# One-Way Slab Design Strength

Both flexural moment and shear strength is controlled automatically according to

**7.5.1.1**.

Dimensions of the cross-section should be satisfy

**ACI Eq. (22.5.1.2).**It’s automatically controlled and users are warned if the rule is not satisfied.

**Symbols**

* M_{u }= *factored flexural moment at section, lb

*nominal flexural strength at section, in.-lb*

**M**_{n }=**f'**specified comprehensive strength of concrete, psi

_{c}=*area of concrete used to determine shear stress, in*

**A**_{c-sh }=^{2}

*gross area of concrete section, in*

**A**_{g }=^{2}

*web width or diameter of circular section, in.*

**b**_{w }=*distance from extreme compression fiber to centroid of longitudinal tension reinforcement, in.*

**d =***overall thickness, height, or depth of member, in.*

**h =***center-to-center spacing transverse reinforcement, in*

**s =***nominal shear strength provided by concrete, lb*

**V**_{c }=*nominal shear strength, lb*

**V**_{n }=*nominal shear strength provided by shear reinforcement, lb*

**V**_{s }=*factored shear force at section, lb*

**V**_{u }=To design one-way slab under flexural moment, one-way slab design strength is provided ΦS_{n }≥ U. Both flexural moment and shear strength is controlled according to **7.5.1.1**.

ΦM_{n} ≥ M_{u}

ΦV_{n} ≥ V_{u}

**Moment**

M_{n} is determined according to **22.3** as nominal flexural strength * M_{n}* is calculated as shown below. Detailed information: Flexural Strength

**Shear**

V_{n} is determined according to **22.5**. Nominal one-way shear strength at a section, * V_{n}*, is calculated by eq.

**22.5.1.1**.

The shear strength is based on an average shear stress over the effective cross section, * b_{w}d*. Therefore dimensions of the cross-section should be satisfy

**ACI Eq. (22.5.1.2)**. Detailed information: One-Way Shear Strength