ABSTRACT
Lightweight concretes can be used in civil construction, such as thermal and acoustic insulation, slab cover, plate production and others. Produced from expanded clay, which have a unit mass between 300 and 2000 kg / m3, the materials guarantee a reduction of the weight of structures favoring the reduction of the costs with the foundations. In this work, the best granulometric arrangement of expanded clays of 22, 15 and 5 mm diameter granulometry was studied in order to produce concrete slabs with low specific gravity and with no change in mechanical resistance to flexural strength, compared to those made with from conventional crushers. The raw materials were characterized by means of unit mass, specific mass, water absorption, particle size analysis, chemical analysis and X-ray diffraction. Next, Winkler's triangular diagram was used in order to obtain the unit masses and The respective packaging. This diagram is not very widespread in the construction segment and can be very useful for mixing up to three components and evaluating any property, defining an optimum working region. The points of the diagram were chosen with different unit masses for the production of test specimens with expanded clay and with the conventional aggregate. The specimens were submitted to three - point flexural strength and apparent density test. The results showed that there was a reduction of 30% to 50% in the weight of the pieces, without altering the mechanical resistance in formulations A and D. It is worth mentioning that the density and mechanical strength of the formulations A and D were the largest in relation to the lightweigth, probably due to the smaller slump presented, besides the high unit mass presented in the ternary diagram.
Keywords:
Lightweight; concrete; plates
