Concrete Roads
and Their Construction

CONCRETE KERBING 175 to road level, and above the road levels three to one concrete con- sisting of one part |-in. crushed ballast, one part |-in. to dust granite chippings (to give “ case hardening”), one sand and one Portland cement, is added and tamped against the shutters and smoothed off on top. To eliminate the sharp angular edge a chamfer is trowelled on the kerb about one inch wide, or to effect the same purpose a hard wood fillet can be nailed to the front shutter. On gradients where traffic in many instances uses the kerb to form a “drag” upon the vehicle, a protecting steel strip is embodied in the kerb immediately below the chamfer. It is Fig. 124.—Method of constructing concrete kerbs in Surrey. in. by jV in., and is secured every 2 ft. by bent wire nails as shown in Fig. 124. The nails are countersunk into the steel and are finished flush, so that no “ bite ” can be got of them by wheels, which would cause damage difficult to repair. It is essential when removing the shutters to cover over the kerb for at least a month to ensure thorough setting, as it is subjected to a considei’able amount of grinding and buffeting from the wheels of vehicles. Many miles of this kerb have been, laid and give every appearance of proving entirely successful, both from a constructional and financial point of view, the cost at present prices being little more than one-third the cost of granite. For this class of work a gang of eight men is required, and, when experi- enced, 50 to 60 yds. per day can be averaged. The shutters can