Any contractor can build attractive exposed aggregate sidewalks easily if he takes a little time to experiment beforehand and observe a few simple precautions. One, order a mix containing a high proportion of coarse to fine aggregate. Two, a compatible water-reducing retarding admixture should be use, particularly in warm weather. Three, slump should be low- from 1 to 3 inches- so coarse aggregate remains near the surface. Four, apply a surface retardant as soon as screeding is complete. Five, slab with plastic, paper or burlap to prevent drying out. If fog cure is employed, start no sooner than one hour after application of surface retardant. Six, check retarded surface at regular intervals to determine optimum time for removing retarded surface mortar. Seven, after aggregate is exposed, proceed with proper curing. And finally, during cold weather avoid additional calcium chloride in the mix. Instead heat the mixing water and the aggregates.