Analysis of the influence of different types of cement on the resistance to attack by sulfates

Abstract

The diversity of the types of cement manufactured, driven by the extensive use of additions, has given cementitious composites properties that can directly interfere in the durability and useful life of concrete. Considering the interaction of sulfate ions with cement hydration products, in order to understand it becomes essential for the proper choice of materials in order to protect the structures from this aggressor agent. In order to verify the influence of the choice of cement type on the resistance to attack by sulfates, this article analyzes the compressive strength; sulfate content, electron microscopy and energy dispersive spectroscopy of mortars made with cements CP II-F-32, CP IV-32 and CP V-ARI submitted to calcium, sodium and magnesium sulfate solutions for 4 months. The specimens exposed to calcium and sodium sulfate solutions showed increased compressive strength at early ages due to the formation of ettringite in the pores. On the other hand, CP II-F-32 cement showed the greatest deterioration due to magnesium sulfate attack.

Keywords

• Ettringite
• Sulphate attack
• Microstructure