INFLUENCE OF NATURAL POZZOLAN ON THE BEHAVIOR OF SELF-COMPACTING CONCRETE UNDER SULPHURIC AND HYDROCHLORIC ACID ATTACKS, COMPARATIVE STUDY

摘要

Acidic attack is a topic of increasing significance, owing to the spread of damage to concrete structures in both urban and industrial areas. Mineral addition type is an important factor affecting performance of Self-Compacting Concrete (SCC) in an aggressive environment. Pozzolan from natural sources in Algeria is rarely used in SCC due to the absence of a thorough study of its properties. The goal of this study was to compare the hydrochloric and sulphuric acid behaviors of a SCC-containing Algerian natural pozzolan with SCC-containing fly ash and limestone filler additions. For this purpose, twelve formulations were prepared with three different strength classes (30, 50, and 70 MPa). After 28 days of curing, the samples were immersed in hydrochloric sulfuric acid solutions for a period of 12 weeks. The changes in mass loss and compressive strength loss for each acid solution within the test period were recorded. The Scanning Electron Microscope (SEM) and XRD analysis were used to better understand the mechanism of deterioration of each type of concrete. In spite of their economical properties, the results confirm that the use of Algerian natural pozzolan contributes to the improvement of resistance of SCC under sulphuric and hydrochloric acid attacks.