Avaliação da utilização do concreto autoadensável em uma obra de edificação vertical

Abstract

Self-compacting concrete (CAA) arose from the need to obtain more durable, economical and less time-consuming concrete structures. Its use avoids pathological manifestations due to a dense badly executed at the time of concreting. In addition, it can address shortcomings in the CCV through its ability to move on its own, to fill all spaces intended for it in the form without any form of densification or compaction, and not to segregate or trap excess air. It also reduces the noise generated in the execution, the number of employees and, consequently, also the risks of accidents at work. However, despite the many advantages, this technology is still not widely used in vertical building works in Brazil. Specifically in the city of Fortaleza / CE there is no knowledge of any vertical building work where the CAA has been applied throughout the structure (slabs, beams and pillars) with a compressive strength of 30 MPa. Based on this idea, the objective of this work is to evaluate the use of CAA in substitution of conventional concrete (CCV) in a vertical building work in the city of Fortaleza. In order to do so, a CAA trace was developed. Tests were carried out in the fresh state and in the hardened state, where it was possible to verify the compliance with the prescriptions of the respective Brazilian standards in force. Subsequently, two concretions with CAA were executed in a vertical building. For comparison purposes a slab with CCV was also performed and evaluated. The following variables were evaluated: time of concreting, appearance of pathological manifestations, quantity of work required for concreting and costs. After this analysis, it was seen that the use of the CAA is compensatory and that, in the end, its cost was 56.46% of the cost of the CCV, and the workforce reduced by 67%. With this, it is expected that it will be possible to spread this idea in Fortaleza's construction market.