Concreto autoadensável com utilização de resíduos de concreto

Abstract

The self-compacting concrete is relatively new, and it has its main characteristics and advantages by its flow capacity without segregation, and filling the entire inside of the forms without the internal concrete vibrator. This research seeks a sustainable alternative for the waste disposal produced in the construction, so that it can contribute in the physical and mechanical properties of self-compacting concrete. Four treatments were tested, being used as the reference concrete dosed without addition of waste. Seeking to find a trace to get the same performance of the reference trace, the traces were tested by replacing 35, 40 and 45% of fine aggregate for concrete residue with a view to workability. The amount of additive was determined experimentally by testing in the fresh state. The properties of the treatments for resistance to segregation, passing ability, workability, absorption, compressive strength and elastic modulus were evaluated and compared. With the results obtained in the fresh state, it is possible to assess the traits with the addition of self-compacting concrete residue maintained the characteristics of being able to sort their use according to the results required in standard. For the tests in hardened condition, the traces with the addition of 35% and 45% of concrete residue obtained resistances below the reference trace in 17% and 24%, respectively, only the trace with 40% added exceeded the reference trace, after 56 days, proving the effectiveness of the material used. The absorption results corroborate the compressive strength results, because the lowest percentage was found for the trace with 40% added, suggesting a better particle packing. For the modulus of elasticity, the reference trace performed best, which was expected due to concrete residue characteristics.