1. There are three indicators for the porosity of materials: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
2, when the wetting angle a is less than or equal to 900, it is _ _ _ _ material, and when a is greater than 900, it is _ _ _ _ material.
3. The mineral composition of cement clinker is C3S and C3S. ______、_______、_______。
4. Any cement _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
5. The four basic materials of concrete are _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _.
6. The cube compressive strength is measured by cube specimens with side length of _ _ _ _ _ mm under standard curing conditions. ..
7. The purpose of water reducing agent is _ _ _ _ _ _ _ _ _ _ _ _ _.
8. According to chemical composition, steel can be divided into _ _ _ _ _ steel and _ _ _ _ _ _ steel.
9, roofing waterproof practices can be divided into _ _ _ _ _ waterproof and _ _ _ _ _ _ _ _.
Two, true or false (2 points for each question, ***20 points)
() 1, bulk density refers to the mass per unit volume of a material in an absolutely dense state.
() 2, thermal conductivity, such as less than 0.25w/(m? The material of k) is heat insulation material.
() 3. In order to eliminate the harm of quicklime, the "aging" time is longer than 1 week.
() 4. The setting and hardening of cement can be divided into initial setting and final setting.
() 5. Improving the compactness of cement slurry can enhance the anti-corrosion ability of cement slurry.
() 6. Sand is divided into coarse sand, medium sand and fine sand according to fineness modulus.
() 7. The maximum particle size of concrete solid slab and aggregate shall not exceed 30mm.
() 8. The workability of mortar includes fluidity, cohesiveness and water retention.
() 9. Sulfur, phosphorus and oxygen are harmful elements in the chemical composition of steel.
() 10, cold working can improve the yield strength and save steel.
Three. Explanation of nouns (5 points for each question, *** 15 points)
1, strength:
2, admixture:
3, workability:
Four, correct the wrong question (***25 points)
1, what is the volume safety of cement? What are the bad reasons and hazards? (8 points)
2. What are the factors that affect the workability of concrete? How to improve the workability of concrete? (8 points)
3. What are the main indexes for evaluating the technical performance of steel? (9 points)
V. Calculation questions (10)
It is known that the experimental mix ratio of a concrete is 1: 2.3 1: 4.29 and 1m3. The cement content in concrete is 320Kg, the water cement ratio is 0.60, the water content of sand is 3%, and the water content of stone is 2%. Find the concrete construction mixture ratio of 1m3 and the amount of various materials.
Building materials answer
Fill in the blanks
1, porosity, pore size, pore size
2. Hydrophilic and hydrophobic
3、C2S、C3A、C4AF
4, initial setting time, magnesium oxide, magnesium trioxide slip, volume stability.
5, water, cement, sand, stone
6、 150* 150* 150、28
7. Increase fluidity, improve strength and save cement.
8. Low-carbon structure and alloy
9. Stiffness and flexibility
Second, the judgment question
1.× 2.∨ 3.× 4.∨ 5.∨ 6.∨ 7.× 8.× 9.∨ 10.∨
Third, the noun explanation
1, the ability of materials to resist destructive force under external force.
2. In addition to cementitious materials, fine aggregate in concrete group and materials with water content not more than 5% that can obviously improve concrete performance shall be used as required.
3, refers to the concrete mixture is convenient for construction operation, and can obtain the performance of concrete with uniform structure and compact molding.
Fourth, correct the wrong questions.
1, whether the volume changes uniformly during the setting and hardening of cement is called the volume safety of cement.
Uneven volume change after cement hardening will cause expansion cracks in cement products or concrete components, reduce the quality of buildings and even cause serious accidents.
2. The influencing factors are: cement, water, admixture and aggregate.
Environmental conditions, temperature, humidity and wind speed.
C time
Measures: A Under the condition of constant water-cement ratio, reduce the dosage of cement.
Reasonable sand ratio is adopted through experiments.
Change the continuous gradation of sand or stone
Change the particle size of sand and stone.
E admixture
Specific environmental conditions will reduce the transportation time of concrete.
3. Main properties: mechanical properties, tensile properties, impact properties, hardness, technological properties, cold bending properties, weldability, durability and cold drawing properties.
Verb (abbreviation of verb) calculation problem
Solution: construction mixture ratio
( 1)x( 1+wx):y( 1+wy)= 1:2.3 1( 1+0.03):4.29( 1+)
Dosage of various concrete materials:
Cement: mc=320Kg.
Sand: ms = 320 * 2.38 = 761.6kg.
Stone: mg = 320 * 4.38 =1401.6kg.
Water: 320 * 0.60—2.31* 320 * 0.03—4.29 * 320 * 0.02.
= 192—22. 176—27.456 = 142.368kg
As can be seen from the above:
Cement 320Kg water 142.37Kg sand 76 1.6Kg stone1401.6kg.
Construction mix ratio: 1: 2.38: 4.38.
answer ........................