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PRESENTED BY:

ajmal

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Millions of people are losing their life due to earthquake every year. Major loss is due to collapse of masonry structures. For new construction Reinforced hollow concrete block masonry (RHCBM) be adopted as it can resist seismic force effectively. For existing non-engineered masonry structures retrofitting techniques has to be adopted.

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INTRODUCTION CONCEPT OF RHCBM STRUCTURAL FEATURES & ADVANTAGES CONSTRUCTIONAL SPECIFICATIONS &

SEQUENCE CONSTRUCTIONAL& OTHER ADVANTAGES STUDIES ON COST ECONOMICS EXPERIMENTAL PRORAMMES RETROFITTING TECHNIQUES

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Earthquake is not killing people directly

Collapse of structures is taking life of people

Masonry structures are the first casualties during earthquake

Seismic zones from 1-5 are present in INDIA

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Construction should be safe and economical RHCBM is such a method & can lateral forces

effectively Retrofitting should be adopted for enhancing

earthquake resistance of existing non reinforced structures

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Three-dimensional structural integrity will help to resist lateral forces

Fully reinforced walls are the ideal solution but not economical

RHCBM is the practically feasible solution It will act as load bearing wall as well as

shear wall Reinforcement will run in both horizontal &

vertical direction

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No additional formwork or any special construction machinery is required for reinforcing the hollow block masonry.

Only semi-skilled labor is required for this type of construction.

It is a faster and easier construction system, when compared to the other conventional construction systems.

It is also found to be a cost-effective disaster resistant construction system

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Hollow block with concrete & grout will provide higher compressive resistance

Weather durability, fire protection & safety increases

Resilience & ductility is imparted by reinforcement

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Placing reinforcement

Hollow blocks are inserted into the vertical rods

U shaped concrete blocks at sill and lintel level

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Vertical as well as horizontal continuity at roof & floor level

Practical difficulty in construction

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No additional formwork or any special construction machinery is required for reinforcing the hollow block masonry.

Only semi-skilled labor is required for this type of construction.

It is a faster and easier construction system

It is also found to be a cost-effective disaster resistant construction system

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Provide better acoustic & thermal insulation

Durable & Maintenance free

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Detailed cost estimate shows it is a cost effective method

Provide additional benefits also

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Proposed construction system of reinforced block masonry

Conventional construction systems

As compared to load bearing brick masonry

As compared to RC framed structure with brick masonry

1 Percentage saving in cost

-2.19 1.26

2 Percentage increase in floor area

6.10 2.15

3 Percentage reduction in total dead load at foundation level

35.19 15.34

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One of national R&D laboratories

took up detailed & experimental investigations on materials, assemblage, full scale wall of different kind of masonry

Results are as follows

PARAMETERS Reinforced

Brick Masonry Panel

ReinforcedHollow Conc. Block Masonry

panel

Ultimate lateral load

4.79 t 6.35 t

Displacement Ductility Obtained

2.66 3.14

In crease of ductility when compared to unreinforced brick masonry

28.50 % 51.69 %

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Retrofitting Techniques should be adopted for buildings in earthquake prone zones

Grouting & wire mesh technology are effective methods

By grouting connection b/w orthogonal walls cannot be obtained

Wire mesh technology is more costlier but help provide orthogonal connections

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RHCBM is suitable for rehabilitation /reconstruction system as it simple, safe & faster.

RHCBM provide seismic resistance without involvement of additional cost

Advantages like increased floor area, lighter dead weight , higher ultimate load capacity, improved ductility

Retrofitting techniques will enhance the earthquake resistance of existing structures

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Bhagvan N G ,Sreenath H G, Sivarama Sarma B, Vimalandam V (1997):State of the art report on Reinforced Hollow Concrete Block Masonry for disaster resistant low rise building construction , Project report SSP003141,SERC Chennai.

Bhagvan N G ,Sreenath H G, Sivarama Sarma B, Ramachandra Murthy A (2001): “Earthquake Resistant Construction with Reinforced Hollow Concrete Block Masonry –An Ideal Reconstruction Strategy for Gujarat” Proceedings of seminar on ‘Earthquakes in Built Environment’, Indian Building congress, New Delhi.

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