concretebasics.org: your guide to cement & concrete

Types of Cement

DSP Cement

This is a type of cement having very high strength.This is a cement which has been "Densified with Small Particles" (DSP).

The DSP recipe blends cement grains (size 0.5-100µ) with fine particles of silica fumes (size 0.005-0.5µ) --a by-product of silicon metal and alloy production--or other materials. The fine particles pack snugly between the cement grains, filling the voids to the maximum possible extent, decreasing pore size and reducing the amount of water needed. The ratio of silica fume added generally varies from 5 to 25%.

Compressive strength of upto 270 MPa has been achieved with DSP cement.

An added benefit of using silica fume or other silica particles is that they react with and eliminate calcium hydroxide crystals, implicated in the deterioration of concrete exposed to seawater.

DSP-type cements are also used on bridge decks in cold areas because their high densities and low porosities make them highly resistant to attack from the salt routinely used to melt ice.

And because DSP cements resist abrasion, they are used in processing coal, fly ash and other abrasive powders.

Researchers envision other applications too, from coatings on runways to nuclear waste disposal.