{HEAD ~ A further typical concrete structure} is illustrated in FIG 10 at 28 having {TAIL ~ buttresses} 29 each with ducts 30 
having
{ HEAD ~ A further typical concrete structure } is illustrated in FIG 10 at 28 having { TAIL ~ buttresses } 29 each with ducts 30
HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH