Evaluation of Durability and Mechanical Properties of the Cement Mortar Added with Slag Blast Furnace

Abstract

An evaluation of durability and mechanical strength in a cement mortar is presented in this work. A slag coming from steelmaking processes has been added to the mortar. This slag has similar properties to the ones of cement, and it has been added to the mortar in different proportions with two sizes of granulometry. With this addition, better properties against the action of sulfates are expected, and therefore, the presence of fracture and wear in the structures can be reduced. This allows more safety and increased life in the mortar, and the most important thing is that, this will contribute to decrease the environmental contamination because the slag used in this work is coming from the industrial waste, which is produced in big amounts in the steel sector worldwide. The studied materials are mortar cubes in which the mechanical strength has been evaluated. The dimensions of the samples are around 50×50×50 mm 3 and, according to the standard ASTM C109, these cubes should be evaluated during 1, 3, 7, 28, 56 and 118 days. The expansion tests to evaluate the sulfates attack is performed according to the standard ASTM C1012, in bars of around 25×25×285 mm 3 . These bars were submerged in water with lime and when the bars obtained a strength bigger than 20 MPa, they were also submerged in a sulfate solution, which was prepared 24 hours earlier with a pH that should be between 6 and 8. In this way, from the point of view of strength to sulfate attack, the mortar durability is evaluated by employing techniques such as X-ray diffraction, X-ray fluorescence and scanning electron microscopy, which allow us to determine the presence of different components that are responsible for the expansion as the formation of gypsum, ettringite, and thaumasite. As a result of this research, it is evident that slag with smaller particle size shows positive behavior against the action of sulfates, thus revealing minimum expansion percentages.

Influence of slag content and water-binder ratio on leaching behavior of cement pastes

“…The unleached slice specimens, as well as those leached in ammonium chloride solution for 1, 3, 5, 7, 9, 12, or/and 15 days, were subjected to porosity measurements in accordance with the procedure described in the existing document [24]. The SEM observation and XRD phase analysis for the slice specimen immersed into the solution for different leaching time were respectively carried out to investigate the microstructure morphology and mineral composition of the slag-cement pastes [2,20,33,35,36].…”

Performa Beton Dengan Ground Granulated Blast Furnace Slag Terhadap Sulfate Attack

“…GGBFS telah digunakan secara luas untuk meningkatkan performa durabilitas beton (Zuquan et al, 2018). Penambahan GGBFS terbukti berdampak positif terhadap ketahanan mortar dan beton melawan serangan sulfat (López, Pineda and Gutiérrez, 2015;Atahan and Arslan, 2016). Namun, GGBFS masih tergolong material baru di Indonesia dan potensinya dalam meningkatkan durabilitas beton belum dimanfaatkan secara luas.…”

The properties of slag-silica fume ternary blended mortar with quarry dust

“…The utilization GGBS and DSF has improved the performances ternary blended mortar incorporating quarry dust as a fine aggregate in terms of mechanical strength, drying shrinkage and total porosity tested. The high strength ternary blended mortar incorporating GGBS and DSF exhibited optimum mechanical and durability performance at the OPC:GGBS:DSF ratio of 50:38:12. journal.ump.edu.my/jmes ◄ optimum usage of 50-60% GGBS achieved higher mechanical strength than neat OPC mortar or concrete [7][8][9]. The performance showed a decline when the replacement level increased up to 80% [10].…”

“…The mechanical strength of mortar or concrete also showed improvement with the fineness of GGBS due to the increased effectiveness pore refinement by formation of secondary C-S-H bonds in the pore structure [11]. Moreover, the utilization of GGBS enhanced the workability of fresh mortar or concrete by better particle dispersion however may lead to bleeding and segregation above 60% of its substitution level [9].…”