Non-porous, spherical, non-aggregated and dispersed in water free from chlorides and low alkali, Tytro RC rheology control modifier functions as a pozzolan and silica fume
Cementec also manufactures Silica Fume
products that are used to densify and strengthen concrete.
effectively mops up lime and affords enhanced resistance to chemical attack.
Using silica fume
and metakaolin with increasing content of up to 10% as binary and ternary cement components, due to their fineness and increased heat of hydration, supports the strength development.
RAC-SFO, RAC-SF5, RAC-SF IO and RAC-SF20 were prepared with 0%, 5%, 10% and 20% of silica fume
with partial replacement of cement by weight and 100% of recycled aggregate concrete.
However, at high metakaolin doses and low water/binder ratios, the concrete can be difficult to work without superplasticizer ; Dhir  has shown that metakaolin concrete normally requires a smaller superplasticizer dose than does the equivalent silica fume
For small percentage of silica fume
, (3%) and any percentage of lime, there is a decrease in the optimum water content with slight increase in maximum dry density.
The first seven chapters survey types of admixtures and additions: natural pozzolans, fly ash, blast furnace slag, silica fume
, limestone powder, and others.
Use of other materials such as calcined or bentonite clay, rice husk ash, bagasse ash and silica fume
may be effective against ASR.
5 ordinary Portland cement, ultrafine active silica fume
, river sand (the maximum particle diameter is 1.
A grey dandified grade 920 D silica fume
(which is a byproduct from the manufacture of silicon or ferro-silicon metal) was used.
2015) Prediction of long-term chloride diffusion in silica fume
concrete in a marine environment, Cement and Concrete Composites, 59, 10-17.