Reinforced Concrete I - Chapter 1

<p>1875 (C)</p> Signup and view all the answers

<p>Joseph Lambot (B)</p> Signup and view all the answers

<p>Too much water reduces strength (D)</p> Signup and view all the answers

<p>Water basins and tubs (C)</p> Signup and view all the answers

<p>Written documentation of construction methods (B)</p> Signup and view all the answers

<p>It has a lower heat of hydration than Type I. (A)</p> Signup and view all the answers

<p>Retarding admixture (C)</p> Signup and view all the answers

<p>Increases resistance to freezing and thawing. (A)</p> Signup and view all the answers

<p>Type IV (C)</p> Signup and view all the answers

<p>To improve workability while reducing water content. (C)</p> Signup and view all the answers

<p>Type III (A)</p> Signup and view all the answers

<p>Reduced compressive strength. (C)</p> Signup and view all the answers

<p>Infrequency of concrete mixing. (B)</p> Signup and view all the answers

<p>21MPa to 50MPa (C)</p> Signup and view all the answers

<p>Concrete with a compressive strength exceeding 70MPa (C)</p> Signup and view all the answers

<p>Ambient temperature during mixing (A)</p> Signup and view all the answers

<p>Compression test on 150 mm cylinders aged for 28 days (C)</p> Signup and view all the answers

<p>Cylinders have roughly 80% of the strength values of cubes (C)</p> Signup and view all the answers

<p>Super-high-strength concretes (C)</p> Signup and view all the answers

<p>The slope of the stress-strain diagram at the curve's origin (A)</p> Signup and view all the answers

<p>Low permeability and increased durability (D)</p> Signup and view all the answers

<p>Grade 75 (A)</p> Signup and view all the answers

<p>Reduced bonding between steel and concrete (C)</p> Signup and view all the answers

<p>It ensures consistent thermal expansion and contraction. (A)</p> Signup and view all the answers

<p>Dead loads (C)</p> Signup and view all the answers

<p>28 mm (C)</p> Signup and view all the answers

<p>Formation of more space-occupying oxides (C)</p> Signup and view all the answers

<p>24 MPa (D)</p> Signup and view all the answers

<p>It ensures uniform expansion under temperature changes. (D)</p> Signup and view all the answers

<p>To increase the estimated loads applied to structures (D)</p> Signup and view all the answers

<p>American Concrete Institute (B)</p> Signup and view all the answers

<p>Seismic load (B), Wind load (C)</p> Signup and view all the answers

<p>Reinforced concrete member design strength (D)</p> Signup and view all the answers

<p>Temperature load (A)</p> Signup and view all the answers

<p>They remain constant regardless of the structure type (B)</p> Signup and view all the answers

<p>It serves as a global influence on concrete codes (D)</p> Signup and view all the answers

<p>American Railway Engineering Association (B)</p> Signup and view all the answers

<p>The slope from the origin to a point between 25% and 50% of the ultimate compressive strength (C)</p> Signup and view all the answers

<p>$E_c = w^{1.5}(0.043) ext{ } ext{ } ext{sqrt}(f_c)$ (A)</p> Signup and view all the answers

<p>The ratio of the lateral expansion to longitudinal shortening (D)</p> Signup and view all the answers

<p>The surface area of the member relative to its volume (C)</p> Signup and view all the answers

<p>90% (B)</p> Signup and view all the answers

<p>Minimize the amount of mixing water (D)</p> Signup and view all the answers

<p>0.11 to 0.21 (A)</p> Signup and view all the answers

<p>$E_c = 4700 ext{ } ext{sqrt}(f_c)$ (D)</p> Signup and view all the answers

A composite material combining concrete's compressive strength with steel's tensile strength.

A mixture of aggregates (sand, gravel, crushed rock), cement, and water, often with admixtures.

A type of cement crucial for concrete, invented by Joseph Aspdin in 1824, named after the Isle of Portland's stone.

A material's ability to withstand pulling forces without breaking.

A material's ability to withstand pushing forces without crushing.

Steel used to reinforce concrete, especially to resist tensile forces.

A pioneer in reinforced concrete, creating patents for various applications (basins, reservoirs, etc.) from 1867 to 1881.

Materials added to concrete to modify its properties (workability, durability, hardening time).

Concrete's strength compared to its weight. A low ratio means it needs substantial support structures (shoring).

Concrete's properties can differ significantly due to inconsistencies in mixing, placing, and curing.

Different types of Portland cement have varying properties, like heat generation and sulfate resistance.

Cement type that reaches strength quickly. Useful for precast and emergency repairs.

A substance added to concrete to increase its resistance to freezing and thawing.

Substances that speed up concrete's setting and strength gain.

Chemical admixtures that reduce concrete water content, improving workability and strength.

Cement that produces less heat during hydration, important in massive concrete structures.

The ability of concrete to withstand pushing forces without crushing, measured by testing 28-day-old cylinders.

Concrete with compressive strength exceeding 70 MPa, often with high durability.

Concrete with strength exceeding 140 MPa; very strong.

Concrete's elasticity varies based on strength, age, loading type, and cement/aggregate.

The initial slope of the stress-strain curve.

The slope of the stress-strain curve at a specific point (e.g., 50% of ultimate strength).

Ultimate strength of concrete after 28 days, a standard measurement.

Materials added to concrete to alter its properties, such as workability or setting time.

The slope of a line from the origin to a point on the stress-strain curve, typically 25-50% of ultimate compressive strength.

A modulus of elasticity calculated from stress/strain observations after time.

A standard formula (using variables like weight and compressive strength) to calculate concrete modulus.

The ratio of lateral expansion to longitudinal shortening under load. Typically 0.16.

The reduction in size of concrete as water evaporates after mixing.

Describes the ease with which concrete can be placed and compacted.

Techniques that reduce shrinkage, including controlling mixing water and proper curing.

The time by which approximately 90% of the concrete's shrinkage occurs. Usually within one year.

Different strengths of steel bars used in reinforced concrete, measured in MPa.

Conditions like deicing salts, seawater, and sprays that damage reinforced structures.

How well concrete and steel work together, with complementary properties.

Constant loads in a fixed position like the weight of the structure itself.

Steel's stiffness or resistance to deformation under stress.

Standard dimensions of reinforcing steel bars in the metric system.

Standard strengths of concrete measured in MPa.

Estimating all possible loads and the worst load combinations a structure might experience.

The American Concrete Institute standard for reinforced concrete design, referenced in the IBC.

International Building Code, a comprehensive building code that reflects several regional codes.

Numbers greater than 1.0, used to increase estimated loads in structural design.

Different combinations of loads considered in structural design, like dead load, live load, and others, as defined in ACI equations.

The design strength that must be met or exceeded for reinforced concrete members according to ACI code.

The weight of the structure itself and its permanent components.

Loads imposed on the structure by people, furniture, and other movable items.

The values of load factors are not based on high-risk situations, like hospitals or high-rise buildings.