Fabricação e caracterização de argamassas recicladas: Uso de agregado miúdo proveniente de resíduos da fabricação de elementos Pré-Moldados de concreto

Abstract

The construction sector is known to have great influence on the world economy and, in the same magnitude, causes several environmental problems, among them the intense extraction of non-renewable raw materials and the large generation of waste, being considered the largest generator of waste. In the world, which are called RCC (Construction Waste) or RCD (Construction and Demolition Waste. In Brazil, the average solid waste generation reaches 300 kg/m², while in developed countries it is only 100 kg/m², this is directly influenced by the building standards, which in Brazil are mostly handcrafted, ie based on conversion and not on assembly.In view of this, there is a need for the implementation of new sustainable construction techniques and methods to minimize existing problems. As most of the waste comes from within the construction industry, the solution is to recycle these RCCs and reuse this material within the construction industry itself, bringing it back to the production chain. In this context, the present research sought to produce recycled mortars with different aggregate contents from waste precast concrete elements. Firstly, the RCC was collected at a local factory and then subjected to a granulometric test, as well as natural sand, for comparison between the two aggregates, being found a difference in grain size of the two materials. an adjustment of the particle size of the recycled aggregate was made based on the sand particle size.. For the production of mortars, the trait of 1: 2: 9 (Cement: Lime: Aggregate) was chosen, replacing natural sand with recycled aggregate in different proportions and setting a water / cement ratio. Prismatic specimens were manufactured for mechanical strength tests and cylindrical specimens for capillary water absorption testing. After completing 28 days of cure, the specimens were submitted to the flexural tensile strength test, where all recycled mortars had better behavior than the common mortar, among them, those with 15% and 20% recycled aggregate presented higher resistance values. After this test, the axial compressive strength test was performed, where most of the recycled mortars had better results than the common mortar, in which the ones containing 15% and 20% of RCCs stood out. Finally, the capillarity water absorption test was carried out, where it was found that with the exception of the 20% recycled mortar, which obtained an increase in absorption, the others remained with slower absorption levels than the standard reference mortar. In short, it was found that it is possible to manufacture recycled mortar with aggregate from residues of precast concrete elements, since in the submitted tests, these presented better results than those of ordinary mortar (without residue). Thus contributing to the sustainable development of the construction sector, reducing the use of non-renewable resources and the consequent generation of waste