Experimental Model of Suction Head on Expansive Soil Subgrade with Concrete Wall Moisture Barrier

Abstract

Soil expansivity generally occured caused by the presence of a clay mineral of smectite group, such as montmorillonite, illite, bentonite, etc, which could absorb so much water. The impact of losses incurred by soils ekspansivity on buildings and infrastructure primarily on lightweight structures are staggering. Technology is often applied as a solution to problems such as improvement of material characteristics, providing early treatment of constructive and structural engineering support to overcome the adverse effects of expansive soil. Erecting concrete moisture barrier on the side of the road is a combination of the provision of early treatment and support in structural engineering change control water content in the soil layer of expansive.This study aims to determine the behavior of suction, moisture barrier effects on suction head reduction, and the experimental model of suction head profile with the erecting and testing of the models tested in the laboratory.The test model was made to resemble half of the road width with a load of 30 kPa on it. On the side of the road mounted concrete wall moisture barrier with a variation of the depth of 20 cm, 35 cm and 50 cm. Observation of time and water absorption carried out on 8 observatories, also the amount of swelling through a dial that is placed above the concrete slab load. The results showed an increase in capillary water in front bulkhead for all variations of depth moisture barrier and water absorption height reduction occurred in the rear bulkhead respectively 3.25%, 21.25% and 45% for the ratio of height bulkhead and expansive soil thickness h/H = 0.44, h/H = 0.78 and h/H = 1.11. Also the reduction of swelling respectively by 4.46%, 52.69% and 82.53% for each ratio h/H above.