ব্যাখ্যা: Shell structure মূলত RCC নির্মিত পাতলা বাঁকানো প্লেট কাঠামো বিশেষ। এটি দেখতে আঁচ- এর মতো বাঁকানো। এটি কাঠামোর টেনসাইল, শিয়ার পীড়ন এবং চাপ প্রতিরোধ করতে সক্ষম কিন্তু এতে কোনো রকম বেন্ডিং মোমেন্ট উৎপন্ন হয় না।
4262. 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.
4264. The shear reinforcement in RCC is provided to resist-
ব্যাখ্যা: Reinforcement which is designed to resist shear or diagonal tension stresses. Shear reinforcement is usually provided in the form of stirups to hold the longitudinal reinforcement and also to take the shear to which the structure is subjected to
4266. 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.
4267. 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
4273. The columns whose slendeness ratio is less than 80, are known as-
ব্যাখ্যা: When the columns slendeness ratio is less than 80 is called short column and columns slendeness ratio is greater than 80 is called long column. It is generally fails by buckling.
4275. 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.
4279. 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.
4280. 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.