Item 407 Concrete Structures

31問 • 1年前

問題一覧

Unless otherwise shown on the Plans or specified in Special Provisions, concrete shall be of _______

Class A

If lean concrete is required in the Plan or as directed by the Engineer prior to placing of reinforcing steel bar, the lean concrete should have a minimum compressive strength of ______

13.8 MPa

When placing operations would involve dropping the concrete more than _____, concrete shall be conveyed through sheet metal or approved pipes

1.5m

The discharge end of the line shall not be more than _____ from the point of deposit

Concrete deposited in water shall be of Class Seal concrete with a minimum cement content of _______ of concrete

380 kg/m³

The slump of the concrete shall be maintained between ______

4 to 8 inches

A tremie shall consist of a tube having a diameter of not less than ______ constructed in sections having flanged couplings fitted with gaskets with a hopper at the top

250mm

The concrete in walls, beams, columns and the like shall be placed in horizontal layers not more than ____ thick except as hereinafter provided

30cm

The intensity of vibration shall be such as to visibly affect a mass of concrete with a _____ slump over a radius of at least _____

3 inches, 50cm

An inset formwork shall be used to produce an edge thickness of not less than _____ in the succeeding layer

15cm

The concrete shall be allowed to set for at least ______ before the caps are placed

20 hours

The load of the superstructure shall not be allowed to come upon the bents until they have been in place at least _____ unless otherwise permitted by the Engineer

14 days

The bond between stem and slab shall be secured by means of suitable shear keys which may be formed by the use of timber blocks approximately _____ in cross-section having a length of _____ less than the width of the girder stem

50mm x 100mm, 100mm

These key blocks shall be placed along the girder stems as required, but the spacing shall not be greater than _______ center to center

300mm

Ordinary Finish

Class 1

Rubbed Finish

Class 2

Floated Finish

Class 3

The surface finish on piers and abutments shall include all exposed surfaces below the bridge seats to _____ below low water elevation

20cm

The surface finish on piers and abutments shall include all exposed surfaces below the bridge seats _____ below finished ground level when such ground level is above the water surface

50cm

Wing walls shall be finished from the top to _____ below the finished slope lines on the outside face and shall be finished on top and for a depth of _____ below the top on the back sides

50cm, 20cm

On all surfaces the cavities produced by form ties and all other holes, honeycomb spots, broken corners or edges and other defects shall be thoroughly cleaned, and after having been kept saturated with water for a period of not less than ______, shall be carefully pointed and made true with mortar of cement and fine aggregate mixed in the proportions unsed in the grade of the concrete being finished.

3 hours

Mortar used in pointing shall not be more than _____ old

1 hour

The rubbing of concrete shall be started as soon as its condition will permit, the concrete shall be kept thoroughly saturated with water for a minimum period of _____

3 hours

The float shall then be moved forward _____ of each length and the above operation repeated

1/2

The Contractor shall furnish and use an accurate 3 m straight-edge swing handless _____ longer than ______ the width of the slab

1m, 1/2

Advancement along the deck shall be in successive stages of not more than ____ of the length of the straight-edge

1/2

The straight-edge testing and refloating shall continue until the entire surface is found to be free from observable departure from the straight-edge and the slabs has the required grade and contour, until there are no deviations of more than _____ under the 3 m straight-edge

3mm

The strokes shall be square across the slabs from edge to edge, with adjacent strokes slightly overlapped, and shall be made by drawing the broom without tearing the concrete, but so as to produce regular corrugations not over ____ in depth

3mm

The surface shall not vary more than ____ under a 3 m straight-edge

3mm

In Water Method, the concrete shall be kept continuously wet by the application of water for a minimum period of ______ after the concrete has been placed

7 days

The compound shall be applied with a pressure spray in such a manner as to cover the entire concrete surface with a uniform film and shall be of such character that it will harden within ______ after application

30 minutes

Project Engineer EXAM

Vaantoote · 62問 · 2年前

Project Engineer EXAM