Estudo da durabilidade e influência da adição da cinza do bagaço de cana-de-açúcar nas propriedades do concreto

As Brazil is the largest sugar producer in the world, sugarcane plays an important role in the country's economic scenario. The most attractive residue of this raw material for the sugar-alcohol industry is its bagasse, which can be used in several ways; one of them is the cogeneration of electric energy, in this process the bagasse is burned generating a new byproduct: sugarcane bagasse ash (CBC). Such ash is generated in sugar mills, but, although little known, are also generated in the furnaces of the pizzerias having their use as fuel instead of wood. With the advances of the researches, it was analyzed that the predominance of the chemical compounds of the sugarcane bagasse ash (CBC), is of SiO2 silicon dioxide, thus presenting potential for use as mineral addition. The general objective of this research is to analyze the durability of the concrete with the partial addition of sugarcane bagasse ash CBCA), originating from a pizzeria in the metropolitan region of the city of Recife and the ashes of sugarcane bagasse, (CBC-B) obtained from a sugar mill in the municipality of Palmares, Pernambuco. In the experimental procedure, at first the ashes (CBC-A and CBC-B) were sieved in a No. 200 mesh sieve, using the through material, after which their characterizations were carried out. Through the characterizations it was possible to observe the similarity of the ashes to the pozolanic materials (through some characteristics). The main objective of this study was to observe the evolution of the chemical reactions present, with the later consumption of Portlandite and generation of CSH over time (28, 63 and 91 days). Subsequently, the indirect analyzes were performed, being possible to observe the chemical reactions comparing them with the other techniques and reinforcing the hypothesis of the existence of the expected reactions, giving subsidy to the other durability analyzes. For tests of durability, test bodies were made, where resistance to compression and traction were tested. The capillary absorption, voids index and absorption by immersion tests were performed. Also regarding the durability, test bodies were submitted to the accelerated carbonation test and finalized with the chloride migration test. With the results, it was evidenced the possible use of 15% addition of ashes (CBC) in the manufacture of mortars and concrete. Concluding that the reuse of a material that would have final destination the dump, can have reuse in the mortars and the concrete, presenting good results. Research such as this is important to enrich the range of materials available to the construction industry, as well as indicating a better use of previously discarded resources.