Preparing the Layer

Free O6 questions: Preparing the Layer

These questions are in the practice set above. Answer them there to see the correct option and the explanation for each.

• Scenario: a service connection is to be made in an old asphalt footway. The surfacing round the opening has gone dry and brittle with age and crumbles at the edges as soon as it is cut, so more of it will have to come out than the job would normally need. The ganger says the undertaker always has to pay for any area reinstated beyond the normal one. Under the SROH guidance, who meets the cost of the larger area?
• Scenario: an opening in a carriageway runs through surfacing that is badly crazed and breaking up, and a compliant reinstatement is not considered possible. The undertaker has recorded the condition. The gang is concerned that compacting an ordinary hot-lay surface course against the broken surround will disturb it further. Under SROH, which means does the Code name for managing that risk?
• Scenario: a small opening in a road with a porous asphalt surface course is to be reinstated using SMA. The existing porous asphalt surface course is 60 mm thick. The ganger plans to saw cut the edges to the full thickness of the surface course before the permanent reinstatement. A new operative says a 50 mm cut is all the Code asks for. Under SROH, who is right, and to what depth must the edges be cut?
• Scenario: a trim-line for a hot-lay reinstatement in a footway falls 100 mm from a stop-cock valve box. The box is 200 mm wide on the side facing the reinstatement and 400 mm long in the other direction. The ganger says the trim-line can stay where it is. A new operative says it must be extended to the box, because the box is 400 mm long. Under SROH, who is right, and on what ground?
• Scenario: two openings in the same carriageway have been found undercut beneath their bound edges. In the first, the sub-base and base are to be PMMA. In the second, they are to be a foamed concrete for reinstatement (FCR), and nothing has been produced about that material beyond its strength. The ganger proposes to leave out the trimback at both, since each material will fill the space under the edge. Under SROH, which opening may go ahead without trimback?
• Scenario: a surface box in a carriageway has been re-set beside a new hot-lay reinstatement and stands 8 mm above the surface immediately around it. The ganger says a fixed feature left a little proud is the safe way to leave it. A new operative says it has to be taken up and re-set. Under SROH, who is right, and what tolerance applies?
• Scenario: an access cover and frame is being reinstated in a carriageway on the approach to a busy roundabout, where vehicles brake and turn over it all day. A new operative asks whether the Code says anything about the material to use round a frame in a location like this. Under SROH, what does it say?
• Scenario: a small reinstatement has to be made in the narrow gap between two small surface boxes set close together in a footway, too tight for any compaction plant to work between them. The ganger plans to use PMMA for the backfill, sub-base, base and surfacing. A new operative says PMMA can only be the surfacing, the layers beneath needing a material that is compacted. Under SROH, who is right, and for what reason?
• Scenario: a frame in a carriageway is to be bedded, and the gang plans to fill the excavation round it with C32/40 concrete bedding up to 60 mm below the road surface before the surfacing goes on. The ganger says bedding can come up as far as the surfacing above it allows. Under SROH, how far up may the bedding come?

More free O6 practice

• Find It in the SROH — 3 free questions