Single choice 1When the beam height is 900mm, the angle between the bent steel bar and the beam axis is ().
a 60°b 45°
c 90°d 75°
Analysis: The bent steel bar is bent by the longitudinal tension steel bar, and sometimes the bent steel bar is also specially arranged. The bent reinforcement can bear the positive bending moment in the vicinity of the midspan as well as the longitudinal tension reinforcement. The number and position of the bending steel bar are determined by the calculation, and the order of the bending of the steel bar is generally the inner layer and then the outer layer, the inner side and then the outer side, and the angle between the bending steel bar and the beam axis (called the bending angle) is generally 45 °;When the beam height h>800mm, the bending angle is 60°. The corner reinforcement in the bottom reinforcement of the beam should not be bent, and the corner reinforcement in the top reinforcement should not be bent down, which is obviously the second case.
Answer: A single choice 2When the height of the parapet wall of a multi-storey small block house exceeds () m at least, a structural column or core column anchored to the ring beam of the top floor should be added.
a 0.5b 0.75
c 0.9d 1.2
Analysis: The parapet height of a multi-storey small block house is more than 0When 5m, the structural column or core column anchored in the top ring beam should be added The top of the wall should be provided with a pressure collar beam, and its cross-sectional height should not be less than 60mm, and the longitudinal reinforcement should not be less than 2 10
Answer: A multiple choice. Regarding the statement of the waterproof grade and fortification requirements of the building roof, the correct one is ().
A Class I waterproofing layer, reasonable service life of 25 years, suitable for important or high-rise buildings.
Class B waterproof layer, reasonable service life of 15 years, the use of two waterproof fortification.
Class C waterproof layer, reasonable service life of 10 years, the use of two waterproof fortification.
Class D waterproof layer, using two waterproof fortifications.
Class E waterproof layer, reasonable service life of 5 years.
Analysis: The roofing project should be fortified according to different levels according to the nature of the building, the degree of importance, the functional requirements of the use and the reasonable service life of the waterproof layer, and the roof waterproof grade is divided into I-level. Class I waterproof layer, reasonable service life of 25 years, the use of three or more waterproof fortification. It is suitable for buildings of special importance or have special requirements for waterproofing;The waterproof layer has a reasonable service life of 15 years, and two waterproof fortifications are adopted. Suitable for important buildings and high-rise buildings;The waterproof layer has a reasonable service life of 10 years, and a waterproof fortification is adopted. Suitable for general construction;The waterproof layer has a reasonable service life of 5 years, and a waterproof fortification is adopted. Suitable for non-permanent buildings.
Answer: BE