Light weight cement concrete seminar report presentation

Seminar report presentation

1. LIGHT WEIGHT CONCRETE

2. CONTENTS :- INTRODUCTION PRINCIPLE OF LIGHT WEIGHT CONCRETE (LWC) PROPERTIES OF LIGHT WEIGHT AGGREGATES (LWA) AERATED CONCRETE NO-FINES CONCRETE ADVANTAGES DISADVANTAGES APPLICATIONS

3. INTRODUCTION :- Light weight concrete is a special concrete which weights lighter than conventional concrete. Density of this concrete is considerably low ( 300 kg/m3 to 1850 kg/m3 ) when compared to normal concrete ( 2200 kg / m3 to 2600 kg / m3 ). Three types of LWC :- Light weight aggregate concrete Aerated concrete No-fines concrete

4. PRINCIPLE OF LWC :- The basic principle behind the making of light weight concrete is by inducing the air in concrete. To achive the above principle practically, there are 3 different ways. By replacing the conventional aggregates by cellular porous aggregates ( Light weight aggregates concrete ). By incorporating the air or gas bubbles in concrete ( Aerated concrete ). By omitting the sand from the concrete ( No-fines concrete ).

5. LIGHT WEIGHT AGGREGATES :- Natural light weight aggregates are less preferred over artificial aggregates. Artificial light weight aggregates are usually produced by expanding the rocks such as shale, slate, perlite, etc. Type of aggreagtes used for making the concretee decides its density. Density of concrete as low as 300kg / m3 can be achived. Compressive strength varies from 0.3 Mpa to 40Mpa. Basically two types of light weight aggreagtes are used for making LWC Natural light weight aggregates Artificial light weight aggregates

6. NATURAL LIGHT WEIGHT AGGREGATES ARTIFICIAL LIGHT WEIGHT AGGREGATES SAWDUST PUMICE STONE THERMOCOL BEADS EXPANDED PERLITE FOAMED SLAG COKE BREEZE SCORIA ROCK DIATOMITE

7. AERATED CONCRETE :- Autoclaved aerated concrete (AAC) is a lightweight, precast, foam concrete building material suitable for producing concrete masonry unit (CMU) like blocks. Composed of quartz sand, calcined gypsum, lime, cement, water and aluminum powder, AAC products are cured under heat and pressure in an autoclave. Forms include blocks, wall panels, floor and roof panels, cladding (facade) panels and lintels. Aluminum powder is used at a rate of 0.05%-0.08% by volume (depending on the pre-specified density).

8. NO-FINES CONCRETE :- No-fines ( Pervious concrete ) concrete is made using large aggregates with little to no fine aggregates. Pervious concrete is a special type of concrete with a high porosity used for concrete flatwork applications that allows water from precipitation and other sources to pass directly through, thereby reducing the runoff from a site and allowing groundwater recharge. Pervious concrete is traditionally used in parking areas, areas with light traffic, residential streets, pedestrian walkways, and greenhouses.

9. ADVANTAGES :- Reduce the dead load of the building . Easy to handle and hence reduces the cost of transportation and handling. Improves the workability. Relatively low thermal conductivity. Comparatively more durable. Good resistance to freezing action when compared to conventional concrete.

10. DISADVANTAGES :- Very sensitive with water content in the mixture. Difficult to place and finish because of porosity and angularity of the aggregate. Mixing time is longer than the coventional concrete to assure proper strength. The depth within which corrosion can occur under suitable conditions is nearly twice than that of normal concrete.

11. APPLICATIONS :- Screeds and thickening for general purposes especially when such screeds or thickening and weight to floors roofs and other structural members. Screeds and walls where timber has to be attached by nailing. Casting structural steel to protect its against fire and corrosion or as a covering for architectural purposes. Heat insulation on roofs. Insulating water pipes. Construction of partition walls and panel walls in frame structures

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