29-03-2017, 04:16 PM
Foundry sands used represent the largest amount of solid waste generated by foundries. Classified by the European Union as non-hazardous waste, they represent a relevant source to be reused in several industrial sectors, mainly in building construction. In the present work, the properties of mortars and concretes containing different doses of used cast iron (UFS) were investigated as partial replacement of sand under both fresh and hardened conditions. In particular, the higher percentages of addition, but smaller if reference is made to the whole aggregate (fine and coarse), were considered in concretes than in mortars. Both mortars and concretes were evaluated for the consistency of the fresh mixture and the compressive strength of the cured material. The determination of the elastic modulus of the hardened material was carried out on concrete. A low amount (10%) of spent casting sand does not change the performance of the mortar. In the presence of larger additions a decrease in workability can be outlined, and then a higher dose of superplasticizer is required to keep it constant. Mechanical yields of less than about 20-30% are observed than those of the conglomerate without foundry sand used. The higher penalty seems to affect the conglomerates of better quality (ie, lower water-cement ratio).
We investigated the possible reuse of the waste casting sand in the production of high strength concrete. The natural fine sand is replaced with residual smelting sand (0%, 5%, 10% and 15%). The results of a series of test programs have shown a reduction in compressive and tensile strengths and modulus of elasticity which is directly related to the inclusion of the casting of waste in the concrete. However, the concrete with 10% of foundry sand residues presents results almost similar to those of the control. The decrease and workability of the fresh concrete decreases with increasing the proportion of sand casting waste. Although freezing and thawing significantly reduces the mechanical and physical properties of the concrete. The results obtained meet the acceptable limits established by the American Concrete Institute (ACI).
We investigated the possible reuse of the waste casting sand in the production of high strength concrete. The natural fine sand is replaced with residual smelting sand (0%, 5%, 10% and 15%). The results of a series of test programs have shown a reduction in compressive and tensile strengths and modulus of elasticity which is directly related to the inclusion of the casting of waste in the concrete. However, the concrete with 10% of foundry sand residues presents results almost similar to those of the control. The decrease and workability of the fresh concrete decreases with increasing the proportion of sand casting waste. Although freezing and thawing significantly reduces the mechanical and physical properties of the concrete. The results obtained meet the acceptable limits established by the American Concrete Institute (ACI).
