adequate solubility in the liquid phase to be able to stabilize air in the liquid phase and a sufficient affinity to solid phases present in order to attach the air bubble, so that it stays in the mortar.

While factors such as low cement contents, coarse cements or high alkali contents may facilitate air entrainment, slag (Carbon contaminated) cements, decreasing w/c  values, high fines contents, increasing stiffness or temperatures tend to compromise air entrainment. Other mortar admixtures influence air entrainment as well as does the duration/intensity of mixing.

Air entrainment also affects such diverse properties of mortars such as rheology or strengths.

The objectives for formulating air entraining agents vary, they includebetter air particle size and distribution, reducing water sensitivity or late activation potential by reducing surfactant quantities or improved handling properties.

Relevant mortar properties are affected by air entraining agents, as shown below. The amount of air entrained by formulated air entraining agents can be high, comparable to the amounts entrained by pure surfactants from which they may derive:

Formulation 1 – competitive formulated AEA

Formulation 2 – commercial 90% purity surfactant technology 1

Formulation 3 – commercial “pure” surfactant technology 2

(Formulations 4 - commercial “pure” surfactant technology diluted to 90% actives)

Formulations 5,6– formulated AEA (LP18.1 and LP18.1.1)

The mortar formulation determines the relative performance of air entraining agents:

For example, in mortar 1, LP18mod1 led to constant, LP18mod3 to highest air entrainment:    

                                          After cycle 1                                 After Cycle 3

Mortar1 without AEA     270                                                274

LP18mod1                       262                                                262

LP18mod3                        258                                               240

LP18mod4                        257                                               251

In mortar 2, LPmod5 or 6 may be preferable products:

The source of foaming agents may be critical for the performance of AEAs

Product                              dosage water demand  entrained air        [%]

Without                             0,03      21,50                  13,50

Alpha olefin sulfonate1  0,03      20,00                   22,00

Alpha olefin sulfonate2  0,03      20,00                   21,00

Alpha olefin sulfonate3  0,03      20,00                   20,50