Editorial Responsibility, page-30

Hi Dst16.

I have for a long time agreed that EC is the only additive I know of which gives benefits of all properties, that is compressive strength, abrasion, flexural strength, permeability, shrinkage. I would argue the amount of applications where all of these properties are needed is very small and specialised. Generally the design engineers will only be chasing one or two properties.

Shrinkage is a common problem in concrete and there are many additives on the market. Sika has a popular one "Sika40". You can add plastic or metal fibers "fibrecrete" into the concrete which also reduce shrinkage.

Compressive strength and abrasion are related and can be easily and cheaply achieved by adding more cement to the mix. This is extremely cheap. eg: http://www.eurekaconcrete.com.au/pricing. Going from 1 cube of 32MPa to 40MPa would cost about $16/cube. This is retail pricing including delivery so the big companies will get it much cheaper.

For flexural strength the easiest way is to add steel. Although more expensive it is well known concrete does not have much tensile strength, so adding an "extra 40%" of nothing is still virtually nothing. If flexural strength was an issue in design then steel is the answer.

For water ingress a product called Xyplex is on the market and well accepted as good quality and a affordable price.

There are many others, some with draw backs, some cost alot some cost very little. It all comes down to the properties which are required in the concrete.