ABSTRACT
Theyaremadeofgradedhardlimestone,granite,crushedbrickorshale(blaes) anddependontheirabilitytoholdmoistureandthestructureofthepaniclesfor theirstability;theyareself-bindingandunlikebitumenmacadamtheyarenotheld togetherwithabinder.Blaesorcrushedstonefromalocalsourcecanbeusedasa cheaperalternative.Ifthistypeofmaterialisusednoparticlesshouldbelarger than5mm,though3mmispreferred.Thespecialistcontractormaylaythebase, oritmaybelaidbythelandscapecontractor;atypicalbaseisformedof:
Plate 28 A rubber rile impact absorbing surface laid wnder children's swings. This shows clearC, the extent of the safety surfacing required. Surfacing and swings by SMP Playgrounds. (Photograph &, courteS1 of SMP Playgrounds.)
Typical bases provided for specialist surfaces are:
paverslaidonDoTgranularmaterialonthegeotextile.Rigidcementmortar beddingisliabletomovementintheextremesoftemperaturefoundonhighroofs, andthemovementofthebuildingstructureitselfwillhavetobematchedby correspondingmovementjointsinthehardpaving.Flexibleconstructionthatcan accommodateitselftothebuildingmovementislessliabletofailure.
