Concrete Technology Set-1 0 votes, 0 avg 3 Concrete Technology Set-1 1 / 25In symmetrically reinforced sections, shrinkage stresses in concrete and steel are respectively Compressive and tensile Both tensile Both compressive Tensile and compressive 2 / 25Critical section for shear in case of flat slabs is at a distance of At the periphery of column d/2 from periphery of column/capital/ drop panel Effective depth of slab from periphery of column/drop panel At the drop panel of slab 3 / 25The purpose of reinforcement in pre-stressed concrete is To resist tensile stresses All of the above To impart initial compressive stress in concrete To provide adequate bond stress 4 / 25The temperature reinforcement in the vertical slab of a T-shaped R.C. retaining wall is Provided more on front face than on inner face Provided more on inner face than on front face Not needed Provided equally on inner and front faces 5 / 25The main object of compaction of concrete, is: To achieve maximum density To provide intimate contact between the concrete and embedded materials All the above To eliminate air holes 6 / 25Due to shrinkage stresses, a simply supported beam having reinforcement only at bottom tends to Deflect downward Deflect downward or upward None of the above Deflect upward 7 / 25Which of the following has high tensile strength? Heat treated rolled wires Cold drawn wires All have same tensile strength Plain hot rolled wires 8 / 25To determine the modulus of rupture, the size of test specimen used is 100 × 100 × 500 mm 150 × 150 × 500 mm 100 × 100 × 700 mm 150 × 150 × 700 mm 9 / 25For road pavements, the cement generally used, is Blast furnace slag cement Rapid hardening cement Low heat cement Ordinary Portland cement 10 / 25For construction of structures in sea water, the cement generally preferred to, is Portland-pozzolana cement Quick setting cement Low heat Portland cement Rapid hardening cement 11 / 25In counterfort retaining walls, the main reinforcement in the stem at support is Provided only on front face Not provided Provided both on inner and front faces Provided only on inner face 12 / 25Bulking of sand is maximum if moisture content is about 6 % 2 % 10 % 4 % 13 / 25Curing of pavements, floors, roofs and slabs, is done by Ponding method Sprinkling water method Covering surface with bags Membrane method 14 / 25For concreting of heavily reinforced sections without vibration, the workability of concreteexpressed as compacting factor should be 0.75 – 0.80 Above 0.92 0.80 – 0.85 0.85 – 0.92 15 / 25For a slab supported on its four edges with corners held down and loaded uniformly, the Marcuscorrection factor to the moments obtained by Grashoff Rankine’s theory Is always less than 1 Is always greater than 1 Can be less than 1 Can be more than 1 16 / 25Tricalcium aluminate (C3A) Does not contribute to develop ultimate strength Generates less heat of hydration Reacts fast with water Causes initial setting and early strength of cement 17 / 25When shear stress exceeds the permissible limit in a slab, then it is reduced by Using thinner bars but more in number Increasing the depth Providing shear reinforcement Using high strength steel 18 / 25Due to circumferential action of the spiral in a spirally reinforced column Capacity of column is decreased Ductility of column reduces Capacity of column is decreased but ductility of column increases Both the capacity of column and ductility of column increase 19 / 25The workability of concrete is directly proportional to All of above Time of transit Aggregate cement ratio Grading of the aggregate 20 / 25To minimise the effect of differential settlement, the area of a footing should be designed for Dead load + live load Dead load only Live load + fraction of dead load Dead load + fraction of live load 21 / 25The diameter of ties in a column should be More than 5 mm and also more than one-fourth of diameter of main bar More than or equal to 5 mm More than or equal to one fourth of diameter of main bar More than 5 mm but less than one-fourth of diameter of main bar 22 / 25Diagonal tension in a beam Remains same Is maximum at neutral axis Increases below the neutral axis and decreases above the neutral axis Decreases below the neutral axis and increases above the neutral axis 23 / 25Addition of pozzolana to ordinary portland cement, causes Reduction in chemical action with sulphates Increase in shrinkage All the above Decrease in early strength 24 / 25According to IS: 4561978, the column or the strut is the member whose effective length is greaterthan 4 times the least lateral dimension 3 times the least lateral dimension 2 times the least lateral dimension The least lateral dimension 25 / 25Concrete gains strength due to Hydration of cement All the above Evaporation of water from concrete Chemical reaction of cement with sand and coarse aggregates Your score isThe average score is 25% LinkedIn Facebook Twitter 0% Restart quiz Send feedback You Might Also Like Concrete Technology Set-3October 31, 2020 Concrete Technology Set-2October 31, 2020