Cement-lateritic gravels mixtures: Microstructure and strength characteristics

Microstructure of cement-lateritic gravels mixes, containing up to 8 wt% cement, was investigated by means of X-ray diffraction, infrared spectrometry, differential thermal analysis, scanning electron microscopy and energy dispersive spectrometry. Also, strength characteristics of the mixtures were measured. The results show that cement admixtures resulted in the formation of 1.4 nm-tobermorite, ettringite, iron oxyhydroxide, portlandite and calcite. The increasing amount of tobermorite, due to the increase of the cement content, was attended with a noticeable reduction of particles segregation. In addition, its marked crystallization, observed for the high curing time (28 days), contributed to the improvement of the mechanical strength. As regards the application aspect, the results show that cement amended lateritic gravels are convenient for base course construction.