Desain Pelat Satu Arah SNI 2847-2019

Summary

This video provides a detailed guide to designing reinforced concrete slabs, focusing on one-way slabs as per SNI 2847:2019. It covers the essential steps, including load calculation, moment determination, slab thickness, and reinforcement detailing. The presenter explains how to calculate both positive and negative moments, and how to select the right reinforcement based on these moments. The video also demonstrates how to apply the minimum reinforcement requirements for different slab types, ensuring structural safety and compliance with design standards.

Takeaways

• 😀 Understanding the role of one-way slabs in building structures and how they support loads from floors and ceilings.
• 😀 The importance of calculating both dead load (beban mati) and live load (beban hidup) when designing a slab, with reference to SNI 1727.
• 😀 Key distinction between one-way and two-way slabs, and how the span of the slab influences load distribution and design.
• 😀 The process for determining the minimum thickness of a slab according to SNI 2847:2019, factoring in span length and load type.
• 😀 The use of coefficients from SNI 2847 to calculate moments and determine whether a slab design can withstand expected forces.
• 😀 Explanation of effective depth in slab design, which is essential for determining the amount and placement of reinforcement.
• 😀 The necessity of including reinforcement in slab designs to resist bending moments, with a specific focus on main and auxiliary reinforcement.
• 😀 Practical example of calculating the ultimate design load and moment based on slab thickness, material properties, and applied loads.
• 😀 Verification step to ensure the slab’s moment capacity meets or exceeds the calculated ultimate moments, ensuring structural integrity.
• 😀 Final reinforcement design details, including the use of D10 bars with 300mm spacing for both longitudinal and transverse reinforcement.
• 😀 The importance of adhering to national standards (like SNI 2847) to ensure safety, durability, and compliance in structural design.

Q & A

What is the main function of a reinforced concrete slab in building design?

The main function of a reinforced concrete slab is to provide a horizontal surface that supports loads and transmits them to beams or columns. It helps unify the structural system and can be integrated with beams to form a monolithic structure.

How do you calculate the thickness of a one-way reinforced concrete slab?

The thickness of a one-way reinforced concrete slab is typically calculated by dividing the span length by 20. However, for cantilever slabs or continuous slabs, the thickness ratio may vary according to specific design codes such as SNI 2847.

What are the key types of loads considered when designing a reinforced concrete slab?

The key types of loads are: 1) Dead load, which includes the weight of the slab and other permanent structural components, and 2) Live load, which includes temporary loads like people, furniture, and equipment.

How do you determine the ultimate combination of loads for the design?

The ultimate combination of loads is determined by adding the dead load to the live load using a specific safety factor. For instance, in combination 2, the load is calculated as dead load plus live load, as specified by design codes like SNI 2847.

What are positive and negative moments in reinforced concrete slab design?

Positive moments occur at the mid-span of the slab, while negative moments are found at the supports. These moments are critical for determining the bending resistance required from the slab and its reinforcement.

Why is the calculation of moments important in slab design?

Calculating moments is essential because they determine the bending stresses on the slab. By knowing the positive and negative moments, designers can appropriately size the reinforcement needed to resist these forces and ensure the slab's structural integrity.

What is the role of reinforcement in a concrete slab design?

Reinforcement, usually in the form of steel bars, is used to resist bending moments and shear forces in a concrete slab. The area and arrangement of reinforcement are designed based on the calculated moments to ensure the slab can safely carry the loads it will experience.

How is the required area of reinforcement calculated for a one-way slab?

The required area of reinforcement is calculated based on the calculated bending moments using formulas provided by design codes such as SNI 2847. The reinforcement should be sufficient to resist the bending moments while maintaining the required safety margin.

What is the minimum reinforcement requirement for a reinforced concrete slab?

The minimum reinforcement requirement is specified by design codes to prevent issues such as excessive cracking or failure due to low reinforcement. In the case of a one-way slab, the reinforcement often meets a minimum percentage based on the slab’s cross-sectional area.

Why is it necessary to use a factor of reduction in the design process?

The factor of reduction, such as 0.9, is used to account for safety and uncertainties in material properties and load predictions. It reduces the calculated moment or load to ensure the slab design remains conservative and safe under real-world conditions.