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167
REPORT ON THE UTILIZATION OF CLINKER CONCRETE
FOR PAVING OF FOOTWAYS.
Town Hall, Old Street,
London, E.C.
November, 1897.
Mr. Chairman and Gentlemen,
As instructed, I have the pleasure of submitting the following for your consideration.
Concrete, either laid in situ or in the form of slabs, cannot be recommended as a suitable
paving for important and busy thoroughfares.
In either case it is brittle and inferior to stone or asphalte in porosity, and when subjected
to having heavy material unloaded on to, or drawn over it, it cracks ; and further, on account
of the inelastic nature of its component parts, there is always a tendency to fissuring and
upheaval with any contraction or expansion of its surroundings or of itself.
It is decidedly inferior to stone paving in regard to affording a stable foot-hold, but in this
instance it may be classed on an equal with asphalte under the same conditions. Otherwise it
is found to withstand ordinary abrasion and wear well under foot.
IN SITU WORK.
When composed of clinker and Portland cement in the usual proportions as if with ballast,
concrete has been found to answer extremely well for the majority of purposes in which it has
been used ; but the Use of concrete laid in situ on footways in the heart of London is so unusual
as to afford no opportunity of ascertaining its merits, and where I have been able to see the
same in our suburbs, or in less busy places, the question of its usefulness or otherwise is so
unsettled as to lead me to suggest that the Vestry would be well advised in laying a sufficiently
large area for an experiment before generally adopting the idea on what may be termed
thoroughfares of secondary importance.
The natural appearance is decidedly dull, and any attempt to relieve it by blending the
surface when in a soft state with granite chippings, or small broken-up crockery, is not found
to be permanent or satisfactory after wear.
Clinker pavement is found to be especially affected by the heat of the sun, and spreads for
some five or six years at least after laying.
In this kind of work, it is impossible to execute trench or other small repairs without permanently
disfiguring the whole of the surface, unless, of course, the full width of the footway
is taken up and relaid.
In trying the use of a clinker-formod paving, I would suggest that the same be laid in the
following manner:—
The ground to be excavated to a depth of 6 inches, a bed of clinker ash about 1 inch thick
being then spread over the bottom, then a thickness of broken clinker to pass through a 3 inch
ring to be laid in up to within 2 inches of the finished surface level, and this to be rolled with
an ordinary hand roller after well wetting and packing up the interstices. On this foundation