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Silica Fume in Polymeric Grout

posted Jun 10, 2019, 7:39 AM by jeffery jim

Silica fume is one great addictive which increases the performance of Ordinary Portland Cement (OPC) concrete. It gives that robustness from good curing in the critical 24 hours of the concrete formation by providing denser concrete, higher 28th day strength, durability against destructive agents ingress such as chlorine and several others.

Nevertheless, is it good in polymeric concrete where the bonding is beyond just cementitious? It depends, and for new mix, it have to be tested in the lab rigorously. There has not been much studies conducted and if there is, it is merely hypothetical and in small batching scale. Test-oriented may shows a good direction, however no major study conducted based on time frame with the assistance of petrographic observation. We never know but studies does shows that agglomerated flakes of compacted silica fume can induce Alkali-Silica Reaction (ASR) in the long run if it is not mixed appropriately.

There are better and controlled ways to inherit the goodness of silica fumes into polymeric grout. The best would be the use of appropriate addictive or admixture which are meant to work with grout in a proportionate way. Cebex by Fosroc works well with non-shrink grout or maybe Intraplast N by Sika works well with cements (with other pozzolanic materials) to form higher strength grout. These are better than theoretical testing reported in journals which are still subjective with their mix design. Some said below 4% by cement weight and some even raised up to 10% of cement weight for good workability and so on but none of these testings have reported the outcome under the high power microscope through petrographic analysis.

Therefore, as a pragmatic approach; it would be desirable to increase the strength and grout properties through silica fume but it should be under controlled conditions and proportionate mix by using additive that have been proven. Secondly, fitness of the mix should be guided with the material datasheet.