Print ISSN: 1681-6900

Online ISSN: 2412-0758

Keywords : permeability

Effect of Polymer Additives on Permeability of Asphalt Concrete Mixtures

H.H. Jony; M.M. Hilal; D.S. Helan

Engineering and Technology Journal, 2018, Volume 36, Issue 1, Pages 75-83

The presence of water in the pavement structure causes early deterioration and leads to less pavement durability as a result of loss of bond between aggregate and binder and may causes loss of strength and stability in mixture, The main goal of this study was to investigate the effect of various polymer additives on permeability of asphalt concrete mixture. The surface wearing coarse type IIIA was chosen in this study. Three types of polymer additives were used in this study; (7% Latex Emulsion (LE), 7% Poly Vinyl Acetate with 4% Styrene Butadiene Styrene (PVA + SBS) and 8% Ethylene Diamine (ED)). The results appeared that the permeability average of all mixtures were (27.745, 17.18, 7.773 and 11.409 * 10 -5 cm/s) for (control blend, LE, PVA+SBS and ED) and the percent of decreasing in permeability were (48.52%, 74.547% and 58.312%) for (LE, (PVA + SBS) and ED) respectively.

Stability Behavior of Lime Stabilized Gypseous Soil

Abdulrahman Aldaood; Marwen Bouasker; Amina A Khalil; Ibrahim Al-Kiki

Engineering and Technology Journal, 2013, Volume 31, Issue 20, Pages 324-338

In arid and semi-arid zones, gypsum (CaSO4.2H2O) is one of the soluble of the common minerals that found in soils. In Iraq, gypseous soils is a worldwide stability problem that causes extensive damage upon wetting, and occur in certain areas characterized by variation of climatic conditions. The results of the stability behavior of lime stabilized gypseous soil where present in this paper under different tests. These tests were erosion, leaching and soaking. Erosion test was conducted under different variables such as water temperature, water velocity and flow duration. The soil used in this study was taken from a site near Al – Hader district about (80 km) from Mosul city. Its main geotechnical index properties are liquid limit is (46%), plastic limit (22%) and specific gravity is 2.58. The amount of the gypsum was 20%. The soil samples were treated with optimum lime percent (4%) depending on the Illinois procedure. A gypseous soil with 20% gypsum content was used and stabilized with 4% lime. All stabilized soil samples were cured for 2 days at 490 C. The results indicate that, the loss in weight increased for samples subjected to the flowing water, further increase in weight losses with increasing flow duration. High water velocity causes increasing in weight losses and loss in gypsum content , more loss in weight and more loss in gypsum content, for all values of flow duration and water temperature. Unconfined compressive strength decreased during the soaking process and further decrease in strength with increasing soaking duration. The leaching effect causes a continuous increasing in the permeability value of unstabilized soil samples, while it has an insignificant effect on the permeability of lime stabilized soil samples. Leaching

is a time-dependent process. The results showed that the pH values of natural and lime stabilized soil samples decreases during leaching process.