Study and analysis by means of surface response to fracture behavior in lime-cement mortars fabricated with steelmaking slags

The objective of this work is to study the fracture behavior of lime-cement masonry mortars prepared with various proportions of lime and cement. Different amounts of Electric Arc Furnace - EAF-(black) slag and Ladle Furnace -LF-(white) slag were used in substitution of conventional aggregate. By varying the Water/Binder ratio the characteristics of the mortars in the fresh and the hardened state have been studied, it is about the density, occluded air, water absorption and compressive strength at 28 days. The fracture properties were examined by Response Surface Methodology (RSM). The effects of slag content, binder content and age on fracture energy were analyzed using Central Composite Design and compared with experimental data from a three-point bending test. The results of the model closely coincide with the test results in their analysis and prediction of the mechanical strength of the mortars. In these results, it was noticed that the EAF (black) slags had an unfavorable effect on the lime-cement mortars with high cement contents, unlike those dosed with LF (white) slag and different compositions of lime and cement that significantly improved their fracture behavior in comparison with the other lime-cement mortars under study.