ABSTRACT Nowadays, there is an increasing interest in the development of eco-friendly materials. Thus, environmental challenges due to the necessity of reducing worldwide levels of CO2 emissions, to limit the energy consumption and to use industrial waste are promoting an increasing effort to find viable alternatives to minimize pollution from the main productive processes. Thus, this paper addresses the results of an investigation on the influence of stone powder, residue from the production of crushed aggregates, on the mechanical performance of concrete reinforced with steel fibers. The effect of the amount of stone powder sand was evaluated using 0%, 50% and 100% natural sand replacement. Workability and mechanical properties were evaluated by compressive, elastic modulus, four-point bending and abrasion tests. Economic impact study of the composite production was also carried out. Based on the results obtained, it is possible to conclude that the use of crushed stone sand in steel fiber reinforced concrete is beneficial in terms of the workability and abrasion resistance but was some disadvantages. For instance, when 100% manufactured sand was added, the compressive and bending strength was reduced. However, the elastic modulus was not changed. It is also important to highlight that with 100% stone powder content, the compressive strength is still higher than 30MPa and the cost for producing is about of 32% cheaper.

This paper addresses the results of an investigation on the influence of the Brazilian raw materials on the mechanical performance of Strain Hardening Cementitious Composites (SHCC). The mixtures were produced with variations of fly ash/cement and sand/cement proportions and with different maximum sand particle. Mechanical properties were evaluated by direct tension, bending and compression tests. Crack formation under direct tension and bending loads was also investigated. The results indicate that the use of high quantities of fly ash with low quantities of fine sand is the ideal combination to obtain strain hardening composites with tensile strain capacity superior to 3% using local materials. The increase in the sand content and particle size affects the behavior of the composites and tended to reduce the strain capacity of the specimens by up to 30%. Keeping constant the fly ash/cement and sand/cement rates it was found that the crack density and width measured under direct tension are only affected by the diameter of the sand for tensile strains in the range of 2%. The same general trends were observed for specimens submitted to compressive and bending loads.