A comparative research study concerning the cements composition influence on the durability and physical-mechanical properties of the concretes

Abstract

The CEM I 42.5 R European cement (SR EN 197-1) and the CD 40 (SR 10092) Romanian road unitary cement with a different content of tricalcium aluminate (C₃A): 6.4 and 0.84%, respectively, with a cementation supplement – furnace slag and with an active hydraulic supplement – thermal plant ash, used for the fabrication of road concretes, have been studied. The pH tests, the investigations of the electric conductivity and the Ca²⁺ ions concentration, have been made out of the cement suspensions in water, as well as the flexural and compression strengths of the concretes obtained with these cements. The tests were made on prismatic specimens (40 × 40 × 160 mm), maintained in water and in aggressive environments with 6000 mg /L MgSO₄ and (NH₄)₂SO₄ aqueous solutions. The experimental results demonstrate the dependence of the interaction rate of the studied cements with water, with the cements basicity and also with the electrostatic field intensity of the resulted cations, through the hydration process. A concrete corrosion was noticed in case of CEM I 42.5 R cement and in case of the same cement enhanced with furnace slag and thermal plant ash. A similar influence of the supplements on the mechanical strengths of the samples exposed to aggressive environments was found. The added supplements have a positive role on the studied strengthened binder systems.

Keywords:

• concrete composition
• durability
• aggressive environments
• mechanical strengths

Disclosure statement

No potential conflict of interest was reported by the authors.