Page 9 - Haddonstone

2.0 Manufacture

Cast stone is finding growing favour
with both designers and users as a
high-quality facing material which
looks good and performs well at a
realistic cost. This special form of
concrete calls for particular skill and
care and application of technology
in its production.

Major advances have been made in mix design, batching, manufacture
and curing. The manufacturer’s aim is to produce a material, which
resembles quarried natural stone products as closely as possible. The
colour and texture of most stones can now be matched using crushed
rock fines and/or carefully selected and graded natural sands, usually
mixed with white cement. The range of shades can be extended by the
use of grey cement and pigments.

Correct curing of all types of cast stone is essential both for the
resistance to damage during transport and construction as well as
durability and appearance over time. BS 1217:2008 states “Cast stone
should not be transported or installed before it is 14 days old unless
accelerated curing processes allow a reduction of this time” and this
period may need to be extended for structural units. However, some
UKCSA members employ enhanced curing techniques to significantly
reduce the timescale required from production to site, and all UKCSA
Members are required to achieve a minimum level of curing as a
condition of their membership.