Introduction to Loads and Reinforced Concrete Analysis

Vocabulary flashcards covering structural load types, NSCP and ACI load combinations, and formulas for reinforced concrete beam and slab analysis.

Dead Loads

Loads of constant magnitude that remain in one position, including the weight of the structure and any fixtures permanently attached to it.

Live Loads

Loads that can change in magnitude and position, such as occupancy loads, warehouse materials, construction loads, and equipment operating loads.

Environmental Loads

Loads caused by the environment in which the structure is located, such as rain, snow, wind, temperature change, and earthquake.

Slab's self-weight

$$\text{Unit Weight of Concrete} \times \text{Thickness of the Slab}$$

Beam's self-weight

$$\text{Unit Weight of Concrete} \times \text{Gross Area of the Beam}$$

One-way slab ratio

$$m = S/L < 0.5$$

Two-way slab ratio

$$m = S/L \geq 0.5$$

Modulus of rupture ($f_r$)

The bending tensile stress at which the concrete begins to crack, calculated as $f_r = 0.62\lambda\sqrt{f'_c}$

Cracking Moment ($M_{cr}$)

The moment at which tensile cracks begin to form in the bottom of the beam, calculated as $M_{cr} = \frac{f_r I_g}{y_t}$

Modification factor ($\lambda$)

A multiplier used for lightweight concrete; it is $1.00$ for normal-weight concrete and $0.75$ for all-lightweight concrete.

$\beta_1$ (for $17 \leq f'_c \leq 28\,MPa$)

According to Table 422.2.2.4.3, the value is $0.85$.

Modulus of elasticity ($E_s$)

For non-prestressed bars and wires, it shall be permitted to be taken as $200,000\,MPa$.

Maximum concrete strain ($\epsilon_c$)

At the extreme concrete compression fiber, it shall be assumed equal to $0.003$.

Strength Reduction Factor ($\phi$) for Tension-controlled sections

The factor is equal to $0.90$ when the net tensile strain $\epsilon_t \geq 0.005$.

Minimum Flexural Reinforcement ($A_{s,min}$)

The greater of $\frac{0.25\sqrt{f'_c}}{f_y} b_w d$ and $\frac{1.4}{f_y} b_w d$.

Minimum horizontal clear spacing ($cs_{min}$)

The greatest of $50\,mm$, $d_b$, and $\frac{4}{3}d_{agg}$.

Maximum spacing for deformed reinforcement in one-way slabs

The lesser of $3h$ and $450\,mm$.

Minimum ratio of reinforcement ($A_{s,min}$) for slabs with $f_y < 420\,MPa$

The ratio is $0.0020 A_g$.

Column Load (from beam load)

Equivalent concentrated load calculated as $P = w \times \text{Tributary Length}$.

ACI Coefficient Method Limit (Live to Dead Load)

$L \text{ (live load)} \leq 3D \text{ (dead load)}$.