Use of shell fishing in the manufacture blocks cast of simple concrete for masonry

Abstract

One of the relevance activities in the city of Igarassu-PE corresponds to shell fishing Anomalocardia brasiliana, in which the local fishing community maintains an expressive social relation, cultural and economic dependence. The shell fishing Anomalocardia brasiliana processing, after the extraction of the mollusc, generates shells residue, which discard, in considerable volume in a mangrove, can cause silting in large areas and, therefore, environmental imbalance, mainly reflected by the reduction of the food chain, in addition to the triggering of vectors and accident risk. The aim of this research is to verify the feasibility of using this residue, located in Beira Mar II community, city of Igarassu-PE, to product a simple concrete masonry blocks, from the formulation of different trace compositions, aiming at the determination of the optimal composition. Therefore, the percentage of mass used on crushed stone of the conventional concrete traces was replaced by the equivalent mass of shell fishing Anomalocardia brasiliana ground in a disc mill with spacing between disks corresponding to 9.5 mm. These blocks produced with shell fishing Anomalocardia brasiliana in the granulometric conditions imposed by the milling and formulations of pre-established traits were used as test pieces for submission to quality verification tests. The production of the blocks was carried out according to the recommendations of ABNT-NBR 6136:2016’s standards - blocks cast of simple concrete for masonry – requirements and water absorption, liquid area determination, compressive strength and drying shrinkage tests were performed in accordance with ABNT-NBR 12118:2013 - concrete blocks for masonry - test methods. The tests results indicated that the blocks produced with shell fishing Anomalocardia brasiliana, under all trace conditions, can be used in masonry with structural function, being categorized in class B. The best substitution is represented to change 100% gravel/shell, followed the normative resistance requirements. The use of shells would result in the aggregation of economic and social advantages, by the development of jobs and the reduction of environmental impacts caused by the inadequate disposal of the waste resulting from the processing of artisanal shell fishing Anomalocardia brasiliana.