تأثير حامض الكبريتيك على الخصائص الجيوتكنيكية

Abstract

This study deals with the effect of sulphuric acid with different concentration (10%, 50% & 98%) on the geotechnical properties of clayey silt soil brought from Al-Mussayab south of Baghdad.The study deals with natural soil contamination by adding sulphuric acid with different concentrations at 25% as a percent of dry weight of soil with different percents of water content for curing periods (0, 3, 7 & 14) days, Oedometer tests are carried out to study the behavior of soil after adding the acid. It has been found that a severe reaction happens between acid and calcium carbonate in the clayey silt soil accompanied with volume increasing producing gypsum. Prevention of volume increasing by surcharge generated a swelling pressure. This pressure increases with the increasing of acid concentration and decreases with the increasing of curing period. The maximum value of swelling pressure is about 530 kPa. The study shows that the maximum dry density of soil reduces after adding 98% and 50% concentration acid while it increases for 10% conc. acid. The values of liquid limit and plasticity index of contaminated soil are reduces for 10% conc. acid and increases for other concentration.