1- Introduction

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Hollow Blocks Slabs

Photos Hollow Blocks Slabs

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Hollow Blocks Concept

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Types of Hollow Slabs

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2- Code Requirements for H.B. Slabs

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ECP 203/2017 P6-16 - p 6-17 Sectors are commonly used

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Types of Hollow Blocks Slabs

One Way Hollow Blocks Slabs Two way Hollow Blocks Slabs

𝐿𝑠 ≤ 5

𝐿𝑠 > 5

𝐿𝑠 ∶ Short DirectionEffective Length

𝐿 ∶ Long Direction

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Calculation of Loads

D.L=

One Way Hollow Blocks Slabs

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Load / Rib. Design of Strip

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Two way Hollow Blocks Slabs

Use Table (6-3) , Page (6-17)Use Table (6-2) , Page (6-10)

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Simple Span

Two Span

Continues Span

Difference of spans & Loads ≤ 20 %

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Difference of spans & Loads > 20 %

Uniform Load Concentrated Load

𝑀−𝑣𝑒 =𝑊𝐿 ∗ 𝐿𝐿

′ 3 +𝑊𝑅 ∗ 𝐿𝑅′ 3

8.5 𝐿𝐿′ + 𝐿𝑅

′

𝐿′ = 𝐿

𝐿′ = 0.8𝐿

𝑀−𝑣𝑒 =𝑘𝐿 ∗ 𝑃𝐿 ∗ 𝐿𝐿

′ 2 + 𝑘𝑅 ∗ 𝑃𝑅 ∗ 𝐿𝑅′ 2

𝐿𝐿′ + 𝐿𝑅

′

0.700.600.500.400.30a1/𝐿𝐿&a1/𝐿𝑅0.1280.1580.1760.1820.168𝑘𝐿&𝑘𝐿

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Design of Sections

+ ve Section + ve Section

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Details of R.F.T

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Details of R.F.T

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Notes:

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Example : 1

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Example : 2

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Arrangement

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Example : 3

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Inclined Hollow Block Slab

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Example : 4

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Design of beams

1-Projected beams

a-For one way H.B. Slabs

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a-For two way H.B. Slabs

i- Load for Moment

ii- Load for Shear

Beam 1

Beam 2

i- Load for Moment

ii- Load for Shear

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2-Embedded (hidden) beams

Method 1

Method 2

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Check shear on hidden beam

4-2-2-1-2 p 4-16

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4-2-2-1-3 p 4-18

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4-2-2-1-3 p 4-19

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4-2-2-1-2 p 4-17

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p 4-20

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p 4-21

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