By:

Dr.Islam M. El-Habbal

2011

Photos of Hollow Blocks Slabs

Hollow Blocks Concept

Used Blocks

Dimensions of Hollow Blocks Slabs

Types of H.B. Slabs

Hollow Blocks Slabs

One way H.B. Slab

With Projected Beams

With Hidden Beams

Two Way H.B. Slabs

With Projected Beams

With Hidden Beams

Lc1= 200 x n1 + 100 x ncr

Lc2= 500 x n2 – 100Solid Part: 0.25m – 0.50m (Roofs

With Projected beams)0.80m – 2.0m (Roofs With Hidden beams)

Live Loads Span Condition

≤ 3.0 kN/m2 ≤ 5.0 m No Cross Ribs

≤ 3.0 kN/m2 > 5.0 m One Cross Rib

> 3.0 kN/m2 4.0 m to 7.0 m One Cross Rib

> 3.0 kN/m2 > 7.0 m Three Cross Ribs

Cross Rib Requirements

Design of One way slab

General Case

Blocks Available in Egyptian Markets

Common Case

Wu = [1.40 * (WH.B. + Wf.c.) + 1.60* (WL.L.)] * 0.50

From Hollow Blocks Table Area served by Ribs

Design of Two way slab

Design of Two way slab

General Case

Common Case

Wu = [1.40 * (WH.B. + Wf.c.) + 1.60* (WL.L.)] * 0.50

From Hollow Blocks Table Area served by Ribs

2-Hidden Beam

1. Reinforcement details of one way slabs.

2. Reinforcement details of two way slabs.

3. Reinforcement details of solid parts.

4. Reinforcement details of hidden beams.

5. Reinforcement details of cross ribs.

Special Case