Feasibility of Producing Lightweight Concrete Using Indigenous Materials Without Autoclaving
This research shows the feasibility and sequential approach for producing lightweight concrete without autoclaving using indigenous ingredients and appropriate technology of Bangladesh. Ingredients were mixed chronologically using trial-and-error method to reduce unit weight. Specific volume principle was utilized to observe the effect of inclusion of cement, water, sand, lime and aluminium in the mixture to achieve the goal. Molds were used to accommodate volumetric expansion of mixture. Both 50 mm and 150 mm cubic specimens were prepared for tests. Density and compressive strength were determined for specimens. Absorption capacity and thermal conductivity were also determined to get the product performance. From the results, it was seen that density and compressive decreased with increased water-cement ratio. Volumetric expansion was high for higher volume surface ratio. Finally, lightweight concrete with density, compressive strength and thermal conductivity within range of 700-1000 kg/m3, 0.5-2.0 MPa and 0.2-0.5 W/m-k respectively was produced.
KEY WORDS: Volumetric expansion; Lightweight concrete; Water-cement ratio; Mix design.