Improved freeze-thaw resistance, strength and durability of concrete products Diatomaceous earth as a functional additive

摘要

Concrete needs to exhibit a high freeze-thaw resistance to ensure long service lives, particularly in the case of concrete products used in road construction. This characteristic is primarily achieved by adding a suitable air void system (using surfactants or hollow microspheres). A research project was initiated to investigate the application potential of natural and calcined diatomaceous earth as a concrete additive. Diatomaceous earth is also referred to as diatomite, kie-selgur, natural/amorphous silica, or moler earth. This porous lightweight mineral based on silicon dioxide (SiO_2) is mainly composed of marine or freshwater deposits of fossilized remains of unicellular algae (Fig. 1). Tectonic movements in the Earth's crust and various glacial influences have made them readily available for extraction at a large number of sites.