ব্যাখ্যা: A flat slab is a two-way reinforced concrete slab that usually does not have beams and girders and the loads are transferred directly to the supporting concrete columns.
43. A column is considered long if the effective length of column to its least lateral dimension is more than-
ব্যাখ্যা: Long column is considered to be long if the ratio of effective length of column to its least lateral dimension is greater than 12 and short column is considered to be short if the ratio of effective length to its least lateral dimension is less than or equal to 12.
44. The spacing of transverse reinforcement of column is decided by the following considerations-
ব্যাখ্যা: Transverse reinforcement means column stirrups. Spacing ≤16 dia of main bar. Spacing ≤48 dia of fit bar and speacing so lateral dimension of column.
The least lateral dimension of the column
Sixteen times the diameter of the smallest longitudinal reniforcing rod is the column
Forty-eight times the diameter of transverse reinforcement
ব্যাখ্যা: Mild steel is a ferrous metal made from iron and carbon. It is a low-priced material with properties that are suitable for most general engineering application. Low carbon mild steel has good magnetic properties due to its high iron content.
47. The transverse reinforcement provided at right angles to the main reinforcement in a slab-
ব্যাখ্যা: The distribution reinforcement have termed as transvers reinforcement is provided that to resist the stresses produced by temperature changes and shrinkage of concrete in that direction.
49. Minimum number of reinforcing bars required in a circular column is-
নোট: (i) Min of 6 bars in circular arrangement enclosed by spiral reinforcement.
(ii) Min of 4 bars in rectangular or circular arrangement enclosed by ties reinforcement.
(iii) Min of 3 bars in triangular arrangement of ties.
50. What is the live load for residential building?
ব্যাখ্যা: Building codes specify a uniform live loud of 40 pound per square foot for most residential floor designs. This load is intended to account for the large number of load that can occur in a residence.
55. The steel used for the manufacture of rails, is-
ব্যাখ্যা: Bessemer steel was used in the United States primarily for railroad rails. During the construction of bridge should be used of bessemer steel.
58. A Slab may be designed as one way if the ratio of its longer side to shorter side exceeds.
ব্যাখ্যা: One way slab is a slab which is supported by beams on the two opposite sides to carry the load along one direction. The ratio of longer span to shorter span is equal or greater than 2, consider as one way slab because this slab will bend in one direction.
59. A pretensioned concrete beam, 100 mm wide and 300 mm deep in prestressed by straight wire. Modulus of elasticity of steel and concrete are 210 N/mm² and 35 N/mm² respectively. Find modular ratio.
60. The spacing of stirrups in a rectangular beam is-
ব্যাখ্যা: Maximum spacing of vertical stirrups in a rectangle beam is at its midspan. It's because the shear force at the midspan is very less. The spacing of vertical stirrups is minimum near the supports due to maximum shear force at the supports.