- return period
- rill
- rim
- rim lock
- ring arm
- ring beam
- ring bolt
- ring burr
- ring cantilever
- ring conduit
- ring crypt
- ring cutter
- ring dam
- ring deformation
- ring driver
- ring flash
- ring formation
- ring foundation
- ring gall
- ring gap
- ring gate
- ring highway
- ring main
- ring reamer
- ring road
- ring rot
- ring shake
- ring stone
- ringing
- ringing trommel
- ringstone
- rip saw
- rip sawing
- rip-rap
- riparian land
- riparian lands
- ripe drum
- ripper
- ripping
- ripping saw
- riprap foundation
- riser board
- riser height
- riser wedges
- rising
- rising arch
- rising hinge
- risk
- risk assets
- Risk capital
- rival
- rive closing
- river bank
- river beacon
- river bend
- river bridge
- river construction
- river dam
- river diversion
- river dredger
- river fall
- river levee
- river pollution
- river runoff
- river terminal
- river transport
- river weir
- rivers regulation
- riverside outlet
- rivet set
- rivet spacing
- rivet tail
- riveted bridge
- riveted girder
- riveted plate
- riveted structures
- riveter
- riveting
- riveting gun
- riveting set
- riveting shop
- retyre
- reusable formwork
- reusable pipe
- revaluation
- reverse bend
- reversed image
- reversible deformation
- reversible rod
- revetment
- revise
- revolution door
- revolution solid
- revolving mirror
- revolving ripper
- rhenish brick
- rheological model
- rheology
- rhythmical spacing
- ribbed arch