reichert conereinforced concretereinforcementrejectsrelative humidityrelative roughnessrelease fracturesrelease meshremote sensingreolitreomexreplacementreplacement texturerepresentative fractionrepresentative sampling horizonreserveresidence timeresidual exposed halosresidual friction angleresidual shear strengthresidual soilsresidual stressresinresin anchored rockboltresistivity methodresistorresourcesrespirable dustrestricted krigingretaining meshretaining wallretreating longwall methodreturn airwayreturn idlerreverse circulation systemreverse faultreverse flotationrhomboid exploration gridrhythmic sequenceriffleriffle samplerriffle separatorriffle splitterrigid steel setrim pullrim synclinering dikering holesring separatorrip