Ettringite formation under varying storage conditions and mechanical loads

Photo: RWTH

Specimen in the four-point bending test carried out for the static and dynamic loading scenario

Photo: RWTH

EDX analysis of the phase constituents on the crack surface of the dynamically loaded specimen of series 2 (20/5 °C): calcium carbonate

Photo: RWTH

SEM images of a mineral aggregate surface with accumulated calcium hydroxide (a) and ettringite (b) in the contact zone

Photo: RWTH

SEM images of a mineral aggregate surface with accumulated calcium hydroxide (a) and ettringite (b) in the contact zone

Photo: RWTH

EDX analysis of the phase constituents in the matrix zone close to the crack of the dynamically loaded specimen of series 2 (20/5 °C): ettringite

Photo: RWTH

Damage to structural concrete components with high compressive strengths was investigated at the Institute of Building Materials Research at RWTH AachenUniversity. A combination of raw material characteristics, micro-cracking caused by dynamic loading, and weather impact was assumed to be the damaging mechanism.

Damage to dynamically loaded structural concrete components was investigated at the Institute of Building Materials Research at RWTH AachenUniversity (ibac). Despite their high compressive strengths, the affected components showed signs of cracking and spalling. Using scanning electron microscopy, relatively large amounts of ettringite were detected in the cement paste matrix. The damaging mechanism was assumed to arise from a combination of raw material characteristics (particularly from the relatively high sulfate and alkali contents of the Portland cement used), micro-cracking caused by...