Paper Title
STUDY ON THE RESISTANCE OF CONCRETE WITHOUT AND WITH KAOLIN TO SEVERE ATTACKS OF SULFURIC ACID

Abstract
Abstract - Concrete, the most commonly used material for construction, is normally alkaline, so it has less resistance to the attack of sulfuric acid. Deteriorations of concrete are usually found in building infrastructures when situated near the sulfuric acidic environment and hence it leads to annual losses in economic for repairing and maintaining them to preserve their performances. This study aims to investigate the flexural strength losses and mass losses of concrete without and with kaolin after the attacks of sulfuric acids with severe levels of pH values 1, 2, 3, and 4 for time intervals from 0 to 180 days and, to give the equations for estimating the percentages of flexural strength loss and mass loss of the concrete. The necessary tests were carried out following the American Society for Testing and Material standard procedures. The concrete mix design was calculated by complying with the rules of the Absolute Volume method. The predicted equations were obtained by performing the regression analysis on the data. It was found that the concrete without kaolin showed greater percentages in flexural strength loss and mass loss when compared to the concrete with kaolin, which means 10% adding kaolin by mass of cement caused the concrete stronger in strength and better in resistance to the severe attacks of sulfuric acid. Keywords - Flexural Strength Loss, Mass Loss, Sulfuric Acid, Kaolin, Severe Attacks.