**2.2.3 Cement products**

Cement products are the most widely used materials for the open spaces of Athens, and of every other Greek city. Concrete with visible aggregates of various sizes (gravel cement), which is poured on site, is mainly used for the paving of squares, pedestrian streets and urban furniture, such as sitting areas. Slabs are used in sidewalks, while blocks are used in pedestrian and low-traffic streets. As was expected, the light-coloured materials (gravel cement and the white slabs) were cooler than the dark-coloured ones (the grey cement slabs, the red mosaic slabs, the gravel cement slabs and the grey cement blocks). It should be noted that the surface temperatures of all the materials, except of the white slabs, were 3.5 to 5.5 oC hotter than the air around sunset. Also, that the differences in the surface temperatures of exposed and shaded materials were in all the cases significant.
