Sub-base & Base Materials

Free S4 questions: Sub-base & Base Materials

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

• Scenario: a Type 3 flexible road has been opened up and its existing base is a cement bound granular mixture, which the design repeats for the reinstatement. None of that mixture is available today. The crew proposes foamed concrete at base level instead, pointing to the Code's own foamed concrete table, which gives foamed concrete a thickness and a strength class at base level in this road type. What should the supervisor decide, under SROH?
• Scenario: a hydraulically bound mixture is being supplied for a footway reinstatement. Its 28 day results put it at compressive strength class C9/12. The crew treats that as comfortable, since it is the ceiling the Code's table carries for the material. What should the supervisor decide, and why, under SROH?
• Scenario: an excavation in a carriageway has cut through a continuously reinforced concrete base whose slabs are connected with dowel bars. The gang has worked through the Code's own structure options for the road and brings the supervisor the nearest of them to sign off as the reinstatement design for the base. What should the supervisor decide, under SROH?
• Scenario: a hydraulically bound mixture has been delivered to site and is about to go in. The producer made its designation and description pack, with the four supporting items, available to the undertaker; when the authority asked the producer for the pack, the producer declined, saying the undertaker already has it. The mixture itself is not in question. What should the supervisor decide, under SROH?
• Scenario: a cement bound granular base is being supplied under the Code's alternative route rather than to the single strength class its British Standard table names. The mixture's coarse aggregate is gravel, and the delivery ticket shows compressive strength class C8/10. The gang says that is the class the Code gives a base under that route. What should the supervisor decide, and on what ground, under SROH?
• Scenario: an alternative reinstatement material approved through the Code's own trials process is to go in 300 mm below the road surface, inside the depth the Code protects from frost susceptible material. The existing material at that level is not frost susceptible, and the construction to go above it is not wholly bituminous. The producer's data sheet says nothing about frost susceptibility, and the site engineer says the depth rule is a backfill classification rule that does not reach an approved alternative material. What should the supervisor decide, under SROH?
• Scenario: 3 specimens of a hydraulically bound mixture specified at C3/4 are tested. The mean of the 3 results comfortably exceeds the specified class, but one of them comes in at about 60% of the strength requirement class. The producer says strength is taken as the average and the average is well clear. Which decision is right, and for what reason, under SROH?
• Scenario: the crew offers a frost heave test certificate as its acceptance check on today's delivery of granular material. The certificate was run on material taken from a different working of the same quarry, and the crew proposes to have one run for every delivery from here on. What should the supervisor decide, under SROH?
• Scenario: in a Type 3 flexible road the design takes 105 mm of Type 1 granular material out at sub-base level and makes it up with an extra 20 mm of bituminous binder course. 260 mm of granular material is left in place, and the gang says the swap is the Code's own equivalence. What should the supervisor decide, under SROH?
• Scenario: in a Type 4 flexible road the design applies the Code's granular and bituminous equivalence to replace all the granular material at both base and sub-base level, and takes the surface course down as part of the same calculation. What should the supervisor decide, under SROH?

More free S4 practice

• Find It in the SROH — 3 free questions